Energy and greenhouse balance of photocatalytic CO₂ conversion to methanol

EnBW Energie Baden-Württemberg AG, Research & Innovation Department, 76131, Karlsruhe, Germany

^a e-mail: d.haumann@enbw.com

Abstract

Within the Leading-Edge Cluster “Forum Organic Electronic”, the research project “Solar2Fuel” funded by the German Ministry of education and research (BMBF) (2009 – 2012), EnBW, BASF, Karlsruhe Institute of Technology and Ruprecht-Karls-University of Heidelberg aim to develop a future solar powered CO₂ to methanol conversion technology. CO₂ from stationary sources such as power plants shall be catalytically converted together with water to a product such as methanol by use of solar irradiation. For this purpose a catalyst shall be developed. EnBW investigates the required boundary conditions to make such a principle interesting with respect to energy and greenhouse gas balance as well as economic evaluations. The assessment of boundary conditions includes the analysis of the whole chain from power generation, CO₂ capture and transport, a virtual photocatalytic reactor, the product purification and use in the traffic sector. Most important technical factors of the process such as CO₂ conversion efficiency is presented. CO₂ capturing and liquefaction are the most energy intensive process steps, CO₂ transport in pipeline is highly energy efficient and depending on energy need of the photoconversion step and the product purification, the overall greenhouse gas balance is comparable with the underground storage of the captured CO₂.