Selecting different raw materials for methanol production using an MINLP model

Abstract

This paper aims at selecting different raw materials, using an MINLP (mixed-integer nonlinear programming) model, when considering the usage of more favourable raw materials for methanol production.The best selection of raw material alternatives was sought for methanol production. Methanol is produced from synthesis gas that is produced from different raw materials – natural gas or biogas. The basic starting point when comparing them is the same mass inlet flow rate for both raw materials. Methanol production was simulated for both – natural gas or biogas as the raw material, using an Aspen Plus simulator with a real chemical thermodynamic. Methanol production can be enlarged by simultaneous structuring such as selecting the usage of more favourable raw materials, and parameter optimisation using the MINLP. The selection of raw methanol with optimal parameters has the greatest impact on higher methanol production.Optimal methanol conversion can take place during this operation, by applying optimal parametric data within a reformer unit (temperature = 840 °C and pressure = 8 bar), using natural gas. The optimal production of methanol from natural gas was 17 510 kg/h under optimal parameters for 8.4% higher production than under existing parameters.