【Haichuan rolls up his sleeves to work on environmental protection】How to carry out sealed purging, material removal, and maintenance without releasing pollutants

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This post was last edited by Desert Fish on 2017-3-16 at 10:45. It concerns a company mentioned on the Petrochemical News Network; during maintenance periods, to avoid releasing pollutants, it uses closed-system methods for material removal and purging, ensuring that no emissions occur into the air, no waste is released underground, and the environment remains free of any unpleasant odors. There are some detailed actions mentioned in the report, which I think are worth emulating. I also welcome discussions on this topic, as this year is also a year of environmental protection decisions for chemical and petrochemical enterprises. To take action on environmental protection means working on details step by step to make improvements. ——— A shutdown for maintenance during a special period: March is an important time when national ** meetings are held, and the requirements regarding environmental protection are quite stringent. Especially on March 1, at the request of the **Ministry of Environmental Protection, the Shandong Provincial Environmental Protection Department went to Qilu Petrochemical for a comprehensive environmental inspection. The local authorities in Zibo City and Linzi District also conduct random environmental inspections on enterprises from time to time. On March 2, upon leaving after completing their inspection, the Provincial Environmental Protection Department posted environmental protection reporting phone numbers in prominent locations such as the office building of Shengli Refinery. At this highly significant moment, ensuring safety, environmental protection, and the absence of accidents during the shutdown for maintenance is a huge challenge for everyone at Qilu Petrochemical. “\"No emissions in the air, no discharge on the ground, and no unpleasant odors in the environment\" are the overall requirements for environmental protection during this shutdown and maintenance period at the Qilu Petrochemical Refinery. Well in advance of the plant’s shutdown, the factory conducted several rounds of review and refinement of the safety and environmental protection plans prepared by various departments, to ensure that material removal, purging, and emissions all took place in a sealed manner, with no details or corners overlooked. When formulating plans for shutting down, maintaining, and restarting the equipment, the plant places schedule and time control points at the bottom of the four main objectives related to maintenance; it considers the maintenance schedule only after ensuring \"safety, environmental protection, and quality\". As a result, this year the overall maintenance duration for the 10 units undergoing spring maintenance at Qilu Petrochemical was extended by 1 to 2 days on average. “Starting the maintenance equipment one day earlier can generate an additional day of profit for the company. But to ensure that no safety, environmental, or quality incidents occur, we prefer to delay the startup of the maintenance equipment by two days. ”Liu Zhimin, the director of the refining plant at Qilu Petrochemical, said this. Environmental protection-related shutdowns: The maintenance teams use various tactics to get the job done. The heavy oil hydrogenation workshop is the main site for the shutdown and maintenance work at Qilu Petrochemical, and it represents both a key focus and a challenge in terms of environmental protection requirements. Li Dongping, the workshop director, explained that this year, Qilu Petrochemical requires that all materials be recovered when the plants are shut down for maintenance. Since the materials in two units such as the heavy oil hydrogenation unit are mostly viscous heavy oils, it is particularly difficult to remove these materials and to clean the units during shutdown. In recent years, the heavy oil hydrogenation plant has made efforts to establish a relatively comprehensive shutdown procedure; materials that could not be directly returned to the raw material tanks and sludge tanks in the past can now be almost completely recovered. However, this year the workshop has prepared a large amount of adhesive tape. By using this tape to establish a processing procedure, it is possible to completely recover the materials from dead corners and certain pipeline equipment. During the phase of purging with high-temperature and high-pressure steam, the workshop requires a sealed purging process; all vent valves must remain closed. The steam from the pipelines, distillation towers, and washing towers must be cooled to 80 degrees using air coolers before it can be sent to the sewage tank and wastewater treatment plant. The condensate is sent to the waste oil tank and wastewater treatment facility, while the non-condensable gases are sent to the gas pipeline network and gas holders for recovery. Li Dongping said that heavy oil hydrogenation is a high-pressure process, and during the cooling phase of the equipment, thermal expansion and contraction often lead to leaks in the flange seals, resulting in unpleasant odors. This year, the workshop has controlled the rate of cooling; while cooling down, some flange bolts were tightened to prevent material leakage. This