Project

Name

Construction Location

Construction Unit

Environmental Impact

Evaluation Agency

Project

Overview

Major Environmental Impacts and Proposed Preventive Measures

Henan Yongchang Environmental Protection

Technology Co., Ltd.

1. Exhaust gases. The main exhaust gases generated by the project include: exhaust from the phthalic anhydride unit (naphthalene distillation exhaust, switching condensation exhaust, phthalic anhydride distillation exhaust, and phthalic anhydride pelletization dust); exhaust from the storage tanks of the phthalic anhydride unit; exhaust from the calcium hydroxide silo supporting the phthalic anhydride unit; and exhaust from the plasticizer unit (DIBP production exhaust: isobutanol charging exhaust, activated carbon charging exhaust, sulfuric acid preparation exhaust, non-condensable gas from the separation column, non-condensable gas from alcohol–water separation, non-condensable gas from alcohol removal, and diatomaceous earth charging exhaust;DOA production exhaust: adipic acid charging exhaust, activated carbon charging exhaust;Non-condensable gas from the separation tower, non-condensable gases from alcohol removal, and diatomaceous earth charging exhaust;3GO production exhaust: exhaust from activated carbon feeding, non-condensable gas from the separation tower, non-condensable gas from dehydrogenation, non-condensable gas from dehydration, and exhaust from diatomaceous earth feeding; DOS production exhaust: exhaust from sebacic acid feeding, exhaust from activated carbon feeding, non-condensable gases from the separation tower, non-condensable gases from alcohol removal, and exhaust from diatomaceous earth feeding; exhaust from the plasticizer storage tank area; exhaust from the regenerative thermal oxidizer (RTO) in the plasticizer production line; exhaust from the resin unit (including ortho-type unsaturated polyester resins, bicyclic-type unsaturated polyester resins, vinyl-type unsaturated polyester resins, and para-type unsaturated polyester resins: feeding exhaust, polycondensation vacuum exhaust, dilution exhaust, and filling exhaust; low-shrinkage unsaturated polyester resins: feeding exhaust, dilution exhaust, and filling exhaust; alkyd resins: feeding exhaust, reaction exhaust, dilution exhaust, and filling exhaust); exhaust from the resin section’s tank farm; exhaust from the resin incinerator (TO); exhaust from the wastewater treatment station; laboratory exhaust; exhaust from the hazardous waste temporary storage room; and cooking fume from the canteen, among others.

Waste gases from the phthalic anhydride unit (including naphthalene distillation off-gas, switch-over condensation off-gas, and phthalic anhydride distillation off-gas), waste gases from the phthalic anhydride unit storage tanks, laboratory exhaust, and exhaust from the hazardous waste temporary storage room: after treatment by a “catalytic oxidation (CO) + wet desulfurization + wet electrostatic precipitator” system, they are discharged through a 35-meter-high stack. Emissions of phthalic anhydride, maleic anhydride, and SO₂ shall comply with the Special Emission Limits specified in the Amendment to the Emission Standard of Pollutants for the Petrochemical Industry (GB 31571-2015); particulate matter emissions shall comply with the Level 2 standards set forth in Table 2 of the Comprehensive Emission Standard for Air Pollutants.

Waste gases from the plasticizer production unit (including waste gases from DIBP production—such as waste gases from isobutanol feed, activated carbon feed, sulfuric acid preparation, non-condensable gases from the separation column, non-condensable gases from alcohol–water separation, non-condensable gases from alcohol removal, and waste gases from diatomaceous earth feed; waste gases from DOA production—such as waste gases from adipic acid feed, activated carbon feed, non-condensable gases from the separation column, non-condensable gases from alcohol removal, and waste gases from diatomaceous earth feed; waste gases from 3GO production—such as waste gases from activated carbon feed, non-condensable gases from the separation column, non-condensable gases from dehydrogenation, non-condensable gases from dehydration, and waste gases from diatomaceous earth feed; and waste gases from DOS production—such as waste gases from sebacic acid feed, activated carbon feed, non-condensable gases from the separation column, non-condensable gases from alcohol removal, and waste gases from diatomaceous earth feed), as well as waste gases from the plasticizer storage tank area, the wastewater treatment station, and the regenerative thermal oxidizer (RTO) for the plasticizer production line—specifically, waste gases from adipic acid feed and sebacic acid feed after preliminary treatment by bag filters, and waste gases from sulfuric acid preparation after preliminary treatment in an alkaline scrubbing tower—shall, following such preliminary treatment, be combined with waste gases from isobutanol feed, activated carbon feed, non-condensable gases from the separation column, non-condensable gases from alcohol–water separation, non-condensable gases from alcohol removal, waste gases from diatomaceous earth feed, non-condensable gases from dehydrogenation, non-condensable gases from dehydration, waste gases from the plasticizer storage tank area, and waste gases from the wastewater treatment station. These combined waste gases will then be treated by a single “plasticizer waste gas scrubber plus regenerative thermal oxidation (RTO) unit (using natural gas as auxiliary fuel)” and subsequently discharged through a 15-meter-high exhaust stack together with the waste gases from the RTO of the plasticizer production line. Particulate matter, sulfuric acid mist, SO₂, and nitrogen oxides shall comply with the Level 2 standards specified in Table 2 of the Comprehensive Emission Standard for Air Pollutants (GB 16297–1996), while ammonia, hydrogen sulfide, and odor concentration shall comply with the standards set forth in Table 2 of the Emission Standard for Odorous Substances (GB 14554–1993).

