AndreaBozzo/ceres-open-data-index huggingface dataset:
EXPERIMENT IN UNDERGROUND GASIFICATION OF COAL, GORGAS, ALA

"The Bureau of Mines and the Alabama. Power Co., jointly, conducted the first experiment undertaken in the United States in ,underground gasification of, coal in place, at Gorgas,,. Ala. Milton H. Fies, manager  of coal operations, Alabama Power Co., proposed the cooperative investigation to Arno C. Fieldner, chief, Fuels and Explosives Branch, Bureau of Mines, and assisted in supervising the experiment. The objectives of the experiment, were to determine whether coal in place could be burned successfully and whether the burning could be controlled; the effect of the fire on the coal bed and the overlying strata; and the yield and quality of gas that could be obtained."

Tags: kmd
PRELIMINARY REPORT ON ADSORPTION OF PB, CD, HG AND SE BY COAL

The distribution of Pb, Cd, Hg, and Se between a coal sample (72-56764) and local groundwater was measured by adding known amounts of the elements to an 8% (wt) suspension of the coal in artificial groundwater and measuring the amount of the element remaining in solution. Pb and Cd were very strongly adsorbed. Hg fairly strongly adsorbed and Se was not adsorbed at all. The experiments were complicated by the low solubility's of Pb and Cd in the groundwater.

Tags: kmd
THEORETICAL AND EXPERIMENTAL INVESTIGATIONS OF UNDERGROUND COAL GASIFICATION  Annual Report August 31, 1979 to August 31, 1980

"The main purpose of his annual report is to provide a brief  summary of the productivity and achievements of the program involved. The present format has been selected to illustrate these accomplishments. While it is difficult to assess research benefits, publications represent one of the best indicators and these are summarized next."

Tags: kmd
"THE ROLE OF FIELD AND LABORATORY DATA AND MATHEMATICAL  MODELS IN REDUCING THE UNCERTAINT Y OF ECONOMIC STUDIES"

"In order to complete an economic study of UCG, a preliminary design must be made for the process. The design and economic study both require the estimation of a considerable number of variables such as depth and thickness of the coal seam, well spacing, gas heating value and production rate, air injection requirements, well  spacing, percentage coal recovery, thermal efficiency of the process, and rate of advance of the gasification zone. Almost never will sufficient experimental data be available to determine all variables with confidence. Furthermore, not all of the variables cited are independent of each other. The purpose of this paper is to show how mathematical models and laboratory data can lead to a major reduction in uncertainties resulting from  assumptions associated with economic analyses of UCG. An economic analysis is used to illustrate this method.  Mathematical model calculations are used to establish the relationships between variables such as the gas heating value and thermal efficiency. The actual correlations  are developed from operating data from the Hanna field tests, but model calculations provide the theoretical explanation for the shape and sensitivity of the experimental curves. Model calculations also allow  confident interpolation and extrapolation of the experimental data. The end result is an economic analysis with improved accuracy and few assumptions. Finally, it is shown how economic studies can provide valuable feedback for an ongoing research program. Certain variables have yet to be fully determined such as maximum well spacing , probable gas leakage due to subsidence and long term average gas heating value. Economic studies show which of these variables have the greatest economic impact. Those variables with maximum impact should receive the greatest emphasis  in research."

Tags: kmd
BIOTREATMENT OF UCG WASTEWATER CONDENSATE

"The process of underground coal gasification (UCG) generates a wastewater stream during the cooling and processing of the product gas. The wastewater stream  is of large enough volume and contains a wide array of pollutants to pose a significant water pollution problem. The character of UCG condensate is similar to that produced by above-ground gasifiers although some differences are apparent. The treatment options studied during this laboratory experimental project were activated sludge treatment of raw condensate, activated sludge treatment of stripped condensate, and activated sludge with powdered activated carbon (PAC) addition for treatment of stripped condensate. The condensates used in the laboratory study were obtained from large-scale  field tests in Wyoming. Design and kinetic information for the various activated sludge options are presented along with detailed performance and kinetic data. Major variables among the treatment options were the amount of dilution water needed to achieve stable operation, the  degree of treatment achieved by each option, and the stability of the biological reactor."

