Par Karim Thibault & Vincent Mougammadoussane
For the first two days of our fieldtrip week, we travelled to Henan province to visit several industries in the region, and to discover another side of China’s development. Our train stopped in Xinxiang, which is a prefecture-level city nicknamed -not without humour- New-York by Chinese people themselves (as Xin 新, actually stands for New in Chinese). Xinxiang, though experiencing a rapid growth, remains a middle-sized Chinese prefectural city with its 5,707,801 inhabitants and an area of 8,629 km².
There, we were warmly welcome by local government officials from the bureau of environmental protection, who accompany us to Weihui City where we were to visit the Chunjiang cement factory (春江水泥有限公司). The Chunjiang group was created in September 2006, and first established there, by a PRC representative of the People’s congress who invested 30 million RMB to start this company, which has then become the biggest in Henan. Nowadays, it covers a wide range of activities ranging from cement production to financial services.
After an instructive introduction on the background of the group, we were invited to visit the cement factory to discover the process of production from the initial raw material to the final output. The cement is initially made from inorganic material such as limestone, bauxite or magnesium. These are blended into appropriate proportion and further grinded before entering the preheater tower. The heated mixture of raw materials then enters a rotary kiln, where it is partially melted to form a new material known as clinker. Finally, the clinker is cooled down and further grinded to give the end product. Each of these steps is monitored carefully in the control room.
In an effort to protect the environment and the health of their fellow citizens, the company also implemented specific measures. The dust emissions are limited by covering the coal storage, and also by installing a dust collector at each end of the rotary kiln. Moreover, fly ash issued from coal burning is added to the clinker to alter the quality of the cement. Finally, the heat recovered from the cooling process is recirculated into the rotary kiln in order to save energy.
After the visit at Chunjiang, we were given a presentation by the delegate from the local government who introduced us to the city, its history and its environmental background. The geographic situation of the city is particularly challenging as the neighbouring Yellow River is higher, in terms of elevation, than the city, and the average wind direction is perpendicular to the river’s bed. It leads to high water risk and a potentially high pollution. In order to deal with this peculiar situation, the local environmental policy is based on five pillars:
- Improve control on coal burning
- Promote an adjustment of the local industry structure
- Save energy
- Develop circular economy
- Improve technologies in the sense of carbon efficiency
The economy of the Henan province has been mainly based on the mining exploitation and heavy industries, it is the fourth producer of coal in China. In the afternoon of our first day in the Henan province, we had the opportunity to visit the sub-critical coal power plant operated by the Huadian Qudong Power Generation Company in the Xinxiang city.
The Xinxiang coal power plant has an installed capacity of 1,320 MW with two generating units of 660 MW, the main goal of the visit was to get an overview of the general process to produce electricity from coal:
1/ The coal is crashed into powder by the pulveriser grinds before being mixed with hot air, it is then moves to the firebox of the boiler for an optimal combustion.
2/ The coal and hot air mixture heats the water of the boiler which turns into steam reaching 500 degrees at a pressure of 165 kg/cm2.
3/The steam is then released to power a turbine turning the heat from the steam into mechanical energy which is used to spin the turbine engine.
4/ The spinning turbine is linked to a generator: magnets spin within copper coils to produce electricity.
5/ The steam moving through the turbine is cooled by a condenser. in this step, a nearby water source is used to pump cool water through a tubes network. As the steam is cooled, it turns back to water which is reused in the process by returning in the boiler.
The company running the coal power plant also underlines some effort made to reduce the environmental impact of the coal power plant process: dust collection, by electrostatic precipitators, NOX (nitrogen oxides) control by non-catalytic reduction system, SO2 (sulphur dioxide) reduction in the preparation of coal.
To bring that first day to a close, we went back to our hotel where we had a taste of the local food, before returning to our respective rooms for a night of sleep.
The next morning, we appreciated a hearty Chinese breakfast providing us an energetic start for our last day in the Henan province. Our environmental friendly group then headed in the direction of the Henan Xinlianxin Fertilizer company located at the ancient riverbed of the Yellow River in the Xinxiang Economic Development Zone.
