Without The Aid Of Coal Combustion, Tannery Sludge Can Be Converted Into Continuous Heat And Electricity.

No need to use coal to support combustion.

In the eyes of most experts, it is almost impossible to convert sludge into continuous heat and electricity.

But in the tannery industrial zone of Xinji, "impossible" is about to become a reality.

As one of the key projects in Hebei last year, the comprehensive utilization project of sludge resources in Xinji was put into operation. The tannery sludge that has long plagued Xinji has been completely terminated by landfill disposal, and it has been pported to the project in advance for sludge reclamation.

Storage center, waiting for "turning waste into treasure".

Water control is no more than mud.

As the largest fur distributing center in the country, the tannery Industrial Zone in Xinji province has gathered hundreds of tanning enterprises and become a pillar industry in the region, which has also brought heavy environmental pressure to the local area.

In order to solve the problem of tannery sewage treatment, Xinji has constructed three level governance system, including primary management of enterprises, centralized professional treatment of tanning areas, and final comprehensive treatment of urban sewage treatment plants, effectively reducing the pollution of sewage.

However, the associated sludge still uses simple dewatering and landfill treatment, which consumes tens of mu of land every year, and still has the risk of contaminated soil, groundwater and even air.

"Harnessing the water without harnessing the mud is equal to the white treatment". With the introduction of the national "water ten" and the further development of water pollution control, it has become the consensus of more and more environmental experts.

In particular, after the state promulgated the action plan for soil pollution prevention and control (hereinafter referred to as "the ten soil"), the traditional landfill disposal mode will also be difficult to continue.

Under such circumstances, Xinji has pioneered the comprehensive utilization of sludge resources in the province.

According to the introduction, the project was invested by 240 million yuan by Hebei Guo Hui Environmental Protection Technology Co., Ltd., and the patent technology, the closed semi dry sludge treatment process, was used to refine, modify, process and produce the sludge as a new fuel suitable for the combustion of the boiler. It was sent to the boiler for incineration. The flue gas was treated by the company's unique desulphurization and denitrification integrated technology to solve a series of technical problems such as sludge dewatering, deep processing, incineration, power generation, desulphurization and denitration, and removal of volatile organic compounds. In 2014, it passed strict EIA and energy efficiency assessment, which was included in the key construction project of our province last year, and will be formally put into operation in the second half of this year.

Burning coal without coal is the only one in China.

Recently, the reporter went to the west of Xinji tannery industrial area on the west side of the sludge comprehensive utilization project site to explore.

The most conspicuous entry into the factory area is the resource storage center of the cuboid sludge, which occupies thousands of square meters and has about five storeys. Now, the brown tannery sludge from the more than 20 sewage treatment plants in the tannery industrial area has been stored in bulk.

Because after initial dewatering treatment, the smell of sludge is not too big.

Wang Lianzu, deputy general manager of Hebei Guo Hui company, said that the resource storage center of sludge has adopted 28 technological measures for seepage control and anticorrosion to ensure that there will be no two pollution to soil and groundwater.

At present, two specially designed 35 ton boilers will be put in place, and the first batch of sludge is to be stored in advance. First, in order to terminate the landfill disposal early, two is that the project can handle about 500000 tons of sludge annually, while the annual output of tannery sludge in the industrial area is about 220 thousand tons, and it is not enough to feed a boiler.

Once the boiler has been installed and debugged, it can not be stopped at any time after grid connected.

Therefore, it is estimated that one boiler will be started in the initial stage of operation, and the other will be put into operation after expanding the scope and quantity of the sludge collected and stored.

There are two small boilers for pilot plant on the north side of the plant, of which 0.5 tons of boilers are being tested and used to adjust the incineration mode to the optimal state.

Workers often send deep processed sludge fuel rods into the furnace.

Wang Lianzu said that the most outstanding feature of the technology is that it can realize the self combustion of sludge without adding any combustion supporting agent. The trick is to process colloidal sludge into flammable fuel rods through unique processes and modifiers.

Because there are more organic matter in tannery sludge, the calorific value is much higher than municipal sludge. Once full combustion is achieved, a large amount of heat energy can be generated and used for power generation.

For a long time, the domestic sludge power plants almost all adopt the technology of coal blending and combustion supporting, and the technology adopted in Xinji project effectively solved the dependence on coal.

Wang Lianzu said that as the invention patent of the company, the technology is now the only one in the country.

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Changing the burden to solve the leather crisis

There is no need for coal to support combustion, but the key is whether we can achieve the core goal of sludge treatment - sludge reduction, harmlessness and resource utilization.

"We are also in the leading position."

