dwsim-users Mailing List for DWSIM - Open Source Process Simulator (Page 5)
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From: Daniel W. <dan...@gm...> - 2016-04-27 22:29:00
|
I´ll only have access to your simulation if you send the file to me. You can add an additional security layer by defining a password on Settings > Misc and saving the file in the "dwxmz (compressed XML)" format. 2016-04-27 17:21 GMT-04:00 Hector Perez <hpe...@gm...>: > Hi Daniel, > > A friend of mine that I've introduced to DWSIM asked me if the program > back downloads the simulations one builds or if they are kept private > (confidential) on one's own PC. > > Thanks, > > Hector D. Perez > > > On Wed, Apr 27, 2016 at 9:38 AM, Daniel Wagner <dan...@gm...> > wrote: > >> Actually I've designed the reactors in DWSIM based on HYSYS, though I >> don't remember if HYSYS also does pressure drop calculations or not. It was >> quite easy to do it because I already have the routines from the Pipe >> Segment Unit Op. >> >> Thanks! >> Daniel >> >> 2016-04-27 10:35 GMT-04:00 Hector Perez <hpe...@gm...>: >> >>> Ok. That makes sense. Well this is a +1 for DWSIM because ASPEN doesn't >>> seem to take into account the fact that the liquid begins to vaporize and >>> completely ignores the pressure drop. Once again, awesome job! >>> >>> Hector D. Perez >>> Chemical Engineering Consultant >>> >>> On Wed, Apr 27, 2016 at 9:32 AM, Daniel Wagner <dan...@gm...> >>> wrote: >>> >>>> Hector, the pressure drop is at the limit of vaporization. When you >>>> increase the length to 0.22, part of the liquid vaporizes and the pressure >>>> drop goes beyond the charts. :-) >>>> >>>> Daniel >>>> >>>> >>>> 2016-04-27 10:16 GMT-04:00 Hector Perez <hpe...@gm...>: >>>> >>>>> Yes. Here it is. >>>>> >>>>> Thanks, >>>>> >>>>> Hector D. Perez >>>>> Chemical Engineering Consultant >>>>> >>>>> > |
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From: Hector P. <hpe...@gm...> - 2016-04-27 21:22:20
|
Hi Daniel, A friend of mine that I've introduced to DWSIM asked me if the program back downloads the simulations one builds or if they are kept private (confidential) on one's own PC. Thanks, Hector D. Perez On Wed, Apr 27, 2016 at 9:38 AM, Daniel Wagner <dan...@gm...> wrote: > Actually I've designed the reactors in DWSIM based on HYSYS, though I > don't remember if HYSYS also does pressure drop calculations or not. It was > quite easy to do it because I already have the routines from the Pipe > Segment Unit Op. > > Thanks! > Daniel > > 2016-04-27 10:35 GMT-04:00 Hector Perez <hpe...@gm...>: > >> Ok. That makes sense. Well this is a +1 for DWSIM because ASPEN doesn't >> seem to take into account the fact that the liquid begins to vaporize and >> completely ignores the pressure drop. Once again, awesome job! >> >> Hector D. Perez >> Chemical Engineering Consultant >> >> On Wed, Apr 27, 2016 at 9:32 AM, Daniel Wagner <dan...@gm...> >> wrote: >> >>> Hector, the pressure drop is at the limit of vaporization. When you >>> increase the length to 0.22, part of the liquid vaporizes and the pressure >>> drop goes beyond the charts. :-) >>> >>> Daniel >>> >>> >>> 2016-04-27 10:16 GMT-04:00 Hector Perez <hpe...@gm...>: >>> >>>> Yes. Here it is. >>>> >>>> Thanks, >>>> >>>> Hector D. Perez >>>> Chemical Engineering Consultant >>>> >>>> |
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From: Daniel W. <dan...@gm...> - 2016-04-27 14:38:46
|
Actually I've designed the reactors in DWSIM based on HYSYS, though I don't remember if HYSYS also does pressure drop calculations or not. It was quite easy to do it because I already have the routines from the Pipe Segment Unit Op. Thanks! Daniel 2016-04-27 10:35 GMT-04:00 Hector Perez <hpe...@gm...>: > Ok. That makes sense. Well this is a +1 for DWSIM because ASPEN doesn't > seem to take into account the fact that the liquid begins to vaporize and > completely ignores the pressure drop. Once again, awesome job! > > Hector D. Perez > Chemical Engineering Consultant > > On Wed, Apr 27, 2016 at 9:32 AM, Daniel Wagner <dan...@gm...> > wrote: > >> Hector, the pressure drop is at the limit of vaporization. When you >> increase the length to 0.22, part of the liquid vaporizes and the pressure >> drop goes beyond the charts. :-) >> >> Daniel >> >> >> 2016-04-27 10:16 GMT-04:00 Hector Perez <hpe...@gm...>: >> >>> Yes. Here it is. >>> >>> Thanks, >>> >>> Hector D. Perez >>> Chemical Engineering Consultant >>> >>> |
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From: Daniel W. <dan...@gm...> - 2016-04-27 14:06:57
|
Can you send me your file again? 2016-04-27 9:52 GMT-04:00 Hector Perez <hpe...@gm...>: > Daniel, there may be a bug then because my absolute pressure leaving the > PFR is ~0.8 atm. If I increase the reactor length by 1 cm more, then I get > the pressure drop error. > > Nice, yes we are close. Ainda nao tem ido ao Brasil mas tenho escutado que > e muito bonito la. > > Hector D. Perez > Chemical Engineering Consultant > > On Wed, Apr 27, 2016 at 8:42 AM, Daniel Wagner <dan...@gm...> > wrote: > >> Hector, the actual criteria for throwing the pressure drop error in the >> PFR model is a negative pressure value after the pressure drop calculation >> step: >> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb#L828 >> >> Hey, we live relatively close to each other. I'm in Manaus, Amazonas. >> Could we say that both of us live in the Amazon? :-) >> >> Regards, >> Daniel >> >> >> 2016-04-27 9:30 GMT-04:00 Hector Perez <hpe...@gm...>: >> >>> I see. Thank you Daniel for taking the time to answer my questions. I >>> look forward to continuing to use DWSIM and spread the word here in >>> Colombia. You've done an amazing job with this program. >>> >>> Have a nice day, >>> >>> Hector D. Perez >>> Chemical Engineering Consultant >>> >>> On Wed, Apr 27, 2016 at 8:28 AM, Daniel Wagner <dan...@gm...> >>> wrote: >>> >>>> Hi Hector, >>>> >>>> For liquids, a high pressure drop would be one that vaporizes part of >>>> it... for gases, I guess that it would be worse because gas properties are >>>> heavily dependent on pressure, and that can cause changes in concentrations >>>> and/or fugacities, impacting the final conversion. >>>> >>>> Regards >>>> Daniel >>>> >>>> >>>> 2016-04-27 9:22 GMT-04:00 Hector Perez <hpe...@gm...>: >>>> >>>>> Hi Daniel, >>>>> >>>>> Thank you for the clarification. What is the criteria for "high >>>>> pressure drop" in a PFR? I'm seeing that in the acetate problem, DWSIM >>>>> won't let me go beyond a pressure drop of 0.23 atm. >>>>> >>>>> Thanks, >>>>> >>>>> Hector D. Perez >>>>> >>>>> >>>>> On Wed, Apr 27, 2016 at 8:09 AM, Daniel Wagner <dan...@gm...> >>>>> wrote: >>>>> >>>>>> Hi Hector, >>>>>> >>>>>> I don't know how the volume calculation works on Aspen but, in DWSIM, >>>>>> I do the following: >>>>>> >>>>>> PFR code (use this for line number references in the text below): >>>>>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb >>>>>> >>>>>> - For the PFR, if you have a reactor of volume X, and the volume >>>>>> delta is 0.05, then the ODE (ordinal differential equation system) mass >>>>>> balance calculation will be done in 0.05*X volume steps until the entire >>>>>> volume is calculated (line 832). If you don't care about the actual >>>>>> pressure drop calculation, you can enter any value for the reactor length. >>>>>> Just be sure to input a length that doesn't result in a high pressure drop >>>>>> across the reactor. DWSIM calculates the pressure drop using the reactor >>>>>> volume and length to estimate the internal diameter, then uses the Darcy >>>>>> formula to calculate pressure drop. If the reactor has a catalyst bed, then >>>>>> the Ergun formula is used (line 797). >>>>>> >>>>>> CSTR code (use this for line number references in the text below): >>>>>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb >>>>>> >>>>>> - For the CSTR, the entire reactor volume is used at once and the ODE >>>>>> system is solved one time only (lines 559/111). There is no pressure drop >>>>>> calculation because this is supposed to be a batch (tank) reactor. :-) >>>>>> >>>>>> Regards >>>>>> Daniel >>>>>> >>>>>> >>>>>> >>>>>> 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>> >>>>>>> Hi Daniel, >>>>>>> >>>>>>> Thanks for sending the file along with the updated build! I actually >>>>>>> went through the file and included the reverse reaction by adjusting the >>>>>>> Reverse Order exponents (the Aspen Plus video has both forward and reverse >>>>>>> reactions). I also dropped the conversion on the Conversion reactor >>>>>>> (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to >>>>>>> be k_forward/k_reverse (ratio of rate constants). My numbers are now very >>>>>>> close, if not the same as the ASPEN simulation video. >>>>>>> >>>>>>> One thing I did run into is that the reactor dimensions for the PFR >>>>>>> and CSTR in the aspen video create errors in DWSIM. I had to decrease the >>>>>>> PFR length because it gave me a warning about the pressure drop being too >>>>>>> high. The CSTR volume also had to be decreased because it gave me a mass >>>>>>> balance error. Do you know why the aspen dimensions don't work? This could >>>>>>> perhaps be a lack of feasibility check on the ASPEN side. >>>>>>> >>>>>>> Also, what is "Volume Delta (Relative)" on the PFR specs? >>>>>>> >>>>>>> One other thing I checked was the CSTR duty (compared to the ASPEN >>>>>>> video) and found the DWSIM value to be about 6 times lower than the ASPEN >>>>>>> value (perhaps something having to do with the smaller volume used in >>>>>>> DWSIM?). >>>>>>> >>>>>>> Thanks once again. I am really liking this simulator. It seems >>>>>>> easier to use than aspen. >>>>>>> >>>>>>> Hector D. Perez >>>>>>> >>>>>>> >>>>>>> On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> >>>>>>> wrote: >>>>>>> >>>>>>>> Hi Hector, >>>>>>>> >>>>>>>> By following the Aspen Plus video I was able to make it work, there >>>>>>>> is no reverse reaction. Also, there was a bug in the PFR pressure drop >>>>>>>> calculation, you'll have to use an updated build. Download it from this >>>>>>>> link and unpack the files in DWSIM's installation directory: >>>>>>>> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >>>>>>>> >>>>>>>> Also, I forgot to tell you that, for kinetic reactions, every >>>>>>>> compound in the reaction must be present even if in a small amount, i.e. >>>>>>>> 0.000001. 0 will give you an error. >>>>>>>> >>>>>>>> You can also try the updated simulation file, I've added the >>>>>>>> equilibrium reactor as well. >>>>>>>> >>>>>>>> Regards >>>>>>>> Daniel >>>>>>>> >>>>>>>> >>>>>>>> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>>>> >>>>>>>>> Hi Daniel, >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> For kinetic reactions, what are the units on the activation >>>>>>>>> energy? (same units as those specified for the molar entropy?). I included >>>>>>>>> the DO and RO exponents as well as the base compound and now get a new >>>>>>>>> error on the CSTR: “An error occurred during the mass balance calculation. >>>>>>>>> Check reaction kinetics data and reactor sizing information as well.” >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> The PFR gives me the error: “One or more flash specification >>>>>>>>> values are invalid. Please check the associated UO or Material Stream for >>>>>>>>> incorrect specifications or miscalculated values. