Dino Posted September 10, 2010 Share Posted September 10, 2010 Tom, There appears to be a typo in the Reaction Modeling Guide. On pg 61, "...The mineral's rate of precipatation, should it be oversaturated, however, is zero..." I believe this should be "undersaturated" since the script sets the rate to zero when Q/K < 0. Correct? In this regard, I find that when I need a model with glass dissolution kinetics and analcime kinetics, some analcime dissolves even when I have '0' in the starting mass of analcime. This leads to a positive rate and a negative volume. I believe the solution is to use a script like the one on pg 61. Correct? Thanks, Denis Quote Link to comment Share on other sites More sharing options...
Tom Meuzelaar Posted September 10, 2010 Share Posted September 10, 2010 Hi Denis: Thanks for posting to the forum. Can you tell me what version of the Reaction Modeling Guide you are looking at? Because p. 61 of the v8 manual shows something different than what you are describing. I think the last time we spoke you sent me a script where you were using a combination of a custom rate law and a built-in rate law, and thus your critical saturation index (CSI) of zero was being ignored. So the solution would be to use a script which sets an explicit CSI. I hope that helps, Tom Meuzelaar RockWare, Inc. Quote Link to comment Share on other sites More sharing options...
Dino Posted September 13, 2010 Author Share Posted September 13, 2010 Hi Tom The version is Release 8.0 published October 27, 2009. I am not using a custom and built-in. I am putting in both kinetics as custom rate laws. I have the glass kinetics in the input script. The Analcime rate is embedded in the scrpt: If QoverK < 1 then 20 else 40 20: kinetic Analcime rate_law = "pre_exp*(1-Q/(K))*exp(-act_en/(8.314*TK))" pre-exp = .00551 act_eng = 77000 surface = 1000 nucleus = 100 critSI = .3 sparea = 100 Goto 60 10: kinetic Analcime rate_law = 0.0000 60: Return rate However, I don't think I am getting to the script. I use the call on the command tab with no analcime in the reactants list kinetic Analcime rate_law = "c:\active files\gwb files\analcime.bas" (have to use the quotes because GWB does not understand spaces in the command line and I get a response that one of the words is a command that is not in the command list). This command leads to an entry in the reactants list for analcime, but not with the custom rate law or other input like the surface area, etc. I've tried to put the '.bas' file in a different directory with no success. So, I'm missing something. Denis Hi Denis: Thanks for posting to the forum. Can you tell me what version of the Reaction Modeling Guide you are looking at? Because p. 61 of the v8 manual shows something different than what you are describing. I think the last time we spoke you sent me a script where you were using a combination of a custom rate law and a built-in rate law, and thus your critical saturation index (CSI) of zero was being ignored. So the solution would be to use a script which sets an explicit CSI. I hope that helps, Tom Meuzelaar RockWare, Inc. Quote Link to comment Share on other sites More sharing options...
Tom Meuzelaar Posted September 13, 2010 Share Posted September 13, 2010 Hi Denis: If you attach your React script, .bas file and thermo database I can take a look (or email to me if you need to keep it proprietary). By the way, while (1-Q/K) can take on a negative value, Q/K cannot. So you'll need to fix this in your script at a minimum... Regards, Tom Quote Link to comment Share on other sites More sharing options...
Tom Meuzelaar Posted September 16, 2010 Share Posted September 16, 2010 Hi Denis: If you attach your React script, .bas file and thermo database I can take a look (or email to me if you need to keep it proprietary). By the way, while (1-Q/K) can take on a negative value, Q/K cannot. So you'll need to fix this in your script at a minimum... Regards, Tom This thread was concluded and resolved here.... Quote Link to comment Share on other sites More sharing options...
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