The evaporation treatment technology adopted by Sinopec in the treatment of petroleum refining wastewater is an efficient and environmentally friendly process, mainly used to treat high salt and high organic content wastewater, especially suitable for complex wastewater that is difficult to treat by traditional biochemical or physicochemical methods. The following will explain the technical principles, application scenarios, process flow, advantages and challenges, and case studies:

      one Characteristics of Petroleum Refining Wastewater

      -High salt content: Contains a large amount of inorganic salts (such as sodium chloride, sodium sulfate, etc.), which are prone to scaling and corrosion of equipment.

      -High COD: Contains difficult to degrade organic compounds such as oils, phenols, and sulfides.

      -Complex composition: may contain heavy metals, emulsified oil, suspended solids, etc.

      -High calorific value: Some wastewater can be treated with energy-saving measures through thermal energy recovery.

      two The core principle of evaporation treatment technology

      Evaporation technology vaporizes water in wastewater through heating, concentrates salt and pollutants, and crystallizes and separates them, ultimately achieving:

      -Water recycling: Condensed water can be reused for production or meet discharge standards.

      -Salt solidification: Crystalline salt can be used as an industrial byproduct or safely disposed of.

      -Pollutant reduction: Concentrate residue for further harmless treatment (such as incineration, landfill).

      three Common types of evaporation technologies used by Sinopec

        (1) Multiple Effect Evaporation (MED)

      -Principle: Connect multiple evaporators in series, use the secondary steam from the previous effect as the heat source for the subsequent effect, and gradually reduce energy consumption.

      -Advantages: Significant energy-saving effect (more than 60% energy-saving compared to single effect evaporation), suitable for large-scale processing.

      -Application scenario: High salt wastewater (such as electric desalination wastewater, alkali residue wastewater).

        (2) Mechanical Vapor Recombination (MVR)

      -Principle: The secondary steam generated by evaporation is pressurized and heated by a compressor, and circulated as a heat source.

      -Advantages: Low energy consumption (only a small amount of electricity is needed to drive the compressor), small footprint.

      -Challenge: High corrosion resistance is required for steam compressors, and pre-treatment is needed to reduce the risk of scaling.

        (3) Thermal Vapor Reconstruction (TVR)

      -Principle: Using a steam jet pump to boost some secondary steam and mix it with fresh steam to improve thermal efficiency.

      -Applicability: Medium scale processing, suitable for refineries with sufficient steam resources.

      four Typical process flow

      Sinopec often uses combination processes in practical applications, such as:

      one Preprocessing stage:

      -Oil removal: Air flotation and centrifugal separation to remove floating oil and emulsified oil.

      -Filtration: Ultrafiltration (UF) and microfiltration (MF) reduce suspended solids.

      -Adjust pH: neutralize acidic or alkaline wastewater to prevent equipment corrosion.

      two Evaporation and concentration stage:

    -The multi effect evaporation/MVR system concentrates wastewater to a near saturation state.

      three Crystallization drying stage:

    -Forced circulation crystallizer separates salt, and solid salt residue is generated after centrifugal drying.

      four Post processing:

    -Reuse or advanced treatment of condensate water (such as further desalination by reverse osmosis).

    -Dispose of the residue according to hazardous waste standards (such as solidification landfill).

      five Technical advantages and challenges

        Advantages:

      -Efficient desalination: Processing total dissolved solids (TDS) can reach over 20%.

      -Resource recycling: Reuse 80% to 90% of water resources to reduce fresh water consumption.

      -Reduction: The volume of wastewater is reduced by over 90%, significantly reducing disposal costs.

      -Environmental compliance: Meet the "Emission Standards for Pollutants in Petroleum Refining Industry" (GB 31570-2015).

        Challenge:

      -Scaling and corrosion: High salt wastewater is prone to scaling in the evaporator (such as CaSO ₄, silicates), and regular cleaning or addition of scale inhibitors is necessary.

      -Energy consumption cost: Although MVR is energy-saving, its electricity consumption is still relatively high (which needs to be optimized in conjunction with waste heat utilization).

      -Adaptability to complex wastewater: When containing volatile organic compounds (VOCs), condensation recovery or tail gas treatment is required.

      six Sinopec's Technological Innovation Direction

      -Combination process optimization: for example, "evaporation+advanced oxidation (such as ozone, Fenton)" to treat recalcitrant organic compounds.

      -Material upgrade: using corrosion-resistant materials such as titanium alloy and duplex steel to extend equipment life.

      -Intelligent control: Optimizing evaporation parameters (such as temperature and pressure) through AI algorithms to reduce energy consumption.

      -Zero Liquid Discharge (ZLD): Combining evaporative crystallization and drying technology to achieve complete wastewater recovery.

      seven Practical Application Cases

      -Treatment of electric desalination wastewater from a certain refinery:

      -Adopting MVR evaporation system with a processing capacity of 50m ³/d, TDS is concentrated from 5% to 20%, and the condensed water is reused in the circulating cooling system.

      -Energy consumption is reduced by 40% compared to traditional multi effect evaporation, saving approximately 3 million yuan in steam costs annually.

      -Alkali residue wastewater treatment:

      -After pre-treatment (neutralization+filtration), it enters the three effect evaporation, and the crystalline salt is washed and sold as industrial salt to achieve resource utilization.

      8. Future Development Trends

      -Green and low-carbon: coupling renewable energy (such as solar evaporation) and waste heat recovery technology.

      -Modular design: Small and portable evaporation devices can adapt to different scale requirements.

      -High value utilization: Extracting valuable components from crystalline salts (such as Na ₂ SO ₄ for glass manufacturing).

      Through the above technical paths, Sinopec has achieved a balance between environmental and economic benefits in the treatment of petroleum refining wastewater. Baihuipu Multi effect Evaporator Equipment is a one-stop service manufacturer for research, production, and sales, with multiple sub factories and subsidiaries, serving multiple leading domestic and foreign enterprises. It has passed ISO9001 system certification and has been specializing in the treatment of sewage and wastewater for many years. It provides on-site survey, formulation of plans, equipment production, installation, and after-sales one-stop service, with a 10 second quotation, a 30 minute solution, and 24-hour on-site service. When it comes to sewage treatment, find Baihuipu Environmental Protection!