When will fossil fuel reserves be diminished

Underground coal gasification: From fundamentals to applications

Biomass gasification converts into syngas, then into other chemicals via Fischer-Tropsch (F-T) synthesis is promising for renewable energy utilization. Although gasification is a sustainable and environmental-friendly technology for value-added utilization of biomass, tar formation is the major problem during the biomass gasification. Tar could condense on the reactor then block and foul equipment. An optimized gasifier and highly active catalyst were proved to be effective for biomass tar elimination. Furthermore, tar formation mechanism and the decomposition pathway were also important to advance the optimization of gasification reactors and catalyst design. This paper summarized the fundamentals, such as gasifier types, Ni-based catalyst, and reaction and deactivation mechanism. This review also sheds light on other excellent catalysts, effective gasifiers and mathematical models of biomass catalytic gasification, and catalyst reaction mechanisms and mathematical models are also discussed in detail. At last, the paper ends with a conclusion and prospective discussion to the latter lab and industrial-scale research.

Recent advances in syngas production from biomass catalytic gasification: A critical review on reactors, catalysts, catalytic mechanisms and mathematical models

Underground coal gasification: A new clean coal utilization technique for India

Coal gasification is a promising option for the future use of coal. Similarly to gasification in industrial reactors, underground coal gasification (UCG) produces syngas, which can be used for power generation or for the production of liquid hydrocarbon fuels and other valuable chemical products. As compared with conventional mining and surface gasification, UCG promises lower capital/operating costs and also has other advantages, such as no human labor underground. In addition, UCG has the potential to be linked with carbon capture and sequestration. The increasing demand for energy, depletion of oil and gas resources, and threat of global climate change lead to growing interest in UCG throughout the world. In this article, we review the current status of this technology, focusing on recent developments in various countries.

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Underground Coal Gasification: A Brief Review of Current Status

Underground Coal Gasification (UCG) is the process of in-situ conversion of coal into combustible products (syngas) which can be used either as fuel or as a chemical feedstock. In this study, the gasification channel is viewed as a one-dimensional packed bed reactor. The packed bed reactor model is solved incorporating chemical reactions and mass transfer effects. A pseudo-transient model is simulated for temperature and composition profiles of the gas and solid phases. The movements of the pyrolysis and the reaction front are obtained. The model results are in qualitative agreement with literature. The effects of various operating parameters are studied in detail. Steam/O2 ratio, inlet O2 and total pressure determine the solid temperature profile and hence the outlet gas composition. The simulations are performed for two sets of kinetics parameters. The solid temperature profile and outlet gas compositions change significantly with a change in kinetics parameters. The main motivation behind this study is to provide a theoretical base for understanding the critical aspects of UCG and to provide a tool which coupled with experiments will help in determining the commercial feasibility of the UCG process.

Anil N. Khadse

Papers

Underground coal gasification: A new clean coal utilization technique for India

Reactor Model for the Underground Coal Gasification (UCG) Channel

Resources and economic analyses of underground coal gasification in India