1、开停车装置检修停车时，装置内的物料首先要排出，气体送至火炬系统，液

1. When the shutdown <BR>device is turned on for maintenance and shutdown, the materials in the device must first be discharged, the gas is sent to the torch system, and the liquid materials are poured into the storage tank. After the pressure in the system drops to normal pressure, the system is replaced and steam purged with nitrogen. , The small amount of oil and gas that is replaced is led to the flare system. The oil and gas entering the flare system is subjected to liquid separation and filtration, and the condensate is returned to the device; the uncondensed combustible gas is compressed by the combustible gas recovery system and sent to the dry gas desulfurization device for treatment, and the desulfurized dry gas is sent to the fuel system for recycling. The unrecoverable combustible gas is vented after combustion, and most of the bright components are converted into CO2 and water, and a small amount of SO2 produced by combustion is discharged into the atmosphere. <BR>Before the device is started up, the system needs to be purged and replaced with nitrogen again. The purging/replacement gas contains a small amount of dust, which can be directly discharged into the ambient air. <BR>(1) Start-up and shutdown of gas and hydrogen production unit The gas production and hydrogen production unit of <BR>this project adopts GE coal-water slurry pressurized gasification chilling process. Set up 6 gasifiers, with 4 openings and 2 preparations. When starting the gasifier, the gasifier needs to be driven one by one, and the crude synthesis gas can be sent to the downstream purification device after the commissioning is normal and reaches a certain load. The crude synthesis gas generated in the previous gasification process needs to be sent to the torch for processing Combustion treatment. In addition, the gasifier needs to be regularly replaced and maintained, and the unqualified crude synthesis gas generated when the gasifier is put into use also needs to be sent to a high-pressure torch for combustion treatment. At this time, the sulfur in the crude synthesis gas will all be converted into SO2 and then discharged into the atmosphere. At the same time, since the downstream purification device has not been put into operation, the hydrogen sulfide-containing waste gas discharged from the high-pressure flash separator also needs to be sent to the torch for combustion treatment. <BR>(2) Start-up of <BR>the power station boiler The power station boiler of this project adopts a circulating fluidized bed boiler, which uses diesel fuel injection during the start-up phase of the boiler. However, the denitrification facility cannot operate normally for a short time during the start-up phase, and the normal denitrification efficiency cannot be achieved. The start-up phase generally lasts no more than 4 hours. The NOx emission concentration in this phase is about 100mg/n?, and there will be a short-term NOx concentration exceeding the standard. <BR>2. Equipment pressure relief <BR>All the pressure relief gas discharged when the device is unstable are sent to the torch in the factory for treatment. The torch is an important part of petrochemical enterprises.<BR>One of the safety and environmental protection facilities, used to deal with the flammable gas emitted by the production equipment and auxiliary facilities during normal production, starting and stopping, inspection and maintenance and other abnormal conditions, as well as in the event of an accident, to protect the safety of people and equipment. <BR>According to the operating characteristics of each device, maintenance grouping, emission law, boundary pressure, the composition and heating value of the flare gas, the capacity limit of a single flare, etc., the flare gas of the whole plant is reasonably allocated. The project has a total of 7 sets of flare systems, of which 6 are Elevated torch, 1 ground torch. <BR>3. The production of pollutants during the inspection and maintenance process. <BR>This project is an integrated refining and chemical project. On average, inspection and maintenance are carried out every 4 years, and the time for each inspection and maintenance is about 1.5 months. The "three wastes" pollutants will be generated during the inspection and maintenance process, and the main sources and production conditions are as follows: <BR>(1) The exhaust gas generation during the inspection and maintenance process