Title:
Biomass Gasification for Syngas Generation in a 100 KWth Steam-Oxygen Blown CFB Gasifier - Gas Quality Optimization and Tar Reduction
Author(s):
Siedlecki, M., Litinas, A., de Jong, W.
Document(s):
Paper
Abstract:
Syngas production based on biomass gasification is an attractive, feasible alternative to fossil fuel feedstock for the production of transportation fuels. However, gasification product gas using biomass as feedstock must be cleaned and tailored to comply with strict syngas quality requirements, as it consists of a wide variety of major and minor components and impurities. The characterization of such species is important to determine downstream gas treatment steps, and to assess the efficiency of the gasification process. This paper gives an overview of the results obtained during experiments on steam-oxygen gasification of biomass using the Delft 100 kWth,max circulating fluidized bed gasifier (CFBG). The experiments were performed in the framework of a large European project “Chrisgas”. The unit is equipped with a high temperature ceramic gas filter and downstream reactors for upgrading of the gas. In the experiments both woody and agricultural fuels, namely miscanthus and straw, have been used. These represent clean wood, demolition wood, an energy crop species and a true residue, respectively. Moreover, different bed materials have been applied, like sand, treated/untreated olivine and magnesite. During the experiments extensive measurements of gas composition have been carried out throughout the integrated test rig. The gas characterization includes the major gas components as well as certain minor gas components. The results show that with the use of magnesite as bed material, remarkable increases of hydrogen yield were attained as compared to sand or olivine until almost 40%vol. (dry, nitrogen free basis) and that the H2/CO ratio was increased from values near or lower than 1 to 2.3-2.6. This is near values needed for e.g. Fischer-Tropsch diesel production, indicating a potential for simplification of the gas upgrading. Moreover, by using magnesite tar was reduced to values near 2 g/mn3. Finally, magnesite appeared to have a positive impact on agglomeration prevention for the agricultural fuels containing alkali’s and chlorine. Correlations were determined between the operational conditions like process temperature, equivalence ratio, type of biomass and product gas composition.
Keywords:
circulating fluidised bed (CFB), gasification, syngas, tar reduction
Topic:
Thermochemical conversion - Gasification for synthesis gas production
Subtopic:
Catalytic upgrading and syngas cleaning
Event:
18th European Biomass Conference and Exhibition
Session:
OB8.5
Pages:
809 - 822
ISBN-13:
978-88-89407-56-1
ISBN-10:
88-89407-56-5
Paper DOI:
10.5071/18thEUBCE2010-OB8.5
Price:
FREE
