Vietnam Cement Industry: Energy-Efficient Technology Needed

2:57:00 PM | 7/8/2011

The world is facing severe lack of energy, so energy saving is one of the problems that enterprises and society are now extremely concerned about. Cement production is relatively large energy consuming sector, thus it is essential to apply new and energy efficient technologies, especially when the government has approved a Strategy for cleaner production in industry to 2020 and the vision by 2025 aiming to promote cleaner production in industries nationwide.

 

Greater production - larger power consumption
According to a report by Service of Science Technology and Environment - Ministry of Construction at the workshop held in Hanoi by the Danish Embassy in coordination with the Vietnam Cement Corporation and  FLSchmith Group, the production and consumption of cement of Vietnam enterprises in 2011 is about 72 million tonnes, of which the rotary kiln cement production is 65 million tonnes, vertical kiln cement production is about 3 million tonnes, and about 2 million tonnes is expected to export. Production of cement left for domestic consumption in comparison with demand is 60 tonnes (oversupplied about 6 million tonnes). Besides, the total consumption of energy and natural resources in the enterprises is increasing. On average, consumption level is 100 Kwh /tonne of cement, so with 68 million tonnes of cement, the total power consumption is estimated at 6.8 billion kWh. From now to 2020 there will be 55 projects put into operation with a total designed capacity up by 66.96 million tonnes, which will increase the total cumulative designed capacity of all sectors in 2020 up to 129.52 million tonnes, the total power consumption is about 11.7 billion kWh . In addition, the cement producing enterprises are consuming large amounts of fuels such as coal and oil. Therefore, to save energy in production, the Ministry of Construction has drafted the basic norms of technology and environmental protection such as thermal energy consumption is less than 730 Kcal / kg clinker, power consumption is less than 90 kwh / ton of cement, and dust emission is less than 30mg/Nm3 for rotary kiln cement plants having modern technology with the high level of mechanisation and automation.

 

Energy saving and environment protecting new technologies
The technology using excess heat recovery system, utilising excess heat in the exhaust gas to produce electricity and waste utilising technology for burning industrial or  household waste to replace the current coal burning by energy saving and environment protecting technologies introduced by FLSchmith Group has attracted the attention of enterprises operating in the field of cement. It is considered as two potential technologies to bring "green solutions" for many cement plants. This new technologies have superior efficiency of about 20-40 per cent compared with traditional technologies without adversely affecting the environment. Thanks to utilising exhaust gas and waste, this new technology help to save significantly input costs without affecting the price of cement. This new technology is considered as a solution to help cement producing enterprises to have a cleaner cement producing process.

 

The study and ulitising the exhaust heat of kilns to generate power and to use in cement plants are much interested in by the Vietnam cement industry, in which the Vietnam Cement Industry Corporation (Vicem) has not stopped innovating technology and improving the efficiency of manufacturing processes. Vicem have been successfully deployed the utilising exhaust heat of rotary kilns through the project at Ha Tien 2 cement factory to generate power. Over seven years, emitted gas thermal plant of the factory has brought significant benefits in terms of socio-economy, energy saving, environmental protection and dramatically reduced the production cost of cement.

 

For the last only four years, the above technology has provided a total nearly 72 million kWh of power for the production line of The Ha Tien 2 cement factory, saved over 2.1 million liters of ADO oil from drying the fuel. This generation system also reduces heat input and output of  raw material millers and electrical dust filters to make the raw material millers work stable and indirectly to improve the milling productivity by about 10-15 tonnes per hour, and the performance of dust filtering has also improved. From the results of applying the technology in the Ha Tien 2 Cement factory, Vietnam Cement Corporation is actively implementing the investment project to build power plants ultilising exhaust heat of the kilns at the factories such as Hoang Thach, Bim Son, Binh Phuoc, and Tam Diep. If all production lines of cement rotary kiln with drying technology of Vietnam are equipped with power generating system ultilising emitted gas, the capacity of power plants would be calculated at about 200 MW, being equal to a capacity of a big power plant and generating an amount accounting for up to nearly 20 per cent of power consumption from the power net.

 

Nguyen Mai