Studies On The Oil Vapor Recovery System Of Crude Oil Piers

Over the past 30 years,China’s crude oil consumption and imports have been continuously rising,with more than 500 million tons(506 million tons)of crude oil imported in 2019.Barges are the main way of transportation for the import and transshipment of crude oil in China.During the loading and unloading of crude oil,especially during the loading operation at crude oil terminals,a large amount of crude oil vapor are volatilized into the air,which not only causes critical environmental pollution,but also result in huge energy waste,and there are also safety hazards associated with volatile oil vapor.The oil vapor recovery system of crude oil piers is studied in the case of an oil product transfer enterprise in the seaport area of Ningbo-Zhoushan Port Dinghai,one of the world’s largest port.This enterprise is a subsidiary of a large national central enterprise holding,storing and transferring tens of millions of tons of petroleum and petrochemical products per year,with an annual throughput of more than 30 million tons of all kinds of oil products,among which the loading volume of all kinds of crude oil is more than 10 million tons per year,which is a typical representative of China’s petrochemical storage enterprises.Previously,due to the absence of oil vapor recovery devices of crude oil piers,the crude oil vapor are discharged directly into the atmosphere,with an annual exhaust volume of more than 12 million cubic meters,resulting in environmental pollution and energy waste.The oil vapor recovery of crude oil piers is a technical problem in China that needs to be solved urgently.The research and installation of oil vapor recovery system of crude oil piers can not only meet the requirements of environmental protection and reduce the emission of volatile organic compounds(VOCs),but also use the recovered oil as fuel,which can generate considerable environmental and economic benefits.Therefore,the study of oil vapor recovery system of crude oil piers is of great practical significance and necessity.By reviewing a large number of literature,field investigation and analysis of the current situation of oil vapor recovery system at home and abroad,and taking into account the actual situation of crude oil handling process,crude oil properties,crude oil import and transshipment quantity of the subject enterprise,the representative crude oil is selected and its vapor composition spectrum is analyzed,and SOUTH PARS,SU TU DEN,DAR BLEND and SARIR are obtained.Data on the composition of crude oil vapor in the barges loading process provide indispensable basic data for the study of oil and gas recovery system.Based on the analysis of representative crude oil composition spectrum,five oil vapor recovery processes are proposed for crude oil piers barges loading,namely:torch combustion process,buffer tank+incinerator combustion steam generation process,multi-stage activated carbon enrichment oil vapor+boiler combustion steam generation process,multi-stage activated carbon enrichment oil vapor+incinerator combustion steam generation process and multi-stage activated carbon enrichment oil vapor+oil vapor storage and monitoring+boiler combustion steam generation process.In order to determine the optimal process plan,on the one hand,the advantages and disadvantages of different processes were analyzed qualitatively according to the actual situation of the enterprise,and on the other hand,different oil vapor recovery processes were evaluated quantitatively by using a combination of hierarchical analysis and fuzzy comprehensive evaluation method.Through the comprehensive evaluation,the multi-stage activated carbon enrichment process+oil vapor storage and monitoring+boiler combustion steam generation process is identified as the optimal solution for the enterprise.During the construction of crude oil vapor recovery system at the terminal,advanced foreign equipment and related technologies were introduced,the construction of China’s first oil vapor recovery system at the crude oil piers was completed through a combination of introduction and absorption and independent innovation.The research and application of this crude oil vapor recovery system has remarkable effect and outstanding contribution to the emission reduction of VOCs in the loading process of crude oil piers in China,which can reduce about 570 tons to 760 tons of VOCs emission per year,and can reduce the VOCs emission of crude oil piers loading in China by about 1.2%.At the same time,combined with the actual operation of the crude oil vapor recovery system,summarize the system process,construction,management and other aspects of experience,to provide reference for the construction and operation of China’s crude oil piers vapor recovery system.