VOC emission from oil refinery and petrochemical wastewater treatment plant estimation

Abstract

The introduction of environmental legislation improvement for industrial producers in Serbia, notably the Integrated Pollution Prevention Control (IPPC) license, will oblige the industrial producers to provide annual report on the pollutant emissions into the environment, as well as to pay certain environment fee. Wastewater treatment plant can be a significant source of volatile organic compounds (VOCs) diffuse emissions, which are difficult to measure directly. In the near future reporting obligations might expend to benzene and other VOCs. This paper deals with gaseous emissions calculations from API separator based on the emission factors and the adequate software applications. The analyzed results show that the estimated emission values differ depending on the applied method. The VOC emissions have been estimated using US EPA and CONCAWE emissions factors. The calculated emissions range from 40 to 4500 tons/year for oil refinery WWTP of 2,000,000 m3/year. The calculations of benzene and toluene emissions have been performed using three methods: US EPA emission factors, WATER9, and Toxchem+ software. The calculated benzene and toluene emissions range from 5.5-60 and 0.7-20 tons/year, respectively. The highest emission values were obtained by the US EPA emission factors, while the lowest values were the result of Toxchem+ analysis. The sensitivity analysis of obtained results included the following parameters: flow, temperature, oil content, and the concentration of benzene and toluene in the effluent. Wide range of results indicates the need for their official interpretation for the conditions typical for Serbia, thus establishing adequate national emission factors for future utilization of the “polluter pays principle” on the VOC and benzene emissions