A company called Yellow Diesel B.V. says they have succeeded in producing biodiesel in a continuous fixed-bed micro plant based on heterogeneous catalysis, which provides pure biodiesel plus a cosmetics/food grade glycerol with much lower waste streams. 

Their process eliminates all the aqueous waste streams that stem from using the conventional homogeneous acid/base catalyst technology.   Combined with integrated process design, they claim the process saves up to 40% of the capital costs and 30% of the operating costs compared to a conventional plant.

Yellow Diesel has produced the biodiesel in its continuous micro plant, and is now scaling up the process to pilot-scale. They say this process can be adjusted to various types of feedstock, including low-quality oils, waste oils and fats.

The following sample shows the quality specifications of the biodiesel made from industrial-grade rapeseed oil, as determined by the independent laboratory NofaLab.

Analysis results             YellowDiesel      EN14214

Ester content                 99.5%               >96.5%

Density at 15ºC             0.8740              0.860–0.900

Flash point                    >120 ºC            >120 ºC

Methanol content           0.02%               <0.2%

Monoglyceride               0.57%               <0.8%

Diglyceride                    0.19%               <0.2%

Triglyceride                    0.15%               <0.2%

The biodiesel specifications are better than required by the European norm EN14214.   Yellow Diesel B.V. is a spin-off company of the UvA Holding B.V., the holding company of the University of Amsterdam.