BioSNG—process simulation and comparison with first results from a 1-MW demonstration plant

TLDR: In this paper, a steam blown dual fluidized bed gasifier coupled with a catalytic conversion of the product gas to BioSNG is used to produce a medium calorific product gas, which is nearly free of nitrogen and has a H2/CO ratio favorable for synthesis processes.

Abstract: High oil prices and peak oil, next to ecological aspects, increase the necessity of governmental support regarding the use of renewable energy resources. Biomass is a renewable energy source, which allows a sustainable utilization for several reasons. Its carbon dioxide neutrality and high availability in countries across Europe make economic usage of this source possible. Nowadays, biomass is used in rather conservative ways to produce heat and/or electric power. A more sophisticated way of using wood is transforming it into a secondary energy source by liquefaction and gasification. The product of the gasification process—considered in this paper—is a medium calorific product gas, which is nearly free of nitrogen and has a H2/CO ratio favourable for synthesis processes. Therefore, the product gas can be converted into a synthetic natural gas (BioSNG). In Gussing (Austria), the concept of a steam blown dual fluidized bed gasifier coupled to a catalytic conversion of the product gas to BioSNG could be proven successfully. A slipstream was used to run a demonstration unit with a capacity of 1 MW BioSNG. The resulting BioSNG exceeded the regulations for injection into the natural gas grid. The compressed BioSNG was stored in a fuelling station to supply CNG cars with energy. Thus, the applicability of using BioSNG in CNG cars was proven as well. The simulation software IPSEpro was used to model the overall system of gasification, gas cleaning, methanation and upgrading to BioSNG. The aim of this modelling work was to evaluate the optimization potential within the system and improve the economic and ecologic situation. Moreover, this tool will also be used to scale-up the process hereafter.