THE ROLE ASSESSMENT OF THE CATALYSTS BASED ON METAL OXIDES IN THE WASTE

BIOMASS GASIFICATION PROCESS

E. David^1*,  S. Preda²,  A. Armeanu¹, C. Sandru¹, D. Mocanu¹

¹National Institute for Research and Development for Cryogenics and Isotopic Technologies - ICIT Rm. Valcea,

Uzinei Street no. 4, P.O. Box Raureni 7, 240050, Ramnicu Valcea, Romania

ABSTRACT

Biomass is a promising sustainable energy source. Managing renewable energy such as  residual biomass in an effective way is a challenge for the energy industry. The biomass gasification technologies to produce hydrogen-rich fuel gas present highly interesting possibilities for biomass utilization as the sustainable energy. In this work was  investigated  the  catalysts behaviour  based on metal oxides in   the process to obtain hydrogen-rich gas  by applying the steam gasification technique of the residual biomass. Characteristics of steam gasification of two kinds of biomass (rapeseed oil cakes and walnut shells ) at different heating rate (in the order of 10-20°C s⁻¹) and different metal oxide catalysts ( CaO, MgO  and a mixture 50% CaO and 50% MgO) in a gas–solid concurrent down flow free-fall reactor were investigated. The effects of steam/biomass (S/B) mass ratio, the  reactor temperature and the role of the catalysts  on the product yields and  the compositions of product gas were determined. The experimental results show that the gas yields and the content of H₂ in the gas increase with reactor temperature, while the yields of tar, char and the content of CO and CH₄ in the product gas decrease. The presence of steam increases the gas yield and reduces the tar and char yields. The results verify that the presence of steam and catalyst favor the tar decomposition and lead to increasing of hydrogen content in gas yield.

Keywords: biomass, gasification, steam, catalyst, hydrogen, fuel gas