Gas Control Technology Research Articles

Gas control technology of working face in single, high-gas and medium -thick coal seam

Aiming at solving the problems of large gas emission and difficult control of working face in single, high-gas and medium -thick coal seam, the author prefers the drainage way of head-on along layer drill hole by comparing several kinds of drainage ways. Based on analyzing all kinds of factors affecting drainage result, such as the arrangement of drill hole ,the span of drill hole, the depth of sealing hole, drainage negative pressure and drainage duration, The author designs gas drainage at working face in single, high-gas and medium-thick coal seams. According to the author's gas drainage parameters in the design, it is summarized as follows: the rate is as high as 62.71% at working face; the great hidden danger to safety is reduced and it is great significant to control gas disasters in single, high-gas and medium -thick coal seam.

Simulation of entrained flow coal gasification

Integrated gasification combined cycle (IGCC) with carbon capture and storage (CCS) is a viable greenhouse gas control technology in using coal for power and/or hydrogen generation. This work describes the development of a pilot-scale pressurized entrained flow coal gasification facility and the parallel computational fluid dynamics (CFD) based simulation capability for the purpose of advancing commercial coal gasification technology. The gasification simulation approach, its present predictive performance and the potential areas for further improvement are presented.

Sequestration of Carbon Dioxide in Coal with Enhanced Coalbed Methane RecoveryA Review

This article reviews the storage of captured CO2 in coal seams. Other geologic formations, such as depleted petroleum reservoirs, deep saline aquifers and others have received considerable attention as sites for sequestering CO2. This review focuses on geologic sequestration of CO2 in unmineable coalbeds as the geologic host. Key issues for geologic sequestration include potential storage capacity, the storage integrity of the geologic host, and the chemical and physical processes initiated by the deep underground injection of CO2. The review topics include (i) the estimated CO2 storage capacity of coal, along with the estimated amount and composition of coalbed gas; (ii) an evaluation of the coal seam properties relevant to CO2 sequestration, such as density, surface area, porosity, diffusion, permeability, transport, rank, adsorption/desorption, shrinkage/swelling, and thermochemical reactions; and (iii) a treatment of how coalbed methane (CBM) recovery and CO2-enhanced coalbed methane (ECBM) recovery are performed (in addition, the use of adsorption/desorption isotherms, injection well characterization, and gas injection are described, as well as reservoir screening criteria and field tests operating in the United States and abroad); (iv) leak detection using direct measurements, chemical tracers, and seismic monitoring; (v) economic considerations using CO2 injection, flue gas injection, and predictive tools for CO2 capture/sequestration decisions; (vi) environmental safety and health (ES&H) aspects of CO2-enhanced coalbed methane/sequestration, hydrodynamic flow through the coal seam, accurate gas inventory, ES&H aspects of produced water and practices relative to ECBM recovery/sequestration; (vii) an initial set of working hypotheses concerning the chemical, physical, and thermodynamic events initiated when CO2 is injected into a coalbed; and (viii) a discussion of gaps in our knowledge base that will require further research and development. Further development is clearly required to improve the technology and economics while decreasing the risks and hazards of sequestration technology. These concerns include leakage to the surface, induced seismic activity, and long-term monitoring to verify the storage integrity. However, these concerns should not overshadow the major advances of an emerging greenhouse gas control technology that are reviewed in this paper.

Recovery of CO2 with MEA and K2CO3 absorption in the IGCC system

Recovery of CO2 with monoethanolamine (MEA) and hot potassium carbonate (K2CO3) absorption processes in an integrated gasification combined cycle (IGCC) power plant was studied for the purpose of development of greenhouse gas control technology. Based on energy and exergy analysis of the two systems, improvement options were provided to further reduce energy penalty for the CO2 separation in the IGCC system. In the improvement options, the energy consumption for CO2 separation is reduced by about 32%. As a result, the thermal efficiency of IGCC system is increased by 2.15 percentage-point for the IGCC system with MEA absorption, and by 1.56 percentage-point for the IGCC system with K2CO3 absorption. Copyright (C) 2004 John Wiley Sons, Ltd.

Oxidative decomposition of aromatic hydrocarbons by electron beam irradiation

Decomposition of aromatic volatile organic compounds (VOCs) under electron beam irradiation was studied in order to examine the kinetics of the process, to characterize the reaction product distribution and to develop a process of waste gas control technology. Toluene, ethylbenzene, o-, m-, p-xylenes and chlorobenzene were used as target materials. The experiments were carried out at doses ranging from 0.5 to 10kGy, using a flow reactor utilized under electron beam irradiation. Maximum degrees of decomposition carried out at 10kGy in air environment were 55–65% for “non-chlorinated” aromatic VOC and 85% for chlorobenzene. It was found that a combination of aromatic pollutants with chlorobenzene would considerably increase the degradation value up to nearly 50% compared to the same compounds in the absence of chlorine groups. Based on our experimental observation, the degradation mechanism of the aromatic compounds combined with chloro-compound suggests that a chlorine radical, formed from EB irradiation, induces a chain reaction, resulting in an accelerating oxidative destruction of aromatic VOCs.

自動車産業における技術紹介と将来展望講座 （ＩＩ） 自動車の燃費向上と排気ガス対策技術

自動車産業における技術紹介と将来展望講座 （ＩＩ） 自動車の燃費向上と排気ガス対策技術

On the regulation of municipal solid waste resource recovery incinerators.

The US Environmental Protection Agency (EPA) has recently performed a risk analysis of the nationwide health impacts of municipal solid waste (MSW) incineration. On the basis of this risk analysis, the EPA has proposed that acid gas and particulate control technology be included on all new MSW/RDF-fired resource recovery incinerators built in the US. Although scrubbers reduce acid gas emissions, it has never been demonstrated that such reductions are needed to protect health. The authors believe that the EPA's analysis is misleading and leads to the incorrect conclusion that scrubbers are necessary on new incinerators. They present an alternative assessment.