Jiangsu issued opinions to guide nitrification enterprises to improve their intrinsic safety

Global Coatings Network News:

The Emergency Management Department of Jiangsu Province issued guidance on further improving the intrinsic safety of nitrification enterprises on August 13, aiming to effectively control the safety risks of nitrification processes, eliminate safety hazards, and resolutely curb the occurrence of various production safety accidents of nitrification enterprises.

In order to effectively control the safety risks of the nitrification process, eliminate potential safety hazards, and resolutely curb the occurrence of various production safety accidents in nitrification enterprises, the existing nitrification process has fast reaction speed and large heat generation, and the reaction materials, nitrification products, by-products and hazardous wastes are explosive.

Nitrification enterprises should comprehensively evaluate the interaction between different processes in the nitrification workshop, and improve the fire and explosion isolation measures.
If the nitrification device and other production devices are arranged in the same building (structure), the rectification shall be carried out by means of relocation in another place or effective isolation of the explosion-proof wall from other production devices.
The nitrification device and adjacent devices should be automatically controlled, and there should be no more than 3 on-site operators at the same time.

The nitrification control room shall not be adjacent to the nitrification device or located in the nitrification workshop (device).
Handover rooms, offices, rest rooms, outdoor exercise rooms, and inspection rooms shall not be arranged in the nitrification upstream and downstream process production plants and nitrification warehouses, and centralized shifts shall not be carried out on-site.

3.
Improve the level of automatic control and be equipped with a safety instrument system

The nitrification unit should be controlled by DCS, and in accordance with the requirements of the Provincial Emergency Management Department on Printing and Issuing the Basic Requirements for Intrinsic Safety Diagnosis and Governance (Su emergency [2018] No.
53), the raw material processing, reaction process, distillation and refining, products should be completed by the end of 2020 Storage (packaging) full-process automatic control system.
The nitrification reaction process should be equipped with an independent safety instrumented system, and the safety instrumented system shall be SIL rated.
Enterprises should formulate management systems to clarify the maintenance and testing cycles of automatic control systems and safety instrumented systems, and strictly implement them as required.

In the event of an accident, if the nitrification kettle, nitrification kettle, nitrification tank and other facilities will affect each other, automatic isolation facilities should be added.
Nitration kettles involving flammable and explosive media should be protected by nitrogen.
The nitrification kettle should be equipped with dual thermometers in the liquid phase.
If the nitration reaction temperature exceeds the boiling point of the materials in the kettle, the gas phase space should also be equipped with a temperature detection device and interlocked with the emergency shutdown system.
Strictly control the upper and lower limits of the nitrification reaction temperature, and prohibit the temperature exceeding the limit, especially the state of exceeding the lower limit, to avoid the process out of control caused by the accumulation of materials and the reaction delay.
The nitrification kettle should be equipped with emergency cooling facilities, with interlocking and remote operation functions, and equipped with a cooling medium with sufficient cooling capacity.
The key equipment of the nitrification system such as nitrification kettle stirring and emergency cooling facilities should be equipped with independent emergency power supply (EPS).
Storage warehouses involving nitrification hazardous waste should be equipped with temperature and humidity detection instruments to monitor the temperature and humidity in the warehouse and the temperature in the stack in real time.

The nitrification enterprise should form an interlocking relationship between the temperature in the nitrification reactor and the stirring in the reactor, the flow rate of the nitrifying agent, and the cooling water inlet valve of the jacket of the nitrification reactor.
An emergency shutdown system should be set up at the nitrification reactor.
When the temperature in the nitrification reactor exceeds the standard Or the mixing system fails, it can automatically alarm and automatically stop feeding.
The nitrification reaction process involves the feeding operation that exotherms heat and needs to control the feeding speed.
Automatic feeding should be realized and safety interlocks should be set.
According to the maximum allowable flow rate required by the process control, a fixed non-over-adjustable flow limiting measure and a pipe view of the dripping material should be set.
mirror.

4.
Improve safety release measures and realize automatic monitoring and early warning

The nitrification enterprise shall determine the type of the safety release device according to the nature of the release medium of the nitrification reactor, the characteristics of the overpressure conditions and the performance of the safety release device, set up a downward or upward explosion release system, and set up a safe collection and treatment of released materials facility.
The downward emergency discharge collection system set up in the nitrification reactor should be able to discharge the reaction materials through the valve at the bottom of the reactor by gravity when the reaction is out of control, and all transfer to the dumping tank containing the quencher or/and inhibitors and other facilities , No transfer pump shall be installed between the reactor and the dumping tank and other facilities, and the dumping tank and other facilities shall be installed outside the nitrification plant.

