Bio-SNG production by means of biomass gasification combined with MCEC technique

About the project

Biomass gasification is an attractive technology that efficiently converts forest biomass, biomass-based wastes and other types of renewable feedstocks into transportation fuels, chemicals or elec­tricity. However, one important bottleneck for commercialisation of the technology in biomass gasification plants is the choice of engineering solutions for the downstream product gas cleaning and conditioning, before using the produced synthesis gas. Gas cleaning and conditioning technologies are capital intensive, and the investment costs for these technologies in biomass gasification production sys­tems are initially very large, leading to large business risks. One way to promote the commercialisation of biomass gasification is to invest in small to medium-scale plants, where the total costs are more reasonable and the financial risks are lower.

The main aim of this study has been to make a preliminary evaluation of the technical and economic feasi­bility of combining biomass gasification with molten carbonate electrolysis cell technol­ogy (MCEC) in systems for production of biomass-based substitute natural gas (bio-SNG). The study is based on a literature survey and a conceptual techno-economic investigation of using a MCEC as a gas cleaning and conditioning process step in a biomass gasification system for bio-SNG production. To enable a comparison with a real case, the GoBiGas plant was selected as a reference case. Five different sce­narios were evaluated in relation to energy and economic performance.

The project results are positive with regard to integrating a MCEC. Introducing a MCEC in the gas cleaning and conditioning process of a biomass gasification system provides with the opportunity for process intensification with a potential integration of three process units into one.

Mass and energy balances show that the production of bio-SNG can be boosted by up to 60% when integrating a MCEC, compared to the same biomass input in a stand-alone operation of a plant similar to GoBiGas. Additionally, the economic assessments re­vealed price ranges for biomass, SNG and renewable electricity, allowing for a wider margin in terms of the Investment Opportunity index for the considered process configurations, as com­pared to the stand-alone SNG plant.