Tags: kmd
MULTI-CHANNEL FORWARD COMBUSTION IN COAL OF VARIABLE DEGREE OF DEVOLATILIZATION FINAL REPORT AUGUST 5, 1982-DECEMBER 31, 1986

"A research program has been carried out to facilitate incorporation of rubble formation and burnout phenomena in mathematical modeling of the production stage of underground coal gasification (UCG). Forward combustion in single channels in coal has been investigated by a computer model. The state of the coal ranges from virgin coal to completely charred coal. Usefully rapid regression of a UCG cavity wall is brought about by a sequence of roof or sidewall collapses. An extensive theoretical analysis of collapse mechanisms has been performed. Failure mechanisms include failure due to strength loss, formation of cracks which intersect bedding planes, and moisture induced stresses. These competing mechanisms are unified in a comprehensive model. Cavity growth by permeate flow of hot reactive gases from the cavity through the natural fissure pattern in the coal has been analyzed. It is shown that this mechanism is too slow to be of practical significance unless the fissures are much more open than would be anticipated in realistic seams.  A cavity wall regression model has been developed and coded for application in a computer program for cavity system performance. This model synthesizes the comprehensive roof and wall collapse model with information describing thermal attack on the cavity wall and roof, obtained from a rubble consumption model."

Tags: kmd
PROBLEMS SOLVED AND PROBLEMS NOT SOLVED IN UCG

"Several different processes of UCG (Underground Coal Gasification) are being investigated in North America. Of these, the linked vertical well process, developed by the Laramie Energy Research Center, has been field tested most extensively and is closest to eventual  commercialization. There is, consequently, substantial participation in further field testing of the linked vertical well process or minor variations of it. Partial or complete industrial participation is involved in the field testing programs of the Alberta Research Council, Texas A~M University, and Texas Utilities. Problems, some solved and some not solved, which are associated with UCG are discussed in this work. Discussion of these problems outlines the current status of the linked vertical well process. The purpose is to provide perspective concerning what has been accomplished already and  what remains yet to be done on the road to  commercialization of UCG."

Tags: kmd
FUNDAMENTAL RESEARCH NEEDS IN UNDERGROUND COAL GASIFICATION

Before discussing basic research needs in UCG , we need to address a still more fundamental question. Does  the nation need a synfuel industry? The technical community in the energy field seems to agree almost universally that the nation does need such an industry. The prevailing opinion is that the United States is currently living in a "fool's paradise." Oil prices have dropped recently by as much a5 25% which is small compared to the 12 to 15 fold increase in cost since 1973 . A world wide  recession has produced a small surplus in the oil export market, but that recession resulted in part from the  rapid rise in the cost of energy. Economic recovery will quickly dry up the oil surplus. In the meantime, three  separate , simultaneous wars in the Middle- East underline the precarious political balance in that area which produces about 50% of the exported oil. In essence, current conditions have given us only little extra time to complete the mammoth undertaking of developing available syn fuels industry. A second question: Even if synfuels are needed, does the nation need an UCG industry? UCG probably offers economic and some environmental advantages. UCG may be the only viable method for recovering  coal energy from thick deep lying coal seams. But, for the near future, one advantage probably overrides all others. In times of national emergency, UCG can be developed more rapidly than any other synfuel industry. This fact may be important should the " fool's paradise" end too swiftly.

Tags: kmd
COALS AND COAL-BEARING ROCKS OF THE HANNA COAL FIELD,  WYOMING

Although most of the Hanna Coal Field of south-central Wyoming lies within Carbon County, a small portion extends eastward into Albany County as well (Figure 1). This coal-bearing area coincides with the Hanna and Carbon topographic and structural basins and is  considered part of the U.S. Geological Survey's Rocky Mountain Coal Province. As defined, however, the coal field is limited to those portions of the basins that are underlain by rocks of the Mesaverde Group. With this convention, all other coal-bearing rocks of the Hanna Coal Field occur within the outcrop of the Mesaverde since they all overlie that group. The boundary between this field and the Rock Creek Coal Field to the east is usually drawn to coincide with the alluvial deposits associated with Rock Creek.   Based on past and present mining activity, Glass and Roberts (1979)  defined four mining districts within the field the Hanna, Carbon, Seminoe, and Corral Creek districts. The boundaries of these districts are shown on Figure 2. Areas barren of near-surface coals serve to roughly delimit one district from another.

