VATIS UPDATE Article

Researchers at Lancaster University, the United Kingdom, have discovered a technique to considerably increase the efficiency of the process, thus hugely increasing biofuel from coffee’s commercial competitiveness. The researchers combined the existing multi-stage process into a single step (transesterification), which incorporates extraction of the oils from the used coffee grounds and the transformation of it into coffee biodiesel.

In the traditional process, manufacturers blend used coffee grounds with hexane and cook the mixture at 60 °C for about 1 to 2 hours. Once the hexane evaporates, only the oils are left behind. Methanol and a catalyst are then added to create biodiesel and a glycerol by-product - which also requires separating. The team re-alized that they could combine the processes by using only methanol and a catalyst.

Thus, eliminating the need for hexane totally, and therefore saving on chemical waste. Furthermore, they also discovered that the optimum time for the process was 10 minutes to obtain the same yield of oils from the used coffee grounds – a substantial reduction in time and associated energy costs. The process looks promising and could enable 720,000 tonnes of biodiesel to be produced annually from used coffee grounds.