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Thank you, I really appreciate your assistance. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Hector D. Perez >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> *From: *Daniel Wagner <dan...@gm...> >>>>>>>>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>>>>>>>> *To: *Hector Perez <hpe...@gm...> >>>>>>>>> *Cc: *dws...@li... >>>>>>>>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> For the existing reactions, you've missed the compound >>>>>>>>> concentrations' direct and reverse order exponents. You also didn't define >>>>>>>>> the base compound, which should be the main reactant. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> For the conversion and equilibrium reactors, you must define the >>>>>>>>> corresponding reactions. Kinetic reactions only work with the PFR and the >>>>>>>>> CSTR. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> I am trying to replicate the following ASPEN tutorial to set up >>>>>>>>> the liquid reaction for ethyl acetate formation from ethanol and acetic >>>>>>>>> acid using different types of reactors: >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Unfortunately, only the Gibbs reactor yielded any result with a >>>>>>>>> ethyl acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The >>>>>>>>> only differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>>>>>>>> whereas my simulation uses NRTL. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> The conversion reactor had zero conversion and both the PFR and >>>>>>>>> CSTR reactors gave the error: "The given key was not present in the >>>>>>>>> dictionary." I'm not sure what this means. I tried different thermodynamic >>>>>>>>> models besides NRTL with no avail. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> I will send my simulation file attached. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> I would really appreciate any light on the matter. >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Obrigado! >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> Hector D. Perez >>>>>>>>> >>>>>>>>> Chemical Engineering Consultant >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> ------------------------------------------------------------------------------ >>>>>>>>> Find and fix application performance issues faster with >>>>>>>>> Applications Manager >>>>>>>>> Applications Manager provides deep performance insights into >>>>>>>>> multiple tiers of >>>>>>>>> your business applications. It resolves application problems >>>>>>>>> quickly and >>>>>>>>> reduces your MTTR. Get your free trial! >>>>>>>>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>>>>>>>> _______________________________________________ >>>>>>>>> Dwsim-users mailing list >>>>>>>>> Dws...@li... >>>>>>>>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> > |
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From: Hector P. <hpe...@gm...> - 2016-04-27 13:52:54
|
Daniel, there may be a bug then because my absolute pressure leaving the PFR is ~0.8 atm. If I increase the reactor length by 1 cm more, then I get the pressure drop error. Nice, yes we are close. Ainda nao tem ido ao Brasil mas tenho escutado que e muito bonito la. Hector D. Perez Chemical Engineering Consultant On Wed, Apr 27, 2016 at 8:42 AM, Daniel Wagner <dan...@gm...> wrote: > Hector, the actual criteria for throwing the pressure drop error in the > PFR model is a negative pressure value after the pressure drop calculation > step: > https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb#L828 > > Hey, we live relatively close to each other. I'm in Manaus, Amazonas. > Could we say that both of us live in the Amazon? :-) > > Regards, > Daniel > > > 2016-04-27 9:30 GMT-04:00 Hector Perez <hpe...@gm...>: > >> I see. Thank you Daniel for taking the time to answer my questions. I >> look forward to continuing to use DWSIM and spread the word here in >> Colombia. You've done an amazing job with this program. >> >> Have a nice day, >> >> Hector D. Perez >> Chemical Engineering Consultant >> >> On Wed, Apr 27, 2016 at 8:28 AM, Daniel Wagner <dan...@gm...> >> wrote: >> >>> Hi Hector, >>> >>> For liquids, a high pressure drop would be one that vaporizes part of >>> it... for gases, I guess that it would be worse because gas properties are >>> heavily dependent on pressure, and that can cause changes in concentrations >>> and/or fugacities, impacting the final conversion. >>> >>> Regards >>> Daniel >>> >>> >>> 2016-04-27 9:22 GMT-04:00 Hector Perez <hpe...@gm...>: >>> >>>> Hi Daniel, >>>> >>>> Thank you for the clarification. What is the criteria for "high >>>> pressure drop" in a PFR? I'm seeing that in the acetate problem, DWSIM >>>> won't let me go beyond a pressure drop of 0.23 atm. >>>> >>>> Thanks, >>>> >>>> Hector D. Perez >>>> >>>> >>>> On Wed, Apr 27, 2016 at 8:09 AM, Daniel Wagner <dan...@gm...> >>>> wrote: >>>> >>>>> Hi Hector, >>>>> >>>>> I don't know how the volume calculation works on Aspen but, in DWSIM, >>>>> I do the following: >>>>> >>>>> PFR code (use this for line number references in the text below): >>>>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb >>>>> >>>>> - For the PFR, if you have a reactor of volume X, and the volume delta >>>>> is 0.05, then the ODE (ordinal differential equation system) mass balance >>>>> calculation will be done in 0.05*X volume steps until the entire volume is >>>>> calculated (line 832). If you don't care about the actual pressure drop >>>>> calculation, you can enter any value for the reactor length. Just be sure >>>>> to input a length that doesn't result in a high pressure drop across the >>>>> reactor. DWSIM calculates the pressure drop using the reactor volume and >>>>> length to estimate the internal diameter, then uses the Darcy formula to >>>>> calculate pressure drop. If the reactor has a catalyst bed, then the Ergun >>>>> formula is used (line 797). >>>>> >>>>> CSTR code (use this for line number references in the text below): >>>>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb >>>>> >>>>> - For the CSTR, the entire reactor volume is used at once and the ODE >>>>> system is solved one time only (lines 559/111). There is no pressure drop >>>>> calculation because this is supposed to be a batch (tank) reactor. :-) >>>>> >>>>> Regards >>>>> Daniel >>>>> >>>>> >>>>> >>>>> 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>> >>>>>> Hi Daniel, >>>>>> >>>>>> Thanks for sending the file along with the updated build! I actually >>>>>> went through the file and included the reverse reaction by adjusting the >>>>>> Reverse Order exponents (the Aspen Plus video has both forward and reverse >>>>>> reactions). I also dropped the conversion on the Conversion reactor >>>>>> (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to >>>>>> be k_forward/k_reverse (ratio of rate constants). My numbers are now very >>>>>> close, if not the same as the ASPEN simulation video. >>>>>> >>>>>> One thing I did run into is that the reactor dimensions for the PFR >>>>>> and CSTR in the aspen video create errors in DWSIM. I had to decrease the >>>>>> PFR length because it gave me a warning about the pressure drop being too >>>>>> high. The CSTR volume also had to be decreased because it gave me a mass >>>>>> balance error. Do you know why the aspen dimensions don't work? This could >>>>>> perhaps be a lack of feasibility check on the ASPEN side. >>>>>> >>>>>> Also, what is "Volume Delta (Relative)" on the PFR specs? >>>>>> >>>>>> One other thing I checked was the CSTR duty (compared to the ASPEN >>>>>> video) and found the DWSIM value to be about 6 times lower than the ASPEN >>>>>> value (perhaps something having to do with the smaller volume used in >>>>>> DWSIM?). >>>>>> >>>>>> Thanks once again. I am really liking this simulator. It seems easier >>>>>> to use than aspen. >>>>>> >>>>>> Hector D. Perez >>>>>> >>>>>> >>>>>> On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> >>>>>> wrote: >>>>>> >>>>>>> Hi Hector, >>>>>>> >>>>>>> By following the Aspen Plus video I was able to make it work, there >>>>>>> is no reverse reaction. Also, there was a bug in the PFR pressure drop >>>>>>> calculation, you'll have to use an updated build. Download it from this >>>>>>> link and unpack the files in DWSIM's installation directory: >>>>>>> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >>>>>>> >>>>>>> Also, I forgot to tell you that, for kinetic reactions, every >>>>>>> compound in the reaction must be present even if in a small amount, i.e. >>>>>>> 0.000001. 0 will give you an error. >>>>>>> >>>>>>> You can also try the updated simulation file, I've added the >>>>>>> equilibrium reactor as well. >>>>>>> >>>>>>> Regards >>>>>>> Daniel >>>>>>> >>>>>>> >>>>>>> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>>> >>>>>>>> Hi Daniel, >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> For kinetic reactions, what are the units on the activation energy? >>>>>>>> (same units as those specified for the molar entropy?). I included the DO >>>>>>>> and RO exponents as well as the base compound and now get a new error on >>>>>>>> the CSTR: “An error occurred during the mass balance calculation. Check >>>>>>>> reaction kinetics data and reactor sizing information as well.” >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> The PFR gives me the error: “One or more flash specification values >>>>>>>> are invalid. Please check the associated UO or Material Stream for >>>>>>>> incorrect specifications or miscalculated values. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Thank you, I really appreciate your assistance. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Hector D. Perez >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> *From: *Daniel Wagner <dan...@gm...> >>>>>>>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>>>>>>> *To: *Hector Perez <hpe...@gm...> >>>>>>>> *Cc: *dws...@li... >>>>>>>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> For the existing reactions, you've missed the compound >>>>>>>> concentrations' direct and reverse order exponents. You also didn't define >>>>>>>> the base compound, which should be the main reactant. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> For the conversion and equilibrium reactors, you must define the >>>>>>>> corresponding reactions. Kinetic reactions only work with the PFR and the >>>>>>>> CSTR. