Mechanistic investigations in sono-hybrid techniques for rice straw pretreatment.
This paper reports comparative study of two chemical techniques (viz. dilute acid/alkali treatment) and two physical techniques (viz. hot water bath and autoclaving) coupled with sonication, termed as sono-hybrid techniques, for hydrolysis of rice straw. The efficacy of each sono-hybrid technique was assessed on the basis of total sugar and reducing sugar release. The system of biomass pretreatment is revealed to be mass transfer controlled. Higher sugar release is obtained during dilute acid treatment than dilute alkali treatment. Autoclaving alone was found to increase sugar release marginally as compared to hot water bath. Sonication of the biomass solution after autoclaving and stirring resulted in significant rise of sugar release, which is attributed to strong convection generated during sonication that assists effective transport of sugar molecules. Discrimination between individual contributions of ultrasound and cavitation to mass transfer enhancement reveals that contribution of ultrasound (through micro-streaming) is higher. Micro-turbulence as well as acoustic waves generated by cavitation did not contribute much to enhancing of mass transfer in the system.
Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
Kelothu
K
Suresh
Amrita
A
Ranjan
Shuchi
S
Singh
Vijayanand S
VS
Moholkar
D056804:Biofuels; D018533:Biomass; D057446:Hydrodynamics; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D055595:Mechanical Phenomena; D012275:Oryza / Q000737:chemistry*; D013010:Sonication; D014867:Water / Q000737:chemistry
D056804:Biofuels; D014867:Water
ATCLV; Acid hydrolysis; Alkali hydrolysis; Biofuels; Cavitation; GLS; MMTPA; RDS; RS; RSH; STR; TS; US; US-EP; Ultrasound; WB; autoclaving; glucose; million metric tones per annum; reducing sugar; rice straw; rice straw hydrolyzate; stirring; total sugar; ultrasonication; ultrasonication at elevated pressure; water bath