Buhler’s advantage of perspective

As a company working across the food manufacturing industry, a major advantage for Buhler, and its partner Petroncini, has been observing the crossover of trends. When it comes to sustainability, Stefan Schenker, Head of Market Segment Coffee for Buhler, says that the earliest concerns can be traced back to large multinationals.  Schenker says these large companies started looking at their environmental footprints early on, as a way to cut down on costs while also ‘cleaning up’ their corporate image. Leading up to 2007 and beyond, when energy prices started to peak and showed few signs of dropping back, Schenker observes that sustainability has since become a true “hot topic” among every level of industry. In coffee, from the smallest boutique shop roaster to the largest factory manufacturer, no one is being spared swelling energy costs. Couple those costs with an increasing number of current or anticipated regulations aimed at cutting emissions and limiting air pollution, and these days Schenker says you’d be hard pressed to find a company not looking into the long-term sustainability of their roasting equipment. “For smaller companies it may just be about cost reduction,” Schenker says. “But what we’ve really seen in most developed markets is that the norms and regulations about exhaust air are becoming stricter and stricter. This is probably the biggest single problem in the roasting industry in terms of regulations. The authorities are simply less and less tolerant of roasters. And since you cannot completely avoid odours, this is increasingly becoming a problem.” With this broad view of the food processing industry, Buhler is well placed to see what trends are set to come. “We take sustainability very seriously,” says Schenker. “Buhler started on this path towards sustainability long ago in other fields, and we’ve been able to take all that experience and bring it into our roasting equipment.” In terms of energy efficiency, Schenker says the key starts with optimised design in the roasting chamber. Through an efficient transfer of heat from the air to the beans, this can limit energy usage dramatically. Along with its partner, Petroncini, Buhler has worked over the years to optimise the roasting chamber for efficient heat transfer. The beans are evenly distributed throughout the chamber to benefit the most from air transfer. The next step has been to optimise the speed of the chamber. Because beans vary in size, and require different speeds from the beginning to the end of the process, Buhler’s multi-step speed control system optimises these speed cycles. Another step to maximising energy efficiency has been to offer air recirculation. Schenker remembers two decades ago when the norm would see open systems that allow a full escape of air, requiring high amounts of energy to continuously reheat the system. Modern Buhler equipment recirculates most of that air, resulting in significant energy savings. Because recirculated air has largely become the norm in air-roasting equipment, Schenker points to the next step that Buhler has taken. Buhler’s equipment combines the main process of hot air recirculation with the exhaust gas cleaning process, all in one combustion chamber. This means that as the heat is generated for the main process, it also serves to clean the air as a secondary process. This saves a high amount of energy, compared to systems that use catalytic converters in an afterburner process to clean the exhaust gas. Some Buhler equipment still uses catalytic converter systems, and Schenker says the company works individually with clients to see which is most appropriate for them.  An exciting advancement Buhler launched at time of publication, is a coffee preheating unit. Although not unique to Buhler, combined with the company’s leading-edge efficiency in design, this preheating unit is set to push the company to the forefront in terms of energy saving. “It’s a very important system, one that can save up to 30 per cent of energy costs,” Schenker explains. The preheating unit works like a second roasting chamber, using hot recirculated gas to preheat the beans. “But you have to take care not to overheat the beans, because you don’t want to affect the quality,” Schenker says. “This process control is very important.” Beyond just offering the latest advancements in sustainable equipment, Schenker says that Buhler is dedicated to working with clients on an individual level to help them reduce their environmental footprints. The company offers an energy audit service, where they look at the complete processing plant. The Buhler team visits the client’s factory, and looks at both the energy and production streams. The team then produces a Sanki diagram: a tool that shows the plant’s energy and production flows in the plant. “With these diagrams, the client can visualise in the plant the most efficient ways to save on energy,” says Schenker. In all these energy savings measures, Schenker says that there is no need to compromise on quality. He assures that when these technologies are applied properly, there is no impact on quality. “Especially with these air recycling systems, we’ve had many clients ask if this will affect the quality. And the answer is ‘No’,” he says. “As long as the process is optimised, there really is no impact. Quality is the last thing that we would want to affect.” Quality takes priority in all of Buhler’s extensive research and development activities. The company invests an impressive 5 per cent of its turnover into R&D. In the coffee arena, Buhler is currently working on a number of projects with Petroncini. Different to other dedicated roasting equipment manufacturers, Schenker says Buhler’s big advantage will continue to be its ability to leverage across food production fields. “From chocolate to cocoa beans, there are some common sustainability projects that spread out,” he says. In terms of future projects, Schenker says research is heading mainly in two directions. The first is energy recovery, making the most of off-gasses. “I think there’s still a lot of work to be done in terms of recovering energy from that hot off-gas,” he says. Buhler’s partner Petroncini currently holds patents on an RTO system, a thermal oxidation cleaning system that combines the working principle of an after-burner with the energy-saving heat storage capacity of ceramics. The chambers are filled with ceramics, through which the off-gas can flow and collect heat that was previously stored. By directing the gas through a sophisticated stream and pathway, this helps to maintain an exothermic oxidation process in the cleaning unit for decreasing the impurities at lower energy input. Another technology Buhler is only just developing is cold off-gas cleaning through the use of plasma. This is in development with external partners. It generates radicals that clean off-gas at low temperature. Schenker warns not to look out for this plasma technology too soon, because it’s really just the future. However, as one of the earliest providers of sustainable food processing technology, he says you can expect to see it from Buhler first. GCR

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