Environmental Compliance Measures for Oil Sludge Refining

Environmental Compliance Measures for Oil Sludge Refining

To achieve environmental compliance, oil sludge refining projects require systematic pollution control across three core links—waste gas, wastewater, and solid waste—along with full-process monitoring and management. The specific measures are as follows:

I. Waste Gas Treatment: Strict Control of Toxic and Harmful Emissions

Pyrolysis Tail Gas Purification

Sulfur/chlorine-containing exhaust gases and VOCs generated during pyrolysis must first be treated with a spray tower + activated carbon adsorption tower to remove acid gases and organic pollutants; some projects are equipped with a catalytic combustion unit to completely decompose refractory VOCs into CO₂ and water.

Purified tail gas must meet the Emission Standard of Pollutants for Petroleum Refining Industry, with the emission concentration of non-methane total hydrocarbons ≤120mg/m³ and sulfur dioxide ≤100mg/m³.

Flue Gas Recycling and Utilization

Non-condensable combustible gases can be recovered as fuel for pyrolysis furnaces, reducing fossil energy consumption and the total volume of direct emissions.

Unorganized Emission Control

Raw material storage areas and pyrolysis workshops shall adopt a sealed design and be equipped with a negative pressure collection system, which introduces leaked waste gas into purification devices to prevent odor diffusion.

II. Wastewater Treatment: Advanced Degradation of Toxic Pollutants

Oil-Water Separation and Pretreatment

Oil-containing wastewater produced during condensation is first treated with an oil separation tank + dissolved air flotation device to separate floating oil, then undergoes anaerobic + aerobic biological treatment to degrade toxic organic compounds such as phenols and aromatics.

Advanced Treatment and Reuse

Biologically treated wastewater must be further purified through membrane filtration + activated carbon adsorption to ensure COD ≤50mg/L and ammonia nitrogen ≤5mg/L, meeting the Grade I criteria of the Integrated Wastewater Discharge Standard. The treated water can be reused for equipment cooling or factory greening.

Zero Discharge Design

Some projects adopt the evaporation and crystallization process to treat high-salt wastewater, solidify the salt into hazardous waste for compliant disposal, and achieve zero wastewater discharge.

III. Solid Waste Disposal: Closed-Loop Management to Reduce Secondary Pollution

Carbon Residue Stabilization Treatment

Carbon residue from pyrolysis is classified as hazardous waste and must undergo solidification and stabilization treatment (e.g., adding chelating agents to fix heavy metals) before being sent to a compliant hazardous waste landfill; some projects recycle carbon residue into activated carbon or building materials to realize resource utilization.

Pretreatment Waste Residue Disposal

Impurities such as sand and metal chips separated during pretreatment can be recycled as general solid waste if tested non-contaminated, or disposed of as hazardous waste if oil-contaminated.

Fly Ash and Spent Adsorbent Treatment

Hazardous waste such as fly ash and spent activated carbon generated from waste gas purification must be entrusted to qualified units for incineration or safe landfilling.

IV. Full-Process Monitoring and Management

On-Line Monitoring System

Install on-line monitoring equipment at waste gas discharge outlets and the total wastewater discharge outlet to real-time monitor pollutant concentrations, and connect the system to environmental protection departments to ensure traceable data.

Emergency Plan and Account Management

Formulate environmental emergency plans for leaks, fires and other incidents and conduct regular drills; establish accounts for the generation, transfer and disposal of hazardous waste to ensure full-process compliance.

Process Optimization and Energy Conservation & Carbon Reduction

Adopt skid-mounted sealed processes to reduce unorganized emissions, and equip with waste heat recovery systems to lower energy consumption, thereby reducing pollutant generation from the source.