Plant-produced

Air separation plants produce about 99% of the gas, while electrolysis plants produce about 1%. 

It was not until the twentieth century that furfural became important commercially. The Quaker Oats Company, in the process of looking for new and better uses for oat hulls found that acid hydrolysis resulted in the formation of furfural, and was able to develop an economical process for isolation and purification. In 1922 Quaker announced the availability of several tons per month. The first large-scale appHcation was as a solvent for the purification of wood rosin. Since then, a number of furfural plants have been built world-wide for the production of furfural and downstream products. Some plants produce as Httie as a few metric tons per year, the larger ones manufacture in excess of 20,000 metric tons. 

In 1989 U.S. and Canadian plants produced 116,600 t of cmde siUcon carbide valued at 56.4 million (20). Abrasive uses accounted for 46% of the total toimage and 48% of the total value. 

Electrolytic plant producing caustic soda, chlorine, and hydrogen from brine. 

Electrolytic plant producing metallic sodium and chlorine from molten sodium chlorine. 

Electrolytic plant producing chlorine and hydrogen from hydrochloric acid. 

Nonelectrolytic plant producing chlorine and potassium nitrate. 

Electrolytic plant producing magnesium and chlorine from molten magnesium chloride. 

Synthetic Processes. Traditional Solvay plants produce large volumes of aqueous, chloride-containing waste which must be discharged. This fact, in addition to a noncompetitive cost position, is largely responsible for the demise of U.S. synthetic plants. In countries other than the United States, waste is sent to the ocean, rivers, or deep underground wells. The AC and NA coproduct processes produce less aqueous waste than the traditional Solvay and NA mono processes. Related environmental concerns are added whenever a plant complex includes lime quarries and ammonia-producing equipment. 

The alkalized zinc oxide—chromia process developed by SEHT was tested on a commercial scale between 1982 and 1987 in a renovated high pressure methanol synthesis plant in Italy. This plant produced 15,000 t/yr of methanol containing approximately 30% higher alcohols. A demonstration plant for the lEP copper—cobalt oxide process was built in China with a capacity of 670 t/yr, but other higher alcohol synthesis processes have been tested only at bench or pilot-plant scale (23). 

Abaca. The abaca fiber is obtained from the leaves of the banana-like plant (same genus) Musa textilis (banana family, Musaceae). The fiber is also called Manila hemp from the port of its first shipment, although it has no relationship with hemp, a bast fiber. The mature plant has 12—20 stalks growing from its rhizome root system the stalks are 2.6—6.7 m tall and 10—20 cm thick at the base. The stalk has leaf sheaths that expand iato leaves 1—2.5 m long, 10—20 cm wide, and 10 mm thick at the center the fibers are ia the outermost layer. The plant produces a crop after five years, and 2—4 stalks can be harvested about every six months. 

Henequen. Agavefourcroydes grows ia Mexico where it was first cultivated by the Mayans ia the Yucatan (Yucatan Sisal). The plant produces for 20—30 years. The lower bottom leaves, which are up to 2 m long and 10—15 cm wide, are cut, machine decorticated, and cleaned. Henequen fibers are white to yellowish red and are inferior to sisal ia strength, cleanliness, texture, and length, the other grading criteria. Henequen is grown for local use ia Cuba (Cuban Sisal) and El Salvador. Twiae, small ropes, coarse mgs, and sacks are made commercially from henequen. 

The initial biogas recovered is an MHV gas and is often upgraded to high heat value (HHV) gas when used for blending with natural gas suppHes. The aimual production of HHV gas ia 1987, produced by 11 HHV gasification facihties, was 116 x 10 m of pipehne-quaUty gas, ie, 0.004 EJ (121). This is an iacrease from the 1980 production of 11.3 X 10 m . Another 38 landfill gas recovery plants produced an estimated 218 x 10 m of MHV gas, ie, 0.005 EJ. Additions to production can be expected because of landfill recovery sites that have been identified as suitable for methane recovery. In 1988, there were 51 sites ia preliminary evaluation and 42 sites were proposed as potential sites (121). 

The most extensive worldwide program on methanol blend gasoline was in Italy where from 1982 to 1987 a 1.9 x lO" m /yr (5 x 10 gal/yr) plant produced a mixture containing 69% methanol. The balance contained higher alcohols. This mixture was blended into gasoline at the 4.3% level and marketed successfully as a premium gasoline known as Super E (82). 

Table 13. Plants Producing Acetylene in the United States, 1991...

