power_en|Sustainability|Excellent Cases
Resolving the Municipal Sludge Disposal Problem
"2018 was the toughest year for the Haifeng Power Plant sludge-coupled power generation project, and it is also a year of great harvest." Speaking of the topic of sludge disposal, Zhang Zongzhen, who is the leader of the Haifeng Power Plant Sludge Coupling Power Generation Project Team.
Sludge treatment coupled with power generation refers to mixing municipal sludge with coal at a certain proportion and then feeding it into the boiler for incineration. The high temperature of the power plant boiler is used to decompose the sludge. At the same time, the heat value of the sludge is fully utilized to generate clean power and heat for external supply. The noncombustible components contained in the sludge can be produced by the high temperature treatment, and can be recycled in the production of building materials such as cement.
Haifeng Power Plant is located in the Shenzhen-Shantou Special Cooperation Zone in the hinterlands of the Guangdong-Hong Kong-Macau Greater Bay Area. According to statistics, Shenzhen and Shanwei produce over 1 million tons of sludge every year. With the issuance of state regulations like the Water Pollution Prevention & Control Action Plan and Soil Pollution Prevention & Control Action Plan, The landfill disposal with the largest proportion of sludge disposal methods is subject to increasingly rigorous control. Due to the severe shortage of sludge disposal facilities, a great deal of sludge can't be treated in a sanitary way, resulting in an increasingly prominent problem of sludge in the city.
This is a practical problem of urban development and environmental protection, and a new opportunity for clean and green development of coal-fired power. At the end of 2016, Haifeng Power Plant decided to launch the sludge coupling power generation project in hopes of using sludge co-combustion as a profit growth point to resolve the problem of urban sludge, fulfilling its corporate environmental responsibility.
The development and construction of a project in its early stage is very difficult. Since the urban sludge in Guangdong is basically disposed by simple greening and landfill, it contains a great deal of pathogenic bacteria, chromium and mercur y, and many other toxic and hazardous substances that are difficult to degrade. Improper disposal can easily cause secondary damage to the ecological environment. After the establishment of Sludge Co-combustion Research Team at the end of 2016, the team members went to the Bureau of Housing and Urban-Rural Development of Shanwei City and the Water Authority of Shenzhen City many times to introduce the harmless disposal plan of Haifeng Project and received support from rele vant government departments. In August 2017, after several rounds of negotiations with the bid sludge disposal company, we finally signed a 300 t/d disposal cooperation agreement with the cooperation unit, preliminarily securing sludge resources for project initiation.
In October 2017, Haifeng Power Plant signed a formal cooperation agreement with China Energ y Environmental Protection Co., Ltd.("CEEP") to utilize the existing high-efficienc y power generation system and clean and green environmental protection systems of Haifeng Power Plant to give full play to the technical strengths of CEEP in sludge disposal. This partnership focused on joint development and construction of the Haifeng Sludge Coupling Power Generation Project, steering it into a fast track.
In July 2018, Phase I of the Project was completed and put into operation. On July 5, Shenzhen Municipal Government requested Haifeng Power Plant to urgently dispose of municipal sludge. The project team immediately initiated the Emergency Sludge Disposal Plan and disposed of 500 t/d sludge (with a water content ratio of 60%). Although the sudden increased amount of sludge had been disposed, the impact on the plant equipment and the surrounding environment, and whether the unit capacity of sludge co-combustion had reached the design objective needed to be verified. To ensure no secondary pollution during sludge disposal, realize harmless disposal and turn sludge into resources, Haifeng Power Plant and Guangdong Power Research Institute jointly initiated a 3-month test on environmental impact, air monitoring and equipment efficiency evaluation on the Haifeng Sludge Co-combustion Project from July to October 2018. The test results show that the impact of sludge co-combustion on the economic performance of the unit is within the acceptable range. However, in the subsequent operation of the unit, problems such as blockage, coal breakage, and uneven mixing frequently occurred, severely threatening the safety of the unit. In order to fully understand the influencing factors, the coal handling engineer of the Power Generation Department of Haifeng Power Plant conducted on-site inspections, recording comparisons and analyses every day. After a month of observation, he summarized the patterns of the problems and took effective measures to resolve the major safety hazards. The unit’s daily sludge co-combustion amount has increased from 3% to 6%.
Fruitful results only come from hard work. At the end of 2018, Haifeng Power Plant's Sludge Coupling Power Generation Project had disposed of 64,400 tons of municipal sludge, which not only eliminated the municipal sludge accumulated in Shanwei City, but also offers an emergency disposal option for sludge that could not be properly disposed of in Shenzhen. At the same time, through the application of new technology and new equipment and the in-depth de velopment of existing resources, Haifeng Power Plant has explored a series of sludge disposal technologies that can be applied, such as intelligent feed bins, steam drying, and flexible sludge treatment . The program has set a good example for the transformation and upgrading of traditional thermal power plants. The contributions of Haifeng Power Plant in sludge disposal have been fully affirmed by the Shenzhen Municipal Government.
On October 12, 2018, CR Power and CR Cement signed the "Shenzhen Municipal Sludge Disposal Strategic Cooperation Framework Agreement" with Water Au-thority of Shenzhen. According to the agreement, CR Power and CR Cement will exert their respective advantages and jointly advance the CR Haifeng Power Plant 1,500 t/d Sludge Coupling Power Generation Project and CR Cement Sludge Synergic Disposal Project. The second phase of the Haifeng Sludge Coupling Power Generation Project is expected to start construction in May 2019. It will be put into operation in May 2020. The sludge disposal capacity will reach 2,200t/d, and the annual sludge disposal scale will reach 429,000 tons. The project will become a regional sludge disposal center in Shen-zhen. It will play an important role in improving the ecological environment of the Greater Bay Area, reducing the envi-ronmental impact of urban development, and supporting the healthy and sustain-able development of the area.
The villagers of Qingshuidian Village, Zaoyang wore smiles from the heart - the best affirmation of the CR Power Zaoyang Bailu Wind Power Poverty Alleviation Project. As an old revolutionary base area and poverty-stricken area in the Dabie Mountains, Hubei Province, Zaoyang has 77 key poverty-stricken villages and a poverty-stricken population of 51,500. Speaking of the local conditions, the person in charge of the city's Poverty Alleviation and Development Office said, "The poverty-stricken villages are over-populated and have poor natural conditions, backward transportation facilities, and huge unmet needs in public service. Most strikingly, the overall village-level collective economy is backward." More importantly, the remote location deep in the mountains creates high costs on power line construction, so power access has become a huge problem for the villagers, and inhibiting development.