High-pressure conversion

For the dynamic high pressure conversion, also known as shock wave synthesis, an explosive shock wave is used for the conversion of h-BN into c-BN. High pressure and high temperature are reached for a short period of time (milliseconds). To guarantee a fast temperature decrease a metal powder, like copper, is added to h-BN in an amount of 5% [181]. 

HIGH PRESSURE CONVERSION OF SEC-BUTYLBENZENE ON SYNTHETIC ZEOLITES... 

The first type of application exploits the favourable properties of black liquor as a feedstock for high-pressure conversion. In comparison to solid biomass, the advantages of black liquor as a feedstock include ... 

Carbon vaporizes at 4800 K at a pressure of 1000 atmospheres, which is the area where diamond is stable. The high-pressure conversion of diamond from graphite occurs at temperatures of approximately 3000 K and pressures above 125 kbars (in the absence of catalyst) and will be reviewed in Ch. 12. 

At present the main requirement for sulphuric acid plant is in the Third World where simple plant is required for fertilizer production. In the UK development is more likely to be related to energy conservation and environmental control rather than to fluidized-bed and high-pressure conversion. 

It is also the starting step for the cold process for the manufacmrer of sulphuric acid, liquid sulphur trioxide, oleum under high pressure conversion with zero emission of sulphur dioxide. 

Under pressure (p 45 kbar) transformation to NaQ structure and conversion to zincblenpressure released, except near the solid solution limit, where the NaCl phase remained. Therefore two NaCl-type phases resulted from the high pressure conversion. See also Fig. 103. 

Bi-Gas process A high-pressure operation for the conversion of solid fuel into substitute natural gas (SNG) using two stages of gasification. 

In 1957 Standard Oil of Ohio (Sohio) discovered bismuth molybdate catalysts capable of producing high yields of acrolein at high propylene conversions (>90%) and at low pressures (12). Over the next 30 years much industrial and academic research and development was devoted to improving these catalysts, which are used in the production processes for acrolein, acryUc acid, and acrylonitrile. AH commercial acrolein manufacturing processes known today are based on propylene oxidation and use bismuth molybdate based catalysts. 

Pollution Prevention. Procedures haven been developed for recovery of composite ammonium perchlorate propellant from rocket motors, and the treatment of scrap and recovered propellant to reclaim ingredients. These include the use of high pressure water jets or compounds such as ammonia, which form fluids under pressure at elevated temperature, to remove the propellant from the motor, extraction of the ammonium perchlorate with solvents such as water or ammonia as a critical fluid, recrystalli2ation of the perchlorate and reuse in composite propellant or in slurry explosives or conversion to perchloric acid (166,167). 

However, BASF developed a two-step process (25). After methyl formate [107-31-3] became available in satisfactory yields at high pressure and low temperatures, its conversion to formamide by reaction with ammonia gave a product of improved quaUty and yield in comparison with the earlier direct synthesis. 

Because the synthesis reactions are exothermic with a net decrease in molar volume, equiUbrium conversions of the carbon oxides to methanol by reactions 1 and 2 are favored by high pressure and low temperature, as shown for the indicated reformed natural gas composition in Figure 1. The mechanism of methanol synthesis on the copper—zinc—alumina catalyst was elucidated as recentiy as 1990 (7). For a pure H2—CO mixture, carbon monoxide is adsorbed on the copper surface where it is hydrogenated to methanol. When CO2 is added to the reacting mixture, the copper surface becomes partially covered by adsorbed oxygen by the reaction C02 CO + O (ads). This results in a change in mechanism where CO reacts with the adsorbed oxygen to form CO2, which becomes the primary source of carbon for methanol. 

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