Hot and Cold – New Techniques for Energy Recovery

Chemical companies are finding new ways to improve efficiency through energy recovery – with great results. Several new methods and technologies claim to recover as much as two-thirds of wasted energy by converting it into usable heat energy, Muriel Axford reports on new methods to significantly cut energy costs.

According to 2006 data from the UK government, energy consumption in the chemical, food, paper and metal sectors totalled 149.4TWh. At the same time it is estimated that the potential for heat recovery from these four industrial sectors is 5.4TWh in total.

The potential for savings is significant, especially when you consider the potential mentioned in the report for saving an additional 11TWh through the use of heat pumps that could upgrade waste heat to temperatures that could be used within an industrial process unit. Along with improved economic performance for the process industries, there is also the benefit of reduced carbon dioxide emissions.

It is the potential for these significant savings which is prompting both government's and industry to invest in research, development and design efforts.

"The project, known as NanoHex, aims to combat heat build up in high tech industries."

Research efforts

A research programme established by the Engineering and Physical Sciences Research Council (EPSRC) has pulled together researchers from the UK's Newcastle University, along with partners from industry including United Biscuits, to "investigate and develop methodologies for the optimum thermal energy recovery from process waste streams in the food and chemical process. The project aims to improve thermal performance and minimise greenhouse gas emissions from unit and process operations".

At the same time China, with its growing manufacturing base, is looking to make a positive impact on the world stage by reducing its emissions and improving energy efficiency. China Energy Recovery (CER) is an international engineering and manufacturing company specialising in the design, construction and installation of waste heat recovery systems allowing industrial facilities to achieve improved energy efficiency.

As well as designing and installing waste heat recovery systems CER has a focus on research and development. During 2010 the company was granted a 10 year patent covering it cement kiln forced-circulated waste and heat recovery boiler technology. CER says that cement plant waste heat boilers are a new technology that it has developed and it is the only company using this technology. After further research CER says that it expects to develop new energy recovery technology solutions for energy intensive industrial processes.

Major industrial producers

In the meantime there is a worldwide push to make use of the best technology available to improve energy efficiency. Recent months have seen CER awarded a number of contracts to install waste heat recovery systems.

During January 2011 CER announced that it had been awarded a contract, valued at $4.2m, to install a waste heat recovery system at an existing sulphuric acid plant owned by Jiangsu Jihua Chemical Company. Jiangsu Jihua Chemical is a subsidiary of Zhejiang Jihua Group, one of China's largest producers of basic industrial chemicals including polymers and dyes.

Also during January 2011, CER announced two further contracts, valued at $74.7m, to install heat recovery systems for Ningbo Xinfu Chemical Technology Company and Zhenjiang Kalin Clean Heat Energy Company. Both systems are scheduled to be installed during the fourth quarter of 2011.

With the push to cut costs growing, CER says that there is an increasing demand for its services with the company stating that by the first quarter of 2011, its announced contract total for 2011 delivery of nearly $80m is nearly four times its 2009 revenues.

Indeed so significant are the savings, CER has said that one of its customers, Two Lions, a Chinese producer of sulphuric acid was able to attain payback on its energy recovery investment in less than two years. At the same time Two Lions was approved to sell carbon credits with an estimated annual value of more than $2.5m, as a result of its waste heat recovery system.

Software to save energy

Along with the development of physical systems software is also helping companies get to grips with improving energy efficiency. GEA PHE Systems, a leading Germany-based manufacturer of plate heat exchanger technology, has developed a program that allows operators to visualise the influence of differing pasteuriser heat recovery rates on investment costs, energy savings and carbon dioxide emissions.

GEA PHE Systems said that the key to the software's capability is that the reciprocal effects of all components are taken into consideration.

So the specific performance characteristics and energy data of all commercially available pumps, compressors and GEA plate heat exchangers are stored in a database. The prevailing gas price is entered into the software programme. With all the data the programme compares all the available parameters and works out which pasteuriser is the ideal component to guarantee the best possible energy efficiency.

Cooling industrial processes

Efficient cooling is also a vital part of energy efficiency. During the final quarter of 2010 GEA PHE Systems announced that it had been awarded a contract to supply three of its heat exchangers as seawater coolers for a low density polyethylene facility being built by Qatar Petroleum Company in Qatar. The plant is due to become operational during 2011.

"China Energy Recovery is an engineering company specialising in waste heat recovery systems."

Again, desire for improvement and more efficient cooling is leading to ongoing innovation. During March 2010 Thermacore Europe, a leading provider of heat pipe energy and other thermal management solutions announced that it was leading a €8.3m pan European project to develop a next generation liquid coolant that incorporates engineered nano-particles.

The project, known as NanoHex, aims to combat heat build up in high tech industries with a coolant that would be up to 40% more efficient than traditional coolants.

The potential of a nano-fluid coolant could also be developed for applications in areas  such as medical equipment, aerospace, process industries and more. Nano-fluids could help to provide a more economic and efficient cooling system in which the heat may be capture and recycled, leading to reduced emissions and improving fuel efficiency.

The three year NanoHex project began in September 2009 with initial grant funding from the European Commission's Framework 7 Programme.