Tags: kmd
CREEP AND RELAXATION OF OIL SHALE

This paper presents results of a study on the creep and relaxation behavior of oil shale. The set of duplicates test specimens required for creep testing were cut from a single oil shale layer using a wire saw to avoid any surface damage. A rheological model was developed for creep and relaxation behavior of oil shale as a function of stress level and organic content. Data from creep testing together with-ray and Fischer assay analyses were used to demonstrate correlation between various areas levels and organic contents for samples of Wyoming Green River Formation

Tags: kmd
"COAL RESOURCES FOR  IN SITU GASIFICATION"

First it must be admitted that traditional resource and reserve estimates for the United States are somewhat inadequate for calculation of estimates.  They are inadequate because they emphasize the shallow and more conventially minable  resources rather than the deeper and less accessible resources to which in situ gasification will probably be directed.  A further complication is that the original resource estimates occur in many separate reports which often use differing coal thickness, and cover categories as well as different reliability codes.  For example, (1) many states do not even report their resources by depth of cover; (2) reported coal thickness categories vary between states;  (3) the maximum reported thicknesses are generally cut off at greater than 42 inches for bituminous coals and greater than 10 feet for lignite and subbituminous coals-- such thickness categories  do little for delimiting resources of thicker coals;  and (4) resource estimates, especially in the Rocky Mountains, are very conservative.  This is particularly true in regard to the resources greater than 1,000 feet in depth--depths quite within in situ capabilities.

Tags: kmd
"UNEXPECTED ASPECTS OF REVERSE COMBUSTION  EFFECTS OF PRESSURE , VOLATILITY , AND  CHEMICAL REACTIVITY"

"The Kotowski-Gunn one dimensional model is shown to be satisfied by two solutions , not one as previously  believed. Application of the Krantz-Gunn stability model indicates three modes of operation where sustained propagation of a link may be expected in the field. One  mode of operation on the new solution branch indicates that much shorter linking times than previously thought  possible may be achieved. This work also demonstrates the profound influence that pressure, coal volatile content and chemical reactivity have upon reverse combustion performance."

Tags: kmd
PALEOMAGNETIC AND ROCK MAGNETIC STUDIES ON UNALTERED AND ALTERED (BAKED AND FUSED) OVERBURDEN SEDIMENTS FROM THE HOE CREEK UNDERGROUND COAL CONVERSION SITE, HANNA BASIN, WYOMING

In early September, 1981, core from three drill holes (CH133, 2HP-173, and 2HP-174) was taken from Laramie to Golden for preparation of standard specimens (2.54x2.54 cm cylinders) for paleomagnetic measurements. The pieces of drill core were drilled perpendicular to their axis; with large pieces of core, several specimens were prepared (8-10 or more) from each piece. A breakdown of the number of cylinders  collected over specific drilling intervals from each hole is given in Table 1. In some instances, the core is so fragile or so poorly consolidated that standard drilling techniques did little to retrieve cylinders. In these cases, whole (small) portions of core were retained and cubical specimens prepared to fit into small, plastic boxes which could be measured directly. The burned material collected  from the Hoe Creek sites was simply bagged as coarse grit during the field drilling procedures. In these cases, a small vial (approx. 100 cc) of material was collected from each bag. CH133, the section cored prior to any underground gasification experiments, was sampled and is being studied in hopes of compiling a "standard" section of paleomagnetic and rock magnetic data to compare  with results from core taken from holes near the underground burns. Cores 2HP-173 and 2HP-174 were drilled, respectively, at the edge and directly above the Hanna II Phase 2 and 3 site. We anticipated that the data from these cores would exemplify the potential variations in magnetic properties as a function of proximity to a burn.