The sludge that they pform will only leave less than 2% of the ash after being burned, and two is harmless. The project receives sludge after initial drying up to 65%, and then burns through deep processing, which not only eliminates all kinds of organic matter and odour and bacteria, but also reduces the emissions of AO through desulfurization, denitration and dust removal and integrated emission reduction facilities. After burning, the ash can be made into industrial culverts, bricks and other products to be solidified and no longer threaten the environment. Three is the sludge, which needs to occupy land for landfill, which will bring two pollution to the soil and water environment, and turn into fuel power generation. It can generate more than 8000 million kilowatts per year, which is a typical "turning waste into treasure". Zhang Lei, deputy general manager of Hebei state Hui, said: first, the sludge reduction effect is higher than the normal level, and the project design goal is to reduce the quantity by 90%.

In the process of environmental impact assessment and energy efficiency assessment, experts believe that the environmental protection and social benefits are huge, which can effectively eliminate the threat of sludge to the ecological environment of Xinji.

Gao Lianmin, director of the Xinji Leather Industry Industrial Zone Management Committee, also has high hopes for the project.

Gao Lianmin said that it is a headache for people to properly handle sludge in various industrial areas.

The traditional way of landfill disposal is low in cost, but in the new situation, the road is blocked.

The technology of Hebei Guo Hui company is unique and advanced, and its processing methods and effects have obvious advantages. The implementation of comprehensive utilization of sludge resources is the key to achieving circular economy and sustainable development in industrial areas.

Once the project is put into operation, tannery sludge will be converted into energy, which will become a major advantage of the tannery industrial area. It not only means that the hat of the sludge pollution will be removed first in the whole province, but also can help and draw lessons from the sludge disposal in the brothers and counties.

All kinds of sludge are eaten to reduce soil pollution.

As the first project to implement sludge power generation in Hebei, Xinji's sludge is not enough to meet the project's processing capacity. Will the economic and social benefits be discounted?

Wang Lianzu pointed to the garden factory model, like the name of the company, they first sought to benefit the country and benefit the side and become a truly environment-friendly enterprise.

Therefore, the company will invest a lot in technology research and development and reserves, and put economic benefits in a secondary position.

To this end, taking into account the local reality, they will adjust the investment return period from 10 years to 20 years, and the cost of handling sludge will be reduced to 200 yuan per ton, only half of the similar enterprises in the south.

They are convinced that if we first benefit the parties, we will eventually benefit ourselves.

"In fact, this technology can not only digest tannery sludge," he said.

Wang Lianzu is proud to say that municipal sludge such as paper mill sludge and municipal sewage treatment plant can burn power generation through deep processing of their technology, so as to realize the resource treatment of sludge. Besides, only a lot of industrial sludge in the surrounding area of Xinji need to find a suitable outlet.

Combined with the state's continuous strengthening of soil pollution control, they have full confidence in the development prospects of sludge disposal projects.

An environmental expert who is concerned about the project in Xinji said that with the promulgation and implementation of the "ten items of soil", the pressure to prevent soil pollution is multiplying.

For Hebei, on the one hand, we must severely crack down on stealing and stealing sludge and abandon simple landfill disposal. On the other hand, we should also provide a feasible outlet for sludge from all over the country.

Only one sludge comprehensive utilization project is far from enough. What is most anticipated now is the early operation of the project and the demonstration effect, which will substantially reduce the soil pollution problem in Xinji and even more areas.

New trend of sludge treatment at present

China's early sludge production is low and simple, and can be used as fertilizer after simple treatment.

Since 1990s, with the increase of sewage treatment volume, the output of sludge has increased dramatically. At present, the amount of sludge produced annually is as high as tens of millions of tons.

The sludge disposal and disposal methods in China mainly include sludge landfill, land use, fertilizer and incineration.

However, the risk of the two pollution is still limited due to the sludge composition and treatment technology. The clean incineration technology of sludge has become a key development direction.

In recent years, many cities in southeast coastal areas of China have built a batch of sludge drying and incineration facilities. Generally, coal combustion and CO combustion are adopted to solve the problem of higher calorific value, such as paper making enterprises and coal washing plants.

Sludge produced after the discharge of industrial sewage and other industrial sewage.

In the early part of Europe, sludge disposal was mainly landfill and land use.

However, with the increase of sludge treatment pressure and the shortage of land resources, many countries have begun to build sludge dry incineration facilities, and enacted relevant environmental laws and decrees, strictly prohibit the sludge containing biodegradable organic matter to fill the landfill.

About 60% of American sludge (dry weight) is treated by anaerobic digestion or aerobic fermentation to form biological solids and used as fertilizer for farmland.

In addition, there were 17% landfills, 20% incineration, and 3% for mining restoration coverage.

Due to land limitation, the main technical route of sludge disposal and disposal in Japan is incineration.

According to statistics, more than 700 kinds of sludge incineration equipment have been incinerated in Japan, and the proportion of incineration of sludge has exceeded 60%.

In a word, the sludge disposal in every country is developing in a direction. With the goal of reduction, innocuity and resource recovery, combined with the composition of sludge, the suitable way of treatment is selected. The ultimate goal is to avoid heavy metal, organic pollutants and other two pollution to land, water and atmosphere, so as to realize the resource utilization of sludge.