At 5:00 on April 16, 2022, a collapse accident occurred at the refinery of the Qilu Branch of China Petroleum and Chemical Co., Ltd. in Linzi District, Zibo City, causing 11 deaths of , and direct economic losses of 1.8 million yuan. After the accident, the municipal government established an accident investigation team composed of the Municipal Emergency Bureau, Municipal Public Security Bureau, Municipal Federation of Trade Unions and other relevant departments, and invited the Municipal Commission for Discipline Inspection and Supervision and the Municipal People's Procuratorate to send personnel to participate. At the same time, relevant experts were hired to form an expert group to conduct a comprehensive investigation of the accident.
Accident investigation team found out the accident process, cause of the accident, property losses, casualties, etc. through on-site inspection, investigation and evidence collection, comprehensive analysis and expert demonstration, determined the nature of the accident, and put forward handling suggestions and preventive measures. The relevant situation is reported as follows:
01, basic situation
(I) Qilu Branch of China Petrochemical Co., Ltd.
1, refinery
Refinery (hereinafter referred to as the refinery) was founded in April 1966. It is a subsidiary of Qilu Branch of China Petroleum and Chemical Corporation (hereinafter referred to as Sinopec Qilu Branch). The main person in charge is Sun Guansong, who is mainly engaged in the processing of Shengli Oilfield high-sulfur and high-acid crude oil and imported crude oil. The main products include gasoline, diesel, naphtha , liquefied gas, asphalt , petroleum coke, propylene , sulfur and more than 30 products. The refinery has a total of 65 sets of equipment, divided into two production areas: the south and north, with a comprehensive crude oil processing capacity of 13 million tons/year, and the entire plant has more than 1,700 employees.
2, heavy oil hydrogenation workshop
refinery heavy oil hydrogenation workshop was established in 1989. Its equipment under its jurisdiction includes: 1.5 million tons/year VRDS device (accident device), 560,000 tons/year SSOT device, 550,000 tons/year third single tower sewage stripping device, 100,000 tons/year fourth gas desulfurization device, and the second torch gas cabinet recovery device. Each device is located in the northern area of the refinery, covering a total area of about 30,000 square meters, and currently has 106 employees.
3, accident device situation
1 VRDS device in which an accident occurred, namely the residual oil hydrogenation device, was completed and put into production in May 1992, and was expanded and transformed in October 1999. The current processing capacity is 1.5 million tons/year.
residue hydrogenation device mainly desulfurizes, denitrogenates, and demetalizes the reduced pressure residue, and partially cracks, including feed system, reaction system, high-pressure reaction product system, circulation gas system, low-pressure reaction product system, fractionation system, etc. The products mainly include naphtha, diesel and atmospheric residual oil.
The reaction system is to heat the oil and gas mixture feed to the required temperature of the reactor, and hydrotreat the residue under the action of the catalyst. There are 8 reactors in total: R-1505/1506, R-1310/1311, R-1320/1321, R-1330/1331. There are two catalyst beds inside the reactor R-1330. The catalyst grades are FZC-41BT and FZC-2MN-R. The total loading capacity is 70.8 tons, of which FZC-41BT is 69.8 tons and FZC-2MN-R is 1 tons. The catalyst uses porous alumina as the support and is impregnated with metals such as nickel and cobalt.
In the reactor, catalyst will gradually lose its activity and coke, and the catalyst life is about 477 days. After the catalyst loses its activity, the device needs to stop and unload the old catalyst and fill it with new catalyst. This collapse accident occurred during the reactor R-1330 unloader.
Jiangsu Tianpeng Petrochemical Technology Co., Ltd. undertakes the unloading construction project of 8 residual oil hydrogenation reactors in 2022 of the refinery.