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>>>> >>>>>>>> Hi, >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I am trying to replicate the following ASPEN tutorial to set up the >>>>>>>> liquid reaction for ethyl acetate formation from ethanol and acetic acid >>>>>>>> using different types of reactors: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Unfortunately, only the Gibbs reactor yielded any result with a >>>>>>>> ethyl acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The >>>>>>>> only differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>>>>>>> whereas my simulation uses NRTL. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> The conversion reactor had zero conversion and both the PFR and >>>>>>>> CSTR reactors gave the error: "The given key was not present in the >>>>>>>> dictionary." I'm not sure what this means. I tried different thermodynamic >>>>>>>> models besides NRTL with no avail. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I will send my simulation file attached. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> I would really appreciate any light on the matter. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Obrigado! >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> Hector D. Perez >>>>>>>> >>>>>>>> Chemical Engineering Consultant >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> ------------------------------------------------------------------------------ >>>>>>>> Find and fix application performance issues faster with >>>>>>>> Applications Manager >>>>>>>> Applications Manager provides deep performance insights into >>>>>>>> multiple tiers of >>>>>>>> your business applications. It resolves application problems >>>>>>>> quickly and >>>>>>>> reduces your MTTR. Get your free trial! >>>>>>>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>>>>>>> _______________________________________________ >>>>>>>> Dwsim-users mailing list >>>>>>>> Dws...@li... >>>>>>>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> > |
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From: Daniel W. <dan...@gm...> - 2016-04-27 13:42:18
|
Hector, the actual criteria for throwing the pressure drop error in the PFR model is a negative pressure value after the pressure drop calculation step: https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb#L828 Hey, we live relatively close to each other. I'm in Manaus, Amazonas. Could we say that both of us live in the Amazon? :-) Regards, Daniel 2016-04-27 9:30 GMT-04:00 Hector Perez <hpe...@gm...>: > I see. Thank you Daniel for taking the time to answer my questions. I look > forward to continuing to use DWSIM and spread the word here in Colombia. > You've done an amazing job with this program. > > Have a nice day, > > Hector D. Perez > Chemical Engineering Consultant > > On Wed, Apr 27, 2016 at 8:28 AM, Daniel Wagner <dan...@gm...> > wrote: > >> Hi Hector, >> >> For liquids, a high pressure drop would be one that vaporizes part of >> it... for gases, I guess that it would be worse because gas properties are >> heavily dependent on pressure, and that can cause changes in concentrations >> and/or fugacities, impacting the final conversion. >> >> Regards >> Daniel >> >> >> 2016-04-27 9:22 GMT-04:00 Hector Perez <hpe...@gm...>: >> >>> Hi Daniel, >>> >>> Thank you for the clarification. What is the criteria for "high pressure >>> drop" in a PFR? I'm seeing that in the acetate problem, DWSIM won't let me >>> go beyond a pressure drop of 0.23 atm. >>> >>> Thanks, >>> >>> Hector D. Perez >>> >>> >>> On Wed, Apr 27, 2016 at 8:09 AM, Daniel Wagner <dan...@gm...> >>> wrote: >>> >>>> Hi Hector, >>>> >>>> I don't know how the volume calculation works on Aspen but, in DWSIM, I >>>> do the following: >>>> >>>> PFR code (use this for line number references in the text below): >>>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb >>>> >>>> - For the PFR, if you have a reactor of volume X, and the volume delta >>>> is 0.05, then the ODE (ordinal differential equation system) mass balance >>>> calculation will be done in 0.05*X volume steps until the entire volume is >>>> calculated (line 832). If you don't care about the actual pressure drop >>>> calculation, you can enter any value for the reactor length. Just be sure >>>> to input a length that doesn't result in a high pressure drop across the >>>> reactor. DWSIM calculates the pressure drop using the reactor volume and >>>> length to estimate the internal diameter, then uses the Darcy formula to >>>> calculate pressure drop. If the reactor has a catalyst bed, then the Ergun >>>> formula is used (line 797). >>>> >>>> CSTR code (use this for line number references in the text below): >>>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb >>>> >>>> - For the CSTR, the entire reactor volume is used at once and the ODE >>>> system is solved one time only (lines 559/111). There is no pressure drop >>>> calculation because this is supposed to be a batch (tank) reactor. :-) >>>> >>>> Regards >>>> Daniel >>>> >>>> >>>> >>>> 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: >>>> >>>>> Hi Daniel, >>>>> >>>>> Thanks for sending the file along with the updated build! I actually >>>>> went through the file and included the reverse reaction by adjusting the >>>>> Reverse Order exponents (the Aspen Plus video has both forward and reverse >>>>> reactions). I also dropped the conversion on the Conversion reactor >>>>> (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to >>>>> be k_forward/k_reverse (ratio of rate constants). My numbers are now very >>>>> close, if not the same as the ASPEN simulation video. >>>>> >>>>> One thing I did run into is that the reactor dimensions for the PFR >>>>> and CSTR in the aspen video create errors in DWSIM. I had to decrease the >>>>> PFR length because it gave me a warning about the pressure drop being too >>>>> high. The CSTR volume also had to be decreased because it gave me a mass >>>>> balance error. Do you know why the aspen dimensions don't work? This could >>>>> perhaps be a lack of feasibility check on the ASPEN side. >>>>> >>>>> Also, what is "Volume Delta (Relative)" on the PFR specs? >>>>> >>>>> One other thing I checked was the CSTR duty (compared to the ASPEN >>>>> video) and found the DWSIM value to be about 6 times lower than the ASPEN >>>>> value (perhaps something having to do with the smaller volume used in >>>>> DWSIM?). >>>>> >>>>> Thanks once again. I am really liking this simulator. It seems easier >>>>> to use than aspen. >>>>> >>>>> Hector D. Perez >>>>> >>>>> >>>>> On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> >>>>> wrote: >>>>> >>>>>> Hi Hector, >>>>>> >>>>>> By following the Aspen Plus video I was able to make it work, there >>>>>> is no reverse reaction. Also, there was a bug in the PFR pressure drop >>>>>> calculation, you'll have to use an updated build. Download it from this >>>>>> link and unpack the files in DWSIM's installation directory: >>>>>> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >>>>>> >>>>>> Also, I forgot to tell you that, for kinetic reactions, every >>>>>> compound in the reaction must be present even if in a small amount, i.e. >>>>>> 0.000001. 0 will give you an error. >>>>>> >>>>>> You can also try the updated simulation file, I've added the >>>>>> equilibrium reactor as well. >>>>>> >>>>>> Regards >>>>>> Daniel >>>>>> >>>>>> >>>>>> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>> >>>>>>> Hi Daniel, >>>>>>> >>>>>>> >>>>>>> >>>>>>> For kinetic reactions, what are the units on the activation energy? >>>>>>> (same units as those specified for the molar entropy?). I included the DO >>>>>>> and RO exponents as well as the base compound and now get a new error on >>>>>>> the CSTR: “An error occurred during the mass balance calculation. Check >>>>>>> reaction kinetics data and reactor sizing information as well.” >>>>>>> >>>>>>> >>>>>>> >>>>>>> The PFR gives me the error: “One or more flash specification values >>>>>>> are invalid. Please check the associated UO or Material Stream for >>>>>>> incorrect specifications or miscalculated values. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Thank you, I really appreciate your assistance. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Hector D. Perez >>>>>>> >>>>>>> >>>>>>> >>>>>>> *From: *Daniel Wagner <dan...@gm...> >>>>>>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>>>>>> *To: *Hector Perez <hpe...@gm...> >>>>>>> *Cc: *dws...@li... >>>>>>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>>>>>> >>>>>>> >>>>>>> >>>>>>> For the existing reactions, you've missed the compound >>>>>>> concentrations' direct and reverse order exponents. You also didn't define >>>>>>> the base compound, which should be the main reactant. >>>>>>> >>>>>>> >>>>>>> >>>>>>> For the conversion and equilibrium reactors, you must define the >>>>>>> corresponding reactions. Kinetic reactions only work with the PFR and the >>>>>>> CSTR. >>>>>>> >>>>>>> >>>>>>> >>>>>>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>>> >>>>>>> Hi, >>>>>>> >>>>>>> >>>>>>> >>>>>>> I am trying to replicate the following ASPEN tutorial to set up the >>>>>>> liquid reaction for ethyl acetate formation from ethanol and acetic acid >>>>>>> using different types of reactors: >>>>>>> >>>>>>> >>>>>>> >>>>>>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>>>>>> >>>>>>> >>>>>>> >>>>>>> Unfortunately, only the Gibbs reactor yielded any result with a >>>>>>> ethyl acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The >>>>>>> only differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>>>>>> whereas my simulation uses NRTL. >>>>>>> >>>>>>> >>>>>>> >>>>>>> The conversion reactor had zero conversion and both the PFR and CSTR >>>>>>> reactors gave the error: "The given key was not present in the dictionary." >>>>>>> I'm not sure what this means. I tried different thermodynamic models >>>>>>> besides NRTL with no avail. >>>>>>> >>>>>>> >>>>>>> >>>>>>> I will send my simulation file attached. >>>>>>> >>>>>>> >>>>>>> >>>>>>> I would really appreciate any light on the matter. >>>>>>> >>>>>>> >>>>>>> >>>>>>> Obrigado! >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> Hector D. Perez >>>>>>> >>>>>>> Chemical Engineering Consultant >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> ------------------------------------------------------------------------------ >>>>>>> Find and fix application performance issues faster with Applications >>>>>>> Manager >>>>>>> Applications Manager provides deep performance insights into >>>>>>> multiple tiers of >>>>>>> your business applications. It resolves application problems quickly >>>>>>> and >>>>>>> reduces your MTTR. Get your free trial! >>>>>>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>>>>>> _______________________________________________ >>>>>>> Dwsim-users mailing list >>>>>>> Dws...@li... >>>>>>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> >> > |
|
From: Hector P. <hpe...@gm...> - 2016-04-27 13:31:14
|
