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This post was last edited by wang*nhua77020 on 2016-6-5 11:25. Production accidents occur frequently; I hope we can learn lessons from these accidents to improve our production processes. To prevent further human tragedies from occurring: (I) Domestic accidents – The nitrogen oxide poisoning and asphyxiation accident at Jiangsu Nanhua Company’s nitrogen fertilizer plant on June 2. On June 2, 1993, an oxidation nitrogen poisoning accident occurred in the nitric acid production workshop of Jiangsu Nanhua Company’s nitrogen fertilizer plant, resulting in 3 deaths due to poisoning. During the shutdown for major maintenance and replacement in the *ao acid plant, workers mistakenly removed a blind flange, resulting in nitrogen oxide gas escaping from the alkali absorption circulation tank. The Major Explosion and Fire Incident at the Triphenyl Tank Area of Dalian Petrochemical, China National Petroleum Corporation, on June 2, 2013: On June 2, 2013, an explosion and fire broke out at the triphenyl tank area of the First Combined Workshop of Dalian Petrochemical Branch of China National Petroleum and Natural Gas Corporation during welding operations; this incident resulted in 4 deaths and direct economic losses of 6.97 million yuan. The direct cause of the accident was that contractors working for Dalian Petrochemical carried out gas cutting operations in violation of regulations on the roof of a miscellaneous storage tank in the triphenyl tank area of the First Combined Workshop. The cutting flame ignited flammable and explosive gases such as toluene that had leaked, and the backfire spread into the tank, causing it to explode; this in turn led to the explosion and ignition of three other nearby tanks as well. The poisoning accident in the chlorine chemical production section of the Pesticide Plant at Henan Xinyang Chemical Complex on June 11: On June 11, 1994, a poisoning accident occurred in the chlorine chemical production section of the Pesticide Plant at Henan Xinyang Chemical Complex, resulting in 3 deaths and 8 people being poisoned. At the time of the incident, the lower part of washing tank No. 2 in the chlorination section of the Methyl 1605 workshop in the pesticide production plant was blocked; therefore, the upper manhole was opened to stop the operation of the tank for maintenance. Three workers were on duty, one of whom handled the work inside the tank while wearing a filtering gas mask, with the team leader overseeing from outside. As soon as the workers entered the tank, they fainted; the team leader who peered inside also fainted. Another worker noticed this and called for help, and workers from other shifts joined in the rescue efforts. As a result, 11 people inside and outside the tank were poisoned, 3 of whom died despite attempts to save them. The \"6•12\" Hydrogen Sulfide Poisoning Incident at Anning Qitian Fertilizer Co., Ltd. in Kunming On June 12, 2008, an hydrogen sulfide poisoning incident occurred at Anning Qitian Fertilizer Co., Ltd. in Kunming, Yunnan Province, during the pilot production of arsenic-free refined phosphoric acid; this incident resulted in 6 deaths and 29 people being poisoned. At the time of the incident, the operator was adding a sodium sulfide aqueous solution to the phosphoric acid tank. When adjusting the bottom valve, it was found that the valve could not be closed; as a result, the sodium sulfide solution continued to flow into the phosphoric acid tank, causing an excess of sodium sulfide in that tank. The large amount of hydrogen sulfide gas generated escaped from the upper part of the unsealed phosphoric acid tank, leading to poisoning of some of the workers on site as well as those who came to provide assistance. The \"6•12\" hydrogen sulfide poisoning incident at Taizhou Fengrun Biochemistry Company in Zhejiang Province On June 12, 2009, a hydrogen sulfide poisoning incident occurred at Taizhou Fengrun Biochemistry Co., Ltd. in Zhejiang Province, resulting in 3 deaths and 2 people being poisoned. At the time of the incident, a construction worker went down to the bottom of an underground pile hole at a depth of about 10 meters to carry out work; he was poisoned and collapsed due to high levels of hydrogen sulfide. Later, four others tried to rescue him without wearing any protective equipment, and