Conversion of polychlorinated hydrocarbons and acetylene over a nickel modified shape selective zeolite catalyst

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:7285686

Jang, Wen-Long

This dissertation explores the use of a bifunctional catalyst in conversion studies of low molecular weight reactants. The catalyst is a shape selective zeolite (ZSM-5) modified via addition of elemental nickel. The resultant material combines the catalytic activity of the nickel with the acidic/shape selective properties of the zeolite. The catalysts have been employed to achieve two important advances: the complete hydrodechlorination of polychlorinated molecules and the continuous conversion of acetylene to higher hydrocarbons. The hydrodechlorination conversion couples the hydrogenolysis activity of Ni with the shape selective zeolite catalytic properties to achieve complete dechlorination of polychlorinated reactants. This dechlorination has been demonstrated for compounds including trichloroethanes, trichloroethylene, C[sub 2]Cl[sub 4] and dichloromethane. The conversion products consist of a mixture of olefins, paraffins and aromatics with the stoichiometric amount of HCl. Dependent on reaction conditions the hydrocarbon product distribution can be shaped over fairly wide ranges. The hydrodechlorination process offers potential as a more environmentally acceptable disposal process for chlorinated liquid wastes in which these wastes are converted to useful fuels and HCl. The successful continuous conversion of C[sub 2]H[sub 2] to higher molecular weight olefins, paraffins and aromatics (up to C[sub 11] compounds) over the Ni modified ZSM-5 catalyst requires addition of H[sub 2]O to the reactant C[sub 2]H[sub 2] stream. The addition of H[sub 2]O results in intermediate formation of CH[sub 3]CHO which reacts with C[sub 2]H[sub 2] to produce the hydrocarbon products. These hydrocarbon products can be shaped to provide large yields of aromatics (up to 40%). The conversion process offers a new route to synthetic fuel production based on initial conversion of coal or natural gas to acetylene.

• Research Organization: Texas Univ., Arlington, TX (United States)
• OSTI ID: 7285686
• Country of Publication: United States
• Language: English

Related Subjects

10 SYNTHETIC FUELS
100200* -- Synthetic Fuels-- Production-- (1990-)
ACETYLENE
ALKYNES
AROMATICS
CATALYTIC EFFECTS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CYCLIZATION
DECHLORINATION
DEHALOGENATION
ELEMENTS
FUELS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MANAGEMENT
MATERIALS
METALS
MINERALS
NICKEL
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
PROCESSING
SILICATE MINERALS
SYNTHESIS
SYNTHETIC FUELS
TRANSITION ELEMENTS
WASTE MANAGEMENT
WASTE PROCESSING
ZEOLITES