Boiler fuel production

The volatiles contents of product chars decreased from ca 25—16% with temperature. Char (lower) heating values, on the other hand, increased from ca 26.75 MJ /kg (11,500 Btu/lb) to 29.5 MJ /kg (12,700 Btu/lb) with temperature. Chars in this range of heating values are suitable for boiler fuel apphcation and the low sulfur content (about equal to that of the starting coal) permits direct combustion. These char products, however, are pyrophoric and require special handling in storage and transportation systems. 

B. K. Schmid and W. C. Bull, "Production of Ashless, Low-Sulfiir Boiler Fuels From Coal," paper presented at ACS Division of Fuel Chem. Symposium on Pollution Control, New York, Sept. 12, 1971. 

The overall yield of the process is at least 87 mol %, and 2.3 mol of methanol per mole of final product are needed, an excess of 15% over the 2.0 theoretical amount. The methanol can be recycled from the manufacture of poly(ethylene terephthalate). Reported utilities consumptions per kilogram of product are 1.2 kg of 1400-kPa steam, 420 kj of boiler fuel, and 0.5 kWh of electricity (72). 

In the SRC work, coal was slurried with a process-derived anthracene oil and heated to 400—455°C at 12.4—13.8 MPa (1800—2000 psi) of hydrogen for 0—1 h. A viscous Hquid was extracted. The product stream contains some hydrocarbon gases, and H2S. The residue is gasified to generate hydrogen for the process. The remaining filtrate is separated into solvent, which is recycled, and SRC, a low ash, tadike boiler fuel. 

Heating value of the product (SRC) is ca 37 MJ/kg (16,000 Btu/lb). Sulfur contents have been reduced from 2—7% initially to 0.9% and possibly less. Ash contents have been reduced from 8—20% to 0.17% (102). These properties permit compliance with EPA requirements for SO2 and particulate emissions. The SRC is primarily intended to be used as a boiler fuel in either a soHd or molten form (heated to ca 315°C). The soHd has a Hardgrove index of 150 (103). Boiler tests have been successfully carried out using a utiHty boiler. 

Hydrazine Tobacco plants, polymerization catalysts, pharmaceutical products, corrosion inhibitor in boiler water, propellant fuels Production of NO2... 

Fuel oil a general term applied to oil used for the production of power or heat. In a more restricted sense, it is applied to any petroleum product that is used as boiler fuel or in industrial furnaces. These oils are... 

The volatile products from the soaking drum enter the fractionator where the distillates are fractionated into desired product oil streams, including a heavy gas oil fraction. The cracked gas product is compressed and used as refinery fuel gas after sweetening. The cracked oil product after hydrotreating is used as fluid catalytic cracking or hydrocracker feedstock. The residuum is suitable for use as boiler fuel, road asphalt, binder for the coking industry, and as a feedstock for partial oxidation. 

Although the first major use of coal liquids will be as boiler fuels, it is clear that in order to make the largest impact on the U.S. liquid fuel demand, products from direct liquefaction have to be upgraded to quality liquid fuels for both transportation and home heating oil uses. The products coming from the all-distillate coal liquefaction processes such as H-Coal Syncrude, SRC-II and Donor Solvent, along with shale oil production will be candidates for use as refinery feedstock. 

Ethanol conversion facilities can readily be designed to use fuel sources other than oil or natural gas. Small-scale on farm plants can utilize corn stover as a boiler fuel, and larger plants can rely on coal as a boiler fuel to produce process steam. The ethanol production process can then be viewed as a means of converting lower grade energy forms, such as coal, distressed crops or solar energy, into premium transportation fuel. 

Environmental Effects of Ethanol Production. Production of ethanol could potentially produce two forms of air pollution the release of pollutants from the boiler used to produce process steam, and vaporization of ethanol during the production process. If crop residues or lower grade fuels such as coal (low sulfur) are used as boiler fuel, which is preferable from a net energy gain basis, the resulting pollutants may be controlled through use of flue gas stack scrubbers. The release of ethanol vapors at the plant site is not considered a major concern at this time. 

In small-scale farm production of ethanol a possible environmental impact could occur through removal of crop residues for use as a boiler fuel. Crop residues are important because they help control soil erosion through their cover and provide nutrients, minerals, and fibrous material which help maintain soil quality. However, not more than one-third to one-half of the residues from a grain crop devoted to ethanol production need be used to fuel the process. Also, there are several methods, such as crop rotation and winter cover crops, which lessen the impact of crop residue removal. ... 

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