Tags: kmd
PYROLYSIS PROPERTIES OF TEXAS LIGNITE:  UNDER CONDITIONS OF IN SITU GASIFICATION

A study of the effect of certain operating variables upon the products of pyrolysis of Texas lignite has been undertaken to determine if changes in heating rate, carrier gas flow rate, and particle size can affect the yields and composition of pyrolysis products. Slow heating rates (e.g., 3°C/minute), such as occur during underground coal gasification, were used in all experiments. Data for the pyrolysis of a Milam County (Texas) lignite in an inert nitrogen atmosphere were taken from 25 C to a final char temperature of 900°C. These data showed that the carrier gas flow rate and particle size had very little effect upon the products obtained from pyrolysis of the sample. However, healing rate did have an effect. The average results are in good agreement with similar investigations by the U.S. Bureau of Mines.

Tags: kmd
APPLICATION OF REMANENT AND ROCK MAGNETIC PROPERTIES TO THERMAL ALTERATION OF OVERBURDEN AT THE HANNA, WYOMING SITE

Studies of the remanence and rock magnetic properties of host-rock Early Tertiary Hanna Formation at the Hanna II, Phases 2 and 3 underground coal gasification (UCG) experiment, Hanna, Wyoming, have determined the nature of the remanent magnetism of unaltered Hanna Formation and changes in the  remanence and magnetic mineralogy attending the UCG tests.  Core holes ZHP-174, located in the center of their burn cavity, contain intervals approximately 10 m thick immediately above the burn cavity in which the natural remnant magnetization (NRM) intensity (greater than 1.0 A/m), NRM dispersion (k values exceeding 1000), NRM mean inclination (very close to  69, the ambient field inclination during burning), initial susceptibility (greater than 1.0 x 10 4), and demagnetization properties (distributed blocking temperatures and moderate coercivity spectra, suggesting significant coarse magnetite) all are anomalous in comparison to the "background" properties of fresh Hanna Formation.  Post burn core holes located neat the edge of the burn cavity do not contain such intervals of anomalous magnetization properties.   As well, Hanna Formation beneath the burn cavity is not remagnetized.  The origin of the remagnetized zone is due to the production of I-5 volume percent secondary magnetite from detrital ferromagnetism silicates and possibly hematite.  Thermal demagnetization experiments on fresh Hanna Formation show that magnetite production occurs in air at temperatures above about 300 C.  The magnetic data have significant application toward better understanding UCG experiments and attending thermal anomalies. Thermal perturbations on surrounding Hanna Formation units must have been funneled vertically upward form the center of the burn cavity, not radically away from it.  Assuming that magnetite production is solely temperature dependent, the thermal gradient above the burn cavity is estimated to be approximately 700 /m.

Tags: kmd
A MODEL OF WATER INFLUX FOR UNDERGROUND COAL GASIFICATION

"Underground coal gasification (UCG) is a promising way to recover the energy content of one of the United States'most abundant resources. Water influx is a very  important factor affecting the UCG process. Little has  been achieved to date in identifying, understanding, and  modeling water influx. Three principal mechanisms of water influx are identified, described, and modeled in this thesis, in the context of the forward-burn phase of a horizontal-seam, linked vertical Hell UCG process. These components are linked to a cavity-growth model to create a comprehensive, predictive, water-influx model."

Tags: kmd
NUMERICAL MODELING OF GROUNDWATER FLOW AND WATER QUALITY AT UNDERGROUND COAL GASIFICATION SITES FINAL REPORT

"The model presented in this report simulates two-dimensional water quality in a multi-aquifer system with coal gasification sites. It's a finite element program which uses isoparametric eight-noded quadrilateral elements. It is designed to study the effects of cavities created after  burning in coal gasification sites. The accuracy of the program has been verified against several analytic solutions. The program is now ready to be applied to field problems."

