Energy Efficiency Optimisation in Different Plant Solutions for Methanol Production from Biomass Gasification

Methanol production from biomass gasification faces the problem of excess carbon, mostly carbon dioxide, in the produced synthesis gas. The stoichiometric ratio among hydrogen, carbon dioxide and carbon monoxide, required to optimise the energy efficiency of the process, can be achieved either by adding hydrogen produced by water electrolysis or by removing carbon dioxide through Rectisol process. These two processes are analysed and compared by means of a proper plant simulation. Moreover, methanol process demands a high amount of energy to get an almost pure product, implying elevated investments. Pinch analysis has been applied to minimize this energy consumption, designing an optimised heat exchanger network and investigating thermal integration opportunities among different sub-processes.