Energy saving at Do Luong Cement Factory
Cement is an industry that consumes a lot of energy. At Do Luong Cement Factory, the average annual electricity consumption is very large, with 268,770,410 kWh equivalent to 412 billion VND, accounting for 35% of the production cost of each product.
Investment in waste heat power generation technology
With a huge amount of electricity consumption, finding solutions to optimize electricity, reduce costs, and improve product competitiveness is always a concern of The Vissai Cement Group. In particular, investing in residual heat power generation technology is chosen by the enterprise.
The waste gas thermal power generation system is a new advanced European technology solution applied in many industrial sectors. This technology is currently also applied and installed by The Vissai Cement Group in synchronization with the construction process of Do Luong Cement Factory and has been in stable operation since the beginning of 2017.
The waste gas thermal power generation system operates based on the principle of collecting heat from exhaust gas and residual gas of the clinker production line to get steam to run the turbine generator and generate electricity to the factory's power grid to serve the production process, contributing to reducing product costs and protecting the environment. Exhaust gas and residual gas after passing through the waste gas power generation system will be clean of dust and cooled before being discharged into the environment.
This is the best and most modern environmental protection solution in current cement production technology. According to statistics, each year this system produces over 100 million kWh, providing up to 39% of the total electricity consumption of Do Luong Cement Factory.
To reduce power consumption, the residual heat system is installed and operated to recover the waste heat of the furnace system to generate electricity to serve the factory. Thereby, heat is recovered at two locations, hot air discharged when cooling Clinker (AQC furnace) and hot air from the heat exchange tower (SP furnace) on both lines. With this solution, in 2023, the residual heat system saved 159 billion VND.
The factory also installed an inverter to control the motor of 2 ID exhaust fans (6.0 KV-3150 Kw). Control the fan's air flow by changing the fan's rotation speed compared to the previous method of changing the throttle valve and hydraulic coupling. The power consumption of the grinding fan after installing the inverter is reduced by 25%.
According to calculations, in 2024, with an expected Clinker output of 4,460,000 tons, the amount of electricity saved (compared to not installing an inverter) is 8,920,000 Kwh, equivalent to 26.7 billion VND.
In addition, the power consumption of the coal grinding fan after installing the inverter is reduced by 41%. In 2024, with an expected Clinker output of 4,460,000 tons, the amount of power saved (compared to not installing the inverter) is 1,962,400 Kwh, equivalent to 2.94 billion VND.
Synchronize multiple solutions
Along with investing in residual heat power generation technology, in May 2024, Do Luong Cement Factory put into operation a solar power generation system, utilizing installation on the roofs of raw material warehouses. Thanks to that, an average of 170 MWh is generated per month, accounting for about 0.8% of the total electricity used by the factory.
Mr. Pham Xuan Khanh - Deputy Production Director, Song Lam Cement Joint Stock Company said: We also optimize equipment operation, alternately stop equipment during peak hours to reduce electricity costs and production costs per clinker product. Thereby, reducing production costs due to the difference in electricity prices between peak hours and off-peak hours compared to normal hours, while reducing the electricity load during peak hours for the national grid. This solution helps save 14.5 billion VND (the difference in electricity purchase price between peak hours and normal hours). Control the operation of lighting equipment, replace low-efficiency bulbs with higher-efficiency bulbs. When installing new or replacing broken lights, use LED lights. Regulate the lighting time frame for lighting areas in the factory.
Regarding the solution to control the operation of air conditioners, power stations and administrative areas regulate the air conditioner temperature setting from 26 degrees Celsius to 28 degrees Celsius. Seal all air-conditioned rooms, take advantage of natural wind, only use air conditioners after 8:00 a.m. and turn them off 15 minutes before leaving for areas working during office hours. Turn off the air conditioner when not in use and regularly maintain the air conditioner, replace inefficient equipment.
The company also improved its production process to save energy and reduce greenhouse gas emissions. It established an energy management board to monitor the factory's energy consumption. Every three years, the factory hires an energy audit unit to re-audit the factory's energy consumption. Thereby, it detects shortcomings in energy management and will handle them to reduce electricity consumption.
At the same time, optimize equipment operation by: periodically maintaining equipment, replacing old equipment that consumes a lot of energy with advanced equipment that consumes less energy. Stopping peak hours of equipment to reduce electricity costs and avoid grid overload. Checking for electrical and thermal leakage locations in the factory and taking corrective actions. Continuously improving equipment and production processes with the goal of reducing electricity.
Implementing the plan for energy use and efficiency, Song Lam Cement Joint Stock Company has deployed measures, thereby bringing economic efficiency to the company and saving energy for society. According to Deputy Production Director Pham Xuan Khanh: By applying new technology and management methods, from 2023 to now, the factory has saved 131,533,255 kWh, equivalent to 195 billion VND.
Currently, the Factory has built an energy management system: Issued the factory's energy policy; Established an energy management board consisting of many members of the workshop departments. There is an energy manager certified by the Ministry of Industry and Trade. Issued a plan for economical and efficient energy use, and a reward and punishment policy for employees in the issue of economical and efficient energy use. Annually, report on energy usage status and energy usage plan to the Department of Industry and Trade, as well as periodically conduct energy audits every 3 years according to the law...