AndreaBozzo/ceres-open-data-index huggingface dataset:
Field performance of underground coal gasification

Underground coal gasification (UCG) offers a relatively low cost, environmentally sound method to produce clean fuels from coal. The coal resource for UCG is vast, widely distributed and is unminable by present-day techniques. Field tests to date have confirmed the potential economical and environmental advantages. Major milestones of the DOE UCG program include: Gasification with air producing low Btu gas (165 Btu/scf) at a production rate of 8.5 x 10/sup 6/ SCFD. This experiment was conducted by the Laramie Energy Technology Center and was in continuous operation for 55 days. Steam/oxygen gasification produced medium Btu gas (263 Btu/scf) at 1.7 x 10/sup 6/ SCFD. This test was carried out by the Lawrence Livermore Laboratory and was in continuous operation for 58 days of air gasification with a scheduled 2 day oxygen test. The results of the field testing have been very encouraging. The ultimate objective of the DOE program is to develop sources of commercial gas for SNG and power generation by 1987. A number of key issues must be resolved to move the technology into the commercial sector: demonstration of reliable link at bottom of the coal seam, control of water influx, minimization of gas losses, subsidence control, process control with good gas quality, environmental control, technology transfer to industry, and larger multi-module tests to demonstrate control of interacting modules. (LTN)

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Overburden characterization and post-burn study of the North Knobs steeply dipping bed underground coal gasification (SDB-UCG) site, Rawlins, Wyoming

The encompassing sandstones, siltstones, shales and thin conglomerates of the gasified G Coal seam at the North Knobs SDB-UCG site were deposited mainly in fluvial and poorly-drained swamp environments. These beds dip at 65/sup 0/ at the North Knobs site. Thin section and SEM analyses of the sandstones and coarse siltstones show that they are sublithic to subarkosic arenites cemented with clay minerals, calcite hematite, siderite and silica. The sandstones of Unit D directly above the coal seam have the highest concentration of calcite cement, the lowest mean grain size, and are best sorted in terms of quartz grain size variations; however, they are the worst sorted in terms of sieve size variations. Clay minerals in the sandstones are dominantly kaolinite and smectite with lesser amounts of illite and chlorite. These clays are of secondary origin. Heat alteration is present only in coals and overburden rock from cores that penetrated the cavity. Thermally altered rocks including hornfels, buchite, paralava rock and paralava breccia were found in the bottom of the dipping cavity near the injection well. The high temperature minerals of tridymite, cristobalite, mullite, cordierite, monoclinic pyroxene and high temperature plagioclase indicate that temperatures of at least 1200/sup 0/C to 1400/sup 0/C were attained in the lower part of the burn cavity. The mechanical test on the unaltered and altered overburden rock show that the most important lithologic property controlling rock strength and seismic wave velocity is the amount and type of cement in the rock. Other parameters measured were grain size, amount of clay cement, and porosity; sorting had a secondary effect on the rock strength and seismic wave velocity. There is a non-linear and direct relationship between mechanical strength and ultrasonic wave velocities for the rock tests. 30 references.

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Limestone/dolomite sulfation in a vertical pneumatic transport reactor

The sulphation characteristics of limestone/dolomite sorbents in a vertical pneumatic transport reactor operated with or without the spent sorbent recycle were examined. Experiments were carried out in a 25.4 cm pilot-scale reactor where limestone/dolomite reacted with SO/sub 2/ generated from coal combustion. A mathematical model is used to account for the SO/sub 2/ conversion and the sorbent

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Underground coal gasification station at Lisichansk. [USSR facility; 1948-63; 65 references]

This report continues our survey of the Soviet effort in underground coal gasification and summarizes the research conducted at Lisichansk from 1948 to 1963. This facility was operated primarily as an experimental-industrial station, and techniques for in situ coal gasification were developed and improved during this period. The stream method of gasification, which required mined shafts, was investigated first. By the late 1950's, improvements in methods and equipment enabled the Soviets to recover coal reserves at Lisichansk efficiently without using underground labor to create the necessary channels. This report discusses the geological, hydrological, chemical, technological, and economic factors affecting the construction, process optimization, operation, and maintenance of in situ gas generators. The available data for individual generators operated at Lisichansk during this period are also presented.