is <BR>to start and shut down towers, storage tanks and other equipment to purge the combustible waste gas and enter the torch for incineration and cleaning. After cleaning, open the cover for maintenance. The residual gas will bring out a small amount of bright substances and enter the external environment. <BR>(2) The production of wastewater during the maintenance process. <BR>During the shutdown process, the equipment will be steamed and oily wastewater will be produced. The pollutants in the water are mainly petroleum, which can enter the two lOOOOn buffer tanks of the sewage treatment plant for temporary storage, and then limit the flow to discharge. The oily wastewater treatment series of sewage treatment plants are reused after advanced treatment. <BR>(3) Solid waste generation <BR>during the maintenance process. During the start-up, shutdown, and maintenance, a small amount of waste lubricating oil will be generated during the maintenance of moving equipment such as compressors and pumps. The cleaning of reactors, towers, etc. will generate some waste slag, the main component being coke slag , Oily mud sand, etc., can enter the solid waste incinerator in the plant for incineration treatment; in addition, the process equipment and pipeline insulation materials need to be partially replaced during the maintenance process, which will produce waste insulation cotton. The main component is rock wool, which is general waste. It can be dealt with afterwards. <BR>4. Failure <BR>operating conditions of environmental protection facilities (1) Abnormal operating conditions of tail gas treatment of sulfur recovery unit<BR>The sulfur recovery device of this project is also an important environmental protection device of the whole plant. Under normal working conditions, all the acid gas produced by this project is sent to the sulfur recovery device for processing. A total of 4 sets of sulfur recovery devices are set up in this project, with a construction scale of 150,000 t/a and a total capacity of 600,000 t/a. <BR>Under normal circumstances, the total sulfur recovery rate of the sulfur recovery device can reach more than 99.95%, but when its tail gas When the processing unit is operating abnormally, its desulfurization rate decreases, and the SO2 emission concentration in the flue gas cannot meet the special emission limit stipulated in the "Petroleum Refining Industry Pollutant Emission Standard" (GB31570-2015). The SO2 emission concentration is less than 100mg/ Nn? requirements. <BR>The project is equipped with 4 sets of sulphur plants, with a design operating flexibility of 30%~110%. During normal production, 4 sets of plants are running at the same time. According to the current process of the whole plant, the total sulfur output is 386,600 t/a, and the operating load of the sulfur recovery device is about 64.43%. When one of the sulfur recovery device tail gas processing units fails, the other three sulfur recovery devices can still guarantee treatment All acid gas in the whole plant avoids long-term excessive discharge of flue gas or discharge of acid gas to the torch. At the same time, the sulfur recovery device is equipped with a tail gas alkaline washing unit, which can also ensure that the SO2 emission concentration in the flue gas is less than 100mg/Nm3 during the startup and shutdown of the device. <BR>Through the above measures, it is basically possible to ensure that the exhaust gas of the sulfur recovery device meets the emission standard even in abnormal working conditions. <BR>(2) Abnormal working conditions of flue gas desulfurization and denitrification unit of <BR>catalytic cracking unit In addition to the design of wet desulfurization and SCR denitrification facilities, the catalytic cracking unit also considers the use of double-effect additives in the regenerator to complete CO combustion and assist NOx reduction at the same time , In order to achieve the denitrification effect. When the waste heat boiler fails, the flue gas machine fails, or the start-up stage, wet desulfurization can meet high-temperature working conditions and still achieve emission standards. However, if the desulfurization fails and the SCR denitration facility needs to be shut down, the flue gas emission cannot be guaranteed to meet the standard, and the catalytic cracking unit needs to be shut down as a whole. During the shutdown process, there will be short-term flue gas emissions exceeding the standard.

