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In the present study, an oxygen blown pilot scale pressurized entrained-flow biomass gasification plant (PEBG, 1 MWth) was designed, constructed, and operated. This Article provides a detailed description of the pilot plant and results from gasification experiments with stem wood biomass made from pine and spruce. The focus was to evaluate the performance of the gasifier with respect to syngas quality and mass and energy balance. The gasifier was operated at an elevated pressure of 2 bar(a) and at an oxygen equivalence ratio (λ) between 0.43 and 0.50. The resulting process temperatures in the hot part of the gasifier were in the range of 1100–1300 °C during the experiments. As expected, a higher λ results in a higher process temperature. The syngas concentrations (dry and N2 free) during the experiments were 25–28 mol % for H2, 47–49 mol % for CO, 20–24 mol % for CO2, and 1–2 mol % for CH4. The dry syngas N2 content was varied between 18 and 25 mol % depending on the operating conditions of the gasifier. The syngas H2/CO ratio was 0.54–0.57. The gasifier cold gas efficiency (CGE) was approximately 70% for the experimental campaigns performed in this study. The synthesis gas produced by the PEBG has potential for further upgrading to renewable products, for example, chemicals or biofuels, because the performance of the gasifier is close to that of other relevant gasifiers.

PostprintThis is the accepted version of a paper published in Fuel processing technology. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Weiland, F., Nordwaeger, M., Olofsson, I., Wiinikka, H., Nordin, A. (2014) Entrained flow gasification of torrefied wood residues. In this work, four different fuels were gasified in a pressurized entrained flow pilot plant 12 gasifier at approximately 270 kW th . The different fuels were; two torrefied wood 13 residues, one raw wood residue and one torrefied stem wood. The system pressure and 14 oxygen equivalence ratio (!) were held constant for all four gasification experiments. It 15 was found that the torrefaction pretreatment significantly reduced the milling energy 16 consumption for fuel size reduction, which in turn contributed to increased gasification 17 plant efficiency. Furthermore, the results indicate that the carbon conversion efficiency • The torrefaction pretreatment reduced the milling energy consumption. 2• Torrefaction pretreatment contributed to increased gasification plant efficiency. 3• The fuel carbon conversion efficiency was affected by torrefaction pretreatment. 4• The CH 4 yield from gasification was reduced for severely torrefied fuel. 5

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