Gaseous pyrolysis products

The composition of the conversion gas corresponds to the sum of the inorganic and organic gaseous pyrolysis products illustrated in Figure 54... 

Apparatus. Pyrolysis experiments were conducted in a quartz tube heated by an induction furnace. A continuous flow of argon was used to sweep out gaseous pyrolysis products. The materials to be pyrolyzed were contained in alundum boats, which could be readily admitted and removed from the quartz pyrolysis tube. 

The carbon and graphite articles obtained using the above-described processes contain up to 20 to 25% by volume of open pores formed by the escape of gaseous pyrolysis products upon binder carbonization. For many applications it is essential to fill up at least some of the pores by posttreatment or to seal the surface to gases and liquids. This is accomplished with ... 

TABLE II. Gaseous Pyrolysis Products Molar Ratios and Weight - Percent. 

A detailed analysis of the products of thermal destruction of poly-hexamethyleneadipamide and polycaproamide is given in [22]. The polyamides were heated at 300-305°C in a stream of dry nitrogen. The gaseous pyrolysis products contain large amounts of NH3, CO2, H2O, small amounts of n-hexylamine, n-pentylamine, and cyclopentanone. Analysis of the hydrolysis products of the residue obtained after pyrolysis of the polyamides permitted the authors to propose a scheme for the process. 

TABLE 21. Composition of Gaseous Pyrolysis Products of Hardened... 

Recycl Blacks. The pyrolysis of carbon black containing rubber goods has been promoted as a solution to the accumulation of waste tires. In the processes in question, tires are pyrolyzed in the absence of oxygen, usually in indirect fired rotary kiln-type units. The mbber and extender oils are cracked to hydrocarbons which are collected and sold as fuels or petrochemical feedstocks. The gaseous pyrolysis products are burned as fuel for the process. Steel tire cord is removed magnetically and the remainder of the residue is milled into a pyrolysis black. This contains the carbon black, silica, and other metal oxides from the rubber and some newly created char. Typically these materials have 8-10% ash, and contain... 

Krishen [119] has described a procedure for the determination of these monomer units. He quantitatively analysed the gaseous pyrolysis products from natural rubber, styrene-butadiene rubber and ethylene-propylene diene terpolymer rubber by gas chromatography. He showed that the 2-methyl-2-butene peak was linear with the natural rubber content of the sample. Styrene-butadiene rubber was determined from the peak area of the 1,3-butadiene peak. The ethylene-propylene-terpolymer content was deducted from the 1-pentane peak area of the pyrolysis products. Some of the pyrolysis products identified are shown in Table 4.10. 

Several similarities appear in the composition of gaseous pyrolysis products of different polyolefins, but the liquid products have many more peculiarities... 

Krishen quantitatively analysed the gaseous pyrolysis products from natural mbber, styrene-butadiene mbber and ethylene-propylene diamine terpolymer mbber by gas chromatography. He showed that the 2-methyl-2-butene peak was linear with the natural mbber content of the sample. Styrene-butadiene mbber was determined from the... 

Lesser amounts of many other products have been identified by mass spectrometry [12] from the thermal oxidation of Teflon. Also, the value of E of 79 kcal/mole obtained from the isothermal oxidation of Teflon [13] indicates that the attack of the oxygen occurs mainly on the gaseous pyrolysis products of Teflon and not on Teflon itself. 

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