4, accident equipment situation
residue hydrogenation reactor R-1330 is a fixed bed reactor, specifications: Φ3524×11768mm, top manhole size: Φ762mm, two beds are installed inside, porous tower plates are arranged at the top and middle of the reactor, and rectangular channel plates are arranged in the middle of the tower plate (about 1 meter long and 50-60 cm wide).The reactor's working pressure is 15.88MPa, the working temperature is 405.4℃, the equipment material is SA336-F22 TP.309L+TP.347LO.L, and the commissioning time is May 1992.
(II) Jiangsu Tianpeng Petrochemical Technology Co., Ltd. (hereinafter referred to as Tianpeng Company)
1, Tianpeng Company
Tianpeng Company was established in December 1999. Its residence is located in Building 02, No. 100, Tianjiao Road, Jiangning District, Nanjing City, Jiangsu Province, with a registered capital: 54.8 million yuan, Legal representative : Cao Fang, mainly engaged in technical development and technical services in the field of petrochemical environmental protection, technical consultation and services for catalyst heading, unloading and installation of various petrochemical devices in aerobic and anaerobic states, technical consultation and services for cleaning, maintenance, and maintenance of chemical equipment and storage tanks.
Tianpeng Company has the construction enterprise qualification certificate issued by the Nanjing Urban and Rural Construction Committee. The qualification category and level are: General Contracting Level 3 of Petrochemical Engineering Construction, and has the " Safety Production License " issued by the Jiangsu Provincial Department of Housing and Urban-Rural Development.
2, Lianshui Tianzi Engineering Technology Service Co., Ltd. (hereinafter referred to as Tianzi Company)
Tianzi Company is a wholly-owned subsidiary of Tianpeng Company. It was established in December 2015. Its residence is Room 13, Building 40, Yangguang Jiayuan Community, Taishan Road, Lianshui County, Jiangsu Province. The legal representative is: Xu Zhihong, mainly engaged in site cleaning and cleaning services for chemical enterprises.
In the refinery residue hydrogenation reactor unloading construction project undertaken by Tianpeng Company, the on-site construction personnel mainly come from the Tianzi Company.
(III) Progress in the construction project of residual oil hydrogenation reactor unloader
In March 2022, Sinopec Qilu Branch signed the "Reactor unloader contract for heavy oil hydrogenation VRDS device in oil refinery in 2022" and the "Production Safety Management Agreement".
With the joint participation of the process, equipment, safety and other personnel of the heavy oil hydrogenation workshop of the refinery, Tianpeng Company prepared the "Construction Plan for 8 Reactor Catalyst Unloading Project of VRDS Device in the Heavy Oil Hydrogenation Workshop of Shengli Refinery of China Petroleum and Chemical Corporation" (hereinafter referred to as the "Construction Plan"). The head of the equipment of the heavy oil hydrogenation workshop and the head of the relevant functional departments of the refinery approved and signed the "Construction Plan".
Annex 1 of the Construction Plan is the "Work Safety Analysis (JSA) Record Table", which includes hazards such as leakage, poisoning, suffocation, and high falls, as well as corresponding risk control and emergency measures, but does not involve the potential risk of catalyst collapse in the unloading operation. The relevant person in charge of the process, equipment and safety of the heavy oil hydrogenation workshop and the relevant person in charge of Tianpeng Company participated in the risk analysis work and gave safety briefings to the construction personnel.
On April 2, 2022, the reactor began to add film forming agent and perform film forming operations. On April 8, the reactor began to unload the agent on site.
Tianpeng Company's project department has a total of 113 people. The project manager is Chen Xiaochun, manager of the fourth department of the refining and chemical industry of Tianpeng Company. There are 5 on-site management personnel. The remaining personnel are divided into 12 teams. They are continuously constructed 24 hours a day, and are responsible for unloading the agent of 8 reactors. Among them, Zhang Xuegang's team is responsible for unloading R1310 and R1330. The team members include Sang Aichi, Zhang Xuegang, Chen Jian, Qin Lijun, Zhao Yongxiang and Zhang Fei. Zhang Xuegang's team only performs night shift homework, and the homework time is from 19:00 on the same day to 7:00 on the next day.
