Alternative energy valorization routes of black liquor by stepwise supercritical water gasification: Effect of process parameters on hydrogen yield and energy efficiency

RENEWABLE & SUSTAINABLE ENERGY REVIEWS

卷:134

Article

Ozdenkci, Karhan¹  Prestipino, Mauro²  Bjorklund-Sankiaho, Margareta¹  Galvagno, Antonio²  De Blasio, Cataldo¹ 

[1] Abo Akad Univ, Fac Sci & Engn, Energy Technol, Rantakatu 2, Rantakatu 65101, Finland

[2] Univ Messina, Dept Engn, I-98166 Messina, Italy

关键词: Biomass conversion;    Biorefinery;    Black liquor;    Hydrogen;    Supercritical water gasification;    Syngas;    Waste valorization;   

DOI  :  10.1016/j.rser.2020.110146

来源: Elsevier

【 摘 要 】

Supercritical water gasification is potentially suitable for wet biomass; however, commercializing this process requires comprehensive analysis of process conditions and addressing the plugging issue. The objectives of this study are to illustrate a step-wise injection method addressing solid deposition and plugging in the lab-scale tubular reactors and to determine the inter-dependent impacts of process conditions on the yields and reaction phenomena. In contrast to continuous feed, the step-wise injection method introduces solid deposition dispersed over the reactor, thus reducing the risk of reactor opening. However, the industrial application still requires a design enabling solid separation to prevent deposition. The investigated process conditions include stainless steel and Inconel reactors, temperatures of 600-750 degrees C, and short (133-162 s) versus long (300 s) residence times. Among these conditions, the Inconel reactor at 750 degrees C with long residence time provided the highest efficiency (87.8% cold gas efficiency) and hydrogen yield (24.92 mol/kg dry-ash-free, 0.646 mol/kg noninert); also, the lowest char yield (25% carbon conversion to char) promoted gasification and suppressed repolymerization. When comparing various results from the techno-economic assessment viewpoint, the other considerable sets of process conditions include stainless steel reactor at 750 degrees C with short residence time and at 700 degrees C with long residence time. In addition, rather than dry or dry-ash-free basis, it is more informative to compare the yields from various studies in non-inert basis together with residence time and reactor material: implicitly assessing the comparison of investment and operation costs as well.

【 授权许可】

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