Acetylene Activated carbon

Hydrochloric acid may conveniently be prepared by combustion of hydrogen with chlorine. In a typical process dry hydrogen chloride is passed into a vapour blender to be mixed with an equimolar proportion of dry acetylene. The presence of chlorine may cause an explosion and thus a device is used to detect any sudden rise in temperature. In such circumstances the hydrogen chloride is automatically diverted to the atmosphere. The mixture of gases is then led to a multi-tubular reactor, each tube of which is packed with a mercuric chloride catalyst on an activated carbon support. The reaction is initiated by heat but once it has started cooling has to be applied to control the highly exothermic reaction at about 90-100°C. In addition to the main reaction the side reactions shown in Figure 12.6 may occur. 

The anodic behavior of carbon materials, such as acetylene black, activated carbon, and vapor-grown carbon fiber, in LiC104/PC solution was studied by Yamamoto et al. [102]. Irreversible reactions, including gas evolution and disintegration, were mainly observed on that part of the surface occupied by the edge planes of the... 

The pH dependence of nitrogenase activity has been interpreted in terms of a group with a pi a = 6.3 that must he deprotonated for activity and another group with a pi a = 9 that must be protonated for activity 128). The pi a of the latter group was moved about 0.5 pH units more acid in the presence of acetylene and carbon monoxide and the group with the pi of 6.3 was moved about 0.4 pH units more acid by acetylene. The behavior of the group with the pZa of 9 is fully consistent with earlier observations (50) on the effect of acetylene on... 

Interaction of chlorine with methane is explosive at ambient temperature over yellow mercury oxide [1], and mixtures containing above 20 vol% of chlorine are explosive [2], Mixtures of acetylene and chlorine may explode on initiation by sunlight, other UV source, or high temperatures, sometimes very violently [3], Mixtures with ethylene explode on initiation by sunlight, etc., or over mercury, mercury oxide or silver oxide at ambient temperature, or over lead oxide at 100°C [1,4], Interaction with ethane over activated carbon at 350°C has caused explosions, but added carbon dioxide reduces the risk [5], Accidental introduction of gasoline into a cylinder of liquid chlorine caused a slow exothermic reaction which accelerated to detonation. This effect was verified [6], Injection of liquid chlorine into a naphtha-sodium hydroxide mixture (to generate hypochlorite in situ) caused a violent explosion. Several other incidents involving violent reactions of saturated hydrocarbons with chlorine were noted [7],... 

Chen et al. [70] suggested that temperature gradients may have been responsible for the more than 90 % selectivity of the formation of acetylene from methane in a microwave heated activated carbon bed. The authors believed that the highly nonisothermal nature of the packed bed might allow reaction intermediates formed on the surface to desorb into a relatively cool gas stream where they are transformed via a different reaction pathway than in a conventional isothermal reactor. The results indicated that temperature gradients were approximately 20 K. The nonisothermal nature of this packed bed resulted in an apparent rate enhancement and altered the activation energy and pre-exponential factor [94]. Formation of hot spots was modeled by calculation and, in the case of solid materials, studied by several authors [105-108],... 

K. Shinoda, Vapour-phase hydrochlorination of acetylene over metal chlorides supported on activated carbon, Chem. Lett. 3, 219-220 (1975). 

Synonyms Carbon activated carbon acetylene carbon decolorizing carbon actibon channel black furnace black thermal black gas black lamp black ultracarbon... 

The anode layer of polymer electrolyte membrane fuel cells typically includes a catalyst and a binder, often a dispersion of poly(tetraflu-oroethylene) or other hydrophobic polymers, and may also include a filler, e.g., acetylene black carbon. Anode layers may also contain a mixture of a catalyst, ionomer and binder. The presence of a ionomer in the catalyst layer effectively increases the electrochemically active surface area of the catalyst, which requires a ionically conductive pathway to the cathode catalyst to generate electric current (16). 

Ref la). It is miscible with w, ale and eth (See also Ref 7). Various methods of prepn are given in Refs 1.3 9 In Ref 2 is described the catalytic production of acetaldehyde from acetylene and steam over activated carbon and promoted by phosphoric acid. 

Acetylene adsorption, selective, 117 Acoustic cavitation, nanostructured catalysts, 19 Activated alumina commercial, 93 commercial use, 80 pore size distribution, 89 Activated carbon... 

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