15 research outputs found
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PRODUCTION OF FOAMS, FIBERS AND PITCHES USING A COAL EXTRACTION PROCESS
This Department of Energy National Energy Technology Laboratory sponsored project developed processes for converting coal feedstocks to carbon products, including coal-derived pitch, coke foams and fibers based on solvent extraction processes. A key technology is the use of hydrogenation accomplished at elevated temperatures and pressures to obtain a synthetic coal pitch. Hydrogenation, or partial direct liquefaction of coal, is used to modify the properties of raw coal such that a molten synthetic pitch can be obtained. The amount of hydrogen required to produce a synthetic pitch is about an order of magnitude less than the amount required to produce synthetic crude oil. Hence the conditions for synthetic pitch production consume very little hydrogen and can be accomplished at substantially lower pressure. In the molten state, hot filtration or centrifugation can be used to separate dissolved coal chemicals from mineral matter and insolubles (inertinite), resulting in the production of a purified hydrocarbon pitch. Alternatively, if hydrogenation is not used, aromatic hydrocarbon liquids appropriate for use as precursors to carbon products can obtained by dissolving coal in a solvent. As in the case for partial direct liquefaction pitches, undissolved coal is removed via hot filtration or centrifugation. Excess solvent is boiled off and recovered. The resultant solid material, referred to as Solvent Extracted Carbon Ore or SECO, has been used successfully to produce artificial graphite and carbon foam
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Development of Continuous Solvent Extraction Processes For Coal Derived Carbon Products
In this reporting period, tonnage quantities of coal extract were produced but solid separation was not accomplished in a timely manner. It became clear that the originally selected filtration process would not be effective enough for a serious commercial process. Accordingly, centrifugation was investigated as a superior means for removing solids from the extract. Results show acceptable performance. Petrographic analysis of filtered solids was carried out by R and D Carbon Petrography under the auspices of Koppers and consultant Ken Krupinski. The general conclusion is that the material appears to be amenable to centrifugation. Filtered solids shows a substantial pitch component as well as some mesophase, resulting in increased viscosity. This is likely a contributing reason for the difficulty in filtering the material. Cost estimates were made for the hydotreatment and digestion reactors that would be needed for a 20,000 ton per year demonstration plants, with the aid of ChemTech Inc. The estimates show that the costs of scaling up the existing tank reactors are acceptable. However, a strong recommendation was made to consider pipe reactors, which are thought to be more cost effective and potentially higher performance in large scale systems. The alternate feedstocks for coke and carbon products were used to fabricate carbon electrodes as described in the last quarterly report. Gregory Hackett successfully defended his MS Thesis on the use of these electrodes in Direct Carbon Fuel Cell (DCFC), which is excerpted in Section 2.4 of this quarterly report
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DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, coking and composite fabrication continued using coal-derived samples. These samples were tested in direct carbon fuel cells. Methodology was refined for determining the aromatic character of hydro treated liquid, based on Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR). Tests at GrafTech International showed that binder pitches produced using the WVU solvent extraction protocol can result in acceptable graphite electrodes for use in arc furnaces. These tests were made at the pilot scale
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Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products Quarterly Report
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. The Hydrotreatment Facility is being prepared for trials with coal liquids. Raw coal tar distillate trials have been carried out by heating coal tar in the holding tank in the Hydrotreatment Facility. The liquids are centrifuged to warm the system up in preparation for the coal liquids. The coal tar distillate is then recycled to keep the centrifuge hot. In this way, the product has been distilled such that a softening point of approximately 110 C is reached. Then an ash test is conducted
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PRODUCTION OF CARBON PRODUCTS USING A COAL EXTRACTION PROCESS
The purpose of this DOE-funded effort is to develop technologies for carbon products from coal-derived feed-stocks. Carbon products can include precursor materials such as solvent extracted carbon ore (SECO) and synthetic pitch (Synpitch). In addition, derived products include carbon composites, fibers, foams and others
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Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products Quarterly Report
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. There are a number of parameters which are important for the production of acceptable cokes, including purity, structure, density, electrical resistivity, thermal conductivity etc. From the standpoint of a manufacturer of graphite electrodes such as GrafTech, one of the most important parameters is coefficient of thermal expansion (CTE). Because GrafTech material is usually fully graphitized (i.e., heat treated at 3100 C), very high purity is automatically achieved. The degree of graphitization controls properties such as CTE, electrical resistivity, thermal conductivity, and density. Thus it is usually possible to correlate these properties using a single parameter. CTE has proven to be a useful index for the quality of coke. Pure graphite actually has a slightly negative coefficient of thermal expansion, whereas more disordered carbon has a positive coefficient
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Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products Quarterly Report
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. A process has been developed which results in high quality binder pitch suitable for use in graphite electrodes or carbon anodes. A detailed description of the protocol is given by Clendenin. Briefly, aromatic heavy oils are hydro-treated under mild conditions in order to increase their ability to dissolve coal. An example of an aromatic heavy oil is Koppers Carbon Black Base (CBB) oil. CBB oil has been found to be an effective solvent and acceptably low cost (i.e., significantly below the market price for binder pitch, or about $280 per ton at the time of this writing). It is also possible to use solvents derived from hydrotreated coal and avoid reliance on coke oven recovery products completely if so desired
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Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products Quarterly Report
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the facility modifications for continuous hydrotreating, as well as developing improved protocols for producing synthetic pitches
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DEVELOPMENT OF CONTINUOUS SOLVENT EXTRACTION PROCESSES FOR COAL DERIVED CARBON PRODUCTS
This NETL sponsored effort seeks to develop continuous technologies for the production of carbon products, which may be thought of as the heavier products currently produced from refining of crude petroleum and coal tars obtained from metallurgical grade coke ovens. This effort took binder grade pitch, produced from liquefaction of West Virginia bituminous grade coal, all the way to commercial demonstration in a state of the art arc furnace. Other products, such as crude oil, anode grade coke and metallurgical grade coke were demonstrated successfully at the bench scale. The technology developed herein diverged from the previous state of the art in direct liquefaction (also referred to as the Bergius process), in two major respects. First, direct liquefaction was accomplished with less than a percent of hydrogen per unit mass of product, or about 3 pound per barrel or less. By contrast, other variants of the Bergius process require the use of 15 pounds or more of hydrogen per barrel, resulting in an inherent materials cost. Second, the conventional Bergius process requires high pressure, in the range of 1500 psig to 3000 psig. The WVU process variant has been carried out at pressures below 400 psig, a significant difference. Thanks mainly to DOE sponsorship, the WVU process has been licensed to a Canadian Company, Quantex Energy Inc, with a commercial demonstration unit plant scheduled to be erected in 2011
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Development of Continuous Solvent Extraction Processes for Coal Derived Carbon Products Quarterly Report
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. The largest applications are those which support metals smelting, such as anodes for aluminum smelting and electrodes for arc furnaces. Other carbon products include materials used in creating fuels for the Direct Carbon Fuel Cell, and porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, hydrotreatment of solvent was completed in preparation for pitch fabrication for graphite electrodes. Coal digestion has lagged but is expected to be complete by next quarter. Studies are reported on coal dissolution, pitch production, foam synthesis using physical blowing agents, and alternate coking techniques