i would to simulate anaerobic digestion by mean Aspen plus with ADM1 model.
my goal is to investigate the variations of CH4 and CO2 in effluent gas with the variation of CSTR reactor temperature.
The simulations run only with the temperature of 55°C that is reported in model, i try to simulate with lower temperature but the system gives always error :
** ERROR PRE-EXPONENTIAL FACTOR IN POWER LAW EXPRESSION
FOR REACTION NUMBER ‘4’ IS LESS THAN
ZERO. ITS REACTION RATE IS SET TO ZERO.
Can i resolve this problem?
i try also to remove the components of reaction numebr 4 but always the error appear..
The pre-exponential (k) parameter should be a positive number. Perhaps you have it as a negative number? The equation in aspen is usually in the form of -rA = k * concentration_stuff, and you just type in the k, not -k.