Underground coal gasification with CCS: a pathway to decarbonising industry

Abstract

Underground coal gasification (UCG) opens up the prospect of accessing trillions of tonnes of otherwise unmineable coal. When combined with carbon capture and storage (CCS), UCG offers some attractive new low-carbon solutions on a vast scale. This paper has several aims: to review key developments in technologies for UCG, CCS and CO 2 storage in coal seam voids; to quantify the scale of the opportunity that these technologies open up; to examine the scope for linking these developments to other more familiar plans for decarbonising the fossil fuel power generation industry and other carbon-intensive industries; to identify the main hurdles to be overcome in taking forward any large-scale UCG-CCS proposition; and to propose a basis on which UCG-CCS can sit at the heart of plans to decarbonise present day industry in a way that dove-tails with longer-term ambitions for an economy based on renewable energy.

Innovative thermodynamic underground coal gasification model for coupled synthesis gas quality and tar production analyses

“…In deeper view of the basic flowsheet build-up procedure, the integration of main sections (1)(2)(3)(4)(5) was oriented at the in-situ reactor zone distribution known from principal previous UCG field experiments and related excavation experiences that have been well documented in several preceding UCG publications [1,3,8,59,60]. The basic reactor distribution is thus characterized by development of an oxidant impacted high-temperature reduction/partial zone near the injection well (cf.…”

“…Underground Coal Gasification provides a promising technical and economic potential to solve current long-term power supply conflicts worldwide by controlled in-situ conversion of otherwise non-mineable coal reserves [1][2][3][4][5][6][7]. While the technique itself is a rather simple concept in theory, experience from major international field trials over the last decades shows its control in practice is much more complicated.…”

Addressing the CO 2 emissions of the world's largest coal producer and consumer: Lessons from the Haishiwan Coalfield, China

“…[46] The injection of inert CO 2 into coal goaf could reduce oxygen concentrations, decreasing the risk of spontaneous combustion in coal seams. Gas adsorption capacity increases with increasing CO 2 content and decreases with increasing CH 4 content (Fig.16 ) could be stored in the goaf aquifer through adsorption in the free phase and dissolved state [23,47,48].…”

“…To these may be added deep voids produced by coal mining or by underground coal gasification [23,24]. There are various methods for capturing the naturally occurring gas in coal seams to prevent it entering mine airways, most notably the use of pre-drainage boreholes to remove gas before the mine workings reach the strata, as well as post-drainage techniques for coal seams already disturbed by the extraction process.…”

“…2) Underground coal gasification combined with CCS, which offers an extra degree of freedom or an added level of flexibility in reducing the overall carbon footprint of a cluster of carbon-intensive industries [23].…”