I see. Thank you Daniel for taking the time to answer my questions. I look forward to continuing to use DWSIM and spread the word here in Colombia. You've done an amazing job with this program. Have a nice day, Hector D. Perez Chemical Engineering Consultant On Wed, Apr 27, 2016 at 8:28 AM, Daniel Wagner <dan...@gm...> wrote: > Hi Hector, > > For liquids, a high pressure drop would be one that vaporizes part of > it... for gases, I guess that it would be worse because gas properties are > heavily dependent on pressure, and that can cause changes in concentrations > and/or fugacities, impacting the final conversion. > > Regards > Daniel > > > 2016-04-27 9:22 GMT-04:00 Hector Perez <hpe...@gm...>: > >> Hi Daniel, >> >> Thank you for the clarification. What is the criteria for "high pressure >> drop" in a PFR? I'm seeing that in the acetate problem, DWSIM won't let me >> go beyond a pressure drop of 0.23 atm. >> >> Thanks, >> >> Hector D. Perez >> >> >> On Wed, Apr 27, 2016 at 8:09 AM, Daniel Wagner <dan...@gm...> >> wrote: >> >>> Hi Hector, >>> >>> I don't know how the volume calculation works on Aspen but, in DWSIM, I >>> do the following: >>> >>> PFR code (use this for line number references in the text below): >>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb >>> >>> - For the PFR, if you have a reactor of volume X, and the volume delta >>> is 0.05, then the ODE (ordinal differential equation system) mass balance >>> calculation will be done in 0.05*X volume steps until the entire volume is >>> calculated (line 832). If you don't care about the actual pressure drop >>> calculation, you can enter any value for the reactor length. Just be sure >>> to input a length that doesn't result in a high pressure drop across the >>> reactor. DWSIM calculates the pressure drop using the reactor volume and >>> length to estimate the internal diameter, then uses the Darcy formula to >>> calculate pressure drop. If the reactor has a catalyst bed, then the Ergun >>> formula is used (line 797). >>> >>> CSTR code (use this for line number references in the text below): >>> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb >>> >>> - For the CSTR, the entire reactor volume is used at once and the ODE >>> system is solved one time only (lines 559/111). There is no pressure drop >>> calculation because this is supposed to be a batch (tank) reactor. :-) >>> >>> Regards >>> Daniel >>> >>> >>> >>> 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: >>> >>>> Hi Daniel, >>>> >>>> Thanks for sending the file along with the updated build! I actually >>>> went through the file and included the reverse reaction by adjusting the >>>> Reverse Order exponents (the Aspen Plus video has both forward and reverse >>>> reactions). I also dropped the conversion on the Conversion reactor >>>> (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to >>>> be k_forward/k_reverse (ratio of rate constants). My numbers are now very >>>> close, if not the same as the ASPEN simulation video. >>>> >>>> One thing I did run into is that the reactor dimensions for the PFR and >>>> CSTR in the aspen video create errors in DWSIM. I had to decrease the PFR >>>> length because it gave me a warning about the pressure drop being too high. >>>> The CSTR volume also had to be decreased because it gave me a mass balance >>>> error. Do you know why the aspen dimensions don't work? This could perhaps >>>> be a lack of feasibility check on the ASPEN side. >>>> >>>> Also, what is "Volume Delta (Relative)" on the PFR specs? >>>> >>>> One other thing I checked was the CSTR duty (compared to the ASPEN >>>> video) and found the DWSIM value to be about 6 times lower than the ASPEN >>>> value (perhaps something having to do with the smaller volume used in >>>> DWSIM?). >>>> >>>> Thanks once again. I am really liking this simulator. It seems easier >>>> to use than aspen. >>>> >>>> Hector D. Perez >>>> >>>> >>>> On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> >>>> wrote: >>>> >>>>> Hi Hector, >>>>> >>>>> By following the Aspen Plus video I was able to make it work, there is >>>>> no reverse reaction. Also, there was a bug in the PFR pressure drop >>>>> calculation, you'll have to use an updated build. Download it from this >>>>> link and unpack the files in DWSIM's installation directory: >>>>> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >>>>> >>>>> Also, I forgot to tell you that, for kinetic reactions, every compound >>>>> in the reaction must be present even if in a small amount, i.e. 0.000001. 0 >>>>> will give you an error. >>>>> >>>>> You can also try the updated simulation file, I've added the >>>>> equilibrium reactor as well. >>>>> >>>>> Regards >>>>> Daniel >>>>> >>>>> >>>>> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>> >>>>>> Hi Daniel, >>>>>> >>>>>> >>>>>> >>>>>> For kinetic reactions, what are the units on the activation energy? >>>>>> (same units as those specified for the molar entropy?). I included the DO >>>>>> and RO exponents as well as the base compound and now get a new error on >>>>>> the CSTR: “An error occurred during the mass balance calculation. Check >>>>>> reaction kinetics data and reactor sizing information as well.” >>>>>> >>>>>> >>>>>> >>>>>> The PFR gives me the error: “One or more flash specification values >>>>>> are invalid. Please check the associated UO or Material Stream for >>>>>> incorrect specifications or miscalculated values. >>>>>> >>>>>> >>>>>> >>>>>> Thank you, I really appreciate your assistance. >>>>>> >>>>>> >>>>>> >>>>>> Hector D. Perez >>>>>> >>>>>> >>>>>> >>>>>> *From: *Daniel Wagner <dan...@gm...> >>>>>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>>>>> *To: *Hector Perez <hpe...@gm...> >>>>>> *Cc: *dws...@li... >>>>>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>>>>> >>>>>> >>>>>> >>>>>> For the existing reactions, you've missed the compound >>>>>> concentrations' direct and reverse order exponents. You also didn't define >>>>>> the base compound, which should be the main reactant. >>>>>> >>>>>> >>>>>> >>>>>> For the conversion and equilibrium reactors, you must define the >>>>>> corresponding reactions. Kinetic reactions only work with the PFR and the >>>>>> CSTR. >>>>>> >>>>>> >>>>>> >>>>>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>>> >>>>>> Hi, >>>>>> >>>>>> >>>>>> >>>>>> I am trying to replicate the following ASPEN tutorial to set up the >>>>>> liquid reaction for ethyl acetate formation from ethanol and acetic acid >>>>>> using different types of reactors: >>>>>> >>>>>> >>>>>> >>>>>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>>>>> >>>>>> >>>>>> >>>>>> Unfortunately, only the Gibbs reactor yielded any result with a ethyl >>>>>> acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only >>>>>> differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>>>>> whereas my simulation uses NRTL. >>>>>> >>>>>> >>>>>> >>>>>> The conversion reactor had zero conversion and both the PFR and CSTR >>>>>> reactors gave the error: "The given key was not present in the dictionary." >>>>>> I'm not sure what this means. I tried different thermodynamic models >>>>>> besides NRTL with no avail. >>>>>> >>>>>> >>>>>> >>>>>> I will send my simulation file attached. >>>>>> >>>>>> >>>>>> >>>>>> I would really appreciate any light on the matter. >>>>>> >>>>>> >>>>>> >>>>>> Obrigado! >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> Hector D. Perez >>>>>> >>>>>> Chemical Engineering Consultant >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> ------------------------------------------------------------------------------ >>>>>> Find and fix application performance issues faster with Applications >>>>>> Manager >>>>>> Applications Manager provides deep performance insights into multiple >>>>>> tiers of >>>>>> your business applications. It resolves application problems quickly >>>>>> and >>>>>> reduces your MTTR. Get your free trial! >>>>>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>>>>> _______________________________________________ >>>>>> Dwsim-users mailing list >>>>>> Dws...@li... >>>>>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>> >>>>> >>>> >>> >> > |
|
From: Daniel W. <dan...@gm...> - 2016-04-27 13:28:50
|
Hi Hector, For liquids, a high pressure drop would be one that vaporizes part of it... for gases, I guess that it would be worse because gas properties are heavily dependent on pressure, and that can cause changes in concentrations and/or fugacities, impacting the final conversion. Regards Daniel 2016-04-27 9:22 GMT-04:00 Hector Perez <hpe...@gm...>: > Hi Daniel, > > Thank you for the clarification. What is the criteria for "high pressure > drop" in a PFR? I'm seeing that in the acetate problem, DWSIM won't let me > go beyond a pressure drop of 0.23 atm. > > Thanks, > > Hector D. Perez > > > On Wed, Apr 27, 2016 at 8:09 AM, Daniel Wagner <dan...@gm...> > wrote: > >> Hi Hector, >> >> I don't know how the volume calculation works on Aspen but, in DWSIM, I >> do the following: >> >> PFR code (use this for line number references in the text below): >> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb >> >> - For the PFR, if you have a reactor of volume X, and the volume delta is >> 0.05, then the ODE (ordinal differential equation system) mass balance >> calculation will be done in 0.05*X volume steps until the entire volume is >> calculated (line 832). If you don't care about the actual pressure drop >> calculation, you can enter any value for the reactor length. Just be sure >> to input a length that doesn't result in a high pressure drop across the >> reactor. DWSIM calculates the pressure drop using the reactor volume and >> length to estimate the internal diameter, then uses the Darcy formula to >> calculate pressure drop. If the reactor has a catalyst bed, then the Ergun >> formula is used (line 797). >> >> CSTR code (use this for line number references in the text below): >> https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb >> >> - For the CSTR, the entire reactor volume is used at once and the ODE >> system is solved one time only (lines 559/111). There is no pressure drop >> calculation because this is supposed to be a batch (tank) reactor. :-) >> >> Regards >> Daniel >> >> >> >> 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: >> >>> Hi Daniel, >>> >>> Thanks for sending the file along with the updated build! I actually >>> went through the file and included the reverse reaction by adjusting the >>> Reverse Order exponents (the Aspen Plus video has both forward and reverse >>> reactions). I also dropped the conversion on the Conversion reactor >>> (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to >>> be k_forward/k_reverse (ratio of rate constants). My numbers are now very >>> close, if not the same as the ASPEN simulation video. >>> >>> One thing I did run into is that the reactor dimensions for the PFR and >>> CSTR in the aspen video create errors in DWSIM. I had to decrease the PFR >>> length because it gave me a warning about the pressure drop being too high. >>> The CSTR volume also had to be decreased because it gave me a mass balance >>> error. Do you know why the aspen dimensions don't work? This could perhaps >>> be a lack of feasibility check on the ASPEN side. >>> >>> Also, what is "Volume Delta (Relative)" on the PFR specs? >>> >>> One other thing I checked was the CSTR duty (compared to the ASPEN >>> video) and found the DWSIM value to be about 6 times lower than the ASPEN >>> value (perhaps something having to do with the smaller volume used in >>> DWSIM?). >>> >>> Thanks once again. I am really liking this simulator. It seems easier to >>> use than aspen. >>> >>> Hector D. Perez >>> >>> >>> On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> >>> wrote: >>> >>>> Hi Hector, >>>> >>>> By following the Aspen Plus video I was able to make it work, there is >>>> no reverse reaction. Also, there was a bug in the PFR pressure drop >>>> calculation, you'll have to use an updated build. Download it from this >>>> link and unpack the files in DWSIM's installation directory: >>>> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >>>> >>>> Also, I forgot to tell you that, for kinetic reactions, every compound >>>> in the reaction must be present even if in a small amount, i.e. 0.000001. 