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UCG Reader

[] – University of Leeds: UCG Where in the World? (2014)

[] – Underground coal gasification

UCG History:

1868 – Sir William Siemens introduces UCG to the Chemical Society of London. Dmitri Mendelejev further develops the idea for decades.
1912 – Sir William Ramsay prepared the first field test in Durham/UK, WW1 interrupted the project.
1913 – Lenin picked up the idea from Ramsay.
1928 – Field tests begin in the USSR.
1934 – First successful test in Donbass.
1960 – Five industrial scale UCG plants in the USSR.
1964 – Soviet program downgraded, after large natural gas finds.
2004 – Only Angren/Uzbekistan and Yuzhno-Abinsk/Russia sites continued operations.

[] – The Future of Cheap Energy: Underground Coal Gasification (2011). Nota bene written by the former chairman of, Rembrandt Koppelaar.

The reserve limits for coal, for China as well as the rest of the world, can be postponed for several generations if the technology to gasify coal underground can be commercialized. Underground Coal Gasification (UCG) enables the access of deeper coal layers hitherto unavailable through conventional mining. Several modern pilot projects have been successfully completed in recent years and commercial projects are underway. This article gives an overview of present developments, the technology of the process, costs to produce electricity and liquid fuels from the syngas, and discusses environmental concerns. The article is informed by the excellent presentation given at the ASPO 9 presentation given by Marc Mostade, Technical Director of Clean Coal, and advisor to the UCG Association. The slides of that presentation can be downloaded here, and the video is available here.

[] – Underground Coal Gasification: zeker honderd jaar langer fossiel

[] – Study of Underground Coal Gasification and Carbon Storage in the Residual Cavity (2018)

Underground coal gasification (UCG) is a process of ‘in-situ’ conversion of coal into gaseous products with usable heating value through combustion with oxygen/air and gasification with steam. From the economic and environmental point of view, UCG is a highly promising clean energy technology which has a potential to meet the increasing energy demands in several countries. Moreover, the voids created in deep underground following gasification generate the intriguing possibility of storing carbon dioxide. Since, in-situ UCG is a complex process, laboratory-scale experiments on coal blocks/packed beds can provide significant insight into UCG process. In this study, several laboratory scale experiments have been carried out to observe the effect of feed flow rate, steam injection, initial combustion etc. on product gas compositions. Results and limitations of the experiments are discussed in detail. In general, post-gasification sites consist of a tear-drop shape cavity with ash and rubble left at the bottom. The residual coal seam can be broadly classified as the partially-gasified char layer, the pyrolyzed char layers, and the raw coal layer. A series of carbon dioxide adsorption experiments have been carried out to assess the carbon dioxide capture and storage capacity (CCS) of the coal and pyrolyzed/gasified chars. The results from this study suggested that UCG-CCS process is feasible.

[] – Global Development of UCG (2011). Hallelujah-slides from the Global Syngas Association (2012).

• UCG is now being recognised globally as a viable and economic method for accessing deep otherwise unrecoverable coal reserves, on and offshore
• To become more widespread, we need to convince governments across the world of the environmental, financial and social benefits of UCG ‐ Key to the commercialisation and growth ‐ collaboration

[] – Theunissen project

The Theunissen 50 MW Project

African Carbon Energy, through its subsidary: Africary Holdings (Pty) Ltd and all its related subsidiaries (collectively known as “Africary”) has obtained exclusive rights to develop its 1 billion ton coal resource and wishes to exploit its coal with the clean and environmentally friendly UCG mining method and therefore have agreed with an international power plant developer and operator to construct in the order of 62 MWe gross (50 MW nett) power station on the coal field.

[] – Ergo Exergy is a UCG consultancy

In the USA, following early UCG trials after World War II, a modern and well-funded UCG development program took place in the 1970s and 1980s. Over 30 UCG experiments had been conducted in the States at the time, culminating in the Rocky Mountain 1 in 1988. Decreased natural gas and oil prices eliminated the rationale for the government-funded UCG program in the US, and in 1989 the program was abandoned before it had the chance to produce a commercially applicable UCG technology.

