Energy consumption reduction prospects in zinc oxide technology

Аuthors

Estrin I. A.

Rostov State University of Railway Transport, 2, Rostov-on-Don, Rostov-on-Don, Russia 344038

e-mail: igor1955@bk.ru

Abstract

Zinc oxide is an important component in producing rubber, paint and varnish materials, semiconductors, and a trace element in food additives for agriculture. The zinc oxide production is multi-tonnage and energy-intensive. The existing furnaces for the zinc oxide production have low thermal efficiency. The main energy source is the heat from the natural gas combustion. To determine the trend of ways for the energy efficiency increasing, an exergetic analysis of the technological system, in which the zinc oxide was produced from the metallic zinc in muffle furnaces, was performed. The adduced thermal balance revealed that the heat released in the process of zinc vapors combustion by the air oxygen is about twice as high as the energy requirements of the entire technological cycle. Based on the thermal balance of the oxidation chamber, the actual temperature of the zinc oxide synthesis reaction was determined. Conditions, under which the temperature of the zinc vapor oxidation process may ensure the temperature level necessary for ensuring all stages of the technological process, including the most high-temperature one, namely the zinc vapor generation, are presented. The process thermodynamics analysis reveals that the heat consumption at all stages of the technological process can be ensured by the heat of the exothermic reaction of zinc vapor oxidation. It is demonstrated that the entire technological process can be performed without the natural gas expenditures. The thermodynamic requirements formulated on this basis form the basis to the zinc oxide technology modernization employing only the oxidation reaction heat. However, the existing hardware implementation of the process, such as muffle furnaces, does not allow application of the reaction heat. The heat released in the process dissipates into the environment. The article considers the structure of the plant and its operation allowing refuse outright of the application of natural gas, which is necessary only for the initial start-up of the plant. Further, the plant employs the heat of the reaction for all stages of the technological process. The above said allows thermal efficiency increasing up to 44%. This reduces herewith the technology resource intensity and the process increases environmental friendliness due to the zinc oxide losses reduction to the environment.

Keywords:

energy efficiency, zinc oxide technology, industrial plant

References

1. Gorlovskii I.A., Kozulin N.A. Oborudovanie zavodov lakokrasochnoi promyshlennosti (Equipment of paint and varnish industry plants), Leningrad, Khimiya, 1980, 375 p.
2. Belen’kii E.F., Riskin I.V. Khimiya i tekhnologiya pigmentov (Chemistry and technology of pigments), Leningrad, Khimiya, 1974, 656 p.
3. Semenenko N.A. Vtorichnye energoresursy promyshlennosti i energotekhnologicheskoe kombinirovanie (Secondary energy resources of industry and energy-technological combination), Moscow, Energiya, 1968, 296 p.
4. Kazakov V.G., Lukanin P.V., Smirnova O.S. Termodinamicheskie metody analiza v energoispol’zuyushchikh protsessakh (Thermodynamic methods of analysis in energy-using processes:tutorial), Saint-Petersburg, SPb. GTURP, 2011, 93 p.
5. Gerasimov Ya.I., Krestovnikov A.I., Shakhov A.S. Khimicheskaya termodinamika v tsvetnoi metallurgii. V 8-mi t. (Chemical thermodynamics in non-ferrous metallurgy, in 8 volumes), Moscow, Metallurgiya, 1960, Vol. 1, 230 p.
6. Estrin I.A., Polovnikov V.E., Mikhaltsov E.K., Guzairov I.R. Patent RU 2087569 C1, 20.08.1997.
7. Estrin I.A., Koretsky I.V. Patent RU 2594934 C2, 30.12.2014.