0 >>>> will give you an error. >>>> >>>> You can also try the updated simulation file, I've added the >>>> equilibrium reactor as well. >>>> >>>> Regards >>>> Daniel >>>> >>>> >>>> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >>>> >>>>> Hi Daniel, >>>>> >>>>> >>>>> >>>>> For kinetic reactions, what are the units on the activation energy? >>>>> (same units as those specified for the molar entropy?). I included the DO >>>>> and RO exponents as well as the base compound and now get a new error on >>>>> the CSTR: “An error occurred during the mass balance calculation. Check >>>>> reaction kinetics data and reactor sizing information as well.” >>>>> >>>>> >>>>> >>>>> The PFR gives me the error: “One or more flash specification values >>>>> are invalid. Please check the associated UO or Material Stream for >>>>> incorrect specifications or miscalculated values. >>>>> >>>>> >>>>> >>>>> Thank you, I really appreciate your assistance. >>>>> >>>>> >>>>> >>>>> Hector D. Perez >>>>> >>>>> >>>>> >>>>> *From: *Daniel Wagner <dan...@gm...> >>>>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>>>> *To: *Hector Perez <hpe...@gm...> >>>>> *Cc: *dws...@li... >>>>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>>>> >>>>> >>>>> >>>>> For the existing reactions, you've missed the compound concentrations' >>>>> direct and reverse order exponents. You also didn't define the base >>>>> compound, which should be the main reactant. >>>>> >>>>> >>>>> >>>>> For the conversion and equilibrium reactors, you must define the >>>>> corresponding reactions. Kinetic reactions only work with the PFR and the >>>>> CSTR. >>>>> >>>>> >>>>> >>>>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>>>> >>>>> Hi, >>>>> >>>>> >>>>> >>>>> I am trying to replicate the following ASPEN tutorial to set up the >>>>> liquid reaction for ethyl acetate formation from ethanol and acetic acid >>>>> using different types of reactors: >>>>> >>>>> >>>>> >>>>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>>>> >>>>> >>>>> >>>>> Unfortunately, only the Gibbs reactor yielded any result with a ethyl >>>>> acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only >>>>> differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>>>> whereas my simulation uses NRTL. >>>>> >>>>> >>>>> >>>>> The conversion reactor had zero conversion and both the PFR and CSTR >>>>> reactors gave the error: "The given key was not present in the dictionary." >>>>> I'm not sure what this means. I tried different thermodynamic models >>>>> besides NRTL with no avail. >>>>> >>>>> >>>>> >>>>> I will send my simulation file attached. >>>>> >>>>> >>>>> >>>>> I would really appreciate any light on the matter. >>>>> >>>>> >>>>> >>>>> Obrigado! >>>>> >>>>> >>>>> >>>>> >>>>> Hector D. Perez >>>>> >>>>> Chemical Engineering Consultant >>>>> >>>>> >>>>> >>>>> >>>>> >>>>> ------------------------------------------------------------------------------ >>>>> Find and fix application performance issues faster with Applications >>>>> Manager >>>>> Applications Manager provides deep performance insights into multiple >>>>> tiers of >>>>> your business applications. It resolves application problems quickly >>>>> and >>>>> reduces your MTTR. Get your free trial! >>>>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>>>> _______________________________________________ >>>>> Dwsim-users mailing list >>>>> Dws...@li... >>>>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>>>> >>>>> >>>>> >>>>> >>>>> >>>> >>>> >>> >> > |
|
From: Hector P. <hpe...@gm...> - 2016-04-27 13:22:58
|
Hi Daniel, Thank you for the clarification. What is the criteria for "high pressure drop" in a PFR? I'm seeing that in the acetate problem, DWSIM won't let me go beyond a pressure drop of 0.23 atm. Thanks, Hector D. Perez On Wed, Apr 27, 2016 at 8:09 AM, Daniel Wagner <dan...@gm...> wrote: > Hi Hector, > > I don't know how the volume calculation works on Aspen but, in DWSIM, I do > the following: > > PFR code (use this for line number references in the text below): > https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb > > - For the PFR, if you have a reactor of volume X, and the volume delta is > 0.05, then the ODE (ordinal differential equation system) mass balance > calculation will be done in 0.05*X volume steps until the entire volume is > calculated (line 832). If you don't care about the actual pressure drop > calculation, you can enter any value for the reactor length. Just be sure > to input a length that doesn't result in a high pressure drop across the > reactor. DWSIM calculates the pressure drop using the reactor volume and > length to estimate the internal diameter, then uses the Darcy formula to > calculate pressure drop. If the reactor has a catalyst bed, then the Ergun > formula is used (line 797). > > CSTR code (use this for line number references in the text below): > https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb > > - For the CSTR, the entire reactor volume is used at once and the ODE > system is solved one time only (lines 559/111). There is no pressure drop > calculation because this is supposed to be a batch (tank) reactor. :-) > > Regards > Daniel > > > > 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: > >> Hi Daniel, >> >> Thanks for sending the file along with the updated build! I actually went >> through the file and included the reverse reaction by adjusting the Reverse >> Order exponents (the Aspen Plus video has both forward and reverse >> reactions). I also dropped the conversion on the Conversion reactor >> (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to >> be k_forward/k_reverse (ratio of rate constants). My numbers are now very >> close, if not the same as the ASPEN simulation video. >> >> One thing I did run into is that the reactor dimensions for the PFR and >> CSTR in the aspen video create errors in DWSIM. I had to decrease the PFR >> length because it gave me a warning about the pressure drop being too high. >> The CSTR volume also had to be decreased because it gave me a mass balance >> error. Do you know why the aspen dimensions don't work? This could perhaps >> be a lack of feasibility check on the ASPEN side. >> >> Also, what is "Volume Delta (Relative)" on the PFR specs? >> >> One other thing I checked was the CSTR duty (compared to the ASPEN video) >> and found the DWSIM value to be about 6 times lower than the ASPEN value >> (perhaps something having to do with the smaller volume used in DWSIM?). >> >> Thanks once again. I am really liking this simulator. It seems easier to >> use than aspen. >> >> Hector D. Perez >> >> >> On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> >> wrote: >> >>> Hi Hector, >>> >>> By following the Aspen Plus video I was able to make it work, there is >>> no reverse reaction. Also, there was a bug in the PFR pressure drop >>> calculation, you'll have to use an updated build. Download it from this >>> link and unpack the files in DWSIM's installation directory: >>> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >>> >>> Also, I forgot to tell you that, for kinetic reactions, every compound >>> in the reaction must be present even if in a small amount, i.e. 0.000001. 0 >>> will give you an error. >>> >>> You can also try the updated simulation file, I've added the equilibrium >>> reactor as well. >>> >>> Regards >>> Daniel >>> >>> >>> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >>> >>>> Hi Daniel, >>>> >>>> >>>> >>>> For kinetic reactions, what are the units on the activation energy? >>>> (same units as those specified for the molar entropy?). I included the DO >>>> and RO exponents as well as the base compound and now get a new error on >>>> the CSTR: “An error occurred during the mass balance calculation. Check >>>> reaction kinetics data and reactor sizing information as well.” >>>> >>>> >>>> >>>> The PFR gives me the error: “One or more flash specification values are >>>> invalid. Please check the associated UO or Material Stream for incorrect >>>> specifications or miscalculated values. >>>> >>>> >>>> >>>> Thank you, I really appreciate your assistance. >>>> >>>> >>>> >>>> Hector D. Perez >>>> >>>> >>>> >>>> *From: *Daniel Wagner <dan...@gm...> >>>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>>> *To: *Hector Perez <hpe...@gm...> >>>> *Cc: *dws...@li... >>>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>>> >>>> >>>> >>>> For the existing reactions, you've missed the compound concentrations' >>>> direct and reverse order exponents. You also didn't define the base >>>> compound, which should be the main reactant. >>>> >>>> >>>> >>>> For the conversion and equilibrium reactors, you must define the >>>> corresponding reactions. Kinetic reactions only work with the PFR and the >>>> CSTR. >>>> >>>> >>>> >>>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>>> >>>> Hi, >>>> >>>> >>>> >>>> I am trying to replicate the following ASPEN tutorial to set up the >>>> liquid reaction for ethyl acetate formation from ethanol and acetic acid >>>> using different types of reactors: >>>> >>>> >>>> >>>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>>> >>>> >>>> >>>> Unfortunately, only the Gibbs reactor yielded any result with a ethyl >>>> acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only >>>> differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>>> whereas my simulation uses NRTL. >>>> >>>> >>>> >>>> The conversion reactor had zero conversion and both the PFR and CSTR >>>> reactors gave the error: "The given key was not present in the dictionary." >>>> I'm not sure what this means. I tried different thermodynamic models >>>> besides NRTL with no avail. >>>> >>>> >>>> >>>> I will send my simulation file attached. >>>> >>>> >>>> >>>> I would really appreciate any light on the matter. >>>> >>>> >>>> >>>> Obrigado! >>>> >>>> >>>> >>>> >>>> Hector D. Perez >>>> >>>> Chemical Engineering Consultant >>>> >>>> >>>> >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Find and fix application performance issues faster with Applications >>>> Manager >>>> Applications Manager provides deep performance insights into multiple >>>> tiers of >>>> your business applications. It resolves application problems quickly and >>>> reduces your MTTR. Get your free trial! >>>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>>> _______________________________________________ >>>> Dwsim-users mailing list >>>> Dws...@li... >>>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>>> >>>> >>>> >>>> >>>> >>> >>> >> > |