111 The main tools for unloading operations are: pneumatic pick , iron pick , suction machine, compressor , rubber tube , breathing mask, safety rope, safety belt, anti-falling device , walkie-talkie, etc. The construction workers enter the reactor from the manhole at the upper part of the reactor, and from top to bottom, first smash the coke-catalyst coke block with a pneumatic pick, and then use a rubber tube and a suction machine to extract the crushed coke block from the reactor. In order to ensure the safety of the operators in the reactor, the video surveillance system is equipped on site, and the outside supervisors monitor the operation status in the reactor through the monitor.
htmlOn April 12, Zhang Xuegang's team started R-1310 unloading operation. On the morning of April 14, the R-1310 unloading operation was completed. On the evening of April 14, Zhang Xuegang's team started R-1330 unloading operation.
As of the time of the accident, the unloading operation of 3 reactors had been completed on the site.
(IV) The situation of deaths in the accident
Zhang Fei, male, 36 years old, Tianpeng Company's unloading project construction worker, from Zhuma Town, Lianshui County, Jiangsu Province, was injured in the accident and died on the same day by the hospital's rescue.
02, the accident happened and the aftermath of rescue
(I) The accident happened
htmlOn April 15, the heavy oil hydrogenation workshop applied for the "Entering Confined Space Operation License" for the R-1330 unloading operation, with the time limit from 15:10 on April 15 to 15:9 on April 16. The previous "JHA (JSA) Analysis and Safety Briefing/Risk Notice Confirmation Letter" will be from April 14 to April 16, and the "High-altitude Operation Certificate (Level 3)" is valid from 14:30 on April 14 to 14:30 on April 17.
html At 19:00 on April 15, Zhang Xuegang's team entered the R-1330 unloading construction site. That night, the on-site guardians of the heavy oil hydrogen refueling workshop were Hou Weijun, Ma Feng, and Wang Wandong, the person in charge of Tianpeng Company was Zhong Qinggang, and the video surveillance officer was Wang Fengqing.
htmlAround 19:40 on April 15, Sang Aichi first entered R-1330 homework. At this time, the upper catalyst in the reactor has been cleaned up, the channel plate of the middle tower plate has been removed, and a small hole has been dug out on one side of the lower catalyst, allowing only one person to work. At 23:00 on April 15, Sang Aichi finished unloading operations.
html From 1:00 to 3:00 on April 16, Zhang Xuegang carried out the unloading operation in the R-1330 reactor. When Zhang Xue had just finished the operation, one person could barely stand on one side of the reactor, and the catalyst on the other side had a hard coke block with a diameter of about 1 meter and a thickness of about 60 cm was difficult to break and remove.
htmlAround 3:30 on April 16, Zhang Fei entered the R-1330 reactor operation. At around 4:40, because the temperature in the reactor was still a little high, Zhang Fei spoke with Chen Jian, who was responsible for supervision through the caller and asked to get some dry ice . When Qin Lijun and Chen Jian got the dry ice in a woven bag on the upper platform of the reactor and were about to be transported to Zhang Fei, Chen Jian called Zhang Fei with a telephone. Zhang Fei initially agreed, but when Chen Jian called again, Zhang Fei stopped answering.
The accident investigation team retrieved the video surveillance at that time, showing that the catalyst calcified block (about 1 meter in diameter and about 60 cm thick) hanging above Zhang Fei's operation area collapsed at 5 o'clock and fell on Zhang Fei's body.
(II) Emergency rescue and aftermath handling of accidents
Chen Jian called Zhang Fei continuously without answering, and the construction personnel outside the reactor realized that the accident had occurred. At around 5:10, Zhang Xuegang put on a respirator and other equipment and entered the reactor to check. He found that the catalyst calcified block collapsed and pressed on Zhang Fei's back. So he used the intercom to call other personnel to participate in the rescue. Four construction workers took turns to enter the reactor, smashed the collapsed coke block with an iron pickaxe, pulled Zhang Fei out of the coke block, and rescued Zhang Fei from the reactor at around 5:40.
