As a high-energy-consumption chemical production enterprise with coal, phosphate rock, calcium carbide, and electricity as the main materials, Yihua Chemical Company must take resources recycling and the development of cyclical production of the enterprise, regardless of economic or social benefits. road. Since 2001, Yihua Company has begun to use energy-saving technologies as its core to establish a multi-channel energy-saving system. The first is to adjust the synthetic ammonia raw material route, implement pulverized coal gasification technology, and use cheaper pulverized coal instead of higher-priced lump coal as raw materials to produce synthetic ammonia, which greatly reduces the production cost. In 2004, Yihua produced a total of 800,000 tons of synthetic ammonia, saving 1.04 million tons of high-quality lump coal annually, and this alone can reduce raw material cost expenditure by about 124 million yuan each year. The second is to increase the sensible heat and latent heat recovery in various production processes, and to achieve maximum energy conservation and consumption reduction through the use of synthetic ammonia three gas recovery, sulfuric acid waste heat recovery, and self-powered power plant cogeneration.
Take ammonia recovery as an example. In the production of synthetic ammonia, a large amount of gas-making blow-by gas, synthetic release gas, and decarbonization and air release are produced, which is known as 'three gases' in the industry. It contains a lot of high combustion heat gas components. The flue gas with a temperature of up to 1200 degrees Celsius after combustion is sent to a waste heat boiler to produce steam. The high pressure steam produced is used for power generation, and the low pressure steam generated after power generation is used for production. According to the principle of energy cascade utilization, energy is optimally utilized. The company invested 100 million yuan in funds, has built 11 sets of waste heat recovery and power generation devices, annual by-product steam 2 million tons, annual power generation capacity of 160 million kwh, annual cost reduction of nearly 200 million yuan. The promotion and application of this technology in the production of synthetic ammonia not only drastically reduces the consumption of coal, electricity and other resources, but also greatly reduces the emission of harmful gases such as carbon monoxide.
Yihua, through the development of pentaerythritol mother liquor recovery technology, extracted a value of up to 3,000 US dollars / ton of dipentaerythritol, in addition to the production of sodium formate products, the annual efficiency of 50 million yuan. The separated water is recovered for pentaerythritol production, achieving zero emissions and greatly reducing the impact on the environment.
The gasification slag produced by Yihua's synthetic ammonia production still contains a certain amount of calorific value, with an annual production of 600,000 tons. In view of this situation, the company reused these slags for the production of steam by the circulating fluidized-bed boilers to generate electricity, and took advantage of the coal resources to 'eat dry squeeze'. The calcium carbide slag produced in the production of PVC is a kind of solid waste that is more difficult to use. They invested more than 30 million yuan to introduce the U.S. Monsanto company's power wave calcium carbide slag flue gas desulfurization technology to desulfurize and purify the power plant flue gas, not only Reuse of waste has been realized, and the difficulty in desulfurization of coal-fired power plants in China has been solved. The operating cost is controlled below 0.025 yuan/kwh. In addition, joint development is also carried out with cement plants and brick and tile plants that can use these waste residues in the downstream. Through the comprehensive utilization of waste residues, the company can increase efficiency by 40 million yuan each year.
The history of development of Yihua is such a way to take resources recycling and the development of circular production
From the loss of 38 million yuan in 2000 to the realization of profits and taxes of 400 million yuan in 2004, from a small synthetic ammonia plant to a large-scale enterprise group that now has three pillars: coal chemical industry, phosphorus chemical industry, and salt chemical industry. Hubei Yihua Group Co., Ltd. has become weaker and stronger. What is the secret? Recently, Cai Zhong, deputy chief engineer of the company, told reporters that their secret is to make products one by one.