1. Start and stop<BR>During the overhaul and shutdown of the unit, the materials in the unit shall be discharged first, the gas shall be sent to the flare system, and the liquid materials shall be poured to the storage tank. After the pressure in the system drops to normal pressure, the system shall be replaced and steam purged with nitrogen, and a small amount of oil and gas replaced shall be led to the flare system. The oil and gas entering the flare system shall be treated by liquid separation and filtration, and the condensate shall be returned to the unit; The uncondensed combustible gas is compressed by the combustible gas recovery system and sent to the dry gas desulfurization unit for treatment, and the desulfurized dry gas is sent to the fuel system for recycling. The unrecoverable combustible gas is vented after combustion, most of which are converted into CO2 and water, and a small amount of SO2 produced by combustion is discharged into the atmosphere.<BR>Before the start-up of the unit, the system needs to be purged and replaced with nitrogen again. The purge / replacement gas contains a small amount of dust and can be directly discharged into the ambient air.<BR>(1) Startup and shutdown of gas and hydrogen production unit<BR>The gas and hydrogen production unit of the project adopts Ge coal water slurry pressurized gasification quench process. Six gasifiers are set, four for operation and two for standby. When the gasifier is started up, the gasifier needs to be started up one by one. After the commissioning is normal and reaches a certain load, the crude syngas can be sent to the downstream purification unit. Previously, the crude syngas generated in the gasification process needs to be sent to the flare for combustion treatment. In addition, the gasifier needs to be replaced and maintained regularly, and the unqualified crude syngas generated when the gasifier is put into use again needs to be sent to the high-pressure flare for combustion treatment. At this time, all sulfur in the crude syngas will be converted into SO2 and then discharged into the atmosphere. Meanwhile, since the downstream purification unit has not been put into operation, and the hydrogen sulfide containing waste gas discharged from the high-pressure flash separator also needs to be sent to the flare for combustion treatment.<BR>(2) Power station boiler startup<BR>The circulating fluidized bed boiler is adopted for the power station boiler of the project, and diesel injection is used for combustion support in the boiler start-up stage. However, in the boiler start-up stage, the denitration facilities can not operate normally for a short time and can not reach the normal denitration efficiency. The boiler start-up stage generally lasts no more than 4 hours, and the NOx emission concentration in this stage is about loomg / N?, The NOx concentration will exceed the standard for a short time.<BR>2. Equipment pressure relief<BR>When all units are unstable, the vent gas discharged is sent to the flare in the plant for treatment. The flare is an important part of petrochemical enterprises<BR>As one of the safety and environmental protection facilities, it is used to deal with the combustible gas discharged by production units and auxiliary facilities under abnormal working conditions such as normal production, startup and shutdown, inspection and maintenance, as well as in case of accidents, so as to protect personal and equipment safety.<BR>The flare gas of the whole plant shall be reasonably distributed according to the operation characteristics of each unit, maintenance grouping, discharge law, battery limit pressure, flare gas composition and calorific value, capacity limit of a single flare, etc. the project is equipped with 7 sets of flare systems, including 6 overhead flares and 1 ground flare.<BR>3. Generation of pollutants during inspection and maintenance<BR>The project is a refining and chemical integration project. The maintenance is carried out every 4 years on average, and each maintenance time is about 1.5 months. "Three wastes" pollutants will be generated during inspection and maintenance. The main sources and conditions are as follows:<BR>(1) Exhaust gas generation during maintenance<BR>During the start-up and shutdown of tower, storage tank and other equipment, the combustion containing waste gas will enter the flare for incineration. After cleaning, the cover will be opened for maintenance. The residual gas will bring a small amount of bright substances into the external environment.<BR>(2) Wastewater generation during maintenance<BR>Cooking the equipment during shutdown will produce oily wastewater. The pollutants in the water are mainly petroleum, which can enter the two looons in the sewage treatment plant? The buffer tank is temporarily stored, and then limited flow is discharged into the oily wastewater treatment series of the sewage treatment plant, which is reused after advanced treatment.<BR>(3) Generation of solid waste during maintenance<BR>During startup, shutdown and maintenance, a small amount of waste lubricating oil will be generated during the maintenance of compressor, pump and other dynamic equipment, and some waste residue will be generated during the cleaning of reactor and tower, mainly composed of coke residue and oily mud and sand, which can be sent to the solid waste incinerator in the plant for incineration; In addition, some process equipment and pipeline insulation materials need to be replaced during maintenance, which will produce waste insulation cotton, mainly composed of rock wool, which is general waste, and can be outsourced for disposal after collection.