5:20, Zhong Qinggang reported the accident on site by phone. At around 5:30, Chen Xiaochun rushed to the scene to participate in the accident rescue command. At 5:56, Chen Xiaochun called the 120 emergency number and drove a pickup truck to take Zhang Fei out of the oil refinery. He encountered an ambulance coming on the road. Zhang Fei was sent to Peking University Medical Shandong Hospital for emergency treatment. At 8:20, he died after failed rescue.
htmlAbout April 16, Wang Jiajun, the duty director of the heavy oil hydrogen refueling workshop, discovered the situation at the scene, and reported to the deputy director of the workshop at 6:14. The accident information was immediately reported to the main leaders of the workshop, oil refinery, and Sinopec Qilu Branch, step by step, and reported to the Municipal Emergency Bureau. After the accident, Tianpeng Company discussed the aftermath with the family of the deceased. The body of the deceased was cremated at the city funeral home on April 22, and the aftermath of the accident was basically completed.
03, Causes and Properties of the Accident
(I) Direct Causes
It is estimated that the collapsed catalyst calder weight is about 500kg. When the unloader is carried out in the reactor, the loose catalyst under the catalyst coke block is gradually hollowed out. After the coke block loses support, it collapses instability and hits the construction worker's back, which is the direct cause of the accident.
(II) Indirect reasons
1. Tianpeng Company's safety production responsibility is not implemented
Tianpeng Company's preparation of the "Construction Plan" is a form of formality, safety risk grading and control measures are not implemented, potential collapse risks in unloading operations have not been identified and analyzed, targeted measures have not been taken, and targeted safety training and education have not been carried out; the safety management of on-site construction work is not in place, the supervision and monitoring personnel have not conscientiously fulfilled their safety inspection and supervision responsibilities, and failed to promptly discover the accident hazards of illegal operations of operators in the reactor and the catalyst calculating block hanging in the air.
2. The refinery fails to perform its unified coordination management responsibilities in place
The refinery fails to perform its unified coordination management responsibilities in place for the contractor. The risk classification control and hidden danger investigation and control measures were not implemented effectively, the safety risk analysis of the residual oil hydrogenation reactor unloading operation link was not thorough or in place, the collapse risk existed in the restricted space unloading operation was not recognized, and targeted safety measures and safety briefing were not taken; the on-site construction was negligent, the supervisors did not conscientiously perform their safety inspection and supervision responsibilities, and failed to promptly discover the accident hazards of the suspended catalyst coke blocks in the reactor.
3. Sinopec Qilu Branch has failed to supervise and inspect subordinate units
Sinopec Qilu Branch has not effectively played its role in supervising and inspecting safety production of subordinate units. The collapse risk in confined space unloading operation was not discovered, nor was it found and corrected that Tianpeng Company’s video surveillance personnel were not careful in monitoring and the on-site guardian did not contact the operating personnel at the prescribed time.
(III) Nature of the accident
After investigation, the accident was a general production safety accident.
04, Accident Responsibility Determination and Handling Recommendations
(I) It is recommended to investigate criminally responsible persons
Chen Xiaochun, Tianpeng Company's oil refinery unloading project manager, performs the safety management responsibilities of risk hazard investigation, training and education, supervision and inspection, etc., and fails to urge the operators to strictly implement the operating procedures, fail to promptly discover and eliminate the hidden dangers of production safety accidents in restricted space unloading operations, bear the main responsibility for the occurrence of the accident, and is suspected of constituting a major responsibility accident. It is recommended to transfer it to judicial authorities for investigation and handling in accordance with the law.
(II) Related handling suggestions for state staff
The clues and related materials of relevant state staff in their performance of duties found during the accident investigation process were transferred to the accident accountability review and investigation team. The disciplinary and administrative sanctions on relevant personnel and the handling opinions of relevant units shall be put forward by the disciplinary inspection and supervision organs.
