Pyrolysis Of Natural Gas Research Articles

Improved yield of carbon fibers by pyrolysis of natural gas in stainless steel tubes

Carbon fibers are produced by pyrolysis of natural gas inside stainless steel tubes. Lengthening of unthickened precursor carbon filaments is normally catalyzed by loose metal or carbide particles generated in situ, primarily by fragmentation of the growth tube wall. More direct methods of supplying a greater number of catalytic particles were investigated in an effort to increase fiber yield. Growth of fibers on the inner surface of steel tubes could be enhanced by either: 1. 1) local melting of the surface in the presence of air, or 2. 2) wetting the surface with an aqueous ferric nitrate solution. Both methods increased the number of carbon fibers produced per unit area about 20-fold over as-received stainless steel tubes. Scanning electron microscopy and X-ray diffraction analyses showed that both procedures left the growth substrates covered with a rough, relatively thick layer comprised of a mixture of iron oxides. Precipitation of iron during reduction of the oxide mass is an important mechanism for providing an abundance of particles which catalyze carbon filament growth.

Electrical conductivity of vapor-grown carbon fibers

Carbon fibers grown by pyrolysis of natural gas were heat-treated at temperatures ranging from 1400 to 3000°C, and characterized by X-ray diffraction. Their electrical resistivity is reported for temperatures between 10 and 370 K, and explained for heat treatment above 2200°C using a simple graphitic band model. Filaments heat-treated at lower temperatures and as-grown fibers show a resistivity with a small temperature dependence.

263. Carbon fibers produced by pyrolysis of natural gas in stainless steel tubes

263. Carbon fibers produced by pyrolysis of natural gas in stainless steel tubes

Oxidation resistance of pyrolytically grown carbon fibers

The oxidative behavior of carbon fibers grown by pyrolysis of natural gas (PYROGRAF fibers) has been measured by thermogravimetric analysis and found to be similar to that reported for Endo-Koyama fibers grown by pyrolysis of benzene-hydrogen mixtures. The oxidative test results suggest that PYROGRAF fibers have a greater degree of graphitic order than some polyacrylonitrile and rayon-based fibers.

Carbon fibers produced by pyrolysis of natural gas in stainless steel tubes

Carbon fibers of uniform diameter have been grown by pyrolysis of natural gas in type 304 stainless steel (18% Cr, 8% Ni) tubes at temperatures between 950 and 1075 °C. The method utilizes the circulation of wet hydrogen outside the growth tube in order to promote effective nucleation. Fibers 12 cm long having average moduli of 1.8×1011 Pa have been grown.

Mechanism of the destruction of mullite ? Corundum products in a variable redox medium

In the pyrolysis of natural gas at a maximum temperature of 1500°C the variable redox medium causes the destruction of mullite—corundum refractories as a result of the reduction of the silica and of the SiO2 of the mullite to silicon monoxide during the pyrolysis and of the partial oxidation of the SiO to SiO2 during the heating of the packing. The cyclic changes in the gaseous medium result in an appreciable increase in the porosity and volume of the product as a consequence of the weakening of the structure by the cristobalite forming between the grains during the oxidation of the gaseous SiO in the transition from pyrolysis to heating. The presence of a small amount of cristobalite in the exposed zone of the refractory is evidence that during the period of heating some of the silicon monoxide is oxidized to SiO2.

Isolation and Identification of Acenaphthylene and Pyrene from the Products of the Pyrolysis of Natural Gas

Isolation and Identification of Acenaphthylene and Pyrene from the Products of the Pyrolysis of Natural Gas

HYDROGENATIONS IN A TETRALIN MEDIUM: II. DESTRUCTIVE HYDROGENATION OF COAL WITH TETRALIN AND WITH A MIXTURE OF RELATED COMPOUNDS AS MEDIA

A complex mixture of polynuclear hydrocarbons obtained in the pyrolysis of natural gas has been hydrogenated. The original mixture and the product of hydrogenation have been used as suspension media in the hydrogenation of bituminous and domestic coals, and are compared with tetralin as a medium. The original mixture is much less, and the hydrogenated mixture only slightly less, effective than tetralin.

Fuels and Fuel Testing in Canada

THE Mines Branch of the Canada Department of Mines report on fuels and fuel testing for the year 1930-31 records considerable analytical and other work on the solid, liquid and gaseous fuels, and reflects on the special problems of the Dominion. Interesting large-scale tests on the storage of coal are recorded, notably one at Montreal, where 35,000 tons of Nova Scotia coal stored in a pile 40 ft. high attained a maximum recorded temperature of 88° F. The geographical distribution of fuel supplies in Canada is unfortunate and the storage problem is important. Efforts are being made to increase the supply of Canadian motor spirit by the pyrolysis of natural gas in Alberta and by treatment of the bitumen. By hydrogenation of Alberta bitumen, yields of gasoline reaching 75 per cent could be obtained.