Beijiang Power Plant Desulfurization Wastewater Project

Background:

Tianjin SDIC Jinneng Power Generation Co., Ltd. Established in March 2004.Joint venture between SDIC Power Holdings Co., Ltd., Tianjin Jinneng Investment Co., Ltd., and Tianjin Changlu Hangu Salt Farm Co., Ltd. Designated as a national circular economy pilot unit in 2005 and a domestic desalination industry development pilot unit.

Project Description:

Construction of 4 x 1000MW ultra-supercritical coal-fired power generation units and a desalination plant with a capacity of 500,000 tons/day seawater.
Project implemented in two phases:
Phase 1 (completed Nov. 2009): 2 x 1000MW units and 200,000-ton/day desalination unit (investment: 12.1 billion yuan).
Phase 2 (completed June 2018): 2 x 1000MW units and 300,000-ton/day desalination unit.

Key Achievements:

Highest domestic power generation main engine parameters (28MPa/600℃/620℃).
Reduced coal consumption (263.3g/KW.h) for pure condensation operation.
Increased annual average thermal efficiency (65.6%).

Challenges with Original Wastewater Treatment System (Pre-2021):

• Traditional "triple box + clarifier" process inefficient for ultra-low emission standards.
• Issues caused by high solid and chloride content in wastewater:
• Increased equipment wear and tear.
• Inconsistent effluent water quality.
• Low equipment commissioning rate for zero-discharge system.
• Limited dewatering capacity with only one centrifugal dehydrator (required annual maintenance shutdown).
• High sludge disposal costs.

Upgraded Wastewater Treatment System (2021):

Implementation of HDCY integrated desulfurization wastewater treatment system by Beijing Huade Chuangye Environmental Protection Equipment Co., Ltd. (awarded through open bidding).

System Features:

• Integration of various new water treatment processes (coagulation, flocculation, chelation sedimentation).
• High-efficiency cyclone clarifier with blade-type rotating cloth and cyclonic settling plate design in clean water tank.
• Dedicated single agent dry powder flocculant (integrated adsorption flocculant) with a low dosage range (200ppm-300ppm).

Benefits:

1. Reduced reaction time and improved efficiency.
2. Faster settling speed, better water quality, and easier water quality control during process fluctuations.
3. Lower costs and simpler process due to single agent flocculant.
4. Harmless sludge disposal due to permanent heavy metal capture.

Overall Treatment Process:

1. Desulfurization wastewater from both phases is pumped into the HDCY system.
2. Dosing and efficient cyclone clarification occur within the system.
3. Treated clean water overflows and passes through a precision interceptor for filtering.
4. Clean water is stored in the second-stage reuse pool.
5. Dehydrated sludge is transported with desulfurization gypsum for comprehensive utilization.

Core equipment list

Project Outcomes:

1. The operating conditions are stable and have strong impact resistance to fluctuations in suspended solids in the inlet water, ensuring stable operation within the range of inlet water SS 0-100000mg/L;
2. The types of chemical dosing are reduced and only one type of chemical is added, which provides convenience for actual on-site operation and production management;
3. The quality of the effluent water is stable. After HDCY integrated desulfurization wastewater treatment, the overflowing clean water stably meets the requirements of DL/T997-2006 emission standards. The precision filter at the end is only used as a backup for emergency security equipment;
4. The underflow sludge does not need to be treated separately and is directly pumped to the gypsum dehydration system to complete dehydration, simplifying the process and improving operation reliability.