Solvent extraction, biomass product yields

The ideal HMF production process would use raw biomass as its feedstock, without the necessity for extensive drying or pretreatment (apart fi om mechanical reduction to particle sizes which do not suffer mass transfer limitations). Reactions would proceed in high yield over short time scales under mild conditimis in inexpensive media and use simple, non-foulable catalysts. The HMF product would be isolated without recourse to distillation or protracted solvent extraction, and all materials would be easily recyclable. Except for product yield, none of these objectives has currently been met in such a way as to be reducible to practice on an industrial scale. In the end, it is a matter of economics. When the dust settles, only the most competitive, industrially viable processes will be left standing, and the rest will be consigned to history. 

Cost effectiveness of PHA isolation does not only depend on equipment and chemicals needed, but, most of all, on the yields for product recovery and the possibility to reutilize the compounds needed for the isolation. For direct extraction of PHA from biomass extraction solvents that can easily be recycled will be of interest [69]. Solubility of PHAs, especially pure crystalline PHB, is a complex topic. Unlike most low molecular mass compounds and noncrystaUizing amorphous polymers, the solubility of crystalline polymers such as PHB cannot be predicted... 

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