Journal Article

Catalytic gasification of biomass (Miscanthus) enhanced by CO sub(2) sorption

Girods, P, Rogaume, Y, Debal, M, Courson, C, Matt, M, Zamboni, I, Kiennemann, A

2016

Overview

The main objective of this work concerns the coupling of biomass gasification reaction and CO sub(2) sorption. The study shows the feasibility to promote biomass steam gasification in a dense fluidized bed reactor with CO sub(2) sorption to enhance tar removal and hydrogen production. It also proves the efficiency of CaO-Ca sub(12)Al sub(14)O sub(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 sub(2) sorption (CaO-Ca sub(12)Al sub(14)O sub(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 sub(12)Al sub(14)O sub(33)/olivine sorbent/catalyst presents a good CO sub(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 sub(2) selectivity due to its sorption on the CaO phase. In the biomass steam gasification, the use of CaO-Ca sub(12)Al sub(14)O sub(33)/olivine as bed material at 700 degree C leads to a higher H sub(2) production than olivine at 800 degree C thanks to CO sub(2) sorption. Similar tar concentration and lighter tar production (analyzed by HPLC/UV) are observed. At 700 degree C, sorbent addition allows to halve tar content and to eliminate the heaviest tars.

• Subject: Miscanthus