Substitution of fossil fuels for production of electricity, heat, fuels for transportation and chemicals can be realized using biomass steam gasification in a dual fluidized bed (DFB).

Interaction between biomass ash and bed material in a fluidized bed leads to transformation of the bed particle due to enrichment of components from the biomass ash resulting in the development of ash layers on the bed particle surface. These ash-rich particle layers enhance the catalytic activity of the bed material regarding the water-gas-shift reaction and the reduction of tars.

The water-gas-shift reaction at conditions typical for dual fluidized bed biomass gasification at a temperature of 870 °C was investigated. Diffusion and heat transfer limitations were minimized using a lab-scale experimental set-up consisting of a gas mixing section and a quartz glass reactor in which the catalyst is investigated.

The following new rate expression for the water-gas-shift reaction in dual fluidized bed gasification of biomass was empirically developed, which takes ash layer formation into account:$r_{\mathit{Olivine}\_\mathit{ash}-\mathit{layer}}=8\text{,}9·{10}^{-6}\exp (\frac{-95000}{\mathit{RT}})p_{\mathit{CO}}^{1\text{,}96}{p}_{H2O}^{1\text{,}81}{p}_{\mathit{CO}2}^{-0\text{,}75}{p}_{H2}^{-1\text{,}69}$

可以在双流化床（DFB）中使用生物质蒸汽气化来替代化石燃料来生产电力，热能，运输燃料和化学品。

由于来自生物质灰分的组分的富集，生物质灰分和流化床中床层材料之间的相互作用导致床层颗粒的转化，从而导致在床层颗粒表面上形成灰分层。这些富含灰分的颗粒层增强了床材料在水煤气变换反应和减少焦油方面的催化活性。

研究了双流化床生物质在870°C下典型气化条件下的水煤气变换反应。使用实验室规模的实验装置将扩散和传热限制降到最低，该实验装置由气体混合段和石英玻璃反应器组成，在其中研究催化剂。

根据经验，开发了以下新的生物质双流化床气化中水煤气变换反应的速率表达式，其中考虑了灰层的形成：${\mathrm{[R}}_{\mathit{黄绿}\_\mathit{灰}--\mathit{层}}=8\text{，}9·{10}^{--6}\mathrm{经验值}（\frac{--95000}{\mathit{逆时针}}）p_{\mathit{一氧化碳}}^{\mathrm{1个}\text{，}96}{p}_{H\mathrm{2个}Ø}^{\mathrm{1个}\text{，}81}{p}_{\mathit{一氧化碳}\mathrm{2个}}^{--0\text{，}75}{p}_{H\mathrm{2个}}^{--\mathrm{1个}\text{，}69}$