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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The extraction of tar acids from high temperature tar ...

Lloyd, Theodore Cynric, January 1930 (has links)
Thesis (PH. D.)--Columbia University, 1931. / Vita. "Literature cited": p. [57]. Also issued in print.
12

The extraction of tar acids from high temperature tar ...

Lloyd, Theodore Cynric, January 1930 (has links)
Thesis (PH. D.)--Columbia University, 1931. / Vita. eContent provider-neutral record in process. Description based on print version record. "Literature cited": p. [57].
13

Chemical and physical modification of petroleum, coal-tar, and coal-extract pitches by air-blowing

King, Nathan D. January 2004 (has links)
Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains viii, 181 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 107-112).
14

A study of decomposition processes applicable to certain products of coal carbonization

Bradley, Mansion James. Parr, Samuel Wilson, January 1900 (has links)
Thesis (Ph. D.)--University of Illinois, 1921. / Vita. Caption title: Decomposition processes applicable to certain products of coal carbonization ... by M.J. Bradley with S.W. Parr. "Reprinted from Chemical and metallurgical engineering. vol. 27, no. 15. Oct. 11, 1922." Bibliography: p. 24.
15

Liquid diffusion in porous media, with specific reference to the Athabasca tar sands

Haliburton, James January 1947 (has links)
The velocity of diffusion of the bitumin from sections of 'Tar Sands' has been measured in a specially designed diffusion cell. The solvent used in this case was benzene. The diffusion constant was found to be D = 2.39 x 10⁻⁵/ ft²/hr. / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate
16

Determination of Design Parameters and Investigation on Operation Performance for an Integrated Gas Cleaning System to Remove Tars from Biomass Gasification Producer Gas.

Mwandila, Gershom January 2010 (has links)
Determinations of design parameters and investigation on operation performance of a tar removal system for gas cleaning of biomass producer gas have been undertaken. The presence of the tars in the producer gas has been the major hindrance for the commercialisation of the biomass gasification technology for power generation, hydrogen production, Fischer Tropsch (FT) synthesis, chemical synthesis and synthetic natural gas (SNG) synthesis. The characteristic of the tars to condense at reduced temperatures cause problems in the downstream processing as the tars can block and foul the downstream process equipment such as gas engines reactor channels, fuel cells, etc. Considerable efforts have been directed at the removal of tars from the producer gas where the tars can be either chemically converted into lighter molecular weight molecules or physically transferred from gas phase to liquid or solid phase. In the former, the tars have been removed in a scrubber by transferring them from the producer gas to a scrubbing liquid and then removed from the liquid to air in a stripper and finally recycled them into air to a gasifier to recover their energy. A tar removal test system involving a scrubber and stripper has been designed based on the predicted tar solubility in canola methyl ester (CME) as the scrubbing liquid and its measured properties (CME is a type of methyl ester biodiesel). The tar solubility has been predicted to decrease with increasing temperatures and thus its value increases at lower temperatures. In designing the test system, the design parameters are needed including equilibrium coefficients of the gas-liquid system, molar transfer coefficient and the optimum liquid to gas flow rate ratio. The equilibrium coefficients have been predicted based on thermodynamic theories where the required data are determined from CME composition and known properties of each component of the CME as well as the properties of the model tar (naphthalene). The molar transfer coefficients are then experimentally determined and the correlations as a function of liquid and gas flow rates are proposed which are consistent with literature. The optimum liquid to gas flow rate ratios have been found to be 21.4±0.1 for the scrubber and 5.7±0.1 for the stripper. Using these optimum ratios, the tar removal efficiencies in the scrubber and the stripper are 77 and 74%, respectively. The analysis of the system performance has been achieved after an innovative method of determining tar concentrations in both the liquid and gas phase had been developed based on the concept of the density of liquid mixtures. However, these tar removal efficiencies are low due to the fact that the targeted tar concentration in the scrubber’s off-gas was large. As a result the system has been redesigned based on the determined design parameters and its operation performance retested. In the redesigned system, the tar removal efficiency in the scrubber and stripper is 99%. The redesigned system would be integrated with the UC gasifier for downstream gas cleaning. Since 1% of tars are not removed, a makeup tar free CME of 0.0375 litres per hour for the 100kW UC gasifier has been introduced in the recycle stream between the scrubber and stripper to avoid tar accumulation in the system.
17

Chemistry of mesophase formation

Takekawa, T. January 1987 (has links)
No description available.
18

Extraction and chromatography of supercritical fluids

Kithinji, Jacob P. January 1989 (has links)
No description available.
19

Fixed Bed Counter Current Gasification of Mesquite and Juniper Biomass Using Air-steam as Oxidizer

Chen, Wei 1981- 14 March 2013 (has links)
Thermal gasification of biomass is being considered as one of the most promising technologies for converting biomass into gaseous fuel. Here we present results of gasification, using an adiabatic bed gasifier with air, steam as gasification medium, of mesquite and juniper. From Thermo-gravimetric analyses the pre-exponential factor (B) and activation energy of fuels for pyrolysis were obtained using single reaction models (SRM) and parallel reaction model (PRM). The single reaction model including convention Arrhenius (SRM-CA) and maximum volatile release rate model (SRM-MVR). The parallel reaction model fits the experimental data very well, followed by MVR. The CA model the least accurate model. The activation energies obtained from PRM are around 161,000 kJ/kmol and 158,000 kJ/kmol for juniper and mesquite fuels, respectively. And, the activation energies obtained from MVR are around100,000 kJ/kmol and 85,000 kJ/kmol for juniper and mesquite fuels, respectively. The effects of equivalence ratio (ER), particle size, and moisture content on the temperature profile, gas composition, tar yield, and higher heating value (HHV) were investigated. For air gasification, when moisture increased from 6% to 12% and ER decreased from 4.2 to 2.7, the mole composition of the dry product gas for mesquite varied as follow: 18-30% CO, 2-5% H2, 1-1.5% CH4, 0.4-0.6% C2H6, 52-64% N2, and 10-12% CO2. The tar yield shows peak value (150 g/Nm^3) with change in moisture content between 6-24%. The tar collected from the gasification process included light tar and heavy tar. The main composition of the light tar was moisture. The chemical properties of heavy tar were determined. For air-steam gasification, H2 rich mixture gas was produced. The HHV of the mesquite gas increased first when S: F ratio increased from 0.15 to 0.3 and when the S: F ratio increased to 0.45, HHV of the gas decreased. Mesquite was blended with the Wyoming Powder River Basin (PRB) coal with ratio of 90:10 and 80:20 in order to increase the Tpeak and HHV. It was found that the Tpeak increased with the increase of PRB coal weight percentage (0% to 20%).
20

Respiratory deposition of tar aerosols in cigarette smokers

Pritchard, J. N. January 1987 (has links)
No description available.

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