[
    {
        "id": "authors:q221w-wme32",
        "collection": "authors",
        "collection_id": "q221w-wme32",
        "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151105-115204740",
        "type": "monograph",
        "title": "Silica membranes for hydrogen separation in coal gas processing. Final report, January 1993",
        "author": [
            {
                "family_name": "Gavalas",
                "given_name": "G. R.",
                "orcid": "0000-0003-1468-6835",
                "clpid": "Gavalas-G-R"
            }
        ],
        "abstract": "The general objective of this project was to synthesize permselective membranes suitable for hydrogen separation from coal gas. The specific objectives were: (i) to synthesize membranes by chemical vapor deposition (CVD) of SiO(sub 2) or other oxides on porous support tubes, (ii) characterize the membranes by permeation measurements of various gases and by electron microscopy, and (iii) obtain information about the mechanism and kinetics Of SiO(sub 2) deposition, and model the process of membrane formation. Silica glass and certain other glasses, in dense (nonporous) form, are highly selective to hydrogen permeation. Since this high selectivity is accompanied by low permeability, however, a practical membrane must have a composite structure consisting of a thin layer of the active oxide supported on a porous tube or plate providing mechanical support. In this project the membranes were synthesized by chemical vapor deposition (CVD) of SiO(sub 2), TiO(sub 2), Al(sub 2)O(sub 3) and B(sub 2)O(sub 3) layers inside the walls of porous Vycor tubes (5 mm ID, 7 mm OD, 40 (Angstrom) mean pore diameter). Deposition of the oxide layer was carried out using the reaction of SiCl(sub 4) (or TiCl(sub 4), AlCl(sub 3), BCl(sub 3)) and water vapor at elevated temperatures. The porous support tube was inserted concentrically into a larger quartz tube and fitted with flow lines and pressure gauges. The flow of the two reactant streams was regulated by mass flow controllers, while the temperature was controlled by placing the reactor into a split-tube electric furnace.",
        "publisher": "Caltech Library",
        "publication_date": "1993-01"
    },
    {
        "id": "authors:fzp7x-gr893",
        "collection": "authors",
        "collection_id": "fzp7x-gr893",
        "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20151105-120142265",
        "type": "monograph",
        "title": "Thermally induced structural changes in coal combustion. Final report",
        "author": [
            {
                "family_name": "Flagan",
                "given_name": "R. C.",
                "orcid": "0000-0001-5690-770X",
                "clpid": "Flagan-R-C"
            },
            {
                "family_name": "Gavalas",
                "given_name": "G. R.",
                "orcid": "0000-0003-1468-6835",
                "clpid": "Gavalas-G-R"
            }
        ],
        "abstract": "The effects of the temperature-time history during coal devolitization and oxidation on the physical properties and the reactivity of resulting char were studied experimentally for temperatures and residence times typical of pulverized combustion. Experiments were also carried out at somewhat lower temperatures and correspondingly longer residence times. An electrically heated laminar flow reactor was used to generate char and measure the rates of oxidation at gas temperatures about 1600K. Partially oxidized chars were extracted and characterized by gas adsorption and mercury porosimetry, optical and scanning electron microscopy, and oxidation in a thermogravimetric analysis system (TGA). A different series of experiments was conducted using a quadrople electrodynamic balance. Single particles were suspended electrodynamically and heated by an infrared laser in an inert or oxygen-containing atmosphere. During the laser heating, measurements were taken of particle mass, size/shape, and temperature.",
        "doi": "10.2172/10159795",
        "publication_date": "1992-01-01"
    }
]