The cement industry is a traditional energy consumer. At present, the energy consumption of domestic cement enterprises is mainly coal and electricity. In the past two years, the cement industry has made great progress in energy efficiency, and the level of energy efficiency has been greatly reduced. The latest edition of the national standard "GB16780-2021 Cement Unit Product Energy Consumption Limit" will be implemented from November 1, 2022. What is the actual energy consumption of the cement industry in 2023? What is the level of energy efficiency in the cement industry?
I. Coal
consumption in the cement industry Cement enterprises mainly use raw coal in the clinker burning process. The comprehensive coal consumption per unit product of clinker refers to the amount of coal, diesel oil and other fuels consumed by the energy-using unit in the production of cement clinker during the statistical reporting period, which is converted into the standard coal consumption per ton of cement clinker. The first level of
energy consumption limit is that the standard coal consumption per ton of clinker is below 94 kg. At present, about 6% of cement enterprises can achieve this goal, mainly due to the new production line or the energy-saving technical transformation of the kiln system in the past two years, or the use of alternative fuels, high calorific value hazardous waste and other technical measures in the old line. The standard coal consumption per ton of clinker in
about 25% of the cement enterprises is below 100 kg of the second grade of the national standard. The standard coal consumption per ton of clinker in
about 62% of cement enterprises is between Grade II and Grade III (109 kg). About 7% of the
remaining cement production lines have a standard coal consumption of more than 109 kg, which belongs to the elimination of production capacity or requires technical transformation.
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standard coal is coal with a specified calorific value of 7000 kcal." In fact, this coal does not exist. The calorific value of the raw coal actually used in the cement plant is 5500 kcal, which is converted to 127 by 100 kg of standard coal.
If a standard 5000-ton clinker production line is designed to produce about 1.55 million tons of clinker annually, the physical coal consumption per ton of clinker is 127.3kg. The annual demand for coal is 19. However, at present, the cement industry generally overproduces by 20% and implements peak-staggering production. The actual output of clinker lines in different regions of the country varies greatly, resulting in great differences in coal consumption, which requires specific analysis. In the past
23 years, the coal price fluctuated between 800 and 1200 yuan per ton, the average price was about 970 yuan, and the cost of clinker coal per ton was about 970 * 0.1273 = 123.48 yuan
. In 2022, the coal consumption of the cement industry is about 200 million tons, accounting for 4% of the national coal consumption.
II. Electricity consumption of the cement industry:
The electricity consumption of the cement industry is roughly divided into two parts: electricity consumption per ton of clinker and electricity consumption per ton of cement preparation. There are three professional academic terms: comprehensive power consumption of clinker per unit product, power consumption of cement preparation section, and comprehensive power consumption
of cement per unit product. Comprehensive power consumption of clinker per unit product: the electric energy consumed by the energy-using unit to produce clinker during the statistical reporting period is converted into the electric energy consumed by 1 t of clinker. The following figure shows the proportion of each energy consumption level at present. At present, the comprehensive power consumption per unit output of most cement enterprises is at level 2, and there are not many clinker production enterprises with more than 61 kilowatt-hours of electricity, which belongs to the elimination of production capacity.
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At the same time, domestic clinker lines are basically equipped with waste heat power generation production lines, and the power generation per ton of clinker is about 30 kilowatt-hours, but waste heat power generation still needs about 2 kilowatt-hours of self-use electricity, and the actual net output is about 28 kilowatt-hours. Power consumption of
cement preparation section: only refers to the electric energy consumed from the bottom of cement clinker, gypsum and admixture blending silo to the cement storage silo, which is converted into the electric energy consumed by 1 t of cement. The following table shows the national standard energy consumption limit level and the actual situation of the industry at present.
cement unit product: during the statistical reporting period, the electric energy consumed by the energy-using unit to produce cement is converted into the electric energy consumed by 1 t of cement. Within the scope of statistics are the various energies consumed in the main production process and the auxiliary production process from the raw materials and fuels entering the production plant to the cement products leaving the factory, including the electricity for cement production, the electricity for packaging and shipping, the electricity for the treatment and feeding of mixed materials and gypsum, plus the auxiliary electricity, plus the total electricity calculated by multiplying the comprehensive electricity consumption per unit product of clinker by the total consumption of clinker, divided by the cement output.
