skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals-Phase I

Abstract

The Advanced Hydrogasification Process (AHP)--conversion of coal to methane--is being developed through NETL with a DOE Grant and has successfully completed its first phase of development. The results so far are encouraging and have led to commitment by DOE/NETL to begin a second phase--bench scale reactor vessel testing, expanded engineering analysis and economic perspective review. During the next decade new means of generating electricity, and other forms of energy, will be introduced. The members of the AHP Team envision a need for expanded sources of natural gas or substitutes for natural gas, to fuel power generating plants. The initial work the team has completed on a process to use hydrogen to convert coal to methane (pipeline ready gas) shows promising potential. The Team has intentionally slanted its efforts toward the needs of US electric utilities, particularly on fuels that can be used near urban centers where the greatest need for new electric generation is found. The process, as it has evolved, would produce methane from coal by adding hydrogen. The process appears to be efficient using western coals for conversion to a highly sought after fuel with significantly reduced CO{sub 2} emissions. Utilities have a natural interest in the preservationmore » of their industry, which will require a dramatic reduction in stack emissions and an increase in sustainable technologies. Utilities tend to rank long-term stable supplies of fuel higher than most industries and are willing to trade some ratio of cost for stability. The need for sustainability, stability and environmentally compatible production are key drivers in the formation and progression of the AHP development. In Phase II, the team will add a focus on water conservation to determine how the basic gasification process can be best integrated with all the plant components to minimize water consumption during SNG production. The process allows for several CO{sub 2} reduction options including consumption of the CO{sub 2} in the original process as converted to methane. The process could under another option avoid emissions following the conversion to SNG through an adjunct algae conversion process. The algae would then be converted to fuels or other products. An additional application of the algae process at the end use natural gas fired plant could further reduce emissions. The APS team fully recognizes the competition facing the process from natural gas and imported liquid natural gas. While we expect those resources to set the price for methane in the near-term, the team's work to date indicates that the AHP process can be commercially competitive, with the added benefit of assuring long-term energy supplies from North American resources. Conversion of coal to a more readily transportable fuel that can be employed near load centers with an overall reduction of greenhouses gases is edging closer to reality.« less

Authors:
Publication Date:
Research Org.:
Arizona Public Service Company
Sponsoring Org.:
USDOE
OSTI Identifier:
940179
DOE Contract Number:
FC26-06NT42759
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
03 NATURAL GAS; 01 COAL, LIGNITE, AND PEAT; 08 HYDROGEN; 29 ENERGY PLANNING, POLICY AND ECONOMY; ALGAE; COAL; ELECTRIC POWER; ELECTRIC UTILITIES; ELECTRICITY; ENERGY SUPPLIES; GASIFICATION; GREENHOUSE GASES; HYDROGEN; METHANE; NATURAL GAS; PRICES; PRODUCTION; REACTOR VESSELS; STABILITY; TESTING; WATER

Citation Formats

Raymond Hobbs. Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals-Phase I. United States: N. p., 2007. Web. doi:10.2172/940179.
Raymond Hobbs. Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals-Phase I. United States. doi:10.2172/940179.
Raymond Hobbs. Thu . "Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals-Phase I". United States. doi:10.2172/940179. https://www.osti.gov/servlets/purl/940179.
@article{osti_940179,
title = {Development of a Hydrogasification Process for Co-Production of Substitute Natural Gas (SNG) and Electric Power from Western Coals-Phase I},
author = {Raymond Hobbs},
abstractNote = {The Advanced Hydrogasification Process (AHP)--conversion of coal to methane--is being developed through NETL with a DOE Grant and has successfully completed its first phase of development. The results so far are encouraging and have led to commitment by DOE/NETL to begin a second phase--bench scale reactor vessel testing, expanded engineering analysis and economic perspective review. During the next decade new means of generating electricity, and other forms of energy, will be introduced. The members of the AHP Team envision a need for expanded sources of natural gas or substitutes for natural gas, to fuel power generating plants. The initial work the team has completed on a process to use hydrogen to convert coal to methane (pipeline ready gas) shows promising potential. The Team has intentionally slanted its efforts toward the needs of US electric utilities, particularly on fuels that can be used near urban centers where the greatest need for new electric generation is found. The process, as it has evolved, would produce methane from coal by adding hydrogen. The process appears to be efficient using western coals for conversion to a highly sought after fuel with significantly reduced CO{sub 2} emissions. Utilities have a natural interest in the preservation of their industry, which will require a dramatic reduction in stack emissions and an increase in sustainable technologies. Utilities tend to rank long-term stable supplies of fuel higher than most industries and are willing to trade some ratio of cost for stability. The need for sustainability, stability and environmentally compatible production are key drivers in the formation and progression of the AHP development. In Phase II, the team will add a focus on water conservation to determine how the basic gasification process can be best integrated with all the plant components to minimize water consumption during SNG production. The process allows for several CO{sub 2} reduction options including consumption of the CO{sub 2} in the original process as converted to methane. The process could under another option avoid emissions following the conversion to SNG through an adjunct algae conversion process. The algae would then be converted to fuels or other products. An additional application of the algae process at the end use natural gas fired plant could further reduce emissions. The APS team fully recognizes the competition facing the process from natural gas and imported liquid natural gas. While we expect those resources to set the price for methane in the near-term, the team's work to date indicates that the AHP process can be commercially competitive, with the added benefit of assuring long-term energy supplies from North American resources. Conversion of coal to a more readily transportable fuel that can be employed near load centers with an overall reduction of greenhouses gases is edging closer to reality.},
doi = {10.2172/940179},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu May 31 00:00:00 EDT 2007},
month = {Thu May 31 00:00:00 EDT 2007}
}

