Analyses And Case Study On Environmental Impact Of Continuous Catalytic Reforming Combination Unit Construction Project In Petrochemical Plant

A catalytic continuous reforming combination unit is one of important technologies for manufacturing oil of high octane number and lightweight aromatics (including benzene, toluene and xylene) and hydrogen as by-product, which is the main source of hydrogen supply in the refinery. But it will produce wastewater, waste gas, noise and waste solids, and cause certain impact to the area surrounding the project. Through theoretical research and example analysis, this paper has given a systematical analysis on the environmental impact of a catalytic continuous reforming combination unit construction project, and the following regulations have been found.(1) During its construction period, its brief environmental impacts behave as pollutions of construction waste water (including excavation wastewater, mechanical cleaning wastewater and sewage), construction vehicle exhaust, site dust and construction abandon soil and rubbish.(2) During its operation period, its brief environmental impacts come from pollutants discharged or leaked from various units in process, such as furnace smoke, gas released from relief valves, oily wastewater exited from equipment, light waste oil from devices and sampling points, waste catalysts and Inert ceramic balls uninstalled from various reactors, waste desiccants unloaded from drying tanks, waste desulfurizer unloaded from desulfurization cans and waste activated carbon unloaded from adsorption cans and son on.(3) In order to reduce its possible adverse environmental impacts, it is recommended to adopt certain comprehensive prevention and control measures during the construction, such as adopting closed construction, using ready-mixed concrete, civilization over transporting waste residue mud and so on. Moreover, it is necessary to apply the following prevention and control measures during its operation period:standard draining combustion flue gases, airtight emissions from relief valves, dry gas desulfurization, soda-washing exhaust vent, high-efficient dust removal and aromatic hydrocarbon diffusion reduce and other air pollution control measures. Main wastewater, including sulfur wastewater, oily wastewater, benzene wastewater, may purified according the regulation of "concerned shunting, points of processing". Dechlorine agents, desiccant and ceramic balls may be free-pollutedly disposed after steaming and inert gas sweeping cleanly. Waste pre-hydrogenation catalyst and the waste clay and other hazardous waste must be treated by disposal units having the corresponding qualifications. The main great noise sources during the operation period are high-power pump, compressor, blower, heating furnace, air condenser and others. Their noise may be reduced with selecting low-noise equipments.(4) The evironmenta risks during the operation period come from accident emissions of pollutants from combination equipments, storage system and auxiliary production facilities. It is important to strengthening the safety management and completing the emergency action plans.The project of catalytic continuous refonning combination unit in the Sinopec Guangzhou brench has been taken as example and given practical analyses in this paper.