A Review on Conversion of Biomass to Liquid Fuels and Methanol through Indirect Liquefaction Route

Abstract

Global urbanization and industrialization are energy‐intensive processes. Among different energy resources, fossil fuels meet more than 80 % of the energy demand. The factors such as the depletion of fossil fuel reserves, the unstable price of fossil fuels, and the emission of greenhouse gases (GHGs) due to the burning of fuels draw researchers’ attention towards the development of renewable and sustainable fuels. In this context, biomass may fill the gap between energy demand and petroleum availability in the foreseeable future. Moreover, half of this bioenergy comes from conventional uses of biomass, primarily in cooking and heating, as well as within small‐scale industries (such as charcoal kilns and brick kilns). The Biomass‐to‐Liquid (BTL) technology using Fischer‐Tropsch synthesis (FTS) and the Methanol process offers advantages over the traditional use of biomass. The FT/Methanol process is a propitious route to produce carbon‐neutral, ultra‐clean fuels that generate regulated emissions, including NOx, SOx, and PM. In this article, we have reviewed the processes of biomass gasification, syngas cleaning and conditioning, FTS and methanol synthesis.

Comparative Studies of Co/SBA‐15 Catalysts Synthesized with Different Silica Sources Including Coal Fly Ash for Fischer‐Tropsch Synthesis

“…The interest in the FTS is due to several reasons: i) availability of wide variety of feedstocks (coal, biomass, municipal solid waste, and natural gas); ii) desired product selectivity; and iii) ultrapure aviation grade liquid fuel (zero sulphur and nitrogen). [2,4] Fe, Co, Ni, and Ru are having differential hydrogenation capabilities, hence these are commonly used as catalytic metals for synthesis of FTS catalysts. Fe and Co are the two metals for synthesis of commercial FTS catalysts.…”

“…The major reactions involved in FTS to generate alkanes (Equation 1), alkenes (Equation 2), and alcohols (Equation 3) are given below. [1][2][3]…”

“…The source of “syngas” can vary from different carbonaceous feedstocks. The major reactions involved in FTS to generate alkanes (Equation 1), alkenes (Equation 2), and alcohols (Equation 3) are given below [1–3] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr (2n + 1)H_2 + nCO \to C_n H_{2n + 2} + nH_2 O\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr 2nH_2 + nCO \to C_n H_{2n} + nH_2 O\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr nCO + (2n)H_2 \to C_n H_{2n + 1} OH + (n - 1)H_2 O\hfill\cr}}$$$ …”