scholarly journals Synthesis Gas Composition Prediction for Underground Coal Gasification Using a Thermochemical Equilibrium Modeling Approach

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1171 ◽  
Author(s):  
Christopher Otto ◽  
Thomas Kempka
Keyword(s):  
Synthesis Gas ◽  
Equilibrium Model ◽  
Carbon Capture ◽  
Coal Gasification ◽  
Carbon Capture And Storage ◽  
Equilibrium Composition ◽  
Operating Conditions ◽  
Underground Coal Gasification ◽  
Modeling Approach ◽  
Wide Range

Underground coal gasification (UCG) is an in situ conversion technique that enables the production of high-calorific synthesis gas from resources that are economically not minable by conventional methods. A broad range of end-use options is available for the synthesis gas, including fuels and chemical feedstock production. Furthermore, UCG also offers a high potential for integration with Carbon Capture and Storage (CCS) to mitigate greenhouse gas emissions. In the present study, a stoichiometric equilibrium model, based on minimization of the Gibbs function has been used to estimate the equilibrium composition of the synthesis gas. Thereto, we further developed and applied a proven thermodynamic equilibrium model to simulate the relevant thermochemical coal conversion processes (pyrolysis and gasification). Our modeling approach has been validated against thermodynamic models, laboratory gasification experiments and UCG field trial data reported in the literature. The synthesis gas compositions have been found to be in good agreement under a wide range of different operating conditions. Consequently, the presented modeling approach enables an efficient quantification of synthesis gas quality resulting from UCG, considering varying coal and oxidizer compositions at deposit-specific pressures and temperatures.

Recent developments and current position of underground coal gasification

2017 ◽  
Vol 232 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Michael Green
Keyword(s):  
Carbon Capture ◽  
Coal Gasification ◽  
Academic Research ◽  
Carbon Capture And Storage ◽  
Extraction Process ◽  
Pilot Scale ◽  
The European Union ◽  
Underground Coal Gasification ◽  
Product Gas ◽  
And Storage

Underground coal gasification is a conversion and extraction process, for the production of useful synthetic product gas from an in-situ 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 throughout the world, the recent work has tended to focus on the control of the process, its environmental impact on underground and surface conditions and its potential for carbon capture and storage. Academic research has produced a set of mathematical models of underground coal gasification, and the European Union-supported programme has addressed the production of a decarbonised product gas for carbon capture and storage. In recent years, significant progress has been made into the modelling of tar formation, spalling, flows within the cavity and the control of minor gasification components, like BTEX and phenols, from underground coal gasification cavities (BTEX refers to the chemicals benzene, toluene, ethylbenzene and xylene). The paper reviews the most recent underground coal gasification field trial and modelling experience and refers to the pubic concern and caution by regulators that arise when a commercial or pilot-scale project seeks approval. It will propose solutions for the next generation of underground coal gasification projects. These include the need to access deeper coal seams and the use of new techniques for modelling the process.

Thermochemical equilibrium modeling approach for carbon-rich feedstock gasification validated against laboratory and large-scale experiments

2020 ◽  
Author(s):  
Christopher Otto ◽  
Thomas Kempka
Keyword(s):  
Synthesis Gas ◽  
Reactive Transport ◽  
Large Scale ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Equilibrium Modeling ◽  
Modeling Approach ◽  
Wide Range ◽  
Thermochemical Equilibrium

<p>In the present study, a pre-existing stoichiometric equilibrium model based on direct minimization of Gibbs free energy has been further developed and applied to estimate the equilibrium composition of synthesis gases produced by the gasification of carbon-rich feedstock (e.g., coal, municipal waste or biomass) in a fixed-bed reactor [1]. Our modeling approach is validated against thermodynamic models, laboratory gasification and demonstration-scale experiments reported in the literature. The simulated synthesis gas compositions have been found to be in good agreement under a wide range of different operating conditions. Consequently, the presented modeling approach enables an efficient quantification of synthesis gas compositions derived from feedstock gasification, considering varying feedstock and oxidizer compositions as well as pressures and temperatures. Furthermore, the developed model can be easily integrated with numerical flow and transport simulators to simulate reactive transport of a multi-componentgas phase.</p><p>[1] Otto and Kempka, Synthesis gas composition prediction for underground coal gasification using a thermochemical equilibrium modeling approach, Energies (in review)</p>

Optimization of synthesis gas heating values and tar by-product yield in underground coal gasification

Fuel ◽  
2018 ◽  
Vol 229 ◽  
pp. 248-261 ◽  
Author(s):  
Stefan Klebingat ◽  
Thomas Kempka ◽  
Marc Schulten ◽  
Rafig Azzam ◽  
Tomás Manuel Fernández-Steeger
Keyword(s):  
Synthesis Gas ◽  
Coal Gasification ◽  
Product Yield ◽  
Underground Coal Gasification ◽  
Gas Heating

Distribution and estimates of Australia's identified energy commodity resources

2021 ◽  
Vol 61 (2) ◽  
pp. 325
Author(s):  
Barry E. Bradshaw ◽  
Meredith L. Orr ◽  
Tom Bernecker
Keyword(s):  
Natural Gas ◽  
Carbon Capture ◽  
Coal Gasification ◽  
Carbon Capture And Storage ◽  
Energy Resource ◽  
Gas Production ◽  
Renewable Energy Resources ◽  
North West ◽  
The North ◽  
Energy Provider