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Two-dimensional thermodynamic model (second stage) of in situ underground coal gasification of eastern thin-seam coals

The methodology and results of determining cavity growth via a side wall burn model in underground coal gasification (UCG) in Eastern, swelling coals is presented. Modeling techniques are still in preliminary stages but when perfected will aid in determining the feasibility of a particular site, dictate the design of the multi-well field pattern, and help control the product gas composition and cavity geometry during production. The computerized models generate a three-dimensional cavity based on the flow geometry and a two-dimensional boundary layer approach. The controlling mechanism for combustion is the diffusion of oxygen to the wall reaction zone. Specific results are presented for a simple, chemical energy balance Model IIA with specified wall and gas temperatures. Product gas composition and heating values are given, as well as reasonably good cavity comparisons with field tests at Hanna II, phase 2 in western, shrinking coals and predictions for the Pricetown I burn. Factors affecting the allowable flow rate schedule are found to be the cavity geometry, the oxygen diffusion rate to the reaction zone, and the remaining link zone flow resistance. Quantitative results are presented for Pricetown I. The complex wall-gas energy balance Models IIB and IIC are discussed in detail. The models include heat convection between wall and gas, radiation between walls (optically-thin gas case), and conduction into the wall, as well as the chemical energy transfers. Applications of the model include the Hanna II, phase 2 field test and predictions for the Pricetown I field test. Results from the models with various boundary conditions are compared in an attempt to identify viable mechanisms. The lack of sufficient field test data and the minor effect of the various boundary conditions precludes any definitive conclusion at this time. 45 references.

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Ignition and combustion behavior of spent shale particles

This study examines the ignition and burning of chars left after pyrolysis of 5-cm dia. oil shale samples. The experiments modeled in-situ retorting by minimizing radiation. The effects of shale grade (from 83 to 183 liter/tonne), retorting temperature (600 to 756 K), and combustion gas composition (5 to 21% O/sub 2/) were examined. This study confirms the important role of gasification of the char by CO/sub 2/ released from decomposition of carbonate minerals and explores the transition to that mechanism from the initial direct attach of O/sub 2/ on char. This transition is normally encountered in combustion of chars produced from rich shales. The role of CO combustion within the rock matrix is also considered. The model is presented which successfully predicts the temperature histories and conversions of the spent shales, as well as the change from the direct oxidation mechanism to the gasification mechanism described above.

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Process and apparatus to produce synthetic crude oil from tar sands

A process and apparatus for producing synthetic crude oil from bitumen-bearing sands is described. The apparatus includes a vessel segregated into a pyrolysis zone and a combustion zone, each zone being in the form of a fluidized bed reactor. At least one heat pipe is provided for transferring thermal energy from the combustion zone to the pyrolysis zone where the thermal energy is used to pyrolyze the bitumen. The apparatus may also include additional heat exchange equipment for heating the incoming combustion air for the combustion zone. The combustion air serves as the fluidizing medium for the fluidized bed reactor of the combustion zone while flue gases from the combustion zone serve as the fluidizing medium for the fluidized bed reactor of the pyrolysis zone.

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Oxygen functional groups in Green River oil shale kerogen and trona acids

Carboxyl, ester, amide, hydroxyl, aldehyde, and ketone groups were estimated for oil-shale kerogen and kerogen-derived trona acids from the Green River Formation. Ether groups were estimated by difference. Carboxyl, ester, and ether groups were found to account for the major portion of the oxygen in both the kerogen and trona acid samples. Minor amounts of amide, hydroxyl, aldehyde, and ketone groups were indicated. The reactive oxygen groups, carboxyl and ester, account for about one-half of the total oxygen in kerogen and two-thirds of the total oxygen in trona acids while the unreactive ether group accounts for the other half of the total oxygen in kerogen and one-third of the total oxygen in trona acids.