they too were poisoned and collapsed one after another. The “6•14” blast at the cinder storage area of Cangwu Nitrogen Fertilizer Plant in Guangxi On June 14, 1982, an explosion occurred at the gas-generation cinder storage area of Cangwu Nitrogen Fertilizer Plant in the Guangxi Zhuang Autonomous Region, resulting in 7 deaths, 1 person seriously injured, and 3 people lightly injured. As the scorching coal cinders produce water gas when in contact with water, and this gas accumulates in the gaps between the cinders, when workers remove the cinders from below, the pile becomes loose and collapses. The gas present within the pile then explodes upon coming into contact with the hot coal cinders that have fallen on top of it. The “6•14” reactor explosion accident at the chemical plant in Rui’an, Wenzhou, Zhejiang Province On June 14, 1993, a reactor in the acid preparation section of the trianiline production workshop at the chemical plant in Rui’an, Wenzhou, Zhejiang Province exploded. As a result of this accident, 3 people died, 9 were seriously injured, and 5 suffered minor injuries. The factory building was destroyed, resulting in economic losses of over 2 million yuan. Before the accident, the company improved its production process in order to eliminate the generation of large amounts of waste sulfuric acid during the production of dye intermediates. After modifying the factory’s production equipment, testing was carried out without preliminary trials or pilot tests, and material was fed into the reactor directly, resulting in a severe explosion in the reactor after feeding. The \"6•15\" carbon monoxide poisoning accident at the Second Fertilizer Factory in Shaowu City, Fujian Province On June 15, 1989, a carbon monoxide poisoning accident occurred in the desulfurization section of the Second Fertilizer Factory in Shaowu City, Fujian Province, resulting in 4 deaths and 5 injuries. The section where the incident occurred had a total of 4 desulfurization tanks equipped with activated carbon. The drain valves for carbon beds No. 1 and No. 3 were leaking severely, while the inlet valve of carbon bed No. 2 had serious internal leakage; the blind plate in question was severely deformed and sunken. When the blind plate at the inlet of carbon bed No. 2 was removed and displaced, toxic gases leaked from the inlet valve into carbon bed No. 2, then entered the drain pipe through the open drain valve, and subsequently made their way into carbon bed No. 4. While loading activated carbon into the carbon bed of Desulfurization Tank No. 4 and removing the blind flange at the gas inlet of Carbon Bed No. 2, personnel entering the tank were successively poisoned by carbon monoxide. The “6•16” explosion accident at Anhui Dunan Chemical Group Co., Ltd. On June 16, 2006, an explosion occurred at Anhui Dunan Chemical Group Co., Ltd. in Dangtu County, Ma’anshan City, resulting in 16 deaths, 24 injuries, and the destruction of approximately 200 square meters of factory buildings. The powder emulsification **production line in the company’s powder emulsification workshop operates beyond its approved production capacity. Equipment failures and repairs occur frequently. Moreover, no safety interlock control devices have been installed on high-risk equipment such as screw pumps used for conveying emulsification substrates at high viscosity and high temperatures. At the time of the incident, the operator of pump number 1 violated operating procedures, causing the screw pump to run idle without any material flow for over 12 minutes. This led to the matrix inside the pump chamber heating up due to intense mechanical friction, resulting in an explosion. The explosion in the scrubber tower of the decarboxylation unit at Hubei Yihua Group Company on June 18, 1998: On June 18, 1998, an explosion occurred in the scrubber tower of the decarboxylation unit at Hubei Yihua Group Company, resulting in 4 deaths and 3 injuries, with direct economic losses of around 180,000 yuan. The decarburization section washing tower where the explosion occurred was converted from a liquefied gas storage tank in 1986. Without the approval of the design department, nor regular inspections by a professional pressure vessel inspection agency, only periodic self-inspections of the wall thickness were carried out. The hidden danger posed by the gradual