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a 5,000-ton clinker production line, the annual output of clinker is 1.55 million tons, and the amount of electricity to be purchased from the power grid = 1.55 million tons * (56-28 + 5) = 51.15 million kwh.
A cement grinding station with an annual output of 1 million tons probably needs to purchase electricity from the grid = 1 million tons * (28 + 2) = 30 million degrees.
Most provinces implement time-of-use electricity price, the average price of clinker production enterprises in cement industry is about 0.6 yuan per kilowatt hour, most grinding stations adopt night production mode, and the comprehensive electricity price is lower than 0.
At present, the cement surplus is serious, the overproduction and peak staggering production of production lines coexist, and some clinker production lines also sell clinker. Specifically, the actual electricity consumption of enterprises needs to be calculated according to the actual production of clinker and cement.
3. Diesel oil
consumption in the cement industry The amount of diesel oil used by cement enterprises is relatively small, mainly because 3-5 tons of diesel oil are needed for each kiln ignition and heating, and each line is ignited about 2-10 times a year, mainly because there are more peak staggering production in the north in recent years, and there are more times of ignition, and each line uses tens of tons of diesel oil annually. The total amount is relatively small (some enterprises use fuel oil instead in order to save costs); diesel is relatively used by forklifts, forklifts, excavators and transport vehicles in enterprises and mines, and some enterprises also choose outsourcing mode, and the current policy requires gradual replacement of new energy vehicles. On the whole, the direct use of diesel in the cement industry is relatively small, and the indirect use of diesel in material transport vehicles is relatively large.
4. Comprehensive energy consumption per unit product of clinker and comprehensive energy consumption per unit product of cement (kgce/t)
are also common energy consumption indicators of cement. For example, the energy efficiency leader of the Ministry of Industry and Information Technology declares according to the ranking of comprehensive energy consumption per unit product of clinker. The comprehensive energy consumption per unit product of
clinker refers to the amount of various energies consumed by the energy-using unit in the production of cement clinker during the statistical reporting period, which is converted into the amount of energy consumed by 1 t of cement clinker, including coal, diesel oil and electricity consumption × 0.
All kinds of energy consumed by the energy-using unit to produce cement are converted into the energy consumed by 1 ton of cement. Is the comprehensive coal consumption of clinker unit product × clinker coefficient + comprehensive power consumption of cement unit product ×
0.0.
< IMG SRC = "https://img7.ccement.com/richtext/img/p9welxl2pmp1708422412077. At present, the cement industry is using more and more alternative fuels, especially in the past two years with the rise in coal prices." Cement prices have fallen, and major cement companies have increased the use of alternative fuels in order to reduce production costs. Domestic < a href = "https://price.ccement.com/brandnewslist-1-1000035. hydrogen (ammonia) has been tested in the cement industry, and there is still a long way to go before the real commercial application.". In terms of green power, more and more cement enterprises in China are building photovoltaic power generation and energy storage power stations. With the cost of photovoltaic power generation and energy storage greatly reduced in the near future, more and more cement enterprises will build green power by themselves, and the capacity of self-built green power will become larger and larger.
6. Overview
In 2023, the overall energy consumption of the cement industry is still relatively large, mainly due to the large base of cement production, but due to the impact of the dual-carbon policy, the technological progress of the industry, coupled with market competition, the decline in sales prices forced the industry to tap internal potential. Internal benchmarking and competition among large enterprise groups, as well as the use of new thermal insulation materials, the use of energy-saving equipment such as high-efficiency burners, high-efficiency grate coolers, energy-saving motors, fans and air compressors, the use of coal-saving agents and alternative fuels, the promotion of energy-saving measures such as the "five-to-six" energy-saving transformation of preheaters, and the backward high-energy-consuming enterprises. The energy efficiency level of the cement industry is declining dramatically, and the whole industry is sure to meet the requirements of the Guidelines for the Implementation of Energy Conservation and Carbon Reduction Upgrading in Key Areas of High Energy-consuming Industries (2022 Edition) issued by the National Development and Reform Commission in February 2022, "By 2025, the proportion of clinker production capacity above the benchmark level of energy efficiency in the cement industry will reach 30%." With the joint efforts of all cement industry personnel, the cement industry as a whole has achieved remarkable results in energy saving and carbon reduction, and the green and low-carbon development capacity has been greatly enhanced.