In 1993, when UCG had been in neglect and decline everywhere, Ergo Exergy Technologies Inc started our UCG saga in Montréal, Canada. Within six years, at the end of 1999, we had produced our first syngas in the Chinchilla UCG project in Australia. Australian businessman and UCG enthusiast Dr Len Walker played a decisive role in creating that unique UCG opportunity.

The new UCG history had begun.

Today, Ergo Exergy participates in commercial projects based on εUCG™ technology, which are currently at various stages of development in several regions throughout the world, including South Africa, Australia, the USA, Pakistan, New Zealand, India and Europe. These projects target power generation in IGCC and co-firing configurations, replacement of natural gas as fuel for power plants and production of synthetic liquid fuels, fertilizers, and synthetic methane. Please read more about Ergo Exergy’s projects in the respective sections.

[] – Underground Coal Gasification: An Overview of an Emerging Coal Conversion Technology

The primary reason to gasify coal underground is the low cost of energy production. Estimates from UCG companies on the cost of producing UCG syngas range from US$1–3/GJ depending on the coal deposit and on whether air or oxygen is used as the oxidant. Since 2000, long-term UCG pilots in Australia, China, and South Africa utilizing the technologies shown in Table 2 have successfully demonstrated that deep UCG can be low cost and environmentally benign.

[] – UCG banned immediately in Queensland, laws to follow, Mines Minister Anthony Lynham says

Underground coal gasification (UCG) will be banned in Queensland due to its environmental impact, Mines Minister Dr Anthony Lynham says. There had been only three UCG pilot projects in Queensland — Carbon Energy near Dalby, Cougar Energy near Kingaroy and Linc Energy at Chinchilla. Dr Lynham said no-one had made a success of UCG yet and potential revenue was not worth the environmental risk.

[] – SECUNDA PLANT – Sasol to pull plug on synthetic fuels

The recent completion of Sasol’s nine-year, R14bn mine replacement programme will provide the company’s Secunda synthetic fuels plant with feedstock until 2050. It, however, also marks the end of an era.

The Secunda plant uses coal-to-liquids (CTL) conversion technology and is the world’s largest by many orders of magnitude. Despite being highly profitable, the plant will be the last that Sasol will ever run.

“Categorically, we won’t do it again,” says Sasol joint president and CEO Stephen Cornell. “This is our last coal-to-liquids operation for the world.”

Sasol Mining is SA’s third largest coal producer, producing 40-million tonnes of coal annually. Apart from its chemical products, the CTL plant produces, on average, 60-million barrels of liquid fuel for Sasol to sell into the South African market each year.

But there are a lot of reasons why Sasol would not replace the plant, Cornell tells Business Day. “The basic business case is challenged, in terms of making a return on the investment. The carbon footprint is extremely large,” he says.

The original CTL plant was established in Sasolburg in 1955 but in the early 2000s was converted to produce petrochemicals only. The Secunda plant came onstream in the 1980s.

[] – Coal-to-liquids

[] – Still no clarity on the status of underground coal gasification

[] – Controversial trial of banned gas technology gets tick of approval in South Australia

[] – Modelling Underground Coal Gasification—A Review
[] – The Research of UCG in Laboratory Conditons

[] – Underground coal gasification

On April 16, 2012, it was reported that Linc Energy of Australia is setting up a joint venture with Golden Concord in China for underground coal gasification—the production of energy by burning coal where it lies, deep below the Earth’s surface. Golden Concord will inject US$15 million of working capital into the joint venture, which aims to start building a UCG operation in China within six months of binding legal agreements being signed. Gas produced through the process will be converted to liquid fuels.

[] – Commercialising underground coal gasification in the EU

Modern ‘enabling technologies’ and over a century of research and development have pushed underground coal gasification (UCG) beyond the proof-of-concept phase. Lessons learned from previous trials have demonstrated that UCG can exploit the energy stored in coal efficiently and with limited environmental impact compared with conventional coal-based energy technologies. Many countries in the EU (and worldwide) struggle to meet their energy needs despite containing very large reserves of coal, which cannot be exploited conventionally because of its depth. Application of modern UCG techniques, state-of-the-art drilling and monitoring technologies offer the opportunity to extract the energy from deep coal resources economically and with limited environmental impacts; however, several hurdles, such as public opinion and carbon dioxide (CO2) emission limits, must be overcome before UCG can be commercialised in the EU. Continued support by member states will attract more private investments, enable more field trials and allow Europe’s world-class UCG experts to demonstrate that the technology is ready to provide cleaner energy from coal for the EU in the twenty-first century. This is a review paper that aims to summarise the lessons learned from UCG trials and EU-sponsored work and to discuss what still needs to be done to commercialise UCG.

