Steam pyrolysis process

Hydrogen is also a significant by-product of other industrial processes, such as steam pyrolysis (68) of hydrocarbons to produce ethylene (qv), eg,... 

American Ligurian, Inc. (Stanford, Connecticut) is marketing a pyrolysis process developed in Italy, which generates steam for hot water, air heating, dryers, kilns, and similar installations. A modular plant produces 8000 kg/h of steam from 1 tih of tires. The pyrolysis process produces 0.9 t of fuel ok, 270 t of steel, and 54 t of ash annually. Gas emissions meet the strictest environmental standards (16). 

The Coastal process uses steam pyrolysis of isobutane to produce propylene and isobutylene (as weH as other cracked products). It has been suggested that the reaction be carried out at high pressure, >1480 kPa ( 15 atm), to facHitate product separation. This process was commercialized in the late 1960s at Coastal s Corpus Christi refinery. 

Separation of raw feedstock. The pyrolysis of petroleum feedstream is carried out at 650-900°C at normal pressure in the presence of steam. The so-called steam-cracking process involves carbon-carbon splitting of saturated, unsaturated and aromatic molecules. The following steam-cracker fractions are used as raw materials to produce hydrocarbon resins. 

Raw materials for obtaining benzene, which is needed for the production of alkylbenzenes, are pyrolysis gasoline, a byproduct of the ethylene production in the steam cracking process, and coke oven gas. Reforming gasoline contains only small amounts of benzene. Large amounts of benzene are further produced by hydrodealkylation of toluene, a surplus product in industry. 

Cyclic gas generators converted coke, a by-product of high-temperature pyrolysis process, to a synthetic gas by alternatively exposing the coke to air to provide heat and to steam to produce a gas that burned with a blue flame. The coal gas was know as blue water gas (Probstein, R. F. and Hicks, R. E., Synthetic Fuels, McGraw-Hill, 1982, p. 7). 

The extracts were then atomised and fed into the ROTARC reactor for high temperature treatment. In the first case the atomised extract was mixed with the torch gas (Argon) only. It was a pure pyrolysis, which was effective in the sooting of the reactor walls and it was making the scrubber fluid dirty. The disadvantage of the pure pyrolysis process confirmed our theoretical considerations on thermal destruction of PCB s presented in [9]. To avoid sooting, we fed steam into the reaction chamber in the amount of 10% above the stoichiometry. In this case, which we call the wet pyrolysis , we obtained the destruction efficiency of oil- PCB s at least 99.99%. The offgas analysis on the concentration of oil-PCB s were below the detection limit 0.2 ppm. 

Table 6.8 Range of the main operating parameters in pyrolysis and steam gasification processes...

Demirbas, M.F. 2006a. Hydrogen from various biomass species via pyrolysis and steam gasification processes. Energy Sources Part A 28 245-252. 

Demirbas, M.F. 2006. Hydrogen from Various Biomass Species via Pyrolysis and Steam Gasification Processes. Energy Sources, Part A Recov. Util. Environ. Effects, 28, 245-252. 

CPP [Catalytic Pyrolysis Process] A Hybrid DCC-steam cracking process, developed by Stone and Webster and piloted in China. 

Increase in thermal process temperature up to 685-715°C in a fluidized-bed system (Hamburg University Pyrolysis Process-HUPP) and application of a mixture of municipal plastic wastes resulted mainly in gaseous products, over 41 wt%, of which olefins constituted 15%, and aromatic (BTX)-containing liquid products [14], Considerably better results from the point of view of C2 and C3 olefins yield were obtained in other experiments. The application of steam as fluidization agent instead of circulation pyrolysis gas enabled an increase of C2-C3 olefins yield from 48 to 60%, accompanied by decrease in BTX yield from 24 to 11 wt% [15],... 

Typically two major types of rotary kilns are used for pyrolysis processes either internally or externally heated systems. For internally heated kilns a heat exchanger based on steam-... 

Steam pyrolysis is performed at temperatures higher than most other ethylene processes creating more coking potential. Process requires two separate water quench exchangers. 

Handles feeds ranging from gases to liquid hydrocarbons. Process is characterized by a highly selective pyrolysis coil. Steam pyrolysis temperature not as high as the Kellogg process reducing... 

It must be emphasized that the equivalence in costs is based on the assumption that the pyrolysis unit as well as the pellet production is equipped with a steam dryer enabling sales of low-pressure steam. In practice, this is today the situation for several pellet manufacturers, whereas none of the pyrolysis processes has been evaluated with this condition. Hence, if the present pellet production were compared to proposed pyrolysis liquid production, the pellets would be advantageous by some 5-10 USD/MWh (pyrolysis liquid some 5 USD more expensive and the present pellets 5 -10 USD cheaper). 

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