Consecutive Processing of Natural Products and Biofuels Production Using Subcritical Water

Jan 07, 2008 - 15:00

Jan 07, 2008 - 16:00

Creativity Hall (Room 118) Chemical Engineering

Seminars

Dr. Jerry W. King Ansel & Virginia Condray Endowed Profersorship Department of Chemical Engineering University of Arkansas Fayetteville AR 72701 USA

Pressurized fluids (i.e. sub- and super-critical fluids) are versatile agents for the processing of renewable agricultural and forestry materials and can be used in both the extraction and/or reaction modes. Utilizing either or both supercritical carbon dioxide (SC-CO2) and pressurized water i.e. subcritical water (sub-H2O)) provides a universal “green” processing platform that is compatible for producing food and nutritional extracts as well as fuel feed stocks such as bioethanol and biomethane. This lecture will focus primarily on our research utilizing subcritical water in conjunction with SC-CO2 as an additive to change extraction selectivity for solutes and as a catalytic medium to depolymerize carbohydrate-based biopolymers which are constituents of biomass feed stocks. Processing with subcritical water requires a different optimization depending on whether it is to be use as an extraction or reaction solvent.In this presentation the following theoretical and experimental optimization studies will be discussed with respect to: 1. Solvent characteristics of subcritical water as a function of temperature/pressure 2. Prediction and measurement of solute solubility/miscibility in subcritical water 3. Correlation of solute- sub-H2O interaction using solubility parameter theory 4. Solute mass transfer and diffusion in sub-H2O 5. Importance of sub-H2O space velocity in unit processing 6. Concurrent extraction – reaction of solutes when utilizing sub-H2O 7. Dissolved gas (SC-CO2) chemistry in sub-H2O 8. Tandem and continuous processing using SC-CO2 and sub-H2O Several examples will be cited for using sub-H2O for the extraction of nutraceutial ingredients such as natural antioxidants from grape pomace wood bark and vitamins from spent brewery’s yeast. These will include studies initiated with automated pressurized fluid extractors batch autoclave systems and continuous flow systems. Carbonated water initiated depolymerization of carbohydrate polymers in agricultural commodities both with and without enzymes will be described to produce glucose for fermentation to bioethanol. The lecture will conclude with assessment of the “universality” of sub-H2O as a processing medium as well as its substitution and integration into existing chemical extraction and conversion processes.