Australia is endowed with abundant, high-quality energy commodity resources, which provide reliable energy for domestic use and underpin our status as a major global energy provider. Australia has the world’s largest economic uranium resources, the third largest coal resources and substantial conventional and unconventional natural gas resources. Since 2015, Australia’s gas production has grown rapidly. This growth has been driven by a series of new liquefied natural gas (LNG) projects on the North West Shelf, together with established coal seam gas projects in Queensland. Results from Geoscience Australia’s 2021 edition of Australia’s energy commodity resources assessment highlight Australia’s endowment with abundant and widely distributed energy commodity resources. Knowledge of Australia’s existing and untapped energy resource potential provides industry and policy makers with a trusted source of data to compare and understand the value of these key energy commodities to domestic and world markets. A key component of Australia’s low emissions future will be the development of a hydrogen industry, with hydrogen being produced either through electrolysis of water using renewable energy resources (‘green’ hydrogen), or manufactured from natural gas or coal gasification, with carbon capture and storage of the co-produced carbon dioxide (‘blue’ hydrogen). Australia’s endowment with abundant natural gas resources will be a key enabler for our transition to a low emissions future through providing economically competitive feedstock for ‘blue’ hydrogen.

scholarly journals Economic Conditions for Developing Hydrogen Production Based on Coal Gasification with Carbon Capture and Storage in Poland

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5074
Author(s):  
Radosław Kaplan ◽  
Michał Kopacz
Keyword(s):  
Carbon Capture ◽  
Coal Gasification ◽  
Net Present Value ◽  
Carbon Capture And Storage ◽  
Economic Assessment ◽  
Free Cash Flow ◽  
Sensitivity Analyses ◽  
Capital Expenditures ◽  
Hard Coal ◽  
And Storage

This study documents the results of economic assessment concerning four variants of coal gasification to hydrogen in a shell reactor. That assessment has been made using discounting methods (NPV: net present value, IRR: internal rate of return), as well as indicators based on a free cash flow to firm (FCFF) approach. Additionally, sensitivity analysis has been carried out, along with scenario analysis in current market conditions concerning prices of hard coal, lignite, hydrogen and CO2 allowances, as well as capital expenditures and costs related to carbon capture and storage (CCS) systems. Based on NPV results, a negative economic assessment has been obtained for all the analyzed variants varying within the range of EUR −903 to −142 million, although the variants based on hard coal achieved a positive IRR (5.1–5.7%) but lower than the assumed discount rates. In Polish conditions, the gasification of lignite seems to be unprofitable, in the assumed scale of total investment outlays and the current price of coal feedstock. The sensitivity analyses indicate that at least a 20% increase of hydrogen price would be required, or a similar reduction of capital expenditures (CAPEX) and costs of operation, for the best variant to make NPV positive. Analyses have also indicated that on the economic basis, only the prices of CO2 allowances exceeding EUR 40/Mg (EUR 52/Mg for lignite) would generate savings due to the availability of CCS systems.

Fault and top seals thematic collection: a perspective

2021 ◽  
pp. petgeo2020-136
Author(s):  
Quentin Fisher ◽  
Frauke Schaefer ◽  
Ieva Kaminskaite ◽  
David N Dewhurst ◽  
Graham Yielding
Keyword(s):  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Petroleum Reservoirs ◽  
Radioactive Waste Disposal ◽  
Content Type ◽  
Sealing Capacity ◽  
Wide Range ◽  
Research Findings ◽  
New Research ◽  
And Storage

Predicting the sealing capacity of faults and caprocks has been a long-standing uncertainty for those involved in the exploration, appraisal and development of petroleum reservoirs. In more recent years, interest in the topic has increased in a wide range of other applications, particularly those related to the decarbonization of our energy supply such as carbon capture and storage (CCS), radioactive waste disposal, geothermal energy production and underground energy storage (e.g. compressed air, hydrogen). Knowledge of how faults impact fluid flow is also important for management of drinking water supplies. To communicate new advances in research in these areas, the EAGE organized the first international conference on Fault and Top Seals in 2003. These conferences have continued to be held at roughly 4 yearly intervals and have brought together scientists from a wide range of disciplines to discuss new research findings and workflows relevant to predicting fault and top seal behaviour, as well as presenting case studies covering both successful and unsuccessful attempts to predict sealing capacity.Thematic collection: This article is part of the Fault and top seals collection available at: https://www.lyellcollection.org/cc/fault-and-top-seals-2019

scholarly journals Uncertainty in regional estimates of capacity for carbon capture and storage

Solid Earth ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 1707-1715 ◽  
Author(s):  
Mark Wilkinson ◽  
Debbie Polson
Keyword(s):  
Carbon Capture ◽  
Storage Capacity ◽  
Significant Proportion ◽  
Carbon Capture And Storage ◽  
Saline Aquifers ◽  
Storage Site ◽  
Limited Data ◽  
Wide Range ◽  
Regional Estimates ◽  
And Storage

Abstract. Carbon capture and storage (CCS) is a potentially important technology for the mitigation of industrial CO2 emissions. However, the majority of the subsurface storage capacity is in saline aquifers, for which there is relatively little information. Published estimates of the potential storage capacity of such formations, based on limited data, often give no indication of the uncertainty, despite there being substantial uncertainty associated with the data used to calculate such estimates. Here, we test the hypothesis that the uncertainty in such estimates is a significant proportion of the estimated storage capacity, and should hence be evaluated as a part of any assessment. Using only publicly available data, a group of 13 experts independently estimated the storage capacity of seven regional saline aquifers. The experts produced a wide range of estimates for each aquifer due to a combination of using different published values for some variables and differences in their judgements of the aquifer properties such as area and thickness. The range of storage estimates produced by the experts shows that there is significant uncertainty in such estimates; in particular, the experts' range does not capture the highest possible capacity estimates. This means that by not accounting for uncertainty, such regional estimates may underestimate the true storage capacity. The result is applicable to single values of storage capacity of regional potential but not to detailed studies of a single storage site.

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