Kemija u Industriji (Jan 2009)
Thermal Oxidation of Tail Gases from the Production of Oil-furnace Carbon Black
Abstract
This paper describes the production technology of oil-furnace carbon black, as well as the selected solution for preventing the emissions of this process from contaminating the environment.The products of industrial oil-furnace carbon black production are different grades of carbon black and process tail gases. The qualitative composition of these tail gases during the production of oil-furnace carbon black are: carbon(IV) oxide, carbon(II) oxide, hydrogen, methane, hydrogen sulfide, nitrogen, oxygen, and water vapor.The quantitative composition and lower caloric value of process tail gases change depending on the type of feedstock used in the production, as well as the type of process. The lower caloric value of process tail gases is relatively small with values ranging between 1500 and 2300 kJ m–3.In the conventional production of oil-furnace carbon black, process tail gases purified from carbon black dust are freely released into the atmosphere untreated. In this manner, the process tail gases pollute the air in the town of Kutina, because their quantitative values are much higher than the prescribed emissions limits for hydrogen sulfide and carbon(II) oxide. A logical solution for the prevention of such air pollution is combustion of the process tail gases, i. e. their thermal oxidation. For this purpose, a specially designed flare system has been developed. Consuming minimum amounts of natural gas needed for oxidation, the flare system is designed to combust low caloric process tail gases with 99 % efficiency. Thus, the toxic and flammable components of the tail gases (hydrogen sulfide, hydrogen, carbon(II) oxide, methane and other trace hydrocarbons) would be transformed into environmentally acceptable components (sulfur(IV) oxide, water, carbon(IV) oxide and nitrogen(IV) oxide), which are in compliance with the emissions limit values prescribed by law.Proper operation of this flare system in the production of oil-furnace carbon black would solve the air pollution problem in the town of Kutina, especially the concentrations of hydrogen sulfide in the troposphere. Together with the development of this flare system, a continuous air-pollutant (hydrogen sulfide and carbon(II) oxide) monitoring system shall be established and linked with the Environmental Protection Agency
