CHINA: A new manufacturing process being trialled in China could lead to reductions in the price of HFO refrigerants.

Fourth generation hydrofluoroolefin refrigerants are seen as key elements both as pure refrigerants and in blends but their cost is seen by many as a barrier to the widespread take up of these low GWP alternatives.

The refrigerant manufacturers point to the relatively high cost of manufacture for prices which in the case of the R134a substitute R1234yf, for instance, are around €80-€100/kg.

There are, apparently, currently two ways of synthesising HFOs. In simple terms, one process uses  cheap and readily available materials but is complicated, has low yield, produces multiple by-products and is energy intensive. In contrast, the other option is a relatively simple process, has a high yield and produces fewer by-products. However, its raw materials are scarce and expensive.

Also, in both processes the catalysts are easily deactivated due to sintering and/or carbon deposition.

According to a new paper published by Elsevier, a team from Chinese chemical company Juhua Group Corporation and Zhejiang Normal University claims to have developed new catalysts that manage to increase the yield from below 30% to more than 85%. The reaction temperature has also been decreased by 40°C, doubling the lifespan of the catalyst and reducing energy consumption.

Last year, the Juhua Group Corporation used self-developed technology to successfully build process units for manufacturing HFOs with an annual production capacity of 1000 tons in total. The key equipment of the process units — the catalytic reactor — possesses the advantages of excellent heat exchange and easily controllable reaction temperature. These advantages allow it to overcome the technical bottlenecks of conventional catalytic reactors, in which reaction temperatures are difficult to control and often exceed desired limits, leading to catalyst deactivation from carbon deposition and sintering.