Solar-driven pyrolysis and gasification of low-grade carbonaceous materials

• Published in: International journal of hydrogen energy Vol. 42; no. 19; pp. 13598 - 13606
• Main Authors: Arribas, L., Arconada, N., González-Fernández, C., Löhrl, C., González-Aguilar, J., Kaltschmitt, M., Romero, M.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 11.05.2017
• Subjects: Carbonaceous materials; Gasification; High flux solar simulator; Pyrolysis; Solar-driven; Syngas production; Pyrolysis; Carbonaceous materials; Gasification; Solar-driven; Syngas production; High flux solar simulator
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2017.02.026

Three low-grade carbonaceous materials from biomass (Scenedesmus algae and wheat straw) and waste treatment (sewage sludge) have been selected as feedstock for solar-driven thermochemical processes. Solar-driven pyrolysis and gasification measurements were conducted directly irradiating the samples in a 7 kWe high flux solar simulator and the released gases H2, CO, CO2 and CH4 and the sample temperature were continuously monitored. Solar-driven experiments showed that H2 and CO evolved as important product gases demonstrating the high quality of syngas production for the three feedstocks. Straw is the more suitable feedstock for solar-driven processes due to the high gas production yields. Comparing the solar-driven experiments, gasification generates higher percentage of syngas (mix of CO and H2) respect to total gas produced (sum of H2, CO, CO2 and CH4) than pyrolysis. Thus, solar-driven gasification generates better quality of syngas production than pyrolysis. •Solar-driven pyrolysis and gasification of low-grade carbonaceous has been demonstrated in repeatable experiments.•An experimental facility with a high flux solar simulator (7 kWe) is used for the solar driven experiments.•High quality syngas (concentrations up to 90 vol.%) has been produced by solar-gasification of micro-algae, sludge and straw.•Gasification of micro-algae produced the best results, but sludge may be preferred as it is a lower-grade (waste) feedstock.•Low emission of CO2 has been detected. Feedstocks are biomass compounds, so net zero CO2 overall process is may be possible.