Quenching primary

Anti-oxidants can be divided into two classes depending on which part of the radical chain they quench. Primary anti-oxidants are radical scavengers and will react with alkyl chain radicals (R ) or hydroperoxides (ROOH). Secondary antioxidants work in combination with primary anti-oxidants and principally act by converting peroxide radicals (ROO ) into non-radical stable products. Synergism often works when both classes are used together. 

Single hydrophobic-amphiphilic (HA) copolymers with the same HA composition but with different distribution of H and A units along the main hydrophobic chain were also simulated [212]. In particular, regular copolymers comprising H and A units in alternating sequence, regular multiblock copolymers composed of H and A blocks of equal lengths, and the quasirandom protein-like copolymers with a quenched primary structure were studied. These copolymers are schematically depicted in Fig. 24b,c, and d. 

The flame-space walls are stainless steel and are water cooled. No mechanical coke scraper is required. A water quench cools the cracked gas stream rapidly at the poiat of maximum acetyleae and this is followed by a secondary water quench. The primary quench poiat can be adjusted for variation ia throughput, to accommodate the depeadeace of acetyleae yield oa resideace time ia the flame space. 

Naphthalenol. 2-Naphthol or p-naphthol or 2-hydroxynaphthalene/7i3 -/5 -i7 melts at 122°C and boils at 295°C, and forms colorless crystals of characteristic, phenoHc odor which darken on exposure to air or light. 2-Naphthol [135-19-3] is manufactured by fusion of sodium 2-naphthalenesulfonate with sodium hydroxide at ca 325°C, acidification of the drowned fusion mass which is quenched ia water, isolation and water-washing of the 2-naphthalenol, and vacuum distillation and flaking of the product. A continuous process of this type has been patented (69). The high sulfate content ia the primary effluent from 2-naphthol production is greatiy reduced ia modem production plants by the recovery of sodium sulfate. 

Process development of the use of hydrogen as a radical quenching agent for the primary pyrolysis was conducted (37). This process was carried out in a fluidized-bed reactor at pressures from 3.7 to 6.9 MPa (540—1000 psi), and a temperature of 566°C. The pyrolysis reactor was designed to minimize vapor residence time in order to prevent cracking of coal volatiles, thus maximizing yield of tars. Average residence times for gas and soHds were quoted as 25 seconds and 5—10 rninutes. A typical yield stmcture for hydropyrolysis of a subbiturninous coal at 6.9 MPa (1000 psi) total pressure was char 38.4, oil... 

Another class of carbonyl compounds that has received much attention is the cyclohexadienones. The primary photolysis product of 4,4-diphenylcyclohexadienone, for example, is 5. Quenching and photosensitization experiments have indicated that the... 

In a typical gas oil design, the lighter products overhead from the quench tower/primary fractionator are compressed to 210 psi, and cooled to about 100°F. Some Q plus material is recovered from the compressor knockout drums. The gases are ethanolamine and caustic washed to remove acid gases sulfur compounds and carbon dioxide, and then desiccant dried to remove last traces of water. This is to prevent ice and hydrate formation in the low temperamre section downstream. 

Fig. 2 illustrates the ordering process after a quench of a disordered alloy below the ordering spinodal. As it was mentioned by AC, the primary ordered domains are formed after few atomic exchanges A.t 1, while further evolution corresponds to the growth of these domains. Fig. 3 shows that in the absence of APBs the microstructure evolution under spinodal decomposition with ordering is similar to that for disordered... 

An olefin plant that uses liquid feeds requires an additional pyrolysis furnace, an effluent quench exchanger, and a primary fractionator for fuel oil separation. 

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