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From: Daniel W. <dan...@gm...> - 2016-04-27 13:09:43
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Hi Hector, I don't know how the volume calculation works on Aspen but, in DWSIM, I do the following: PFR code (use this for line number references in the text below): https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/PFR.vb - For the PFR, if you have a reactor of volume X, and the volume delta is 0.05, then the ODE (ordinal differential equation system) mass balance calculation will be done in 0.05*X volume steps until the entire volume is calculated (line 832). If you don't care about the actual pressure drop calculation, you can enter any value for the reactor length. Just be sure to input a length that doesn't result in a high pressure drop across the reactor. DWSIM calculates the pressure drop using the reactor volume and length to estimate the internal diameter, then uses the Darcy formula to calculate pressure drop. If the reactor has a catalyst bed, then the Ergun formula is used (line 797). CSTR code (use this for line number references in the text below): https://github.com/DanWBR/dwsim3/blob/master/DWSIM/Objects/Reactors/CSTR.vb - For the CSTR, the entire reactor volume is used at once and the ODE system is solved one time only (lines 559/111). There is no pressure drop calculation because this is supposed to be a batch (tank) reactor. :-) Regards Daniel 2016-04-27 0:06 GMT-04:00 Hector Perez <hpe...@gm...>: > Hi Daniel, > > Thanks for sending the file along with the updated build! I actually went > through the file and included the reverse reaction by adjusting the Reverse > Order exponents (the Aspen Plus video has both forward and reverse > reactions). I also dropped the conversion on the Conversion reactor > (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to > be k_forward/k_reverse (ratio of rate constants). My numbers are now very > close, if not the same as the ASPEN simulation video. > > One thing I did run into is that the reactor dimensions for the PFR and > CSTR in the aspen video create errors in DWSIM. I had to decrease the PFR > length because it gave me a warning about the pressure drop being too high. > The CSTR volume also had to be decreased because it gave me a mass balance > error. Do you know why the aspen dimensions don't work? This could perhaps > be a lack of feasibility check on the ASPEN side. > > Also, what is "Volume Delta (Relative)" on the PFR specs? > > One other thing I checked was the CSTR duty (compared to the ASPEN video) > and found the DWSIM value to be about 6 times lower than the ASPEN value > (perhaps something having to do with the smaller volume used in DWSIM?). > > Thanks once again. I am really liking this simulator. It seems easier to > use than aspen. > > Hector D. Perez > > > On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> > wrote: > >> Hi Hector, >> >> By following the Aspen Plus video I was able to make it work, there is no >> reverse reaction. Also, there was a bug in the PFR pressure drop >> calculation, you'll have to use an updated build. Download it from this >> link and unpack the files in DWSIM's installation directory: >> https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download >> >> Also, I forgot to tell you that, for kinetic reactions, every compound in >> the reaction must be present even if in a small amount, i.e. 0.000001. 0 >> will give you an error. >> >> You can also try the updated simulation file, I've added the equilibrium >> reactor as well. >> >> Regards >> Daniel >> >> >> 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: >> >>> Hi Daniel, >>> >>> >>> >>> For kinetic reactions, what are the units on the activation energy? >>> (same units as those specified for the molar entropy?). I included the DO >>> and RO exponents as well as the base compound and now get a new error on >>> the CSTR: “An error occurred during the mass balance calculation. Check >>> reaction kinetics data and reactor sizing information as well.” >>> >>> >>> >>> The PFR gives me the error: “One or more flash specification values are >>> invalid. Please check the associated UO or Material Stream for incorrect >>> specifications or miscalculated values. >>> >>> >>> >>> Thank you, I really appreciate your assistance. >>> >>> >>> >>> Hector D. Perez >>> >>> >>> >>> *From: *Daniel Wagner <dan...@gm...> >>> *Sent: *Tuesday, April 26, 2016 3:59 PM >>> *To: *Hector Perez <hpe...@gm...> >>> *Cc: *dws...@li... >>> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >>> >>> >>> >>> For the existing reactions, you've missed the compound concentrations' >>> direct and reverse order exponents. You also didn't define the base >>> compound, which should be the main reactant. >>> >>> >>> >>> For the conversion and equilibrium reactors, you must define the >>> corresponding reactions. Kinetic reactions only work with the PFR and the >>> CSTR. >>> >>> >>> >>> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >>> >>> Hi, >>> >>> >>> >>> I am trying to replicate the following ASPEN tutorial to set up the >>> liquid reaction for ethyl acetate formation from ethanol and acetic acid >>> using different types of reactors: >>> >>> >>> >>> https://www.youtube.com/watch?v=_DOdlUDI-kI >>> >>> >>> >>> Unfortunately, only the Gibbs reactor yielded any result with a ethyl >>> acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only >>> differences I can see is that the ASPEN simulation uses the NRTL-hoc, >>> whereas my simulation uses NRTL. >>> >>> >>> >>> The conversion reactor had zero conversion and both the PFR and CSTR >>> reactors gave the error: "The given key was not present in the dictionary." >>> I'm not sure what this means. I tried different thermodynamic models >>> besides NRTL with no avail. >>> >>> >>> >>> I will send my simulation file attached. >>> >>> >>> >>> I would really appreciate any light on the matter. >>> >>> >>> >>> Obrigado! >>> >>> >>> >>> >>> Hector D. Perez >>> >>> Chemical Engineering Consultant >>> >>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> Find and fix application performance issues faster with Applications >>> Manager >>> Applications Manager provides deep performance insights into multiple >>> tiers of >>> your business applications. It resolves application problems quickly and >>> reduces your MTTR. Get your free trial! >>> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >>> _______________________________________________ >>> Dwsim-users mailing list >>> Dws...@li... >>> https://lists.sourceforge.net/lists/listinfo/dwsim-users >>> >>> >>> >>> >>> >> >> > |
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From: Hector P. <hpe...@gm...> - 2016-04-27 04:07:21
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Hi Daniel, Thanks for sending the file along with the updated build! I actually went through the file and included the reverse reaction by adjusting the Reverse Order exponents (the Aspen Plus video has both forward and reverse reactions). I also dropped the conversion on the Conversion reactor (to~70%) and set the equilibrium constant (for the Equilibrium Reactor) to be k_forward/k_reverse (ratio of rate constants). My numbers are now very close, if not the same as the ASPEN simulation video. One thing I did run into is that the reactor dimensions for the PFR and CSTR in the aspen video create errors in DWSIM. I had to decrease the PFR length because it gave me a warning about the pressure drop being too high. The CSTR volume also had to be decreased because it gave me a mass balance error. Do you know why the aspen dimensions don't work? This could perhaps be a lack of feasibility check on the ASPEN side. Also, what is "Volume Delta (Relative)" on the PFR specs? One other thing I checked was the CSTR duty (compared to the ASPEN video) and found the DWSIM value to be about 6 times lower than the ASPEN value (perhaps something having to do with the smaller volume used in DWSIM?). Thanks once again. I am really liking this simulator. It seems easier to use than aspen. Hector D. Perez On Tue, Apr 26, 2016 at 7:11 PM, Daniel Wagner <dan...@gm...> wrote: > Hi Hector, > > By following the Aspen Plus video I was able to make it work, there is no > reverse reaction. Also, there was a bug in the PFR pressure drop > calculation, you'll have to use an updated build. Download it from this > link and unpack the files in DWSIM's installation directory: > https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download > > Also, I forgot to tell you that, for kinetic reactions, every compound in > the reaction must be present even if in a small amount, i.e. 0.000001. 0 > will give you an error. > > You can also try the updated simulation file, I've added the equilibrium > reactor as well. > > Regards > Daniel > > > 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: > >> Hi Daniel, >> >> >> >> For kinetic reactions, what are the units on the activation energy? (same >> units as those specified for the molar entropy?). I included the DO and RO >> exponents as well as the base compound and now get a new error on the CSTR: >> “An error occurred during the mass balance calculation. Check reaction >> kinetics data and reactor sizing information as well.” >> >> >> >> The PFR gives me the error: “One or more flash specification values are >> invalid. Please check the associated UO or Material Stream for incorrect >> specifications or miscalculated values. >> >> >> >> Thank you, I really appreciate your assistance. >> >> >> >> Hector D. Perez >> >> >> >> *From: *Daniel Wagner <dan...@gm...> >> *Sent: *Tuesday, April 26, 2016 3:59 PM >> *To: *Hector Perez <hpe...@gm...> >> *Cc: *dws...@li... >> *Subject: *Re: [dwsim-users] reactor application - ethyl acetate >> >> >> >> For the existing reactions, you've missed the compound concentrations' >> direct and reverse order exponents. You also didn't define the base >> compound, which should be the main reactant. >> >> >> >> For the conversion and equilibrium reactors, you must define the >> corresponding reactions. Kinetic reactions only work with the PFR and the >> CSTR. >> >> >> >> 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: >> >> Hi, >> >> >> >> I am trying to replicate the following ASPEN tutorial to set up the >> liquid reaction for ethyl acetate formation from ethanol and acetic acid >> using different types of reactors: >> >> >> >> https://www.youtube.com/watch?v=_DOdlUDI-kI >> >> >> >> Unfortunately, only the Gibbs reactor yielded any result with a ethyl >> acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only >> differences I can see is that the ASPEN simulation uses the NRTL-hoc, >> whereas my simulation uses NRTL. >> >> >> >> The conversion reactor had zero conversion and both the PFR and CSTR >> reactors gave the error: "The given key was not present in the dictionary." >> I'm not sure what this means. I tried different thermodynamic models >> besides NRTL with no avail. >> >> >> >> I will send my simulation file attached. >> >> >> >> I would really appreciate any light on the matter. >> >> >> >> Obrigado! >> >> >> >> >> Hector D. Perez >> >> Chemical Engineering Consultant >> >> >> >> >> >> ------------------------------------------------------------------------------ >> Find and fix application performance issues faster with Applications >> Manager >> Applications Manager provides deep performance insights into multiple >> tiers of >> your business applications. It resolves application problems quickly and >> reduces your MTTR. Get your free trial! >> https://ad.doubleclick.net/ddm/clk/302982198;130105516;z >> _______________________________________________ >> Dwsim-users mailing list >> Dws...@li... >> https://lists.sourceforge.net/lists/listinfo/dwsim-users >> >> >> >> >> > > |
