In-depth Analysis of a biomassand power-based Methanol Production Route utilizing a direct Python to AspenPlus® Interface

Abstract

The defossilization of the aviation sector represents a major challenge for the realization of a future net-zero society and requires the development of scalable production methods for sustainable aviation fuels. While initial efforts focused on readily available sources such as used cooking oils, there is an ongoing need for sustainable jet fuels with greater availability of feedstocks. The second most important source of carbon and hydrogen for a sustainable jet fuel production could be biogenic waste materials such as straw and bark. However, they are not free of disadvantages: The hydrogen-to-carbon ratio in biogenic sources tends to be equimolar in distribution, which naturally limits the production volumes of jet fuels with a hydrogen-to-carbon ratio of around 2.1 to 40-50%. Worse still, the process releases the unused carbon into the air as carbon dioxide. By adding additional hydrogen, the carbon emissions of the process can be significantly reduced and the product yield increased at the same time. Hence, a sustainable feedstock for a subsequent alcohol-to-jet process can be provided. In this work a methanol production plant is assessed utilizing a biomass gasification, and electrolyzer system and a multi-stage quench reactor system. By reducing the recycling to a minimum, operating the gasifier at atmospheric pressures, applying an experimentally proven gas cleaning train, together with the simple reactor design of a quench reactor system the investment costs are kept as low as possible, which reduces the investment risk for the process significantly. Furthermore, a step-wise integration of the electrolyzer system is investigated. To avoid oversizing or undersizing the reactor stages, a direct link was established between Python and the AspenPlus® flowsheet model. This interface is additionally used to perform heat integration, exergy analysis and economic process evaluation. The study includes varying the integration of electrolyzer systems and adjusting the inlet pressures and temperatures of the methanol reactor stages. This detailed evaluation will examine the relationships between the process design, its efficiencies and production costs.