Description

Thisbookistalkingabouthowtousesupercriticalwater(SCW)torapidlyproduce micro- and nano-particles of metal oxides, inorganic salts, metals and organics. Itcoversbasicprinciples, experimentalmethodologiesandreactors, particlep- duction, characterizationsandapplicationsaswellastherecentadvancement. Fine particlescanbeproducedbybothchemicalandphysicalprecipitationofproducts from SCW. They can be used as catalysts, materials in ceramics and electronic devices andcompositematerials. Particlesareeasilyproduced continuouslyina owreactorinshortreactiontimes(0. 4s?2min)butcanalsobesynthesizedin batchreactorsforlongreactiontimes(e. g.,12h). Theycanbeeasilystudiedin-situ microscopically(optical/IR/Raman/SR-XRD)inanopticalmicro-reactor, diamond anvilcell. Thesize, sizedistribution, crystalgrowth&structure, andmorphologyof particlescanbecontrolledbychangingtheconcentrationsofstatingmaterials, pH, pressures, temperatures, heating&coolingrates, organicmodi cations, reducingor oxidizingatmospheres, owratesandreactiontimes. Thisisthe rstbooktosystematicallyintroduceusingSCWforproductionof neparticles. Itisanidealreferencebookforengineers, researchersandgraduate studentsinmaterialscienceandengineering. vii Acknowledgments I would like to thank Drs. T. Ogi & T. Minowa (Biomass Technology Research Center, NationalInstituteofAdvancedIndustrialScienceandTechnology, Japan), and Profs. K. Arai, H. Inomata, R. L. Smith Jr. and T. Adschiri (Chemical Engineering, TohokuUniversity, Japan), whoinitiallyintroducedthehydrothermal andsupercritical uidsareastomewhenIworkedinJapanfrom1996to1999. Thanks are also due to Profs. J. A. Kozinski, R. I. L. Guthrie (Materials Engineering, McGillUniversity, Canada)andI. S. Butler(Chemistry, McGill)for theirguidanceinmyworkonhydrothermalprocessduringmyworkinCanadafrom 1999to2007. Profs. W. Bassett (Geological Sciences, Cornell University) and D. Baker (Earth&PlanetarySciences, McGill)forinstructionsregardingDAC, Dr. I-Ming Chou(U. S. GeologicalSurvey)forusefuldiscussionsofthepressurecalculation procedure. Drs. M. Watanabe and T. Sato (Research Center of Supercritical Fluid Technology, Tohoku University, Japan) for discussions about the experimental set-upofthebatchand owreactors. Drs. S. Xu, H. Assaaoudi, R. HashaikehandA. Sobhy, whoworkedwithmeat McGillinCanada. ix Contents 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1. 2 RapidExpansionofSupercriticalSolution(RESS)Process . . . 4 1. 3 SupercriticalAntisolvent(SAS)Process . . . . . . . . . . . . . 4 1. 4 OtherPhysicalProcesses . . . . . . . . . . . . . . . . . . . . . 5 1. 5 SupercriticalWaterProcess . . . . . . . . . . . . . . . . . . . . 5 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2 Supercritical Water Process. . . . . . . . . . . . . . . . . . . . . . 11 2. 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 2 BatchReactor . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. 3 FlowReactor. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2. 4 DiamondAnvilCell(DAC). . . . . . . . . . . . . . . . . . . . 20 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3 Metal Oxides Synthesis. . . . . . . . . . . . . . . . . . . . . . . . . 29 3. 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 3. 2 Boehmite(AlOOH) . . . . . . . . . . . . . . . . . . . . . . . . 30 3. 3 Ferrites. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .