embraces manufacturing based on chemical processing of vegetable material by catalytic conversion of polysaccharides to monosaccharides. It uses inedible vegetable material—the wastes from lumbering, sawmills, and wood processing, as well as agricultural wastes—for the production of nutrient yeast, ethyl alcohol, glucose and xylitol, furfural, organic acids, lignin, and other products. The significance of the hydrolysis industry in the national economy is primarily that it uses huge resources of vegetable waste materials to produce a valuable output whose production in other branches of industry requires a considerable amount of food and fodder products (grain, potatoes, syrup, and so on). At the present level of technology (depending on the type of production) it is possible to produce 220 kg of protein nutrient yeast, or 35 kg of yeast and 175 liters of ethanol, or 105-110 kg of yeast and 50-80 kg of furfural by hydrolyzing 1 ton of dry vegetable material.
Despite discoveries by Russian scientists in the field of hydrolysis, and the availability of a huge raw material base, there was no hydrolysis industry in prerevolutionary Russia. In the USSR it came into being in 1935. Until 1943 only ethanol was produced, but production of nutrient yeast was started in 1943, and production of furfural, in 1944-46. The hydrolysis industry of the USSR produces a wide range of products. Its main direction of development is extension of production of nutrient yeast by construction of large yeast-hydrolysis enterprises.
The USSR has at its disposal virtually unlimited reserves of vegetable materials that contain polysaccharides. At the present level of lumber production and wood processing, the total amount of wood waste is about 100 million cu m per year (not including low-quality wood, which is produced in the process of logging and is mainly used as fuel). About 1 million tons of corncobs and cottonseed and sunflower-seed hulls that are collected annually in grading and oil mills can be used as raw material for industrial processing. The polysaccharide content of these vegetable wastes may be as high as 70 percent, or 2-3 times the saccharose content of sugar beets or the starch content of potatoes, and equal to the amount of starch in corn. In the manufacture of ethanol 1 ton of completely dry coniferous wood equals 0.6 tons of grain or 1.6 tons of potatoes. A hydrolysis plant that processes 150,000 compact cu m of lumber wastes and wood will produce an amount of ethanol and nutrient yeast that would require about 36,000 tons of grain or 20,000 tons of molasses. A cubic meter of sawn timber produces 28 rubles’ worth of commercial lumber, but integrated processing of 1 cu m of sawmill wastes yields products worth 60-70 rubles.
Hydrolysis enterprises are located in the Karelian ASSR; in Arkhangel’sk, Leningrad, Perm’, and Irkutsk oblasts; in the Byelorussian, Ukrainian, Moldavian, Georgian, and Kazakh SSR’s; and in Krasnodar and Krasnoiarsk krais; on the middle and lower Volga; in the Urals; and in the Far East. The largest hydrolysis enterprises are the Krasnoiarsk, Biriusinsk (Irkutsk Oblast), Kan (Krasnoiarsk Krai), and Tavda (Sverdlovsk Oblast) plants and the Fergana plant (Uzbek SSR) for making furan compounds. The hydrolysis industry has a strong production base. The data in Table 1 characterize the development of the hydrolysis industry and the production of its main products.
|Table 1. Output of main products of the hydrolysis Industry in the USSR|
Most hydrolysis enterprises cooperate with enterprises for wood sawing and processing, paper and pulp, and oils and fats, receiving their energy resources and wastes directly from them.
The mechanization of labor-intensive processes and operations in the hydrolysis industry has been basically solved technically, but loading and unloading operations have still not been mechanized everywhere. There is partial automation. The funding equipment and labor productivity are shown in Table 2.
|Table 2. Labor productivity and funding equipment in the hydrolysis Industry of the USSR|
|Gross production output per worker (% of 1960)...............||100||146|
|Funding equipment (rubles)...............||8,838||11,252|
The hydrolysis industry is also developing intensively in other socialist countries. Two yeast-hydrolysis plants have been in operation in Bulgaria since 1965. In Hungary and Poland, nutrient yeast is usually made from the wastes of molasses and alcohol production, and in the German Democratic Republic and Czechoslovakia its manufacture is based on sulfite liquor.
In the capitalist countries, the hydrolysis industry is well developed in the USA, France, Italy, Finland, and Japan and is mainly represented by production of furfural and nutrient yeast. Furfural is produced on the largest scale in the USA.
REFERENCESGidroliznaia i sul’fitno-spirtovaia promyshlennost’ SSSR: Sbornik spravochnykh materialov. Moscow, 1957.
Sharkov, V. I. Tekhnologiia gidroliznogo sul’fitno-spirtovogo proizvodstva. Moscow, 1959.
Basin, D. M., and A. I. Kozlov. Voprosy ekonomicheskoi effektivnosti gidroliznoi promyshlennosti. Moscow-Leningrad, 1961.
V. N. SHLIANIN