Combined Microwave And Rotating Pulsed Fluidized Bed Drying Of Poly-hydroxybutyrate

Poly-hydroxybutirate (PHB) is a biodegradable thermoplastic polyester that can be considered analogous to many conventional petroleum-derived plastics currently in use. In Brazil, PHB is produced by bacterial fermentation of the sugarcane in a process integrated to the sugar and ethanol industrial chain. Drying is an important step of PHB production because an adequate post-processing can be achieved only at moisture contents lower than 0.50 % (w.b.). This work aimed at investigating the influence of microwave power level and hot air conditions on drying of PHB in a combined microwave and rotating pulsed fluidized bed (RPFB) dryer. The effects of operational parameters were analyzed by a 2-level factorial design with 3 repetitions at the center point. The results showed final moisture content in the range of 0.38-0.95 % (w.b.). Temperature of the air and microwave power level had a significant influence on the drying process. The dryer proved to be appropriate to dry the PHB granules, resulting in a lower process time compared to convective drying in RPFB.282285Assoc. for Microwave Power in Europe for,et al.,French MTT Chapter of IEEE,Institut National Polytechnique de Toulouse (INP),Research and Education (AMPERE),Universite Paul Sabatier - Toulouse IIIPublisher:Editions CepaduesDoi, Y., (1990) Microbial Polyester, , VCH, New YorkBrandl, H., Gross, R.A., Lenz, R.W., Fuller, R.C., (1990) Adv. Biochem Eng. Biotech., 41, p. 77Holms, P.A., Wright, L.F., Collins, S.H., (1982), Eur. Patent No. 0, 052, 459(1983), Eur. Patent No. 0, 069, 497Zhao, K., Deng, Y., Chen, J.C., Chen, G.-Q., (2003) Biomaterials, 24, p. 1041Gao, Y., Kong, L., Zhang, L., Gong, Y., Chen, G., Zhaoand, N., Zhang, X., (2006) Eur Polym J, 42, p. 764Ma, G., Yang, D., Wang, K., Han, J., Ding, S., Song, G., Nie, J., Organic-soluble chitosan polyhydroxybutyrate ultrafine fibers as skin regeneration prepared by electrospinning (2010) Journal of Applied Polymer Science, 118, pp. 3619-3624Mantelatto, P.E., Nazareno, A.S.D., PHB Industrial S. A., Process for extracting and recovering polyhydroxyalkanoates (PHAS) from cellular biomass (2008) Int CI C12P 7=62, , U. S. 2008=0193987 A1Godoi, F.C., Boin, E.A.S.F., Pereira, N.R., Rocha, S.C.S., Fluid dynamics and drying of cohesive particles of a biodegradable polymer (poly-hydroxybutyrate) in a rotating pulsed fluidized bed (2010) Drying Technology, 28 (11), pp. 1297-1306Drouzas, A.E., Schubert, H., Microwave application in vacuum drying of fruits (1996) Journal of Food Engineering, 28, pp. 203-209Decareau, R., Peterson, R., (1986) Microwave Processing and Engineering, , Ellis Horwood: Chichester, U. KFeng, H., Tang, J., Cavalieri, R.P., Combined microwave and spouted bed drying of diced apples: Effect of drying conditions on drying kinetics and product temperature (1999) Drying Technology, 17, p. 1