Title:
The Effect of Biomass Drying on the Overall Efficiency and Economics of Combined Production of Transportation Fuels and Heat by Steam Gasification and FT-Synthesis
Author(s):
Tuomi, S., Kurkela, E., Hannula, I., Berg, C-G.
Document(s):
Paper
Slide presentation
Abstract:
In this study, we examined the effect of biomass drying on the overall efficiency of the BTL process in combined production of FT product and heat. The proposed BTL process is based on steam-blown dual fluidized-bed gasification of biomass, simplified gas clean-up and once-through FT synthesis. Biomass drying was found to have a significant effect on both the FT wax yield and the overall thermal efficiency of the BTL plant. According to the calculations carried out in Aspen Plus, one percentage-point reduction in biomass moisture content (after drying) increases the FT conversion efficiency by 0.3-0.4 %-points. The highest yield of FT liquids (52-55 %) was achieved when biomass was dried to 8 wt-% moisture content. Among the dryer options studied, Kumera’s innovative two-stage drying concept that combines a belt dryer and an indirectly-heated steam dryer of Kumera was the most feasible option due to its low energy consumption. Using the two-stage dryer, 86-87 % overall thermal efficiencies were reached. Moreover, drying tests to below 15 wt-% moisture content were carried out at the Kumera pilot plant using crushed forest residues and willow wood as feedstock. Excellent results were obtained demonstrating stable operation, high energy efficiency and low gas-phase emissions.
Keywords:
biomass, drying, gasification, biomass to liquid (BtL), Fischer-Tropsch, dual fluidized bed
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Gasification for synthesis gas production
Event:
26th European Biomass Conference and Exhibition
Session:
2BO.14.1
Pages:
521 - 527
ISBN:
978-88-89407-18-9
Paper DOI:
10.5071/26thEUBCE2018-2BO.14.1
Price:
FREE
