What is waste heat recovery technology?

Surapon Oonchuen, Manager of Operations and Maintenance at SCG Cement and Building Materials.

Waste Heat Recovery is a system used to recover the heat of gases discharged during the cement producing process in boilers to produce steam. The steam is used in turbines and generators to produce electricity that can be reused in cement production. The power generation depends on various factors including the capacity of the kiln, specific heat consumption, temperature, and flow rate of waste gas from preheater and cooler.

There are three types of configurations - single pressure and double pressure systems and the flasher system - to suit various cases based on plant layout and other conditions as well as investment and technical conditions.

What are the specific benefits that WHR brings to cement producers?

WHR provides a solution for reducing energy costs and [achieving] sustainability by reducing carbon dioxide (CO2) emissions into the environment. From a business standpoint, it enhances the competitiveness of the company as it is able to reduce electricity costs, which account for a major portion of operation costs. It can make up 30 per cent of the total power consumed by the plant. Moreover, the technology is a great solution for sustainability and environmental conservation thanks to much less carbon dioxide emission that is the main cause of the global greenhouse effect. From a national perspective, WHR can help reduce power shortage, which is quite common in developing countries including Viet Nam.

When did your group begin using WHR?

We are aiming towards a green industry and utilising resources more effectively with a policy geared towards becoming the leader in environment-friendly innovations. Therefore, we installed the first WHR in 2007 in Thailand and a year later other cement manufacturers followed in our footsteps. WHR is applied in all our cement plants to recycle waste heat produced in the manufacturing process and exchanging waste to be used as fuels in cement factories

What do you think are the biggest challenges for local cement producers in adopting WHR technology?

Cement production is one of Viet Nam's most energy-intensive industries. A cement industry development plan for until 2020 requires all plants producing 2,500 tonnes or more of clinker per day to be equipped with a waste heat recovery (WHR) system to reduce electricity consumption by at least 20 per cent by 2015. Viet Nam is in an early stage of WHR application where there might be some obstacles in areas such as finance and know-how. However, this is a mandatory step that they have to take to ensure sustainability in the long term.

What do you think about the Government's plans for the cement industry through 2020 that require all of Viet Nam's cement producers with a clinker capacity of 2,500 tonnes a day to install WHR by 2015?

As a regional pioneer and leader in sustainable development, we agree with the Government's direction for a sustainable cement industry in Viet Nam in the long run, and WHR is just the very first step. We believe this regulation will finally benefit the manufacturers as it provides them to a healthy roadmap for growth.

At our company, we invest US$15-16 million for a plant with a capacity of 5,500 tonnes per day. The operational cost is $0.8 million annually; payback is in four to five years. The carbon dioxide saving from WHR can benefit the company by carbon trading through the Clean Development Mechanism. This allows emission projects in developing countries to earn certified emission reduction credits that can be sold to industrialised countries [for] their emission reduction targets.

In what sectors does your group have interests in Viet Nam?

We began our regional expansion with Viet Nam as the strategic hub in 1992. SCG, established over 100 years ago, now has three core businesses -cement and building materials, chemicals, and paper. We have been making sustainable growth a major focus of our operations. Our company has been recognised by the Dow Jones Sustainability Indexes as a world leader in sustainable development in the construction materials industry for four consecutive years since 2011. The DJSI comprise indexes evaluating the sustainability performance of the 2,500 largest companies listed on the Dow Jones Global Total Stock Market Index. Back in 1995 our group established its sustainable development committee. Currently the group has 19 operations in Viet Nam, chief among which are the SCG Building Materials Co., Viet-Thai Chem, Prime Group JSC, and Long Son Petrochemicals Company, with over $615 million in assets and more than 6,500 employees. We apply our green policy in all places where we operate, including Viet Nam. — VNS