Manufactured gas

As the economic value of coproducts has decreased, it has become more difficult to provide capital for environmental controls on air emissions and wastewater streams such as toxic phenoHc effluents from chemical recovery operations. Some former coke and manufactured gas sites may require remediation to clean up contaminated soil and groundwater. These difficulties will force the shutdown of some operations and discourage recovery of coproducts in future installations. 

The conversion of coal to gas on an industrial scale dates to the early nineteenth century (14). The gas, often referred to as manufactured gas, was produced in coke ovens or similar types of retorts by simply heating coal to vaporize the volatile constituents. Estimates based on modem data indicate that the gas mixture probably contained hydrogen (qv) (ca 50%), methane (ca 30%), carbon monoxide (qv) and carbon dioxide (qv) (ca 15%), and some inert material, such as nitrogen (qv), from which a heating value of approximately 20.5 MJ/m (550 Btu/fT) can be estimated (6). 

Gas oil is a product hoiling slightly higher (235—425°C, or sometimes wider) than kerosene. The main feedstock to the catalytic cracking units (see Feedstocks), it received its name from use as an enriching agent in the production of city or manufactured gas. It is often used as diesel fuel. 

Trace impurities present in commercial benzoic acid include methyl diphenyls and phthaHc acids. The concentration and presence of these impurities vary by product grade and by manufacturer. Gas chromatography and high pressure Hquid chromatography are useful for determining the concentrations of those impurities. 

Process Stream Separations. Differences in adsorptivity between gases provides a means for separating components in industrial process gas streams. Activated carbon in fixed beds has been used to separate aromatic compounds from lighter vapors in petroleum refining process streams (105) and to recover gasoline components from natural and manufactured gas (106,107). 

There are direct substitutions of possible interest that would not be feasible without drastic changes in the feed system or pressure. Thus if the available substitute for natural gas is, eg, a manufactured gas containing much CO, there would almost always be a mismatch of the WIs unless the fuel could be further modified by mixing with some other gaseous fuel of high volumetric heating value (propane, butane, vaporized fuel oil, etc). Moreover, if there are substantial differences in eg, as a result of the presence of considerable H2 as well as CO in the substitute gas, the variation in dame height and dashback tendency can also make the substitution unsatisfactory for some purposes, even if the WI is reproduced. Refinements and additional criteria are occasionally appHed to measure these and other effects in more complex substitution problems (10,85). 

Typical applications in the chemical field (Beaver, op. cit.) include detarring of manufactured gas, removal of acid mist and impurities in contact sulfuric acid plants, recovery of phosphoric acid mists, removal of dusts in gases from roasters, sintering machines, calciners, cement and lime Idlns, blast furnaces, carbon-black furnaces, regenerators on fluid-catalyst units, chemical-recoveiy furnaces in soda and sulfate pulp mills, and gypsum kettles. Figure 17-74 shows a vertical-flow steel-plate-type precipitator similar to a type used for catalyst-dust collection in certain fluid-catalyst plants. 

DEA is prefened when system pressure is above 500psi. The 0.25 grains/100 scf is more difficult to produce with DEA. COS and CS2 have few detrimental effects on DEA. This, and high solution loadings, provide advantages over MEA. DEA will typically be used for refinery and manufactured gas streams that have COS and 082. ... 

Vergasung, /. gasification vaporization destructive distillation carburetion gassing. Vergasungs-gas, n. manufactured gas. -mittel,... 

Although manufactured gas was too expensive for space heating, the small quantities necessary for domestic cooking and water heating provided a desirable market, and several local gas companies actively pursued it. Often a second meter was installed for the heating and cooking service, which was charged at a lower price. Manufacturers of coal stoves responded... 

Manufactured gas Engine exhaust gas Steam (nonoil-bearing)... 

Erickson DC, RC Loehr, EF Neuhauser (1993) PAH loss during bioremediation of manufactured gas plant site soils. Water Res 27 911-919. 

Tiehm A, M Stieber, P Werner, FM Frimmel (1997) Surfactant-enhanced mobilization and biodegradation of polycyclic aromatic hydrocarbons in manufactured gas plant soil. Environ Sci Technol 31 2570-2576. 

However, there is one exception to using the TCLP to identify a waste as hazardous. The DC Circuit Court, in Association of Battery Recyclers vs. U.S. EPA, vacated the use of the TCLP to determine whether manufactured gas plant (MGP) wastes exhibit the characteristic of toxicity. As previously stated, the TCLP replicates the leaching process in municipal landfills. The court found that U.S. EPA did not produce sufficient evidence that co-disposal of MGP wastes from remediation sites with municipal solid waste (MSW) has happened or is likely to happen. On March 13, 2002, in response to the court vacatur, U.S. EPA codified language exempting MGP waste from the toxicity characteristic regulation. 

Natural Gas, Manufactured Gas Liquefied Gas Analysis Part I — Background. Atlantic Analytical Laboratory, Inc., http //www.test-lab.com/gasone.htm... 

Monomeric aromatic hydrocarbons Benzene, toluene, ethylbenzene, xylene (BTEX) Oil industry (P,D) Gasoline stations (P) Manufactured gas plants (P,D) 6 [43]... 

The first gas company was established in 1812 in London to produce gas from coal and to light the Westminster Bridge. In 1816, the first gas plant for the manufacture of syngas from coal was built in the United States to light the streets of the city of Baltimore. By 1826, gas plants were also built to manufacture gas for lighting the streets of Boston and New York City. Soon thereafter, gas plants and distribution networks were built to light the streets of most major cities throughout the world. 

Manufacturer Gas Temp. (Max.) Particle Collection Efficiency Remarks... 

Soil auguring can be applied to a wide variety of sites, including wood treatment facilities, oil and gas production units, bulk storage sites, pipeline, manufactured gas plants and other sites contaminated with residual oils, petroleum products, VOCs, semi-VOCs, and other contaminants. This technology is also applicable to sites with complicated, heterogeneous subsurface geology that can render more traditional approaches ineffective, or at sites where excavation is not cost-effective or practical. 

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