Performance of large-scale biomass gasifiers in a biorefinery, a state-of-the-art reference

Abstract

SUMMARYThe Gothenburg Biomass Gasification plant (2015) is currently the largest plant in the world producing biomethane (20 MW biomethane ) from woody biomass. We present the experimental data from the first measurement campaign and evaluate the mass and energy balances of the gasification sections at the plant. Measures improving the efficiency including the use of additives (potassium and sulfur), high-temperature pre-heating of the inlet streams, improved insulation of the reactors, drying of the biomass and introduction of electricity as a heat source (power-to-gas) are investigated with simulations. The cold gas efficiency was calculated in 71.7%LHV daf using dried biomass (8% moist). The gasifier reaches high fuel conversion, with char gasification of 54%, and the fraction of the volatiles is converted to methane of 34% mass . Because of the design, the heat losses are significant (5.2%LHV daf ), which affect the efficiency. The combination of potential improvements can increase the cold gas efficiency to 83.5%LHV daf , which is technically feasible in a commercial plant. The experience gained from the Gothenburg Biomass Gasification plant reveals the strong potential biomass gasification at large scale.

Advanced biofuel production via gasification – lessons learned from 200 man‐years of research activity with Chalmers’ research gasifier and the GoBiGas demonstration plant

“…This can be achieved by: applying reactor walls that lower the heat losses; preheating the ingoing air and steam streams to higher temperatures; decreasing the overall gasification temperature; lowering the moisture content of the fuel; and preheating the ingoing fuel. Through these measures, the heat demand could be reduced by as much as 20% in a future commercial plant, thereby increasing the chemical efficiency of the gasifier to the same extent (for more details see ). In addition, by introducing an alternative external heat source, for example, direct heating by electricity, the energy content of the produced gas could be increased even further, up to about 120% compared to the chemically bound energy of the ingoing fuel .…”

Economic assessment of advanced biofuel production via gasification using cost data from the GoBiGas plant

“…The chemical efficiency of an ABP plant has previously been evaluated . Here, an efficiency of 70% based on the energy of the dry part of the delivered biomass is assumed.…”

“…An initial breakdown of the investment cost for the GoBiGas plant based on the project summary has been reported elsewhere, showing that a significant proportion of the investment was related to aspects specific to the site or the project. Therefore, a more detailed analysis is performed in this study, so as to generate a more general and realistic estimate of the investment costs of an ABP plant for the production of biomethane.…”

“…The methanation technology, which has been used in commercial plants that are based on fossil fuels, had to be scaled down significantly to match the DFB gasifier. An analysis of the performance of the process concluded that it is technically feasible to reach a biomass‐to‐biomethane efficiency of up to 70% based on the lower heating value (LHV) and dry ash‐free (DAF) fuel …”

“…To achieve this, investment and operational costs were estimated based on data accrued from the GoBiGas demonstration plant. Aggregated reference data and SFs for a commercial APB plant have been established based on a detailed study of the investment costs of the GoBiGas plant, in combination with the previously published technical review of the process …”