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From: Daniel W. <dan...@gm...> - 2016-04-27 00:11:52
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Hi Hector, By following the Aspen Plus video I was able to make it work, there is no reverse reaction. Also, there was a bug in the PFR pressure drop calculation, you'll have to use an updated build. Download it from this link and unpack the files in DWSIM's installation directory: https://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.7/Build5960.rar/download Also, I forgot to tell you that, for kinetic reactions, every compound in the reaction must be present even if in a small amount, i.e. 0.000001. 0 will give you an error. You can also try the updated simulation file, I've added the equilibrium reactor as well. Regards Daniel 2016-04-26 18:17 GMT-04:00 Hector Perez <hpe...@gm...>: > Hi Daniel, > > > > For kinetic reactions, what are the units on the activation energy? (same > units as those specified for the molar entropy?). I included the DO and RO > exponents as well as the base compound and now get a new error on the CSTR: > “An error occurred during the mass balance calculation. Check reaction > kinetics data and reactor sizing information as well.” > > > > The PFR gives me the error: “One or more flash specification values are > invalid. Please check the associated UO or Material Stream for incorrect > specifications or miscalculated values. > > > > Thank you, I really appreciate your assistance. > > > > Hector D. Perez > > > > *From: *Daniel Wagner <dan...@gm...> > *Sent: *Tuesday, April 26, 2016 3:59 PM > *To: *Hector Perez <hpe...@gm...> > *Cc: *dws...@li... > *Subject: *Re: [dwsim-users] reactor application - ethyl acetate > > > > For the existing reactions, you've missed the compound concentrations' > direct and reverse order exponents. You also didn't define the base > compound, which should be the main reactant. > > > > For the conversion and equilibrium reactors, you must define the > corresponding reactions. Kinetic reactions only work with the PFR and the > CSTR. > > > > 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: > > Hi, > > > > I am trying to replicate the following ASPEN tutorial to set up the liquid > reaction for ethyl acetate formation from ethanol and acetic acid using > different types of reactors: > > > > https://www.youtube.com/watch?v=_DOdlUDI-kI > > > > Unfortunately, only the Gibbs reactor yielded any result with a ethyl > acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only > differences I can see is that the ASPEN simulation uses the NRTL-hoc, > whereas my simulation uses NRTL. > > > > The conversion reactor had zero conversion and both the PFR and CSTR > reactors gave the error: "The given key was not present in the dictionary." > I'm not sure what this means. I tried different thermodynamic models > besides NRTL with no avail. > > > > I will send my simulation file attached. > > > > I would really appreciate any light on the matter. > > > > Obrigado! > > > > > Hector D. Perez > > Chemical Engineering Consultant > > > > > > ------------------------------------------------------------------------------ > Find and fix application performance issues faster with Applications > Manager > Applications Manager provides deep performance insights into multiple > tiers of > your business applications. It resolves application problems quickly and > reduces your MTTR. Get your free trial! > https://ad.doubleclick.net/ddm/clk/302982198;130105516;z > _______________________________________________ > Dwsim-users mailing list > Dws...@li... > https://lists.sourceforge.net/lists/listinfo/dwsim-users > > > > > |
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From: Daniel W. <dan...@gm...> - 2016-04-26 20:59:09
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For the existing reactions, you've missed the compound concentrations' direct and reverse order exponents. You also didn't define the base compound, which should be the main reactant. For the conversion and equilibrium reactors, you must define the corresponding reactions. Kinetic reactions only work with the PFR and the CSTR. 2016-04-26 16:43 GMT-04:00 Hector Perez <hpe...@gm...>: > Hi, > > I am trying to replicate the following ASPEN tutorial to set up the liquid > reaction for ethyl acetate formation from ethanol and acetic acid using > different types of reactors: > > https://www.youtube.com/watch?v=_DOdlUDI-kI > > Unfortunately, only the Gibbs reactor yielded any result with a ethyl > acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only > differences I can see is that the ASPEN simulation uses the NRTL-hoc, > whereas my simulation uses NRTL. > > The conversion reactor had zero conversion and both the PFR and CSTR > reactors gave the error: "The given key was not present in the dictionary." > I'm not sure what this means. I tried different thermodynamic models > besides NRTL with no avail. > > I will send my simulation file attached. > > I would really appreciate any light on the matter. > > Obrigado! > > > Hector D. Perez > Chemical Engineering Consultant > > > > ------------------------------------------------------------------------------ > Find and fix application performance issues faster with Applications > Manager > Applications Manager provides deep performance insights into multiple > tiers of > your business applications. It resolves application problems quickly and > reduces your MTTR. Get your free trial! > https://ad.doubleclick.net/ddm/clk/302982198;130105516;z > _______________________________________________ > Dwsim-users mailing list > Dws...@li... > https://lists.sourceforge.net/lists/listinfo/dwsim-users > > |
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From: Hector P. <hpe...@gm...> - 2016-04-26 20:43:35
|
Hi, I am trying to replicate the following ASPEN tutorial to set up the liquid reaction for ethyl acetate formation from ethanol and acetic acid using different types of reactors: https://www.youtube.com/watch?v=_DOdlUDI-kI Unfortunately, only the Gibbs reactor yielded any result with a ethyl acetate flow that was 12 kmol/hr lower than the ASPEN simulation. The only differences I can see is that the ASPEN simulation uses the NRTL-hoc, whereas my simulation uses NRTL. The conversion reactor had zero conversion and both the PFR and CSTR reactors gave the error: "The given key was not present in the dictionary." I'm not sure what this means. I tried different thermodynamic models besides NRTL with no avail. I will send my simulation file attached. I would really appreciate any light on the matter. Obrigado! Hector D. Perez Chemical Engineering Consultant |
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From: Natan P. <nat...@gm...> - 2016-04-01 13:34:16
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Dear all, I am facing a problem in the case attached. I would like to implement a controller to adjust the temperature of the outlet stream of a heat exchanger manipulating the molar flow rate of the cold stream flowing into the equipment. Basically, I have had convergence problems. Could someone give me some hints on procedures that could be adopted to solve this problem? Kind regards, Natan Padoin |
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From: Natan P. <nat...@gm...> - 2016-04-01 12:58:03
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Prezados(as), tudo bem? Estou com um problema em um estudo de caso no DWSIM (em anexo). Basicamente, gostaria de implementar um controlador para ajustar a temperatura da corrente de saída de um trocador de calor manipulando a vazão da corrente de fluido frio no equipamento. Estou com problemas de convergência. Alguém pode me dar algumas dicas sobre como resolver este caso? Saudações. Natan Padoin |
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From: Daniel W. <dan...@gm...> - 2016-03-14 02:00:20
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Hi all, I'd like to let you know that DWSIM Calculator is now available for iPhone, iPad and iPod touch. DWSIM Calculator is an app to calculate Phase Equilibria, properties of mixtures of substances (compounds) and Unit Operation models using advanced thermodynamics. Based on the model library of DWSIM, DWSIM Calculator for iOS features: - An intuitive interface for desktop process simulator users; - Experimental data for more than 400 compounds; - 6 calculation modes: Single Compound Properties, VLE/VLLE Phase Equilibria, True Critical Point, Phase Envelope, T-x-y and P-x-y Binary Envelopes; - 6 thermodynamic model sets: Peng-Robinson Equation of State, NRTL, UNIQUAC, Modified UNIFAC (Dortmund), Raoult's Law and IAPWS-IF97 Steam Tables; - 5 state specifications: Temperature/Pressure, Pressure/Enthalpy, Pressure/Entropy, Temperature/Vapor Fraction and Pressure/Vapor Fraction; - Phase properties: Enthalpy, Entropy, Compressibility Factor, Density, Molecular Weight, Heat Capacity, Thermal Conductivity and Viscosity; - Single-compound properties: Critical Parameters, Acentric Factor, Chemical formula, Structure formula, CAS Registry Number, Boiling Point Temperature, Vapor Pressure, Heat of Vaporization, Ideal gas Enthalpy, Ideal gas Enthalpy of Formation at 25 C, Ideal Gas Gibbs Free Energy of Formation at 25 C, Ideal Gas Entropy, Heat Capacity Cp, Ideal Gas Heat Capacity, Liquid Heat Capacity, Solid Heat Capacity, Heat Capacity Cv, Liquid Viscosity, Vapor Viscosity, Liquid Thermal Conductivity, Vapor Thermal Conductivity, Solid Density, Liquid Density and Molecular Weight; - Unit Operation calculation models: Valve, Heater/Cooler, Pump, Compressor/Expander, Heat Exchanger, Gas-Liquid Separator. The calculation results can be viewed in text reports or charts. Reports can be shared as plain text (send as message, email, publish on facebook, etc) and charts can be shared as PDF or PNG files. More information available at http://dwsim.inforside.com.br/wiki/index.php?title=Calculator DWSIM Calculator on the App Store: https://itunes.apple.com/us/app/dwsim-calculator/id1091045697?ls=1&mt=8 DWSIM Calculator Free on the App Store: https://itunes.apple.com/us/app/dwsim-calculator-free/id1091004601?ls=1&mt=8 Please forward the above links to anyone who may be interested. Thanks, Daniel |
