Study on the steam gasification reaction of biomass char under the synergistic effect of Ca‐Fe : Analysis of kinetic characteristics

Abstract

Biomass char gasification is an important part of biomass conversion technology; the addition of additives can effectively change the gasification reaction rate of char. The kinetic characteristics of steam gasification reaction of biomass char particles were explored by adding CaO, Fe 2 O 3 , and CaFe mixed catalyst to biomass, and the apparent activation energy and pre-exponential factors of char particles were obtained. Experimental results show that the kinetic reaction process of char steam gasification follows the shrinking cylinder model. Through linear fitting, it can be obtained that there is a good linear correlation between activation energy and pre-exponential factor, which follows the dynamic compensation effect. Under the same temperature conditions, CaO can accelerate the reaction rate of char, while Fe 2 O 3 can delay the gasification rate of char particles because of sintering phenomenon at high temperature. The synergistic effect of CaFe can reduce the total activation energy of the reaction. The addition of CaO can greatly change the kinetic performance of the Fe 2 O 3 catalyst, inhibit the sintering deactivation reaction of Fe 2 O 3 at high temperature, increase the diffusion path of steam, and promote the char steam gasification reaction.

Potassium-Induced Phenomena and Their Effects on the Intrinsic Reactivity of Biomass-Derived Char during Steam Gasification

“…In the present study, the Mg content is only 0.26 wt %, and thus, the effect on the gasification reactivity can be considered negligible. A similar reasoning can be applied for Fe; although Fe is known to enhance the direct interaction between carbon and H 2 O, effects are generally observed for much higher Fe contents − compared to the char samples used in the present study.…”

Review on Catalytic Biomass Gasification for Hydrogen Production as a Sustainable Energy Form and Social, Technological, Economic, Environmental, and Political Analysis of Catalysts

“…Depending on their production method, catalysts can be divided into two groups: mineral and synthetic catalysts. Mineral catalysts include calcinated rocks (calcite, magnesite, and calcinated dolomite), olivine, clay minerals, and ferrous metal oxides, while synthetic catalysts include char catalysts, fluid catalytic cracking (i.e., zeolite) catalysts, alkali-metal-based catalysts, activated Al 2 O 3 , and transition-metal-based catalysts (Ni-, Pt-, Zr-, Rh-, Ru-, and Fe-based catalysts). ,, Among these catalysts, natural minerals, alkali metals, transition metals, and noble-metal-based catalysts have been demonstrated to be notably effective for tar conversion and gas generation with good quality at comparatively low temperatures by many authors. − Alkali metal (sodium, potassium, and calcium) and alkaline-earth metal catalysts are the most effective, followed by heavy metals . The Supporting Information of this study shows selected catalysts (Ce/Ni/Al 2 O 3 , Rh/Ce–Zr–O, and Fe/Ca x O) used for tar elimination and hydrogen production.…”