Chemical-Looping Gasification of Biomass for Hydrogen-Enriched Gas Production with In-Process Carbon Dioxide Capture

Abstract

The research presents an innovative idea of developing a continuous H 2 production process employing fluidized-bed technology from agricultural biomass with in situ CO 2 capture and sorbent regeneration. Novelty of the process lies in the generation of relatively pure H 2 from biomass with CO 2 as a byproduct using steam as the gasifying agent. Another unique feature of the process is internal regeneration of the sorbent, fouled in the gasifier. Thus, the technology will serve the twin purpose of regenerating the sorbent and generation of N 2 -free H 2 and CO 2 . This work reports theoretical energy analysis and experimental investigation of the process. The system efficiency of the chemical-looping gasification process at an ideal scenario is found to be 87.49% with biomass as fuel. A sensitivity analysis for system efficiency is also conducted by varying carbon-capture and regeneration efficiencies. The experiments conducted in a batchtype fluidized-bed steam gasifier using CaO as the sorbent shows a 71% concentration of H 2 and nearly 0% concentration of CO 2 in the product gas when sawdust was used as the feedstock. In a separate test using a circulating fluidized-bed reactor as the regenerator, a 40% regeneration of CaO is also achieved at a calcination temperature of 800 °C.

Chemical-Looping Combustion and Gasification of Coals and Oxygen Carrier Development: A Brief Review

“…Chemical-looping combustion with gaseous fuels has been mainly studied and developed in recent years and was reviewed by Adanez et al [3] and Hossain and de Lasa [8]. More recently, CLC research has focused on solid fuels because of rich solid fuel resources [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Figure 1.…”

CO2 capture with calcined dolomite: the effect of sorbent particle size

“…16 [-] Φ Thiele-like modulus defined in Eq. 15 [-] Subscripts 0 Outer, reference, initial value (fully calcined particle) 1 Value at the end of CaO Methods for hydrogen production and net-carbon-dioxidefree power generation from biomass and fossil fuels are currently receiving considerable attention as a result of the perception of the earth's climate being significantly affected by man-induced changes in the atmosphere. A wide range of technologies for carbon-emission-free energy production are currently under development.…”

“…A wide range of technologies for carbon-emission-free energy production are currently under development. A promising option involves in situ CO 2 capture in biomass/coal gasifiers [1][2][3][4] and in advanced configurations of the methane steam reforming process [5,6] as well. The "in situ" CO 2 capture is usually performed by means of a calcium-based solid sorbent and results in the formation of calcium carbonate, which can then be re-calcined for a further CO 2 capture cycle, while a carbon dioxide rich stream is generated amenable to sequestration or utilization.…”

A Review of Life Cycle of Ethanol Produced from Biosyngas

“…and catalyst have also been used, which improve heat transfer and conversion rate of biomass in gasification processes [41,42]. Low temperature operation results in higher selectivity (of Rh-Mn/SiO 2 ) to ethanol and lower methane formation [33].…”

“…The main catalyst groups are natural catalyst (dolomite and olivine), alkali (KOH, Na 2 CO 3 , CaCO 3 , CsCO 3 , ZnCl 2 , NaCl etc.) and nickel-based catalysts [41,48].…”