The present invention relates to a process for thermolytic fragmentation of a sugar into a composition comprising C.sub.1-C.sub.3 oxygenates. In particular, it relates to the use of heat carrying particles providing improved yields of C.sub.1-C.sub.3 oxygenates and improved fluidization characteristics making it suitable for industrial scale production of e.g. glycolaldehyde. It also regards a circulating fluidized bed system comprising the heat carrying particles.

In alternative embodiments, provided are processes for producing propylene glycol from glycerol derived from manufacturing biodiesel. Processes as provided herein can reduce color and/or odor from a converted propylene glycol by removing impurities and by-products produced during the glycerol hydrogenation conversion process. In alternative embodiments, provided are improved process for producing propylene glycol from glycerol at high selectivity and conversion and reduced operating costs.

In alternative embodiments, provided are processes for producing propylene glycol from glycerol derived from manufacturing biodiesel. Processes as provided herein can reduce color and/or odor from a converted propylene glycol by removing impurities and by-products produced during the glycerol hydrogenation conversion process. In alternative embodiments, provided are improved process for producing propylene glycol from glycerol at high selectivity and conversion and reduced operating costs.

The invention relates to a method for obtaining acetoin from a medium containing same, the method comprising a step of dehydration by pervaporation using a hydrophilic membrane. With this method, the acetoin can be satisfactorily isolated and purified, both in terms of quality and yield. Furthermore, with the method of the invention it is possible to dispense with the use of solvents and prevent impurities from being generated.

The invention relates to a method for obtaining acetoin from a medium containing same, the method comprising a step of dehydration by pervaporation using a hydrophilic membrane. With this method, the acetoin can be satisfactorily isolated and purified, both in terms of quality and yield. Furthermore, with the method of the invention it is possible to dispense with the use of solvents and prevent impurities from being generated.

The invention relates to a method for obtaining acetoin from a medium containing same, the method comprising a step of dehydration by pervaporation using a hydrophilic membrane. With this method, the acetoin can be satisfactorily isolated and purified, both in terms of quality and yield. Furthermore, with the method of the invention it is possible to dispense with the use of solvents and prevent impurities from being generated.