thinning of the bottom of the washing tower due to erosion was not detected before the accident, which led to the incident. The \"6•18\" accident at Haohua Branch of Heilongjiang Beidahuang Agricultural Company: On June 18, 2015, an accident occurred in the gas generation workshop of Haolianghe Fertilizer Branch of Heilongjiang Beidahuang Agricultural Co., Ltd., resulting in the suffocation death of 3 people. As the workers in the gas production workshop entered the underground dissolution tank for coal slurry additives in the coal grinding section without obtaining approval to enter confined spaces and without wearing protective equipment, one person suffered asphyxiation. Additionally, two other people attempted to carry out rescue efforts without taking any protective measures, which led to an escalation of the accident and more casualties. The gas poisoning accident at the activated carbon desulfurization tower of Suining County Fertilizer Factory in Jiangsu on June 22: On June 22, 1989, during maintenance work on the activated carbon desulfurization tower in the carbonization workshop of Suining County Fertilizer Factory in Jiangsu, the lack of use of blind flanges to isolate the area led to 3 deaths and 4 people being injured as a result of gas poisoning. Since the carbonization workshop failed to isolate the equipment under maintenance from the system or install blind flanges to cut off the gas supply, and without obtaining a work permit or having any supervision in place, maintenance personnel entered the vessel without authorization, resulting in one person suffering from poisoning. The workshop failed to take effective measures such as cutting off the gas supply to carry out rescue efforts, which led to the escalation of the poisoning incident. The “6•26” explosion accident in the warehouse of Zhengzhou Food Additive Factory caused by perbenzoic acid oxide. On June 26, 1993, an explosion occurred at the Zhengzhou Food Additive Factory in Henan Province, resulting in 27 deaths, 33 injuries, and economic losses of around 3 million yuan. Excessive storage of benzoyl peroxide in the warehouse was the direct cause of the explosion. Other causes of the accident included an unreasonable layout of the factory building, the mixing of warehouses and offices, and no restrictions on employees smoking. The \"6•26\" chemical raw material explosion at Tianjin Dahua Chemical Plant: On June 26, 1996, an explosion occurred at the Tianjin Jinxī Dahua Chemical Plant, resulting in 19 deaths, 14 injuries, and direct economic losses of over 1.2 million yuan. A few days before the incident, there had been persistent high temperatures; the roof of the factory was covered with asbestos shingles, which provided poor insulation, and the high temperatures accelerated the combustion process of the oxidizers. The oxidizing agent sodium chlorate undergoes an oxidation reaction with organic substances, generating heat; this heat in turn accelerates their oxidation reaction, and this cycle ultimately leads to the combustion of the organic substances and combustibles. During the fire fighting process, the acidic water sprayed onto the strong oxidizer (NaClO3) accelerated the oxidative decomposition of the oxidizer, resulting in the production of large amounts of chloric acid. The high-temperature and high-pressure gases generated by the explosion of the chloric acid and NaClO3 mixture caused the explosion of 2,4-dinitroaniline. The explosion in the hydrolysis reactor of the sebacic acid production workshop at Inner Mongolia Tongliao Oil and Fat Chemical Plant on June 27, 1992: On June 27, 1992, an explosion occurred in the hydrolysis reactor of the sebacic acid production workshop at Inner Mongolia Tongliao Oil and Fat Chemical Plant, resulting in 8 deaths, 4 serious injuries, and 10 minor injuries. Due to the medium in the hydrolysis tank being under pressure and at high temperatures, corrosion of the tank walls occurs, as well as erosion and wear of the inner walls by the medium; this leads to a rapid thinning of the tank walls, preventing the tank from withstanding the operating pressure and resulting in a physical explosion. The severe fire and explosion accident at the tank farm of Beijing Dongfang Chemical Plant on June 27 The explosion and fire incident occurred at Beijing Dongfang Chemical Plant on June 27, 