The development of the underground ( insitu) coal gasification (UCG) technique is paving the way to access deep coal seams. Early studies suggest that the use of UCG could potentially increase the world's coal reserves by as much as 600 GT [ 3 ], which represents a 70% increase [ 2 ].
Underground coal gasification (UCG) is an insitu gasification technology where the controlled retreating injection point (CRIP) method is usually adopted to optimize the cavity evolution and gas production stability. However, the reported studies only focus on the gasification behavior of the moving injection backward under fixed time intervals.
Gas properties Gas content. One of the factors affecting the energy release potential of coal is gas content. Gas content is the summation of free and adsorbed gas in coal and is recognized as the key parameter used for determining outburst propensity (Lama 1995).In Australia, gas content is used alone to define a Threshold Limit Value (TLV) in coal mines to assess outburst risks.
1. Introduction. Coal is the most sufficient fossil fuel and accounts for about 27% of energy consumption all over the world in 2020. 1 However, considering the increasingly urgent demand for environmental protection, the conventional method of coal mining and utilization should be replaced. Another alternative process is underground coal gasification (UCG), which is more environmentally ...
Abstract. Underground coal gasification is an in situ coal utilization technique that has immense potential as a future clean coal technology. UCG possesses a number of advantages including the ability to use deep and unmineable coals. The most important component of UCG is the underground "cavity"—which serves as a chemical reactor with ...
One concept for insitu coal gasification involves fracturing thick, deep, coal seams using chemical explosives. The resultant highpermeability zone then would be ignited and reacted with a steam/ oxygen mixture to produce mediumBtu gas suitable for upgrading to pipeline quality in a surface plant.
This chapter deals with coal gasification, which is a process that converts carbonaceous materials, such as coal, petroleum, petroleum coke, or biomass, into carbon monoxide and hydrogen.
article{osti_, title = {Mathematicalmodeling studies of insitu coal gasification}, author = {Krantz, W B and Gunn, R D}, abstractNote = {Commercialization of the insitu or underground coal gasification (UCG) process has been impeded because of uncertainties with respect to its reliability and predictability. Modeling studies when combined with a welldesigned field test program are ...
Modelling studies assumed the coal gasification process is carried out with the participation of separately oxygen and air as a gasification agent, under the specific conditions of the georeactor ...
A 72h ex situ hard coal gasification test in one large block of coal was carried out. The gasifying agent was oxygen with a constant flow rate of m3/h. The surroundings of coal were simulated with wet sand with 11% moisture content. A 2cm interlayer of siderite was placed in the horizontal cut of the coal block. As a result of this process, gas with an average flow rate of m3/h was ...
In order to clarify the competitiveness of deep insitu gasification based coaltohydrogen (deep IGCtH) in the context of carbonconstrained development, based on simulation results, the energy, water consumption and carbon emissions were quantitatively assessed and compared with largescale fossil energy based routes, using life cycle assessment model from feedstock to hydrogen that covers ...
Abstract. Underground coal gasification is a conversion and extraction process, for the production of useful synthetic product gas from an insitu coal seam, to use in power generation, heat production or as a chemical feedstock. While many variants of the underground coal gasification process have been considered and over 75 trials performed ...
Underground coal gasification (UCG) is a method whereby the mining and conversion of coal are accomplished in a single step. Many field tests of UCG have been operated worldwide since the 1930's with varying degrees of success; based on this experience (especially in the USSR and United States), a field design which is applicable to a wide range of geological conditions and coal properties has ...
The Chinese government has authorized an underground coalgasification project in Lineng of Shandong Province recently. This is a model project combining insitcoal gasification and gasfired power generation., as well as being of interest to the British, the Australians and ourselves, to name but a few.
The challenge for Leigh Creek Energy Limited was to design, build and commission a pilot plant to transform coal from its solid state into a gaseous form and monitor the technical and environmental performance of the process. The insitu gasification process (ISG) produces methane, hydrogen and other valuable components. The synthetic gas ...
