The role of hydrogen for the defossilization of the German chemical industry
Felix Kullmann, Jochen Linßen, Detlef Stolten
Abstract
Within the European Green Deal, the European industry is summoned to transform towards a green and circular economy to reduce CO2-emissions and reach climate goals. Special focus is on the chemical industry to boost recycling processes for plastics, exploit resource efficiency potentials, and switch to a completely renewable feedstock (defossilization). Despite common understanding that drastic changes have to take place it is yet unknown how the industrial transformation should be accomplished. This work explains how a cost-optimal defossilization of the chemical industry in the context of national greenhouse gas (GHG) mitigation strategies look like. The central part of this investigation is based on a national energy system model to optimize the future energy system design of Germany, as a case study for a highly industrialized country. A replacement of fossil-based feedstocks by renewable feedstocks leads to a significant increase in hydrogen demand by +40% compared to a reference scenario. The resulting demand of hydrogen-based energy carriers, including the demand for renewable raw materials, must be produced domestically or imported. This leads to cumulative additional costs of the transformation that are 32% higher than those of a reference scenario without defossilization of the industry. Fischer-Tropsch synthesis and the methanol-to-olefins route can be identified as key technologies for the defossilization of the chemical industry.