1997, resulting in 9 deaths, 39 injuries, and direct economic losses of 117 million yuan. At the time of the incident, the operator was carrying out the task of unloading light diesel. When transferring light diesel from railway tank cars into storage tanks, the operator opened the wrong valve, causing the light diesel to enter a tank that was already full of it. This led to an excessive amount of light diesel overflowing from the top of the tank. The vapor of the spilled light diesel ignited upon contact with open flames, which in turn caused explosions and fires in the ethylene spheres and other storage tanks located in that area. The “6•28” **gas leak accident at Dalian Dye Factory in Liaoning Province: On June 28, 1988, a **gas leak occurred in the toluene diisocyanate tetraphenyl unit of Dalian Dye Factory in Liaoning Province, resulting in 3 deaths, 3 people who were rescued, and another 79 people who were admitted to hospital for observation. Due to the breakage of the disc-type sight glass in High-temperature Phosgene Gasification Reactor No. 3 in the workshop, 4.5 tons of toxic gas (containing phosgene, hydrogen chloride, etc.) that was undergoing gasification reacted and was released. When ammonia was used to deal with the phosgene, the phosgene released reacted with the ammonia to form a white mist band located 50–60 meters above the ground and 50–80 meters wide, which drifted with the wind and affected the surrounding residents as well as the oil areas in the port area. The “6•28” fire accident at Lanzhou Petrochemical Company: On June 28, 2006, a leak occurred at the cover of a condenser in the 400,000-ton/year gas fractionation unit at the Lanzhou Petrochemical refinery in Gansu, which triggered a fire. One corporate firefighter lost their life and 10 others were injured during the fire fight. This was because the maintenance personnel failed to remove the plastic film wrapped around the wave-shaped gasket when installing the condenser cover. After the vehicle was started, leakage occurred at the seal of the condenser cover; the high-speed spray of liquid hydrocarbons caused static discharge in the wave-shaped gasket covered with plastic film, which ignited the leaking liquid hydrocarbons and led to a fire. The “6•28” explosion accident at Yidong Jiuding Chemical Company in Ordos, Inner Mongolia On June 28, 2015, an explosion and fire broke out at Yidong Jiuding Chemical Co., Ltd. in Ordos, Inner Mongolia, resulting in 3 deaths and 6 people suffering minor injuries. The explosion occurred because of quality issues with the three-gas heat exchanger. There were pre-existing, through-going cracks at the fillet welds of the desulfurization gas inlet head, which had been repaired and welded four times previously; these cracks led to low-stress brittle fracture, causing the sudden release of desulfurization gas. Due to the high hydrogen content in the desulfurization gas, an explosion occurred at the moment of release, triggering a fire; this resulted in injuries and deaths among the personnel who were carrying out maintenance and insulation work in the vicinity. The “6•29” crude oil tank explosion incident at CNPC Liaoyang Petrochemical Branch On June 29, 2010, an explosion occurred in a crude oil tank at the crude oil transfer station of CNPC Liaoyang Petrochemical Branch’s refinery during tank cleaning operations. This incident resulted in the death of 3 workers inside the tank and injuries to 7 others, causing direct economic losses of 1.5 million yuan. At the time of the incident, the workers were carrying out on-site tank cleaning operations on a 30,000-cubic-meter crude oil tank at the crude oil transfer station. During the operation process, the oil and gas generated mix with air, creating an explosive gas environment. Sparks can occur when non-explosion-proof lighting fixtures are used, or as a result of impacts against the bottom of the tank during operations with iron-based tools for cleaning the tank, which can lead to explosions. The “6•30” explosion accident at the refinery of Nanjing Jinling Petrochemical Company On June 30, 1993, an explosion occurred at the gas supply station in the platinum reforming unit of the refinery operated by Nanjing Jinling Petrochemical Company in Jiangsu Province. The accident resulted in 3 deaths and 2 injuries, with direct economic losses amounting