Waste gases from the resin production unit (including those from ortho-phthalic unsaturated polyester resins, bicyclic unsaturated polyester resins, vinyl-type unsaturated polyester resins, and para-phthalic unsaturated polyester resins: feedstock charging waste gas, polycondensation vacuum waste gas, dilution waste gas, and filling waste gas; low-shrinkage unsaturated polyester resins: feedstock charging waste gas, dilution waste gas, and filling waste gas; alkyd resins: feedstock charging waste gas, reaction waste gas, dilution waste gas, and filling waste gas), waste gases from the resin section’s tank farm, and waste gases from the resin incinerator (TO): after collection, these gases are treated by a “resin incineration unit (TO)” and then discharged through a 35-meter-high stack together with the natural-gas-fired flue gases from the resin incinerator (TO). Particulate matter, phthalic anhydride, styrene, SO₂, nitrogen oxides, non-methane total hydrocarbons, and dioxins shall comply with the special emission limit requirements stipulated in the “Emission Standard of Pollutants for Synthetic Resin Industry” (GB 31572–2015) and its amendment; xylene, methanol, and maleic anhydride shall comply with the special emission limits and amendment requirements set forth in the “Emission Standard of Pollutants for Petrochemical Industry” (GB 31571–2015).

Waste gas from the calcium hydroxide silo supporting the phthalic anhydride unit: After treatment by a baghouse dust collector, the gas is discharged through a 15-meter-high stack, with particulate matter emissions complying with the Level 2 emission limits specified in Table 2 of the Comprehensive Emission Standard for Air Pollutants (GB 16297-1996).

Waste gas from the phthalic anhydride unit (phthalic anhydride flake dust): After treatment by a baghouse dust collector, it is discharged through a 15-meter-high exhaust stack, with particulate matter emissions complying with the Level 2 emission limits specified in Table 2 of the Comprehensive Emission Standard for Air Pollutants (GB 16297-1996).

Canteen cooking fumes: After being treated by an oil-fume purification system, the fumes are discharged through a dedicated flue in accordance with the emission standards specified in Table 1 of the “Emission Standard for Oil-Fume Pollutants from the Catering Industry” (DB41/1604-2018). 

2. Wastewater. The project’s wastewater mainly includes desalinated water production wastewater, boiler system blowdown, plasticizer product process wastewater, resin section process wastewater, equipment cleaning wastewater from the plasticizer and resin sections, vacuum pump blowdown from the plasticizer section, vacuum pump blowdown from the resin section, floor cleaning wastewater, blowdown from the recirculating cooling system, laboratory cleaning wastewater, blowdown from the scrubber prior to the RTO, and office and domestic wastewater.

After being centrally collected, the process wastewater from the resin section and the blowdown from the vacuum pumps are fed into the thermal oxidizer (TO) for incineration; the treated effluent is then discharged in the form of water vapor.

The wastewater generated during desalinated water production is partially reused as ground flushing water and partially discharged as clean effluent.

Process wastewater from plasticizer production, equipment-washing wastewater from the plasticizer and resin sections, condensate discharge from vacuum pumps in the plasticizer section, floor-washing wastewater, laboratory-washing wastewater, condensate discharge from the scrubber (prior to RTO), and office and domestic wastewater are all treated at the project’s on-site wastewater treatment facility—employing a process comprising equalization, flocculation, an EGSB anaerobic reactor, an anoxic biological tank, an aerobic biological tank, and a secondary sedimentation tank, with a design capacity of 100 m³/d—and then discharged via the plant’s main effluent outlet together with clean utility wastewater (including desalinated water production wastewater, boiler system blowdown, and circulating cooling system blowdown) to the Kaifeng Fine Chemical Industrial Development Zone Wastewater Treatment Plant for further treatment. The effluent quality at the project’s main effluent outlet complies with the “Indirect Discharge Standard for Water Pollutants in the Chemical Industry” (DB41/1135-2016) as well as the influent quality requirements of the Kaifeng Fine Chemical Industrial Development Zone Wastewater Treatment Plant.

3. Noise. The eastern plant boundary shall comply with the Class 3 requirements of the Environmental Noise Emission Standard for Industrial Enterprise Boundaries (GB 12348-2008). The southern, western, and northern plant boundaries shall comply with the Class 4 requirements of the Environmental Noise Emission Standard for Industrial Enterprise Boundaries(GB12348-2008).

4. Solid Waste. All solid waste generated by the project shall be properly disposed of or comprehensively utilized. Temporary storage of general industrial solid waste shall be governed in accordance with the “Pollution Control Standard for Storage and Disposal Sites of General Industrial Solid Waste” (GB 18599–2020). The naphthalene distillation residue, phthalic anhydride distillation residue, spent catalyst from oxidation reactions, spent molten salt, spent heat-transfer oil from phthalic anhydride production, spent filter bags from the baghouse dust collector in the phthalic anhydride unit, DIBP filter cake, concentrated filter cake from the three-effect evaporator in the DIBP unit, refined filter cake from the DIBP purification process, DOA filter cake, refined DOA filter cake, 3GO filter cake, refined 3GO filter cake, DOS filter cake, refined DOS filter cake, waste packaging bags (excluding activated carbon and diatomaceous earth), waste packaging drums, spent filter bags from the baghouse dust collector in the plasticizer unit, filtration residue from alkyd resin production, nonconforming resin products, spent heat-transfer oil from alkyd resin production, waste engine oil, physicochemical sludge, and filter cloths discarded after sludge dewatering are classified as hazardous waste. In accordance with the requirements of the “Pollution Control Standard for Storage of Hazardous Waste” (GB 18597–2023), such waste shall be collected and temporarily stored in a dedicated hazardous-waste storage area, and regularly transported for treatment by an entity holding the requisite hazardous-solid-waste disposal license, with strict measures in place to prevent secondary pollution.