Co-production via reverse water gas shift

In an endothermic reaction CO₂ is reformed with H₂ to produce CO and water, the reverse water gas shift (RWGS) reaction. We assume that all carbon is converted into CO (or recycled in the process). The reaction requires heat and runs at temperatures between 800-1000 °C and at pressures up to 30 bar to favour the equilibrium to CO (instead of CO₂ and CH₄). Some electricity is required to run the plant, e.g. for gas compression. The RWGS plant is a net electricity and heat consumer. Both H₂ and CO₂ are provided in this case from external sources. Often RWGS produces mixtures of CO and H₂ in the ratio required for subsequent reactions. Here we assume we produce only CO, while additional H₂ can be provided from the external source. Costs and energy use (for the purification, recycle, heating, and compression steps) are often associated to total mass flow capacities and include H₂ as product (which is excluded from our process). This may cause some deviations in the estimates for costs and energy. CO₂ + H₂ -> CO + H₂O DeltaH(298) = 42 kJ/mol.