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Analysis of preburn three-dimensional flow patterns in underground coal conversion

A three-dimensional numerical study was performed to better elucidate the rather complex flow patterns that can occur during the bed preparation stage of underground coal gasification when the linked vertical well method is applied. This study shows the important effects of the 3-D geometry, gravity, anisotropy, pressure dependent permeability, and dynamic two phase air/water flow. For the first time the dynamic, 3-D growth of the air bubble (i.e., the dewatered region) is studied under simulated field conditions for western subbituminous coal. Interpretation of the 3-D flow and tracer patterns is an important element in an effective site characterization program. The numerical code used in these studies, WAFE3D, was developed at Los Alamos National Laboratory to compute multiphase, multicomponent mass and heat transport in porous/fractured geological media. The code solves the time dependent 3-D conservation equations for mass, momentum, and energy using an integrated finite difference implicit numerical scheme.

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Numerical model of massive hydraulic fracture. Final report. [SYMFRAC1]

This project has involved development of a hydraulic fracture simulator which calculates fracture height as a function of distance from the wellbore in a situation in which a payzone is bounded by two zones in which the minimum in-situ stress is higher (the fracture is vertical). The fracture must be highly elongated (length/height ratio approximately greater than 4) and variations in elastic modulus across zones are ignored. First, we describe the leakoff and spurt loss calculations employed in the modeling. Second, we discuss a revised version of the vertically symmetric simulator (bounding zone stresses equal). The addition of non-Newtonian flow and leakoff (including spurt loss) is described in detail. An illustrative result is given. Third, we describe in detail the vertically asymmetric simulator (bounding zone stresses not equal). To illustrate the last results, we present design calculations for a 30,000 gallon fracture, which was the first stimulation in the Multi-Well Experiment. The 80 ft fracture interval in the Paludal zone has at its upper edge a 520 psi stress contrast, and at its lower edge a 1195 psi contrast. Computed fracture height growth above and below the perforated interval, bottomhole pressure, and width profiles in vertical sections are displayed. Comparison is made with diagnostic measurements of fracture length, height, and bottomhole pressure. The appropriate computer codes are included in this report. 21 references, 11 figures, 4 tables.

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In-situ coal gasification of bituminous coals-A:  development plan

There are in excess of one trillion tons of bituminous coal resources in the United States mostly concentrated in the Appalachian, Illinois and Western Interior Basins. Approximately 220 billion tons of this bituminous resource, which is comparable to the estimated mineable reserves, can be recovered by Underground Coal Gasification (UCG). A technology that would provide for the economic production of gasoline and SNG in the eastern, high energy use markets would provide an essentially new energy source to these markets. The high rank, thin seam, bituminous coals therefore provide an effective target for the development of an economically viable technology for resource recovery. The only recent field test in these thin-seamed, high rank coals was the Pricetown I Field Test performed at Pricetown, West Viriginia. This test demonstrated the feasibility of gasifying deep (approx. 900 feet), thin seam (approx. 8 feet), swelling bituminous coals. This test provided a 72% energy recovery by utilizing only air injection. While the test was successful in meeting all of its objectives, it was only the first step in the development of eastern UCG technology. The data obtained from the test can be used to develop an effective plan which can lead to a commercial demonstration and subsequently, commercial acceptance of this technology for bituminous coals by the 1990's.