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From: Daniel W. <dan...@gm...> - 2016-02-03 11:40:59
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Dear DWSIM users, There's a new DWSIM version to download. Build 5876 introduces a number of changes: - 64-bit support: DWSIM now runs in 64-bit mode by default on Windows systems; - Sour Water Property Package: A new property package based on the USEPA SWEQ model was added to DWSIM. It allows simulation of Sour Water (NH3-H2S-CO2-H2O) systems with support for liquid phase chemical equilibria; - Several Mono bug fixes: Several reported bugs when running on Mono were fixed; - Updated User Interface: Version 3.6 introduces a new UI theme, with lots of minor tweaks and enhancements. - Updated XML report: The XML report style was rewritten from scratch, enabling a better arrangement of simulation objects and their properties. - Excel Add-In online help: An Excel-ready help file was added to DWSIM's Excel Add-In. I also created a .deb package for those running on Debian-based Linux distributions. Go to the downloads page to get the new version: http://dwsim.inforside.com.br/wiki/index.php?title=Downloads Regards Daniel |
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From: Daniel W. <dan...@gm...> - 2015-10-19 17:49:55
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Hi guys, I'd like to let you know that I've uploaded to the Google Play Store two apps based on the DWSIM thermo library (DTL). *DWSIM Calculator* lets you to calculate phase equilibria and properties, phase envelopes and single compound properties and export/share the results as text or png/pdf images. There's a paid version and a free one. The free one has ads and only Water and Ethanol in the database, while the paid version has the entire ChemSep database and no ads. More details on http://dwsim.inforside.com.br/wiki/index.php?title=Calculator_for_Android DWSIM Calculator on Play Store: https://play.google.com/store/apps/details?id=com.danielmedeiros.dwsim_calculator DWSIM Calculator Free on Play Store: https://play.google.com/store/apps/details?id=com.danielmedeiros.dwsim_calculator_free Please forward the above links to anyone who may be interested. Thanks, Daniel |
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From: Daniel W. <dan...@gm...> - 2015-09-16 14:52:18
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Dear users, I'd like to let you know that there's a new beta release available for download (Build 5731). Since Build 5644, Gregor Reichert has been working on a new, better solver for the Gibbs Reactor to take into account temperature variations as the reactions take place. The heat balance was also fixed in this beta release. I (Daniel) am working on optimizing the flowsheet solver so it can work correctly when the background thread modes are selected and there are CAPE-OPEN objects in the flowsheet. This deserves some special attention because the smallest coding mistake here can lead to memory corruption, application lockups and crashes without notice. There are also new features regarding the spreadsheet. You can now write and read values to and from the cells and use these values in the sensitivity analysis and optimization tools. The stable release should be out in a few days, and it will be based on the current beta build with bug fixes mostly. Download Beta Build 5731 Installer for Windows: http://sourceforge.net/projects/dwsim/files/DWSIM/DWSIM%203.4/DWSIM_bin_v34_b5731_beta.exe/download Please let us know if you find critical bugs so they can be fixed before the next release. Regards Daniel |
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From: Daniel W. <dan...@gm...> - 2014-12-31 22:27:08
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Hi Thomas, One way of doing this is to use a mixer to mix two streams, one with hot air and the other with hot water. The outlet stream will contain the equilibrium phases and their properties. To calculate equilibrium you can use PRSV2 or LKP... try different models to see if the amount of dissolved gas changes too much. Use a mixture of N2+O2 instead of the 'Air' compound for more accurate results. Regards, Daniel 2014-12-30 20:07 GMT-03:00 Thomas Schmidt <in...@ex...>: > Hi all, > > I asking myself if it is possible to simulate > the injection of pressurized, hot, fluid water into > pressurized hot air. Ok, no chemical reaction > but may be the software is able to handle this. > > Any comments are appreciated. > > Thanks! > > Thomas > > > ------------------------------------------------------------------------------ > Dive into the World of Parallel Programming! The Go Parallel Website, > sponsored by Intel and developed in partnership with Slashdot Media, is > your > hub for all things parallel software development, from weekly thought > leadership blogs to news, videos, case studies, tutorials and more. Take a > look and join the conversation now. http://goparallel.sourceforge.net > _______________________________________________ > Dwsim-users mailing list > Dws...@li... > https://lists.sourceforge.net/lists/listinfo/dwsim-users > |
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From: Thomas S. <in...@ex...> - 2014-12-31 13:22:32
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Thanx! I am not interested in the fluid flow but want to calculate the equilibrium state after the water injection .. Am 31/12/14 um 13:53 schrieb IV: > If you want to treat this problem on the level of fluid mechanics, you > could use fluid mechanics software, e.g. OpenFOAM or OpenFVM. The > combination of fluid mechanics software with the advanced > thermodynamics software would be interesting. > > > |
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From: Thomas S. <in...@ex...> - 2014-12-30 23:20:42
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Hi all, I asking myself if it is possible to simulate the injection of pressurized, hot, fluid water into pressurized hot air. Ok, no chemical reaction but may be the software is able to handle this. Any comments are appreciated. Thanks! Thomas |
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From: Daniel W. <dan...@gm...> - 2014-11-05 13:35:42
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Hi Michael, The attached simulation is already configured with Water, HCl, H+, Cl- and HCl dissociation reaction. You'll only have to add the remaining compounds. Strangely it is not calculating the stream enthalpy, I'll take a look to see what's going on. I'm also not sure if DWSIM is able to do these calculations, but you can finish setting up this simulation and I'll do the necessary corrections with your help, because I don't have much experience with electrolytes either... :-) Regards, Daniel 2014-11-05 9:01 GMT-04:00 M Steinroetter <ste...@gm...>: > Hi Daniel, > > thank You for Your kind help..... > > I have to absorb adiabatically a nearly 100% w/w stream of HCl in water, > say up to a concentration of 35% w/w and then strip the HCl gas off in a > second column with reboiler, having the azeotrope in the bottom of the > stripper. This azeotrope is fed to the absorption column to get re-enriched > to 35%. > > All is aimed at purification of the HCl gas stream which is contaminated > with CO and CO2. These processes ran well (say) in Aspen+ with Aspen's > electrolyte package using NRTL. Not sure if DWSIM (or COCO) is able to > perform these calculations. > > A point that I have noticed is that in the free DWSIM there is no HCl > present in the compoments database. Did I overlook something? > > Thank You again, > > Michael > > Il 05.11.2014 13:42, Daniel Wagner ha scritto: > > Hi Michael, > > Please take a look at this guide: > http://dwsim.inforside.com.br/wiki/index.php?title=Setting_up_an_Electrolyte_Simulation > > You'll probably get some convergence errors because HCl is a strong acid > and it will dissociate almost completely in water... the algorithm has some > difficult converging to the extremes. > > What are the unit operations you intend to use in your simulation? > > Regards, > Daniel > > 2014-11-05 5:45 GMT-04:00 M Steinroetter <ste...@gm...>: > >> dear dwsim-users, >> >> i have to model an absorption/desorption process for hydrogen chloride >> in water. years ago i used aspen+ with discrete success. >> however, i am new to dwsim and i don't know how to set-up correctly the >> property package for hcl/h2o. does anyone already did it? >> >> thanks for your help, >> >> michael >> >> --- >> This email is free from viruses and malware because avast! Antivirus >> protection is active. >> http://www.avast.com >> >> >> >> ------------------------------------------------------------------------------ >> _______________________________________________ >> Dwsim-users mailing list >> Dws...@li... >> https://lists.sourceforge.net/lists/listinfo/dwsim-users >> > > > -- > M Steinrotter > via Brughiere, 8/D > 21016 Luino (VA) > > > > ------------------------------ > <http://www.avast.com/> > > This email is free from viruses and malware because avast! Antivirus > <http://www.avast.com/> protection is active. > > |
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From: Daniel W. <dan...@gm...> - 2014-11-05 12:42:07
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Hi Michael, Please take a look at this guide: http://dwsim.inforside.com.br/wiki/index.php?title=Setting_up_an_Electrolyte_Simulation You'll probably get some convergence errors because HCl is a strong acid and it will dissociate almost completely in water... the algorithm has some difficult converging to the extremes. What are the unit operations you intend to use in your simulation? Regards, Daniel 2014-11-05 5:45 GMT-04:00 M Steinroetter <ste...@gm...>: > dear dwsim-users, > > i have to model an absorption/desorption process for hydrogen chloride > in water. years ago i used aspen+ with discrete success. > however, i am new to dwsim and i don't know how to set-up correctly the > property package for hcl/h2o. does anyone already did it? > > thanks for your help, > > michael > > --- > This email is free from viruses and malware because avast! Antivirus > protection is active. > http://www.avast.com > > > > ------------------------------------------------------------------------------ > _______________________________________________ > Dwsim-users mailing list > Dws...@li... > https://lists.sourceforge.net/lists/listinfo/dwsim-users > |
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