(III) It is recommended that the units and personnel who impose administrative penalties on
Recommended that the Municipal Emergency Bureau impose administrative penalties on the following units and personnel in accordance with the relevant provisions of the "HD Law of the People's Republic of China ":
1. Tianpeng Company, the responsibility for production safety is not implemented, the on-site construction management is chaotic, the risk classification control measures for production safety is not implemented, the risk analysis, safety training and education, and on-site supervision and inspection are not in place, and the main responsibility for the occurrence of the accident is imposed, and a fine of 400,000 yuan is imposed in accordance with Article 114 of the "Production Law of the People's Republic of China".
2. Cao Fang, the main person in charge of Tianpeng Company, has failed to perform the duties of organizing safety risk hazard inspection and control work, has incomplete risk identification, has failed to supervise and inspect limited space operations, and has failed to promptly discover and eliminate production safety accident hazards in restricted space unloading operations, and is mainly responsible for the occurrence of the accident. According to Article 95 of the "Production Safety Law of the People's Republic of China", a fine of 40% of the individual's annual income in 2021 will be imposed.
3. Sinopec Qilu Branch has failed to supervise and inspect the safety production safety of subordinate units. The oil refinery, its subordinate unit, failed to perform its unified coordination and management responsibilities for the contractor, and failed to implement risk classification control and hidden danger investigation and control measures, and bear important responsibility for the occurrence of accidents. It is recommended to impose a fine of 300,000 yuan on Sinopec Qilu Branch in accordance with Article 114 of the "Production Safety Law of the People's Republic of China".
4. Sun Guansong, the former main person in charge of the refinery, has failed to supervise and inspect the unit for its performance of unified coordination and management responsibilities, organized the risk and hidden danger investigation work without in-depth and meticulous work, failed to promptly discover and eliminate the production safety accident hazards in restricted space unloading operations, and bears important responsibility for the occurrence of the accident. In accordance with Article 95 of the "Production Safety Law of the People's Republic of China", a fine of 40% of the individual's annual income in 2021 will be imposed.
05. Accident prevention and rectification measures
In order to learn from the lessons of accidents, implement the principle of " four not letting go of ", and do a good job in future production safety work, and prevent similar accidents, the following rectification measures and suggestions are put forward:
(I) Governments at all levels and relevant departments should deeply learn from the lessons of accidents, strengthen the awareness of red lines and bottom line thinking, and strictly implement the requirements of "Party and government share responsibility, one post two responsibilities , working together to manage" and "manage the industry must manage safety, business must manage safety, and production and operation must manage safety", further clarify the responsibilities of hierarchical supervision and local supervision, and strengthen local supervision responsibilities.
(II) Enterprises in all industries and fields must strictly follow the relevant requirements of laws, regulations, standards and specifications, and according to their own production and operation characteristics, they must build a dual prevention system of risk classification control and hidden danger investigation and control, establish and improve risk prevention and resolution mechanisms, comprehensively investigate accident hazards, and improve the level of safety production management. The construction of the dual prevention system must not only be carried out in daily production activities, but also include the inspection and maintenance of production equipment, the implementation of technical transformation and technical measures, and the management of external construction teams. It must cover all the production and operation activities of the enterprise, comprehensively and in-depth analysis of risks and hidden dangers, take targeted safety precautions, strengthen safety education and training and safety briefing before operation, strengthen on-site supervision, and effectively eliminate potential accident hazards.
(III) All relevant regulatory departments must conscientiously perform their safety supervision responsibilities, continuously improve the level of safety supervision, urge all types of enterprises to strictly implement various safety management systems, and on the basis of strengthening daily safety management, we will effectively strengthen the on-site management of production equipment inspection and maintenance, external construction team management, and dangerous operations management, and strictly prevent the occurrence of various accidents.
Source: Zibo Emergency Management Bureau, Olefins and high-end downstream
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