8. Packed-Bed Methanation Reactor in CHEMCAD Linked to Mathematica.

This type of reactor needs to be added by the user. CHEMCAD is one commonly used chemical process simulator and we have shown previously that it can be used in tandem with Mathematica for real-time solutions of advanced mathematical problems.[2-8] Our previous work showed application to algebraic solutions. That is, the membrane and flash models in those studies involved solutions of systems of algebraic equations.

This study extends the method to systems of differential equations solved numerically. Specifically, this paper demonstrates the simultaneous solution of the two equations dP/dW=F₁ and dX/dW=F₂, where X is conversion of CO₂, P is pressure in the reactor, and W is catalyst mass[9], in Mathematica coupled to CHEMCAD. Kinetic models used are gas-phase with simultaneous adsorption-desorption on the solid catalyst, with kinetic rate laws and thermochemical properties taken from the literature [10,11].