Underground coal gasification (UCG) is a clean coal mining technology without significant environmental impacts. This technology can also be used in deep, hardtoreach seams or deposits affected by tectonic disturbances, where conventional mining is impossible. Several techniques and methods have been investigated worldwide to support the process control of UCG. Global research focuses on the ...
The resource for UCG is principally unmined coal seams. The gasification process creates synthesis gas that can be used as fuel, or feedstock for further chemical processes such as NH 3 production or liquid fuels. An oxidant (usually air, oxygen, or steam) is injected into the coal seam and reacts with the coal and water present in the seam to ...
This study provides an overview of the systematic methods of the in situ coal gasification process. Furthermore, the model of the porous structure of coal has been presented and the gas movement taking place in the carbon matrix—which is part of the bed—has been described. The experimental tests were carried out with the use of air forced ...
Underground coal gasification (UCG) is the process of converting hydrocarbon materials into synthesis gas insitu. The process has been developed over more than a century and many aspects of the process are well understood. Despite this, no large scale commercial UCG plants have been constructed recently, with only one Sovietera plant from the ...
Increasing global energy demand is a central challenge of the 21st century. Apart from renewable energy concepts, sustainable bridging and buffering technologies are needed which simultaneously offer longterm energy supply guarantees. Underground coal gasification (UCG) shows a promising potential to meet these requirements of future energy markets by in situ conversion of coal to a valuable ...
They can be employed insitu during the gasification reactions or exsitu after gasification reactions for tar removal and syngas quality improvement . In situ gas cleaning ... The effect of dolomite addition on sulphur, chlorine and hydrocarbons distribution in a fluidbed mild gasification of coal. Fuel Process. Technol. 7778 (2002).
This chapter presents an assessment of the technologies that have evolved for the gasification of coal with a description of the current state of the art of the various technologies. Various types of coal are available such as lignite, subbituminous coal, bituminous coal, and anthracite. The gasification process involves two distinct stages ...
In situ coal gasification: a unique means of energy recovery. United States: N. p., 1976. Web. Copy to clipboard. Schrider, L A, Fischer, D D. ... using both air and oxygen/steam injection: both low and mediumBtu gas were produced. The process wells were spaced 18 m (60 ft) apart and completed within m (5 ft) of the bottom of the m ...
Coal extraction by the UCG process, also known as insitu coal gasification, appears to be both technically and economically feasible and exhibits many potential advantages over the conventional mining methods (Kapusta and Stanczyk, 2011; Shuqin et al., 2007). The UCG
The coal is ignited and air is injected underground to sustain a fire, which is essentially used to "mine" the coal and produce a combustible synthetic gas which can be used for industrial heating, power generation or the manufacture of hydrogen, synthetic natural gas or diesel fuel.
An oxidant (usually air, oxygen, or steam) is injected into the coal seam and reacts with the coal and water present in the seam to produce syngas that is extracted through a production well. As the gasification process proceeds, the cavity grows radially outward and upward from the injection well.
Underground coal gasification (UCG) is the process of converting hydrocarbon materials into synthesis gas insitu. Underground coal gasification is sometimes referred to as insitu coal gasification (ISCG). The process has been developed over more than a century, though only a few projects currently operate on a continuous basis.
The Underground Coal Gasification (UCG) offers a clean source of energy by converting coal/lignite insitu into syngas that can be used either as a fuel or as a chemical feedstock [2]. The UCG has the potential to utilize coal and lignite resources which are inaccessible due to depth and are uneconomical to extract using the conventional mining ...
By igniting in the coal seam and injecting gas agent, underground coal gasification (UCG) causes coal to undergo thermochemical reactions in situ and, thus, to be gasified into syngas for power generation, hydrogen production, and storage. Compared with traditional mining technology, UCG has the potential sustainable advantages in energy, environment, and the economy. The paper reviewed the ...
Coal gasification can also be carried out on seams that are still in place, the coal being converted to gaseous fuels without an intermediate mining operation. This process, known as in situ or underground gasification, typically involves drilling boreholes to intersect the seam in at least two places, and providing a passage for gas through the seam from one intersection to the other.
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