[] – Unconventional MEthane Production from Deep European Coal Seams through combined Coal Bed Methane (CBM) and Underground Coal GAsification (UCG) technologies
[] – About MEGA

MEGAPlus is a research project co-funded under the Research Fund for Coal and Steel (RFCS):
Start time: 01.06.2018
Duration: 3 years

Aims and Objectives

The objective of this proposal is to investigate the potential of deep lying coal seams (>900) for the development of the integrated CBM-UCG process for optimum methane production, which can be fed into the European pipeline network and contribute to the European energy supply security.

The MEGA+ project aims to make significant advances beyond “state of the art” and evaluate the potential of deep lying coal seams for the development of the combined CBM – UCG process for the optimum production of substitute natural gas (SNG), which can be integrated into the European pipeline network. The MEGA+ project is focusing on a representative coal deposit in Poland with the ultimate objective to validate the CBM-UCG-SNG technology by considering options of efficiency improvement and in-situ methane formation, and the processing of the syngas at surface for maximum methane and CO2 capture and utilisation by ECBM. The overall objective will be achieved by the following activities:

– Commencement of geological and hydrogeological research, static model development and assessment of the characteristics of the coal fields in Silesia, Poland, German Ruhr district and UK coalfield;
– Interpretation of representative field data as well as characterisation of coal and rocks by laboratory testing;
– Large-scale experimental verification of the production of natural substitute gas oriented from CBM-UCG;
– Investigation of the formation and release of contaminants, as well as evaluation of microstructure and sorption properties of the experimental post-gasification solid residues to specify the impact of the UCG process to the environment;
– Development and validation of advanced multi-scale and multi-physics computational models to account for the coupled processes and interactions (at the reactor scale and surrounding near and far-fields) experienced during the UCG operation;
– Assessment of the overall CBM-UCG-SNG process including ECBM;
– Surface and sub-surface process characterisation and economical modelling;
– Control and optimisation of the process operations and monitoring technique requirements (sub-surface and surface);
– Assessment of environmental, technical and operational risks;
– Preparation of best practice guidelines for an industrial application of the CBM-UCG-SNG technology;
– Review the permitting and regulatory framework requirements and consider implications for regulators for future commercialisation of the technology in Europe.

[] – Graphical analysis of underground coal gasification: Application of a carbon-hydrogen-oxygen (CHO) diagram

Underground coal gasification (UCG) is recognized as an efficient mining technique capable of chemically converting the coal from deep coal seams into synthesis gas. Depending on the main constituents of the synthesis gas, chemicals, electricity, or heat can be produced at the surface. This paper provides a high-level graphical method to assist practitioners in developing preliminary gasification processes and experimental programmes prior to detailed designs or field trials. The graphical method identifies theoretical limits of operation for sensible gasification within a thermally balanced region, based primarily on the basic coal chemistry. The analyses of the theoretical outputs are compared to actual field trials from sites in the USA and Australia, with very favourable results. A South African coal is studied to determine the possible synthesis gas outputs achievable using various UCG techniques: controlled retractable injection point (CRIP) and linked vertical wells (LVW). For CRIP techniques, an important result suggests that pyrolysis, and subsequent char production, are important intermediate phenomena allowing for increased thermal efficiencies of UCG. The conclusion is that South African coals need to be studied for pyrolysis-char behaviour as part of any future UCG programme. The results also suggest that UCG with CRIP would be a preferred technology choice for Bosjesspruit coal where pyrolysis dynamics are important. Lastly, the use of CO2 as oxidant in the gasification process is shown to produce syngas with significant higher heating value.