<BR>4. Failure condition of environmental protection facilities<BR>(1) Abnormal conditions of tail gas treatment of sulfur recovery unit<BR>The sulfur recovery unit of the project is also an important environmental protection unit of the whole plant. Under normal working conditions, all the acid gas generated by the project is sent to the sulfur recovery unit for treatment. Four sets of sulfur recovery units are set in the project, with a construction scale of 150000 T / A and a total capacity of 600000 T / A0<BR>Generally, the total sulfur recovery rate of the sulfur recovery unit can reach more than 99.95%. However, when the tail gas treatment unit does not operate normally, the desulfurization rate decreases, and the SO2 emission concentration in the flue gas cannot meet the special emission limit specified in the emission standard for pollutants from petroleum refining industry (gb31570-2015). The SO2 emission concentration is less than loomg / NN? Requirements.<BR>The project is equipped with 4 sets of sulfur units, with design operation flexibility of 30% - 110%. During normal production, 4 sets of units operate at the same time. According to the current process of the whole plant, the total sulfur output is 386600 T / A, and the operating load of the sulfur recovery unit is about 64.43% O. when one set of sulfur recovery unit tail gas treatment unit fails, the other three sets of sulfur recovery units can still ensure the treatment of all acid gas in the whole plant, so as to avoid excessive discharge of flue gas for a long time or acid gas discharge to the flare. Meanwhile, the sulfur recovery unit is equipped with tail gas alkali washing unit, which can also ensure that the SO2 emission concentration in the flue gas is less than 100mg / Nm3 during the startup and shutdown of the unit.<BR>Through the above measures, it can basically ensure that the tail gas of sulfur recovery unit can be discharged up to standard even under abnormal working conditions.<BR>(2) Abnormal working conditions of flue gas desulfurization and denitration unit of catalytic cracking unit<BR>In addition to designing wet desulfurization and SCR denitration facilities, the catalytic cracking unit also considers the use of double effect additives in the regenerator to complete CO combustion support and assist NOx reduction, so as to achieve denitration effect. In case of waste heat boiler failure, flue gas turbine failure or start-up stage, wet desulfurization can meet high-temperature working conditions and still achieve up to standard emission. However, if desulfurization fails and SCR denitration facilities need to be shut down, the flue gas cannot be discharged up to standard, and the catalytic cracking unit needs to be shut down as a whole. In the process of shutdown, there will be excessive emission of flue gas for a short time.

1. Start and stop the car. When the device is shut down for maintenance, the materials in the device should be discharged first, the gas should be sent to flare system, and the liquid materials should be poured into the storage tank. After the pressure in the system drops to normal pressure, the system should be replaced with nitrogen and purged with steam, and a small amount of replaced oil and gas should be led to flare system. Oil and gas entering the flare system are separated and filtered, and condensate returns to the device; The uncondensed combustible gas is compressed by the combustible gas recovery system and then sent to the dry gas desulfurization unit for treatment, and the desulfurized dry gas is sent to the fuel system for recycling. The unrecoverable combustible gas is vented after combustion, in which most of the brilliant components are converted into co2 and water, and a small amount of SO2 generated by combustion is discharged into the atmosphere. Before the start-up of the unit, the system needs to be purged and replaced again with nitrogen gas. The purged/replaced gas contains a small amount of dust, which can be directly discharged into the ambient air. (1) Start-up and shutdown of gas-making and hydrogen-making device In this project, the gas-making and hydrogen-making unit adopts GE coal water slurry pressurized gasification quenching process. There are 6 gasifiers, 4 on and 2 on standby. When the gasifier is started, the gasifier needs to be started one by one, and the crude synthesis gas can only be sent to the downstream purification device after the commissioning is normal and reaches a certain load. The crude synthesis gas generated in the previous gasification process needs to be sent to the torch for combustion treatment. In addition, the gasifier needs to be replaced and maintained regularly, and the unqualified crude synthesis gas produced when the gasifier is put into service again also needs to be sent to the high-pressure torch for combustion treatment. At this time, all sulfur in the crude synthesis gas will be converted into SO2 and then discharged into the atmosphere. At the same time, as the downstream purification device has not been put into operation, the waste gas containing hydrogen sulfide discharged from the high-pressure flash separator also needs to be sent to the torch for combustion treatment. (2) Power station boiler startup The boiler in the power station of this project is a circulating fluidized bed boiler, which uses diesel fuel injection to support combustion at the start-up stage. However, during the start-up stage, the denitration facilities can't operate normally for a short time, and the normal denitration efficiency can't be achieved. The start-up stage generally lasts less than 4 hours, and the NOx emission concentration at this stage is about lOOmg/n? , there will be a short-term NOx concentration exceeding the standard. 