The GoBiGas Project - Demonstration of the Production of Biomethane from Biomass via Gasification

Report, 2018

In the GoBiGas project, a first-of-its-kind industrial scale biorefinery was built for the purpose of demonstrating and enabling commercial production of biomethane from woody biomass via gasification. This report summarizes the experience, lessons learnt and conclusions from the feasibility study, construction and operation of the GoBiGas plant with the aim of supporting development of commercial production plants for advanced biofuels. The GoBiGas plant, with a production capacity of 20 MW of biomethane gas delivered to the natural gas grid in Sweden, is located in Gothenburg. The plant was built by Göteborg Energi AB with the support of the Swedish Energy Agency and the project was initiated in 2005. This report includes a summary of the main contractors and technology choices made during the project and describes the commissioning of the plant in 2013. The report also describes experience gained from the operation and evaluation of the process until it was decommissioned in 2018. The evaluation of the plant focused on how the technology can be commercialized through construction of a similar stand-alone plant with a production capacity of 100 MW or more. With more than 12,000 hours of operation, the GoBiGas project has demonstrated how the quality of the product gas from a biomass gasifier can be controlled using a range of different feedstocks including bark, wood pellets, wood chips and recovered wood of class A1. Results show that a biomass to biomethane efficiency of up to 70% (based on the lower heating value of the dry ashfree fuel) is possible and that biomethane with a reduction factor for greenhouse gas emissions of over 80% can be produced with this technology. To reach such high efficiency, it is necessary to dry the feedstock and this also benefits the stability of the process. Results also show that gas quality fulfils the European standard for injection into the natural gas grid, thereby showing that large scale production of biomethane delivered by injection to the natural gas grid is possible. The project has demonstrated that this type of process can be applied on a commercial scale with high performance using known technology and that future development should involve improved compatibility between different process steps as well as improved economic feasibility of production. With the current process setup and using forest residues as feedstock, the production cost for a plant with a 200 MW production capacity, estimated based on the economic data from GoBiGas, corresponds to about SEK 600/MWh.