The nitrification device involves the reaction, rectification area, nitrification waste storage site and the storage unit that constitutes a major hazard source of hazardous chemicals.
A remote video monitoring system and a personnel positioning system should be set up to ensure that there is no blind zone for video monitoring, and the nitrification device personnel access and process are monitored all day Operation and inspection of maintenance operations.
The nitrification device and the supporting tank area should be equipped with sound and light alarm devices to ensure that the on-site personnel can evacuate in time when they receive abnormal information.

The on-site control room or central control room of the nitrification device should be equipped with a monitoring and early warning system to realize automatic early warning of abnormal conditions such as nitrification reaction temperature, pressure, stirring current, cooling water interruption, flammable and toxic gas leakage detection alarms, and send the early warning information to nitrification in time Workshop leaders and relevant personnel in the production, equipment, and safety management departments of the company.
The operation information of the nitrification reactor rupture disc, the safety valve operation information, and the emergency operation information of the emergency discharge valve that occurred during the production process should be reported by the post operator in time.

5.
Actively implement process improvement to effectively reduce safety risks

In principle, the newly renovated and expanded nitrification equipment adopts continuous nitrification production processes such as microchannels to further improve the intrinsic safety level of the process and control the source risk; promote the application of mechanized and automated production equipment and facilities throughout the process to achieve mechanized substitution and automated reduction of personnel to the maximum Ground pressure reduces the number of on-site workers.
The newly-built nitrification device shall be arranged separately, and shall not be mixed with other devices or arranged in the same workshop.
The fire separation distance from surrounding buildings (structures) shall at least meet the requirements of the "Design Fire Protection Standards for Petrochemical Enterprises" (GB50160).
Fixed operating positions are set up in the production equipment.

If the nitrification product of the newly renovated and expanded nitrification unit contains flammable organic solvents, it is strictly forbidden to use open or semi-open separation facilities, and the separation of flammable organic solvents should be realized under the condition of nitrogen seal.
The separated materials should be transferred to the next process in time, the intermediate nitrification products and products should be put into the warehouse (tank) in time, and the amount of materials temporarily stored in the nitrification device should be strictly controlled; the nitrification waste storage site should not exceed the designed amount, and the storage amount should be reduced as much as possible , To prevent the spillover of safety risks.

Nitrification enterprises should actively adopt new processes and technologies, implement online volume reduction technology transformation of hazardous chemicals in the nitrification production process, and minimize the storage of raw materials, intermediate and final products with explosive hazardous characteristics.
Improve the solid-liquid separation process of nitrification products to realize automatic control and reduce the risk of manual operation.

6.
Strengthen safety education and training, and comprehensively improve the quality of employees

The main person in charge and the person in charge of production, technology, safety and full-time safety management personnel newly hired by the nitrification enterprise must have a college degree or above in chemistry, chemical industry, safety and other related majors or an intermediate or above professional title in the chemical industry.
Newly hired operators Must have a high school degree or above or a chemical secondary or higher level of vocational education.
Newly recruited operators of production equipment and storage facilities involving explosive hazardous chemicals must have a college degree or above in chemical engineering.
Existing personnel who do not meet the above requirements The personnel should reach the corresponding level by the end of 2021.

The nitrification equipment involved in raw material processing, reaction and separation positions internal operators, external operators and monitors should obtain the special operation qualification certificate of the nitrification process, and those involved in the collection, storage, and transshipment of nitrification waste within the enterprise shall not use labor dispatch personnel.

7.
Revise and improve emergency response plans to improve emergency response capabilities

The nitrification enterprise shall fully identify the various dangerous and hazardous factors in the nitrification plant, analyze the possible direct consequences and secondary and derivative consequences of the accident according to the types and characteristics of different accidents that may occur, and evaluate the degree of harm and the scope of influence of the various consequences.
Revise and improve the emergency plan for production safety accidents of enterprises, prepare special plans for fires and explosions of nitrification installations, on-site disposal plans and post emergency response cards, equip emergency rescue facilities and equipment, and carry out emergency training and actual combat drills on a regular basis to enhance the emergency response capabilities of enterprises.

Emergency Management Department of Jiangsu Province August 13, 2020