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Effect of steam on H/sub 2/, CO/sub 2/, H/sub 2/S, CO, and COS concentrations in combustion-retort offgas

The effect of steam on the offgas composition of combustion retorts was determined by interrupting the otherwise continous steam flow in -24 for one hour while other variable, including temperature, remained relatively constant. The offgas composition was determined by frequent gas analyses. zThe largest effect of interrupting the steam flow was to decrease the rate of H2 production by a factor of 2.6 primarily due to to elimination of the H2O char reaction. The rate of CO2 production decreased by a factor of 1.7. After subtracting the CO2 production due to carbon combustion, this result implies that steam accelerates the rate of carbonate decomposition by a factor 3.0. In the aosence of staem, the H2S production rate dropped by a factor of 1.5, indicating the importance of steam-iron sulfide reactions. Finally, the production rate of CO and COS increased by factors of 1.5 and 1.7. these results are compared to results from laboratory studies of oil shale chemistry and to gas production during other parts of this and other LLNL pilot retorts runs. Finally, the ability of steam to significantly decrease the pour pint of shale oil from combustionr etorts is noted.

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Air pollution and the London fog of December 1952

Four thousand deaths were attributed to this London pollution incident lasting 4 to 5 days. Maximum smoke concentrations in area was 4.46 mg/m/sup 3/ and 3 to 10 times normal at all stations. Maximum SO/sub 2/ concentration was 1.34 ppM and 3 to 12 times normal elsewhere. Ratio of the two avg 2.4 (range 1 to 4) and was remarkably constant. Peak death rate paralleled SO/sub 2/ and smoke levels but remained abnormally high for days after episode. Death rate was also higher than average before actual episode. Eighteen % of 200 million tons coal consumed is used in London for home heating (no pollution control equipment), and these domestic fires contribute 40% of smoke as a whole and 60% in winter. Stacks above fog banks would have little effect. SO/sub 2/ from combustion and CO are mainly from autos.

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Underground-coal-gasification technical summary

There are three basic reasons for the recent emergence of underground coal gasification (UCG) as a leading synfuels candidate: (1) favorable projected economics, (2) ability to use coal seams that are unattractive for mining, and (3) modest environmental impact. The objective of this paper is to list major underground coal gasification results and conclusions, particularly field-oriented results. The twenty field tests and ten years'experience have demonstrated technical feasibility and allow us to make several generalizations concerning underground coal gasification. For example, burns tend to be bowl-shaped after roof collapse, since ash and slag (and high water content in coal) impede downward burning. Burns appear to be symmetrical in plan view, but not in elevation view. Injection and linking at the bottom of the seam can improve performance. Heat losses begin, and heating value of the product gas declines, when the burn reaches the roof and the roof rock begins to collapse. In general, heating value and chemistry appear to be insensitive to operational parameters but are sensitive to process-well geometry and overburden.

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Podmoskovnaya underground coal-gasification station. [1946 to 1963]

This report continues our survey of the Soviet effort in underground coal gasification and summarizes research conducted at the Podmoskovnaya Station until its close in 1963. Techniques for in situ coal gasification without using underground labor to create the necessary channels were employed. Countercurrent combustion linking, electrolinking, hydraulic fracturing, and inclined-horizontal drilling were among the linking methods applied to the relatively flat seams of lignite found near Tula. By the late 1940s, improvements at the Podmoskovnaya Station enabled the Soviets to operate the facility primarily as a small industrial station. This report discusses the geological, hydrological, chemical, technological, and economic factors affecting construction, process optimization, operation, and maintenance of in situ generators. Available data for individual generators operated at the Podmoskovnaya Station are also presented. 59 figures, 59 tables.

