Catalytic gasification of biomass (Miscanthus) enhanced by CO2 sorption

• Published in: Environmental science and pollution research international 2016-11, Vol.23 (22), p.22253-22266
• Main Authors: Zamboni, I., Debal, M., Matt, M., Girods, P., Kiennemann, A., Rogaume, Y., Courson, C.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biomass; Carbon dioxide; Catalysis; Condensed Matter; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fixed bed reactors; Fluidized bed reactors; Fluidized beds; Gases; Gasification; Hydrocarbons; Hydrogen; Hydrogen production; Liquid chromatography; Materials Science; Physics; Reactors; Sorption; Steam; Studies; Synthesis gas; Tar; Technoeconomic Perspectives on Sustainable CO2 Capture and Utilization; Thermogravimetric analysis; Toluene; Waste Water Technology; Water Management; Water Pollution Control; X-ray diffraction
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-016-6444-4

The main objective of this work concerns the coupling of biomass gasification reaction and CO 2 sorption. The study shows the feasibility to promote biomass steam gasification in a dense fluidized bed reactor with CO 2 sorption to enhance tar removal and hydrogen production. It also proves the efficiency of CaO-Ca 12 Al 14 O 33 /olivine bi-functional materials to reduce heavy tar production. Experiments have been carried out in a fluidized bed gasifier using steam as the fluidizing medium to improve hydrogen production. Bed materials consisting of CaO-based oxide for CO 2 sorption (CaO-Ca 12 Al 14 O 33 ) deposited on olivine for tar reduction were synthesized, their structural and textural properties were characterized by Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), and temperature-programmed reduction (TPR) methods, and the determination of their sorption capacity and stability analyzed by thermogravimetric analysis (TGA). It appears that this CaO-Ca 12 Al 14 O 33 /olivine sorbent/catalyst presents a good CO 2 sorption stability (for seven cycles of carbonation/decarbonation). Compared to olivine and Fe/olivine in a fixed bed reactor for steam reforming of toluene chosen as tar model compound, it shows a better hydrogen production rate and a lower CO 2 selectivity due to its sorption on the CaO phase. In the biomass steam gasification, the use of CaO-Ca 12 Al 14 O 33 /olivine as bed material at 700 °C leads to a higher H 2 production than olivine at 800 °C thanks to CO 2 sorption. Similar tar concentration and lighter tar production (analyzed by HPLC/UV) are observed. At 700 °C, sorbent addition allows to halve tar content and to eliminate the heaviest tars.