to 268,000 yuan. In preparation for operation, the company purchased small bottles of electrolytic hydrogen from external suppliers and used them to fill the V204/4 hydrogen cylinders with hydrogen. When the pressure in the V204/4 hydrogen cylinders reached 10.4 MPa, filling was stopped and the blind flanges on the pipelines were removed. At that point, leakage occurred at valve No. 7 located at the top of the V204/4 cylinder; the high-pressure mixed gas escaping generated static electricity sparks, or sparks were produced by friction between metal tools, which led to the explosion of the cylinder. (II) Foreign accidents: The “6·1” cyclohexane air oxidation reactor explosion in the UK. On June 1, 1974, an explosion occurred at a chemical plant in Felixstowe, Lincolnshire, UK, resulting in the release of large amounts of the toxic gas cyclohexane. This incident caused 28 deaths, hundreds of injuries, and losses amounting to $58 million. Due to a small crack that appeared at the temporary piping connection linking the two reaction tanks, the cyclohexane liquid inside the pipe was ejected through this crack. The high-temperature liquid filling the pipe lost its equilibrium as a result of the sudden pressure drop, becoming superheated in an instant. Inside the superheated cyclohexane liquid, countless boiling centers are formed; as the bubbles grow rapidly, they expand violently, causing the internal pressure to rise repeatedly. As a result, the cracks at the interface widened, eventually causing the end of the pipe to separate from the reaction tank; the liquid inside the pipe boiled and sprayed out from the pipe opening. The large amount of cyclohexane that leaked out rapidly vaporized, filling the entire plant with this vapor cloud, thereby causing a vapor explosion of cyclohexane. The “6·3” LPG pipeline leak accident in Ufa, the former Soviet Union, which caused a train derailment: On June 3, 1989, an explosion occurred due to the leakage of liquefied petroleum gas (LPG) from a pipeline near Ufa, the capital of the Bashkir Autonomous Republic in the former Soviet Union. This explosion led to the derailment of a train passing by, which then collided with another train heading in the opposite direction; as a result, more than 600 people died and over 500 were injured in this severe accident. Due to a break in the oil pipeline, the leaked liquefied petroleum gas (LPG) filled the valleys between the hills near the site. The management at the oil transfer station noticed a drop in gas pressure, so they adjusted the pump to increase pressure, which resulted in further gas leakage. At that moment, a train of electric passenger cars passed by, and the sparks generated by the trains’ pantographs triggered an explosion. The “6•3” gas station explosion in Ghana: On June 3, 2015, an explosion occurred at a gas station in the center of Accra, the capital of Ghana, resulting in the death of over 200 people. The gasoline station where the fire broke out is located near Enguma Roundabout, one of the busiest areas in Accra; it is in a low-lying area surrounded by bus stations and marketplaces, with a high population density. Due to continuous heavy rain, water levels rose sharply, causing traffic to come to a standstill; many people trapped there went to gas stations to take shelter from the rain. The direct cause of the accident was that heavy rain caused diesel and gasoline in the gas station to flow toward nearby residences; a source of fire at a location where trucks were parked triggered an explosion, which in turn led to the collapse of the gas station. The “6·25” fire and explosion accident at Port Ahmed in Kuwait On June 25, 2000, a fire and explosion occurred at Port Ahmed in Kuwait, resulting in 5 deaths, 50 injuries, and losses amounting to $380 million. At the time of the incident, the workers were attempting to seal the leak in the condensate pipeline between the NGL unit outside the site and the refinery’s natural gas unit. The lack of inspection and maintenance of the condensate pipelines outside the refinery, coupled with unclear ownership of these pipelines, resulted in the failure to isolate them in a timely manner. The accident caused damage to three crude oil processing units, with two reforming units also being destroyed. It took about nine hours after the initial explosion to put out the fire.