VOCs control in the coking industry is one of the most complex industries in the chemical production industry. It involves many sections, and the pollutants emitted by each section are different, and the requirements for safety and explosion-proof technology are high. Not only should we consider economic benefits, environmental protection effects and rationality of the process, we should also consider the operating cost of and the stability and security of the operating system.
In the past few years, the coking VOCs treatment process experienced pickling and alkali cleaning, oil washing + activated carbon absorption and desorption, to negative pressure + enter coke oven incineration and other processes. At present, the latter is still the main line of the industry, but who knows who the operation effect is used, and almost 10-15 million chemical production lines have been paid. Under , Park Hua Technology Environmental Protection shares a new coking VOCs treatment process.
Coking production areas mainly include cold drum process, desulfurization process, sulfur-ammonia process, elution benzene process, etc. The waste gas characteristic pollutants and emission forms are different in different processes. The exhaust gas discharged from the
cold drum section is continuous, stable, low concentration and high temperature. The exhaust gas mainly includes ammonia gas , hydrogen sulfide , naphthalene and a small amount of VOCs. It comes from tar storage tanks, ammonia sinks, tar intermediate tanks, tar tanks, groundwater seal tanks and other areas. The exhaust gas needs to be continuously treated. The exhaust gas discharged from
desulfurization and ammonium sulfide stages have the characteristics of continuous and high ammonia content. The evacuated gas mainly contains ammonia gas, hydrogen sulfide and a small amount of VOCs, which come from areas such as mother liquor tank, regeneration tank and foam burst tank. The exhaust gas discharged from
crude benzene working section has the characteristics of small waste gas volume and high concentration. The dispersed gas mainly contains benzene , which comes from areas such as crude benzene storage tank, oil lean tank, oil washing tank, underground tank and crude benzene metering tank. The crude benzene components need to be collected and recycled according to the characteristics of intermittent work in the tank pressure changes.
Coking VOCs waste gas is organic matter such as tar gas, benzene, toluene , xylene , naphthalene and other organic matter, as well as NH3, H2S, HCN and other inorganic matters. The direct combustion method is to burn VOCs exhaust gas as fuel. According to relevant literature, when the combustion temperature is generally controlled at 1100 degrees Celsius, the treatment efficiency of exhaust gas is the highest, reaching 95% to 99%.
power generation boiler combustion temperature can reach about 1300 degrees Celsius, and has a sufficiently long combustion reaction time. In theory, the combustion of coking VOCs waste gas in the boiler can be completely decomposed. However, inorganic substances such as NH3, H2S, HCN in the coking VOCs exhaust gas will produce pollutants such as SO2, NOx and other pollutants after burning in the boiler, which will increase the concentration of SO2 and NOx in the boiler combustion exhaust gas. In order to ensure the stable emission of the boiler's combustion exhaust gas, the boiler has simultaneously built denitrification + desulfurization + bag dust collectors during the design and construction process, and both have sufficient processing capacity.
Coking VOCs waste gas is washed with oil + pickling + alkaline washing and multi-stage absorption and washing, and then sent to the power generation boiler for combustion, and then steadily meets the standards after being treated with SCR+SNCR denitrification + desulfurization + bag dust removal . It is an optimal combination of coking VOCs treatment process and is fully feasible.
i.e., after coking VOCs waste gas is collected centrally, it is oil-washed + pickling + alkali-washed multi-stage absorption washing + preheater , and then sent to the pipe network in front of the power generator boiler combustion fan, mix with the air sucked in by the boiler combustion fan, and enter the boiler to burn. The combustion exhaust gas is discharged through the exhaust cylinder after SCR+SNCR denitrification + desulfurization + bag dust removal treatment.
treatment process route is as follows: coking VOCs waste gas → pre-cooling → oil washing → pickling → alkaline washing → exhaust gas preheater → power generation boiler combustion fan → boiler combustion → denitrification + desulfurization + bag dust removal → exhaust cylinder meets the standard emission.