[] – Assessment and Improvement of UCG Modelling (2018)

Underground coal gasification (UCG) is a process to convert coal in-situ into combustible synthetic gas (syngas). Oxidant is brought downhole through an injector for coal combustion and gasification while resulting syngas is extracted from a producer. UCG offers a better way to exploit coal resources over conventional mining with smaller environmental footprint. It has gained considerable attention in emerging economies, e.g., China and India, which are coal-rich nations and have an ever-increasing energy demand. As a complex coal thermal recovery process involving multi-physics and kinetics, knowledge gaps remain before UCG reaches large-scale commercial implementation. To enhance knowledge, this work applies a modified simulation tool to model certain important aspects of UCG, i.e., assessing critically the use of a reservoir simulator to model UCG, exploring the theory of a prior linking method of reverse combustion, studying the role of coal cleats in governing fluid flow and heat transport with regard to aquifer contamination, and investigating the progressive changes in coal pores associated with UCG. Additional modelling efforts were made to explore an extended practical importance of UCG. The prospect of applying UCG to mobilize contiguous heavy oil is studied and the feasibility of linking UCG with carbon storage and sequestration is examined.

[] – In Asia Pacific Underground Coal Gasification Market foreseen to grow exponentially over 2014 – 2020 (2014)

China has conducted 17 UCG trials since 1991 to check the economic viability of UCG. Major power generating enterprise SinoCoking Coal is planning to harness coal reserves in Henan Province which was abruptly shut down because of strict environmental compliance set up by Chinese government. UCG is an environmental friendly approach [uhuh] that empowers companies to scale high power generation. With world’s most populated country, China offers a vibrant platform for energy sector companies to set up their base in China and thereby meet the growing demand of energy in China. Recently, China signed a whooping US $ 1.5 billion major pact with UK for commercial development of UCG in interiors of Mongolia.

Next prominent market is India. In India, mining contributes 10% of India’s GDP. With vast coal reserves, India is looking towards harnessing coal without disturbing ecological balance. There are also some sites which are economically nonviable to mine. Though India’s untapped 88.6 billion tonnes of non-metallurgical coal is found at a depth of 300 to 1200 metre is economically nonviable; UCG makes it economically sound option. Coal India Limited is trying to push the UCG technology to harness the coal in Kaitha (Jharkhand) and Thesgora (Madhya Pradesh) area. These two promising region is expected to generate high return on investment (ROI) by FY 2025.

Next prominent destination is Australia. In Australia, most companies are undertaking R&D to fully harness the concept of UCG. At present, three major UCG trials is being conducted by Linc Energy, Cougar Energy, and Carbon Energy at Queensland. Australian government is paying a vigil eye on these projects until the technology is commercially proven.

[] – Hydrocarbons in Cumbria (2018)

A European trial of UCG in deep coal seams was carried out in Spain in the 1990’s, involving the UK’s Department of Trade and Industry (DTI). The encouraging results of this trial led the DTI to re-evaluate UCG as a longer term option for clean coal exploitation in the UK… The technique is best suited to deep coal seams, 500 metres plus, and can be undertaken both on and off shore. The gas can be used for industrial heating, power generation or the manufacture of fuels, fertilisers, hydrogen, synthetic natural gas or other chemicals. It can also be processed to remove its CO2 content before it is passed to end users, thereby providing a source of clean energy, with minimal greenhouse gas emissions… Three UCG conditional licences have been issued by the Coal Authority, off the coast of Cumbria (see Annex E). One is an off-shore area (UCG/0021N – West Cumbria Offshore) issued to West Cumbria Mining in conjunction with their licences for exploration for coal extraction. Two licences for exploration without prior coal extraction were issued to Cluff Natural Resources Ltd in 2014 [*] on areas shown as off-shore from Workington and Maryport (UCG/0037N Maryport and UCG/0033N Northern Cumbria Offshore).

[*] Seems to contradict this: [deepresource] – UK Government Rejects UCG

[] – Carbon Energy (UCG company)

[] – UCG 19 slides, Prof. S Jayanthu, NIT Rourkela

[botswanaenergy] – Coal Based Energy in Botswana: Coal-to-Liquids, Coal-Bed Methane, and Underground Coal Gasification

[deepresource] – Enormous Coal Reserves Found Under the North Sea
[deepresource] – Underground Coal Gasification
[deepresource] – UK Government Rejects UCG
[deepresource] – North Sea UCG
[deepresource] – In-Situ Steenkool Verbranding in Nederland
[deepresource] – UCG R&D in the US

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