has not happened before. In recent years, the second catalytic workshop has been updating the device’s material withdrawal and purging procedures whenever maintenance is carried out. In January of this year, the workshop carried out another process modification while the plant was operating normally, adding a new liquefied gas return line. Using this pipeline, during this maintenance work, the workshop recovered all the liquefied gas condensate that could not be recovered previously due to the plant being shut down. This year, during the shutdown of the 10 units, all gaseous materials were recovered and fed into the gas pipeline network as fuel; not a single ounce was released into the atmosphere through flares. Ju Haijing said that in addition, the workshop had prepared 20 oil collection tanks and 30 oil collection basins to prevent the fluid inside the pipeline equipment from leaking onto the ground. During the equipment maintenance, hundreds of pipelines were opened, and they were all clean – this is the best result achieved in years. This not only eliminates major safety hazards such as fires and explosions of materials during maintenance work, but also reduces material losses and protects the environment. Everyone should contribute to environmental protection; environmental protection benefits everyone. Uncontrolled discharge of pollutants harms first and foremost the workplace where one works, and the unpleasant chemical odors affect one’s own surroundings first. Protecting the environment means protecting ourselves.” In recent years, the refining plant of Qilu Petrochemical has been vigorously instilling in its employees the concept of \"zero emissions and zero accidents\" in terms of safety and environmental protection during shutdowns for maintenance, and the environmental awareness among managers and workers has been improving and strengthening year by year. This year, the refining plant of Qilu Petrochemical revised its \"Production Accident Management Measures,\" classifying the occurrence of chemical odors as workshop-level production accidents, while those reported due to chemical odors and confirmed by local authorities are classified as plant-level accidents; furthermore, stricter penalties have been imposed. Wang Junjiang, the deputy section chief in charge of environmental protection at the company’s refinery’s safety and environmental protection department, explained that all the materials contained within the pipelines and equipment of the shut-down units must be recovered. Due to the different freezing points of the oils, high-temperature and high-pressure steam is often used to purge or even steam-clean the pipelines and equipment during the process of removing materials from these units when they are shut down. The substance similar to \"scrub water\" that results from pipeline purging and cooking must be cooled using a cooler before being sent to the light contaminated oil tanks and heavy contaminated oil tanks for reuse. If this \"scrubbing water\" and purge steam cannot be cooled down, it will cause chemical odors in the vicinity of the oily waste tank. This year, the Safety and Environmental Protection Department awarded two oil processing workshops the authority to take action in such situations: if the steam from purging cannot be cooled down and chemical odors arise in those workshops, they can close the valves to stop emissions from the upstream equipment ； However, once a chemical odor appears, the responsibility lies with the oil processing workshop, and it will face penalties. Han Xiangdong, the safety officer at the Third Oil Products Workshop, said that during the plant’s shutdown this year, the crew on duty in the workshop took turns to monitor the site closely, and used the walkie-talkies they carried to communicate with the shut down units upstream, in order to control the amount of dirty oil that reached the air coolers and ensure that the gas and oil received in the dirty oil tanks did not evaporate or emit any unpleasant odors. After all, once chemical odors are generated, it is the workers in their workshop who are the first to suffer as a result. Qilu Petrochemical has four sulfur recovery units, and ensuring that the exhaust gas meets emission standards during the shutdown of these units has always been a challenge within Sinopec’s network. The Second Sulfur Workshop of Qilu Petrochemical developed a nitrogen-blown sulfur purging process for shutting down equipment; this approach reduced the concentration of sulfur dioxide emitted into the atmosphere during equipment maintenance from over 10,000 milligrams per cubic meter to less than 100 milligrams per cubic meter, achieving the highest standards of emission control in China. Xu Yongchang, the secretary of the Party branch of the Second Sulfur Workshop, said that in the past, there was insufficient emphasis on environmental protection across the country. Whenever the plants were shut down and steam was used for cleaning or release, the noise generated was extremely loud. Toxic and harmful substances such as sulfur dioxide and hydrogen sulfide were released in large quantities into the environment, causing serious problems even for us working there. Now, as environmental regulations become increasingly strict and employees’ awareness grows, with more effective measures in place, it is we who benefit first.