2. Pressure relief of equipment All the pressure relief gas discharged when the device is unstable is sent to the flare in the plant for treatment, which is important for petrochemical enterprises. One of the safety and environmental protection facilities, which is used to treat combustible gases emitted by production devices and auxiliary facilities under abnormal working conditions such as normal production, startup, shutdown, inspection and maintenance, and accidents, so as to protect personal and equipment safety. According to the operation characteristics of each device, maintenance grouping, emission rule, battery limit pressure, flare gas composition and calorific value, capacity limitation of a single flare, etc., the flare gas in the whole plant is reasonably distributed. There are 7 sets of flare system in this project, including 6 overhead flares and 1 ground flare. 3, inspection and maintenance process of pollutants. This project is a refining-chemical integration project, and it is inspected and maintained once every four years on average, and each inspection and maintenance time is about one and a half months. The "three wastes" pollutants will be produced in the process of inspection and maintenance. The main sources and conditions are as follows: (1) the generation of waste gas during maintenance During the start-up and shutdown of towers, storage tanks and other equipment, the combustible waste gas is purged into the torch for incineration treatment. After cleaning, the cover is opened for maintenance, and the residual gas will bring out a small amount of brilliant substances and enter the external environment. (2) Wastewater generation during maintenance Cooking equipment during shutdown will produce oily wastewater, and the pollutants in the water are mainly petroleum, which can be fed into two lOOOOn in the sewage treatment plant. The buffer tank is temporarily stored, and then discharged into the oily wastewater treatment series of sewage treatment plant with limited flow, and reused after advanced treatment. (3) The occurrence of solid waste during maintenance In the process of start-up, shutdown and maintenance, the maintenance of compressors, pumps and other moving equipment will produce a small amount of waste lubricating oil, and the cleaning of reactors, towers and other equipment will produce some waste residues, mainly composed of coke slag and oily sludge sand, which can enter the solid waste incinerator in the plant for incineration. In addition, thermal insulation materials of various process equipment and pipelines need to be partially replaced during maintenance, which will produce waste thermal insulation cotton, mainly composed of rock wool, which is general waste, and can be disposed of by outsourcing after collection. 4. Failure conditions of environmental protection facilities (1) Abnormal working condition of tail gas treatment in sulfur recovery unit The sulfur recovery unit of this project is also an important environmental protection unit of the whole plant. Under normal working conditions, all sour gas generated by this project is sent to the sulfur recovery unit for treatment. There are 4 sulfur recovery units in this project, all of which have a construction scale of 150,000 t/a and a total capacity of 600,000 t/a0. Generally, the total sulfur recovery rate of sulfur recovery unit can reach more than 99.95%. However, when the unit operation of tail gas treatment is abnormal, the desulfurization rate will decrease, and the SO2 emission concentration in flue gas can't meet the special emission limit specified in Emission Standard for Pollutants in Petroleum Refining Industry (GB31570-2015) that the SO2 emission concentration is less than lOOmg/Nn? The requirements. There are totally 4 sulfur plants in this project, with the designed operating flexibility of 30% to 110%. During normal production, 4 plants will operate at the same time. At present, according to the process of the whole plant, the total sulfur output is 386,600 t/a, and the operating load of the sulfur recovery unit is about 64.43%o When the tail gas treatment unit of one of the sulfur recovery units fails, the other three sulfur recovery units can still ensure that all sour gas in the whole plant can be treated, so as to avoid the situation that the flue gas exceeds the standard for a long time or the sour gas is discharged to the torch. At the same time, sulfur sulfur recovery unit is equipped with tail gas alkaline washing unit, which can also ensure that SO2 emission concentration in flue gas is less than 100mg/Nm3 during the start-up and shutdown of the unit. Through the above measures, it can basically be ensured that even under abnormal working conditions, the tail gas of sulfur recovery unit can reach the discharge standard. (2) Abnormal working conditions of flue gas desulfurization and denitrification unit of catalytic cracking unit In addition to designing wet desulfurization and SCR denitration facilities, the catalytic cracking unit also considers the use of double-effect additives in the regenerator to assist NOx reduction while supporting CO combustion, so as to achieve denitration effect. When the waste heat boiler fails, the flue gas turbine fails or the start-up stage, wet desulfurization can meet the high-temperature working conditions, and can still achieve the emission standard. However, if the desulfurization fails and the SCR denitration facilities need to be shut down, the flue gas can't be discharged up to the standard, and the catalytic cracking unit needs to be shut down as a whole. In the process of shutdown, there will be a short period of excessive emission of flue gas.