Tags: kmd
COMBUSTION PROCESSES IN IN SITU COAL GASIFICATION:  PHENOMENA, CONCEPTUAL MODELS AND RESEARCH STATUS PART I-OVERVIEW AND CONTINUUM WAVE DESCRIPTIONS

"This two-part paper categorizes combustion problems of in situ coal gasification, reviews research progress to date, and suggests directions for future work. Permeation as opposed to borehole concepts are emphasized. The  present manuscript, part I, consists of an overview and a presentation of continuum wave descriptions of reverse and forward combustion. A fully analytic, albeit simplified, treatment of wave propagation rate and salient structure  characteristics is set forth. The main features of previously published numerical models are retained and quantitatively predictable. In Part II, to appear later, a number of hitherto uninvestigated topics will be examined. wave structure results derived from Part I will facilitate  examination of limits of validity of continuum wave theory. Coal face burning transverse to the gas flux vector, rubblization of burning out coal and other phenomena which control the time evolution of in situ gasification systems will also be covered."

Tags: kmd
"Status of the Linked Vertical Well Process in Underground  Coal Gasification"

The Linked Vertical Well (LVW) process, which employs reverse combustion as a preparatory step to forward combustion gasification, will be described from both a practical and theoretical viewpoint. Fifty years of underground coal gasification experimentation has shown that , prior to efficient gasification, a "linkage" between injection and production boreholes must be prepared.  The LERC experimentation has concentrated on the characterization and the development of reverse  combustion linking such that it has become a predictable means of process control . The results of eight different reverse combustion links at Hanna indicate that subbituminous coal is ideally suited to reverse combustion linkage both from a controllability standpoint and the quantity of air needed to complete a linkage. Following reverse combustion linking forward gasification ensues. Eight different well to well gasification periods have been completed since initiation of tests at Hanna. A detailed chemical and physical description of the recent results from Hanna II will be given. This latter experiment  resulted in the gasification of 6690 tons (6070 tons) of coal and production of up to 12 MM scmd (0.36 MM scmd) of 175 Btu/scf (6.2 megajoules/scm) gas. Their reasons for these improved process results will be discussed in detail.

Tags: kmd
"REVERSE COMBUSTION ALONG A BOREHOLE IN A SHRINKING COAL  PRELIMINARY RESULTS"

"Reverse combustion along a bored hole (76 mm  diameter) will be used during Lawrence Livermore Laboratory's next field experiment in underground  coal gasification: Hoe Creek III. The enlarged channel produced by the reverse combustion will allow high gas velocities for the forward combustion phase of gasification.  In the present experiments , reverse combustion along smaller boreholes (6.35 and 12 .7 mm diameter) was investigated in coal blocks which were 0.5 m in diameter and 0.9 m long. In these experiments reverse combustion did not propagate with air as the feed as . Three air velocities (14, 27, and 32 m/s) were tried in the 6. 35 mm borehole and two velocities (7.5 and 21 m/s) were tried in the 12.7 mm borehole . All experiments were conducted at atmospheric pressure. Reverse combustion did propagate when the feed gas oxygen content was  increased to 32%. Rates up to 14 m/ day were found with an inlet gas velocity of 27 m/s. Product gas compositions are reported and discussed."

Tags: kmd
IN SITU COMBUSTION OF COAL FOR ENERGY

"A couple of efficient thermal energy generation through the in-situ combustion of coal , and the on-site conversion of that energy to electricity is discussed and shown to offer distinct advantages in the utilization of our coal reserves. Analysis of data from previous underground coal gasification projects indicates that coal can be completely burned underground and that the burning  process should be maintainable for time periods sufficient to power an electricity generation plant on a commercial level. A discussion is presented related to the  requirements of a 100 Megawatt (thermal) demonstration in-situ combustor, and some of the important problem areas that have to be resolved prior to implementation of the concept."

Tags: kmd
STRUCTURAL AND FRACTURE MECHANICS MODELING ASSOCIATED WITH UNDERGROUND COAL CONVERSION FOR THE PERIOD APRIL 1, 1980-MARCH 31, 1981

"This report presents model formulations and governing equations for the investigation of the thermo-mechanical and consolidation responses associated with UCC. Results from selected two and three dimensional finite element models are presented along with comparisons. Examples  include the simulation of temperature, stress,  consolidation and fracture responses. Supplementary information is provided in the appendices. In  addition, the application of the developed model to field experiments is demonstrated by simulation of sample problems. Progressive roof failure criteria and moving boundary conditions are incorporated in these numerical experiments."

Tags: kmd