Improved syngas processing for enhanced Bio-SNG production: A techno-economic assessment

Abstract

This study analyzes the modification of an existing process configuration train for Bio-SNG production using an indirectly-heated circulating fluidized bed gasifier. Taking the process design of the Gothenburg Biomass Gasification (GoBiGas) project, we investigate four modifications to the process design in order to analyze what the potential effect from implementation of the results from state-of-the-art research activities on bio-syngas conversion is. Firstly, aromatic compounds are converted into Bio-SNG. Secondly, olefin hydration and hydrodesulfurization units are combined in a high-temperature hydrodesulfurization unit. Thirdly, the methanation section is modified and the pre-reformer unit in the syngas conditioning section is eliminated. Finally, H₂S and CO₂ removal are combined in the same unit. In order to provide a comprehensive comparison of current GoBiGas process and the configuration investigated in this work, process flowcharts and energy and material balances are provided. The study reveals that the investigated configuration has the potential to reduce capital investment and operating costs. Considering Phase II of GoBiGas project, a potential reduction of 29% of the capital investment and 7 €/MWh of produced Bio-SNG could be achieved comparing planned and investigated configurations. The results prove that investigated modifications can have a large impact in the future commercialization of Bio-SNG.