Technical Report:

Save / Share:
  • This report presents the results of the research and development conducted on an Advanced Hydrogasification Process (AHP) conceived and developed by Arizona Public Service Company (APS) under U.S. Department of Energy (DOE) contract: DE-FC26-06NT42759 for Substitute Natural Gas (SNG) production from western coal. A double-wall (i.e., a hydrogasification contained within a pressure shell) down-flow hydrogasification reactor was designed, engineered, constructed, commissioned and operated by APS, Phoenix, AZ. The reactor is ASME-certified under Section VIII with a rating of 1150 pounds per square inch gage (psig) maximum allowable working pressure at 1950 degrees Fahrenheit (°F). The reaction zone had a 1.75more » inch inner diameter and 13 feet length. The initial testing of a sub-bituminous coal demonstrated ~ 50% carbon conversion and ~10% methane yield in the product gas under 1625°F, 1000 psig pressure, with a 11 seconds (s) residence time, and 0.4 hydrogen-to-coal mass ratio. Liquid by-products mainly contained Benzene, Toluene, Xylene (BTX) and tar. Char collected from the bottom of the reactor had 9000-British thermal units per pound (Btu/lb) heating value. A three-dimensional (3D) computational fluid dynamic model simulation of the hydrodynamics around the reactor head was utilized to design the nozzles for injecting the hydrogen into the gasifier to optimize gas-solid mixing to achieve improved carbon conversion. The report also presents the evaluation of using algae for carbon dioxide (CO 2) management and biofuel production. Nannochloropsis, Selenastrum and Scenedesmus were determined to be the best algae strains for the project purpose and were studied in an outdoor system which included a 6-meter (6M) radius cultivator with a total surface area of 113 square meters (m 2) and a total culture volume between 10,000 to 15,000 liters (L); a CO 2 on-demand feeding system; an on-line data collection system for temperature, pH, Photosynthetically Activate Radiation (PAR) and dissolved oxygen (DO); and a ~2 gallons per minute (gpm) algae culture dewatering system. Among the three algae strains, Scenedesmus showed the most tolerance to temperature and irradiance conditions in Phoenix and the best self-settling characteristics. Experimental findings and operational strategies determined through these tests guided the operation of the algae cultivation system for the scale-up study. Effect of power plant flue gas, especially heavy metals, on algae growth and biomass adsorption were evaluated as well.« less
  • KRW conducted investigations of calcium-promoted coal pyrolysis and gasification by means of bench-scale studies and an oxygen-blown PDU test. Results were used in a design study of a commercial KRW gasifier-desulfurizer, operating on Pittsburgh No. 8 coal and limestone for production of SNG. Bench-scale fluid-bed reactor studies were conducted with various fluidizing gases at temperatures and pressures of 1650 to 1950 F and 40 to 450 psig, with and without limestone, to give methane-yield and tar-yield data. The gasification kinetics studies of chars produced gave data which showed that limestone increases char reactivity and exerts a catalytic effect. Methane yieldsmore » correlated exponentially to pressure. The bench-scale test results lead to an expectation that feeding some of the coal to the upper portion of the gasifier will increase methane yield and decrease oxygen consumption. In two PDU test-set points, expected operability and performance of the oxygen-blown gasifier-desulfurizer were confirmed. In Set Point 2, in-bed desulfurization efficiency was 88% and the product-gas higher heating value was 302 Btu/scf. The test results provided inputs to the design study of a KRW gasifier-desulfurizer island for production of 125 MM Btu/day of SNG. Results included a 4 to 6% improvement in feedstock inputs when compared to an earlier GRI-sponsored study. Methane yield decreased but the number of operating gasifier-desulfurizers remained at five. Equipment costs are expected to remain well within the previous + or - 25% cost estimate.« less
  • A first-pass design and cost estimate indicates that the levelized constant-dollar cost of gas for a 125 billion Btu/day plant to convert western subbituminous coal to substitute natural gas (SNG) using KRW gasifiers is $4.70/MMBtu. Process development allowances (PDA) increase the gas cost to $5.09/MMBtu. The levelized constant-dollar gas cost for a scaled-up 250 billion Btu/day plant is estimated at $4.17/MMBtu, indicating that smaller plants can be constructed with less capital risk while producing methane at only slightly higher costs.
  • A design and cost estimate was prepared for a 250 billion Btu/day lignite-to-SNG plant that uses Lurgi dry-bottom gasifiers to gasify lignite and the Texaco Partial Oxidation (POX) process to gasify the various hydrocarbon liquids produced by the Lurgi process. Also presented are plant performance and economic comparisons between this plant design and a Base Case design prepared previously in which the Lurgi by-product liquids are burned in boilers and superheaters for steam production. The cost-of-gas for the Study Case is approximately 1.5% higher than the cost-of-gas for the Base Case. It is slightly more economical to burn Lurgi liquidsmore » than to gasify them in an auxiliary unit, primarily because if liquids are gasified, additional coal-fired boilers are required for generation of process steam and these are substantially more expensive than boilers fired with liquid fuel.« less