The Diabrotica spp. com rootworm beetles are specifically attracted to a variety of plant-produced phenylpropanoids, eg, ( )-cinnamaldehyde [14371-10-9] for the southern com rootworm D. undecimpunctata howardr, ( )-cinnamyl alcohol [4407-36-7] for the northern com rootworm D. barberi and indole [120-72-9] for the western com rootworm, D. virgifera virgifera. Especially powerflil lures for these rootworm beetles are 2-(4-methoxyphenyl)ethanol for the northern com rootworm and 4-methoxycinnamaldehyde [71277-11-7] (177) for the western com bootworm. 

The main by-products of mica processiag plants are kaolin, quart2, and feldspar. Some plants produce all of these products for sale. 

Safety provisions have proven highly effective. The nuclear power industry in the Western world, ie, outside of the former Soviet Union, has made a significant contribution of electricity generation, while surpassing the safety record of any other principal industry. In addition, the environmental record has been outstanding. Nuclear power plants produce no combustion products such as sulfuric and nitrous oxides or carbon dioxide (qv), which are... 

Scale-up is the process of developing a plant design from experimental data obtained from a unit many orders of magnitude smaller. This activity is considered successful if the commercial plant produces the product at plaimed rates, for plaimed costs, and of desired quaUty. This step from pilot plant to full-scale operation is perhaps the most precarious of all the phases of developing a new process because the highest expenses ate committed at the stages when the greatest risks occur. 

The hydroperoxide process involves oxidation of propjiene (qv) to propylene oxide by an organic hydroperoxide. An alcohol is produced as a coproduct. Two different hydroperoxides are used commercially that result in / fZ-butanol or 1-phenylethanol as the coproduct. The / fZ-butanol (TBA) has been used as a gasoline additive, dehydrated to isobutjiene, and used as feedstock to produce methyl tert-huty ether (MTBE), a gasoline additive. The 1-phenyl ethanol is dehydrated to styrene. ARCO Chemical has plants producing the TBA coproduct in the United States, Erance, and the Netherlands. Texaco has a TBA coproduct plant in the United States. Styrene coproduct plants are operated by ARCO Chemical in the United States and Japan, Shell in the Netherlands, Repsol in Spain, and Yukong in South Korea. 

American Ligurian, Inc. (Stanford, Connecticut) is marketing a pyrolysis process developed in Italy, which generates steam for hot water, air heating, dryers, kilns, and similar installations. A modular plant produces 8000 kg/h of steam from 1 tih of tires. The pyrolysis process produces 0.9 t of fuel ok, 270 t of steel, and 54 t of ash annually. Gas emissions meet the strictest environmental standards (16). 

The first solar-electric technology to arouse industry interest was solar-thermal energy (1,3,5,6,8). Under favorable circumstances, it can be cost-effective, as evidenced by the fact that solar-thermal gas-hybrid plants produce over 350 MW of commercial power in southern California. This power is used during peak demand to supplement that available from conventional generation. 

Silicones, an important item of commerce, are widely available commercially (9,494). The principal manufacturers of silicone operate direct-process reactors to produce dimethyl dichi orosilane and, ultimately, polydimethyl siloxane. Typical plants produce more than 450 t per year. The siUcone industry is a global enterprise in the 1990s, with principal producers in the United States (Dow Coming, GE, and OSi), Europe (Wacker Chemie, Hbls, Rhc ne-Poulenc, and Bayer), and Southeast Asia (Shin-Etsu, Toshiba SiUcones, and Dow Coming, Japan). Table 15 Hsts the approximate sales of the principal producers for 1991. 

The resulting nitrous oxide can be recirculated to the nitric acid plant or be used for other purposes. Free acid remaining in the impregnation water of sodium nitrate crystals is neutralized by adding some NaOH to the washing water. Whereas several nitric acid plants utilize absorption of nitrous gases to treat tail gases, almost all of these plants produce small volumes of sodium nitrate. 

An alternative method of produciag hydrocarbon fuels from biomass uses oils that are produced ia certaia plant seeds, such as rape seed, sunflowers, or oil palms, or from aquatic plants (see Soybeans and other oilseeds). Certain aquatic plants produce oils that can be extracted and upgraded to produce diesel fuel. The primary processiag requirement is to isolate the hydrocarbon portion of the carbon chain that closely matches diesel fuel and modify its combustion characteristics by chemical processiag. 

Plants producing oleum or Hquid SO typically have one or two additional packed towers irrigated with oleum ahead of the normal SO absorption towers. Partial absorption of SO occurs in these towers, and sulfuric acid is added to maintain desired oleum concentrations. Normally, oleum up to about 35 wt % free SO content can be made in a single tower two towers are used for 40 wt % SO. Liquid SO is produced by heating oleum in a boder to generate SO gas, which is then condensed. Oleums containing SO >40 wt % are usually produced by mixing SO with low concentration oleum. 

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