Research On General Matters Of Environmental Impact Assessment Of Benzene Hydrofining Project

The human economic development has led to the destruction to environment. In order to keep the human health and the living environment of organisms, we must make some restrictive regulations for the content of pollutants produced by human activities and maximally reduce the destruction to pollution. All the countries in the world have realized the importance of environment and has eagerly established the environment impact assessment. In 2003, our country also brought this work within the orbit of law.Through the analysis for benzene hydrofining project, this thinks the environmental influence evaluation of benzene hydrofining construction profect needs to specially grasp these common problems:the correspondence with industrial policy; accurately predicting the load produced by air pollutants and pollutant concentration under various meteorological conditions, analyzing the daily average concentration stacking of related projects and proposing concrete pollution control measures of air pollutants; accurately predicting sewage produced load and pollutant concentration, modifying A2/O biological denitrification equipment, controlling better influent quality of sewage treatment station, making the operating COD volume loading of aerobic tank reach design adopting parameters and some other concrete sewage treatment measures; environmental risk assessment; clean production analysis; total amount control analysis.On the premise of proposing the common problems of environmental impact of benzene hydrofining project, taking the environmental impact assessment of 100,000 tons per year benzene hydrofining project at kailuan as an example, this paper analyses and evaluates deeply many problems, such as the selection of evaluation factor in environment impact assessment, engineering pollution analysis, assessment of current environmental quality and impact assessment, environmental risk assessment, clean production analysis, total amount control analysis and so on. It proposes pollution prevention measures of benzene hydrofining project which is practical in technology and reasonable in economy. Thus control environmental problems made by benzene hydrofining project on the acceptable level.The waste gas from vacuum system of de-heavy oil column of benzene hydrofining and helical groove of solvent recovery tower is sent to the flare system of 100,000 tons per year methanol plant and burnt out. The burning waste gas discharges from a 50-meter-high flare tube. The discharge gas from stable tower top is fixedly sent to gas purification plant of coking plant which is 600m away from the west of this project. And it isn't eff luxed. There are internal floating roofs in the tanks with volatile gas, like materials and product tank, collector groove of predistillation column, collector groove of extractive distillation, gyrus chute of benzene tower, gyrus chute of xylene tower and so on. The prevention measures are fixed at the groove exhaust port, like the nitrogen seal device and so on. This avoids nonorganized dissipation of pollutants of oil grooves. The effect of comprehensive control is up to 95%. Improve the chemical product design of coking related projects. Remove the oil from the tar separated water, like residual ammonia water, final cold surplus water, refining benzene waste water, crude benzene and so on and then send them into the ammonia still. Remove partial COD in order to guarantee the normal operation of ammonia still. Control better the influent quality of sewage treatment station. Decrease the organic loading of phenol-cyanogen waste water treatment system. Concel the gravitational oil-removal bath. The design of waste water treatment station fully uses water regulating tank and make it work in low metal level under normal condition and play an oil removal effect of horizontal sedimentation tank.It selects the main risk factors to predict their risks and uses multiple puff mode. And it analyses the effect of environmental effect caused by benzene leaking. It brings forth the Maximum probable accident risk with 7.6×10-6/a, which is less than 8.33×10-5/a, the risk value of chemical industry.Taking the clean production and controlling the emission of pollutants at the technique source as the principle, select benzene hydrofining engineering on production process and analyze products and the application of energy saving and reducing consumption. Analyze its clean production level from production process and equipments, pollutants produced index and waste comprehensive utilization index and so on.