Overall solution for gas safety monitoring in the petroleum and petrochemical industry

## Recommended Configuration Matrix (by Process Unit)

### Device Area
– **Atmospheric and vacuum**: H2S (PC-TWA 10 mg/m³) + LEL + benzene PID + CO
– **Catalytic cracking**: H2S (regenerator flue gas SO2 + plant area H2S) + NOx combined SIS
– **Hydrogenation refining**: H2 + H2S (high-pressure leakage, laser remote sensing composite) + explosion-proof Ex d IIC T1 (the strictest level for hydrogen gas)
– **Reforming + Aromatics**: Benzene / Toluene / Xylene PID (PPB level) + LEL
– **Ethylene cracking**: ethylene + propylene + butadiene (carcinogen) + high-temperature furnace cracking gas
– **Polyolefin**: dust + electrostatic monitoring + LEL

### Tank Farm
– **Crude oil tank**: H2S (high concentration 0-1000 ppm) + LEL + tank top breather valve VOC + floating roof tilt monitoring
– **Finished oil tank**: Benzene PID + LEL + Vapor space gas phase
– **Spherical tank LPG / olefins**: LEL + explosion-proof IIB + cofferdam isolation
– **Tank farm cofferdam**: 4-6 points per cofferdam for LEL + H2S detection at a height of 0.3m

### Oil and Gas Recovery at Terminals
– Fixed VOC flow rate + concentration in shipment pipelines (calculated recovery efficiency ≥ 95%)
– Oil receiving and dispensing process: LEL + static alarm + grounding status
– Crew members are equipped with a portable 4-in-1 device

### Long-distance pipeline
– Station LEL + H2S + flow rate + pressure interlock
– Fixed NB-IoT methane monitoring for valve interceptors (1 probe per well, 5-year battery)
– Fixed TDLAS laser methane telemetry equipped on drones for line patrols (1-2 times per month)
– Dual monitoring via satellite and fiber-optic cables for critical crossing points (rivers/highways/railways)

## Key Technical Specifications

– Explosion-proof: Ex d IIC T6 (covering the most stringent level for H2/acetylene)
– Protection: IP66 – IP67 (corrosion in coastal chemical sites + high humidity)
– SIL level: SIL 2 – SIL 3 (integrated with SIS safety instrumented system)
– Range: H2S 0-1000 ppm / LEL 0-100% / Benzene 0-100 ppm (PID sensitivity of 0.01 ppm)
– Response time: T90 < 10 seconds (toxic gases)
– Operating temperature: -40℃ ~ +75℃
– Communication: HART + Modbus + Profibus + FOUNDATION Fieldbus

## Implementation Essentials

1. **SIL assessment for the entire device is mandatory**: According to GB 21109 / IEC 61508, assess the SIL level for each circuit, with a focus on critical SIL 3
2. **LDAR Compliance**: Conduct leak detection for flange, valve, and pump sealing points four times a year, utilizing a combination of PID inspection and infrared imaging, and submit the data to the Environmental Protection Bureau
3. **Emergency Linkage**: Ultra-high Alarm → ESD (Emergency Shutdown) + Tank Farm Interlock Shutdown + Activate Accident Water Pool + Emergency Broadcast + Recommend Evacuation Routes via Plant GIS + Warning to Surrounding Communities
4. **Accurate Carbon Emission Measurement**: Flare Tail Gas Burnout Rate + Tank Top VOC Emissions + Shipment Oil and Gas Recovery Efficiency = Accurate Greenhouse Gas Accounting for the Entire Plant, Aligned with ESG Disclosure

## Regulatory Basis

– GB 50493-2019 Standard for Design of Detection and Alarm Systems
– GB 18218-2018 Identification of Major Hazard Installations
– GB 30871-2022 Safety Code for Special Operations in Hazardous Chemical Enterprises
– GB 21109 / IEC 61508 Functional Safety of Safety Instrumented Systems
– HJ 1093-2020 Continuous Monitoring of Pollution Source Flue Gas
– HJ 733-2014 Control of Volatile Organic Compound (VOC) Emissions from Leaks and Open Liquid Surfaces
– AQ 3013 General Specification for Chemical Standardization
– Long-distance pipeline method (2013) + Maritime Safety Administration's oil and gas recovery SOP

## Applicable Customers

Refineries of Sinopec / PetroChina / CNOOC / Sinochem Group, independent refining and chemical companies (Hengli / Zhejiang Petrochemical / Shenghong / Dongfang Shenghong / Wanhua Yantai / Dalian Hengli), coal chemical enterprises (Shenhua Coal Chemical / Yankuang Yulin / Middling Coal Shaanxi Yulin), terminal companies (China Port Group / Shanghai Port Group / Ningbo Port), long-distance pipeline operators (National Gas Grid / natural gas in various provinces).