THE substantial effort put in at Asia Pacific Breweries Singapore (APBS) in a project to analyse its process cooling plant and then retrofit the plant to make it more energy efficient has enabled the company to become one of the winners in the Best Practices category at the EENP Awards 2016.
The energy saving project involved retrofitting of the process cooling plant to reduce sub-temperature cooling demand. It resulted in annual energy savings of 1.25 Gigawatt hour per annum for the company. "Energy efficiency is nothing but using less energy to deliver the same or higher level of service. It is a key element to address the energy cost for the development and growth for any organisation or a sector, as well as for global climate change," says Kannan Prabakaran, engineering manager, APBS, who is responsible for energy efficiency at APBS.
"Energy efficiency in APBS is measured by energy consumption in terms of kwh/HL of beer being produced. The company needs to be very cost effective as far as energy cost is concerned and aims to reduce the energy cost by improving the existing system and modifying/upgrading the equipment that allows short ROI (return on investment)."
Mr Prabakaran adds: "Energy efficiency is one of the key performance indicators for APBS. Eventually it is a continuous programme. For any industry to sustain in the market, it is important to deliver the quality product at a reasonable price. Here, energy efficiency takes a big role.
"Energy deployment at APBS takes place quarterly. From the deployment we will drive a team to access the opportunity for energy efficiency. It could be process optimisation or equipment reliability improvement or equipment upgrade; it is very essential for anyone to be compatible in the market."
At the same time, the building control system is reviewed to obtain the best practice to achieve good energy efficiency to reduce the operating cost. Migration to LED motion sensor technology and upgrading to the frequency drives for motor and conveyors transmission system has helped to improve the energy efficiency.
Mr Prabakaran says: "I would like to share some of the milestones that we have achieved. One of them is the vapour recovery system. In brewing, we have a process called 'wort boiling', in which we use steam to heat up the wort to a desired temperature. When boiling takes place, it generates vapour. We built a heat exchange system named vapour recovery system, which uses the recovered vapour to heat up the water up to 85 degrees C."
Conventional breweries use steam to heat the water, whereas APBS uses the vapour to heat up the water. Hot water plays a big role in cleaning and rinsing of tanks and vessels in the brewing process. The above modification reduced APBS's steam consumption significantly. This project was identified as one of the best practices in the 2013 EENP Awards.
In 2014, APBS replaced its production and warehouse roofs with skylights which reduced dependency on electricity during the day and a significant reduction in electricity consumption was achieved. "Similarly, last November, APBS installed a 2.1MWp solar panel at its packaging, utilities and warehouse roofs in three phases and harvested energy able to meet 20 per cent of our total energy consumption," Mr Prabakaran notes. He points out that from the energy point of view the cooling plant consumes 35 per cent of the total energy consumption of the entire brewery. At APBS the cooling plant was operating with 30-year-old technology and equipment.
"The existing system, able to fulfil our requirements, consumed 4.095kwh/HL for beer being produced, but the industrial benchmark is 3.4kwh/HL," explains Mr Prabakaran. "So we started to access the feasible study to improve the performance of our cooling system. In this project there are two main processes modification to achieve the savings in energy. Firstly, the wort cooling and dilution water cooling requirements were isolated as a standalone process which is supported by new cascading compressors. At the same time, the operating parameters of the wort cooling were changed so that the alcohol water would not be supplied at -4 degrees C (existing set point), and would be increased to 3 degrees C, as well as to achieve better heat transfer (convection) by adding an additional heat exchange plate for the alcohol cooling of the wort. Secondly, the isolation of the wort cooling and dilution water process resulted in a lower demand of -4 degrees C alcohol water which is currently supplied using the 5 STAL compressors. With the new system, the loading of the existing system was decreased. The result is that the cooling plant energy consumption dropped to 3.27kwh/HL, lower than the industry benchmark."
APBS already has a Singapore Certified Energy Manager (SCEM), who is leading the utilities team and is involved in various energy management projects in the company. "The roof modification with skylight project initiated by our facility engineer has delivered good results. We strongly believe that we need more energy efficiency specialists, who can drive and deliver good results in the future. In 2017, we will develop one of our team members for the SCEM certification," adds Mr Prabakaran.