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Stability aspects of the recovery of Navy distillate fuel from reclaimed product project

Stability data collected during the project on the recovery of Navy distillate fuel from reclaimed product are presented and analyzed. This includes the characterization of 20 waste diesel fuel samples and the samples generated during the process evaluation phase of the project. Analyses of the 20 waste diesel samples show that the stability of the waste diesel fuel cannot be successfully correlated with carbon residue, ash, metals, or heteroatom content. This reults from the variable nature of the contaminants in the waste fuel. The process evaluation phase included careful testing of sorbent treatment, chemical treatment, distillation, solvent extraction and hydrotreating. The analysis of the process evaluation phase samples shows that sorbent treatment with clay and distillation processes successfully upgrade the stability of the waste fuel. Specifically, sorbent treatment with a clay dramatically improved the stability of the waste fuel. Distillation also improved the stability. Chemical pretreatment was found not to affect stability. Hydrotreating could not be effectively evaluated independently because of a distillation pretreatment of the feed, which stabilized the fuel prior to hydrotreating. All the stability results generated indicate the compounds causing stability problems are heavy unsaturated, aromatic and/or heteroatom compounds. Because of the extremely good performance of clay, it is recommended that further research be conducted to see if clay might be used to bring a slightly off-specification fuels back into an acceptable range of stability. 6 refs., 16 tabs.

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Underground coal gasification:  status and proposed program

Technical uncertainties remaining in the UCG technology include specific criteria for site selection, large-scale burn interactions, details of process control, multiple well operation, overall system reliability, subsidence, and water quality effects. Considerable effort has been expended on understanding and controlling the process, on predicting and mitigating subsidence, and on maintaining water quality. Some data are available on site acceptability, but as yet information from large-scale field tests are not in the public domain. Commercialization of UCG will not be possible until such data become available. A program plan to commercialize UCG in an orderly, paced manner has been developed. The program would cost $200 million over seven years, some of which could be cost-shared with industry. The proposed program includes development of a more detailed program plan. The laboratory component of the program, although only a small fraction of the budget, is crucial. It contains environmental research, modeling, experimental studies, economic and system studies, instrumentation development, and materials studies. The field component includes UCG of both flat and steeply dipping coal beds as well as of less tractable bituminous coal. The field projects involve development of criteria for site selection and characterization, large block tests in bituminous coal, simple, small-scale field tests, subsequent more complex and longer-running tests, and finally large scale, or pilot tests. Steam-oxygen gasification would probably be used. 48 references, 11 figures, 6 tables.

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Occidental vertical modified in situ process for the recovery of oil from oil shale:  Phase I. Quarterly progress report, November 1, 1977--January 31, 1978

Work at the D.A. Shale site during this quarter involved mainly the completion of Retort 5 processing, and the mining, drilling, and engineering activities required in the preparation of Retort 6. At the C-b tract, work was begun on the clearance and the surface preparation of the shaft area and the mine support area. Also, site offices were established for the site clearance contractor, the surveying contractor, and the managing contractor. During the previous two months, bids for the sinking of four shafts on the tract were reviewed, and a contract was awarded in January. The collaring of the first shaft will commence on about February 15.

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Private sector involvement in underground coal gasification

There is considerable activity in the field of underground coal gasification: several projects are underway in addition to those sponsored by DOE. Basic Resources, Inc., a subsidiary of Texas Utilities Co., has licensed the Soviet technology and is developing underground gasification of lignites near Fairfield, Texas. The Atlantic Richfield Company has executed a successful field gasification test in a 100 ft thick subbituminous coal near Reno Junction, Wyoming. Texas A and M University is carrying out UCG tests in lignite under sponsorship of a consortium of companies. International UCG activities include a field test carried out by the Alberta Research Council near Edmonton, Alberta; further tests are planned. The Federal Republics of Germany and Belgium, with support from the Common Market, are initiating field work for underground gasification of deep (3000 ft) bituminous coal in Belgium. There has been both formal and informal cooperation between DOE and these independent projects which has been of benefit to both parties. To accelerate commercialization it is planned to conduct joint DOE/industry projects in low rank coal by teaming the in-house DOE laboratories with cost sharing industrial partners. A Program Opportunity Notice is planned to solicit the partners. Up to three field tests will be conducted in each of these joint projects, with the scale testing and industry's share of the cost increasing. The final test in each project will be a multisweep pilot operation which will represent the basis for commercial development of underground coal gasification.

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