Xuong Giang paper mill under Bac Giang Import Export Corporation-IMEXCO Bac Giang is the largest energy consumer in the province of Bac Giang. Responding to the energy saving program in recent years, the factory has continuously made improvements to reduce power consumption and protect the environment. However, according to experts of Hanoi Center Energy Conservation Center, energy saving potential in this business is still quite large.

The boiler system of the plant

In 2010, Hanoi Energy Conservation Center in collaboration with experts of Bac Giang Department of Industry and Trade’s Energy management office implemented energy audit for the plant. Through detailed energy audit process, the audit team has examined most of energy consuming equipment and production equipment of the plant, energy consumption process as well as the quantity of energy consumption, special energy features of equipment and the plant. Accordingly, implementing all of energy efficiency solutions, this businesses shall have the opportunity to save additional VND 2.7 billion annually by reducing consumption of over 500 thousand tons of coal and 1.3 million kWh.

Initial design capacity of the plant is 12,500 tons of end-product per year. In 2009, according to the demand of the market, the plant operated at full capacity and produced 13,130 tons of end-product. Thus, the majority of the production equipment has been operating at full capacity, so the maintenance of equipment has always been a primary concern of the plant.

Paper machine system

Previously, since 2006, the equipment system has been uniformly invested and highly automated. The factory has actively applied effective energy efficiency solutions such as installing inverters for all main engines of paper machines; integrating automated control and production management in computer to ensure product quality; recovering entire condensed water to resupply to boilers.

According to Mr. Hoang Quan, Hanoi Energy Conservation Center, the work of energy management has an important role in reducing energy consumption in production units. Xuong Giang Paper Mill has also taken measurements of consumption in areas according to month. Boiler unit, technical department and administrative office have determined indicators on monthly consumption of electricity, coal ... of the plant and submitted to the Company to calculate costs. However, the process of managing fuel and energy consumption has not been finalized; there are still many limitations in the management of energy consumption intensity.

In addition to the establishment of the energy management board, the audit team has also surveyed, analyzed and identified eight additional opportunities to save energy for equipment during operation. These solutions include solutions requiring low investment and those requiring high investment. To implement all the solutions, the plant needs to invest about VND 4.5 billion; payback period is about 1.6 years. Along with saving VND 2.7 billion each year, the plant can reduce 3.7 thousand tons of CO2 emissions.

These solutions include: Installing Powerboss device for engines of coiling machines; installing inverters for motors of tank agitators; installing Powerboss device for motors of hydraulic grinders; replacing the current condensed water pumping system by the high efficiency thermal pumping system; installing inverters for motors of 4-ton-per-hour boiler sucking fans; installing inverters for motors of 6-ton-per-hour boiler sucking fans; insulating steam pipes and steam distribution pipes in paper machine unit; replacing the current boiler system with 10-ton-per-hour boilers (4 t/h and 6 t/h boilers for backup).

However, according to experts, energy audit is only one stage in the entire energy management process. The factory should organize a team of energy managers, who have knowledge in technique and energy, to coordinate with the consulting unit to implement proposed energy saving. Law on energy and efficiency conservation has clearly defined sanctions for businesses using energy wastefully. Therefore, the unit should have policies on rational management and use of energy for long-term interests of the business.

By Minh Duc