Biomass CO2 gasification with CaO looping for syngas production in a fixed-bed reactor

The most important challenge in solid feedstock thermal conversion methods is minimising CO2 emissions. In this work, the gasification of pine sawdust in a mixture of N-2 and CO2 was investigated for the reduction of CO2 by a calcium oxide loop. The experiments were conducted at 600, 700, and 800 degrees C in a fixed-bed reactor. The biomass was mixed with the calcium oxide at a ratio of 1:1. The chemical composition of the syngas was analysed using gas chromatography. Moreover, the high heating values of the received gas samples were calculated, and thermogravimetric analysis and Fourier-transform infrared spectroscopy analysis were performed to investigate the absorption of CO2 by CaO. The results of the gasification process showed that the syngas contained CO, CH4, CO2, H-2, N-2, and other low hydrocarbons. The most significant results were obtained for a 2:1 ratio of N-2 to CO2 at 700 degrees C, and a CO2 reduction of 25% was observed. Moreover, the catalytic properties of CaO increased the concentration of H-2 in the produced syngas by up to 10%. A temperature of 800 degrees C was too high for the carbonation reaction of CaO. This study presents a possible solution for achieving negative carbon emissions. (c) 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

The study found that a 2:1 ratio of N-2 to CO2 at 700 degrees Celsius resulted in a 25% reduction in CO2. The catalytic properties of CaO increased the concentration of H-2 in the produced syngas by up to 10%. However, a temperature of 800 degrees Celsius was too high for the carbonation reaction of CaO.