With more than 6,000 employees and 45 years of experience, the Henan Xinlianxin Fertilizer co. has evolved from a small nitrogen fertilizer plant to one of the major actor in the fertilizer sector in China. The company produces and sells urea, compound fertilizers, alcohol, methanol, melamine products for a total asset of nearly 1.6 billion yuan?. After a cordial greeting from the company team, we had an introduction of the enterprise background and environmental policy. It was first established in 1969 and has changed from a private to a state-owned company in 2003. Xinlianxin fertilizer company owns four production branches of urea and other chemicals in its two factories in the Xinxiang, Henan province and Xinjiang province producing more than 4 million tons of products.
The company has made considerable efforts to reduce its environmental impact, thus it has been awarded « the national petrochemical industry leader of energy efficiency benchmarking enterprises » by the Chinese Ministry of Industry and Information Technology thanks to the optimisation of its process. Research and Development at Xinlianxin Fertilizer Co. is organized in 5 scientific research centres working on various subjects such as: smart greenhouse, waste energy, reused water process in partnership with the Chinese Academy of Sciences and Zhengzhou University. The company has built a strong environment management system and invest more than 500 million yuans to develop circular economy in the manufacturing process of fertilizers.
After the presentation of the background company and its environmental strategy, we had the opportunity to have a tour of the manufacturing site and the different solutions developed to improve the environmental impact of the process. Xinlianxin Fertilizer has gone beyond China’s environmental standard concerning the emission of SO2, NOX, and dust by developing technological solutions to capture NOX in the process by catalyst and conversion to nitrogen. Although, other improvement of the manufacturing process has been implemented to recycle the carbon dioxide : 60 % is reinjected in the process and 20 % is addressed to other companies using carbon dioxide for their own products process.
To conclude the fieldtrip in the Henan province, the afternoon was dedicated to the visit the Xinxiang museum which is one of the largest collection including ceramics, jade, paintings, porcelain art, and calligraphy. After visiting the museum, we then moved towards the train station on our way back home to Beijing…
Back to Beijing, we went to visit a plant for wastewater treatment and reuse of Beijing Beikong (北京北控). This plant is located north of the Shahe Reservoir and south of the Changping county, and is composed of two treatment units. The construction of the first unit was initiated in December 2011 and completed two years later and it currently treats 30,000 tons of municipal wastewater per day. This capacity will increase up to 90,000 tons a day, upon completion of the second unit.
There, we were welcome by the staff, who later toured us through the facility where we discovered the different steps of the water treatment process. It starts with a screening step that aims at removing the large solids from the wastewater. The water is then taken to a pre-anaerobic tank to release the nitrogen and phosphate from recycled water/sludge mix, after which an anaerobic tank is used to reduce the phosphate salinity. The next step is the anoxic tank where nitrates are reduced into nitrogen gas and the oxidation comes at last to lower the microorganism content. After, the water is retained in a sedimentation tank for 4 hours and at the end of this step the sludge is collected, dewatered and the residual water is sent back into the system, to the pre-anaerobic tank. Finally, the water flows to the last step of the process which is ultrafiltration.
The effluent obtained exceeds first grade A of national standard and can be either reused or sent back into nature. At the time of our visit, the Sha river was experiencing some serious drought issues, thus, the treated effluent was integrally discharged into that river.
For the last day of our field trip week we were to visit the headquarters of the Sound Group (桑德集团), an international group covering a wide range of activities linked to environmental engineering, management and consulting over a variety of specific fields such as municipal solid waste treatment, wastewater treatment, water supply, hazard waste treatment and clean energy. The group, founded in 1993, was the first of its kind in China and, nowadays, its expertise is exported to foreign countries such as Saudi Arabia or Bangladesh. They operate all along the business chain from investment, to design, construction, operation & management and production.
After a brief presentation of the group, we were invited to visit the museum of the company located next to the headquarter. It was impressive to see that the group was not only importing cutting-edge environmental technology onto the Chinese market but also innovating decisively. They notably introduced us to two of their patented technologies: the electro-osmotic dehydrator/dry sludge incinerator and their own garbage cleaning treatment technology.
The end of this visit also marked the end of this fieldtrip week; a week rich in discovery, and which demonstrated how, in the field, the companies, in a common effort with the Chinese government, are tackling the environmental challenges that currently undermine China’s development.