Thermal cracking processes from patent

Description The SUPERFLEX process is a proprietary technology patented by ARCO Chemical Technology, Inc. (now LyondellBasell) and exclusively offered worldwide for license by KBR. It uses a fluidized catalytic reactor system with a proprietary catalyst to convert low-value feedstocks to predominantly propylene and ethylene products. The catalyst is very robust thus, no feed pretreatment is required for typical contaminants such as sulfur, water, oxygenates or nitrogen. Attractive feedstocks include C4 and C5 olefin-rich streams from ethylene plants, FCC naphthas or C4S, thermally cracked naphthas from visbreakers or cokers, BTX or MTBE raffinates, olefin-rich streams removed from motor gasolines, and Fischer-Tropsch light liquids. 

The Dubbs process (5) was a continuous thermal cracking process in which a relatively clean feedstock was cracked in furnace tubes with the continuous removal of heavy cracked residue from the system. This process was patented (1,049,667) in 1913. 

Pyrolysis of scrap tires was studied by several mbber, oil, and carbon black industries [14]. Pyrolysis, also known as thermal cracking is a process in which polymer molecules are heated in partial or total absence of air, until they fragment into several smaller, dissimilar, random-sized molecules of alcohols, hydrocarbons, and others. The pyrolysis temperature used is in the range of 500°C-700°C. Moreover, maintenance of partial vacuum during pyrolysis in reactors lowered the economy of the process. Several patents were issued for the pyrolysis of worn out tires to yield cmde oil, monomers, and carbon black in economic ways [15-18]. The major drawback of chemical recycling is that the value of the output is normally low and the mixed oils, gases, and carbon black obtained by pyrolysis cannot compete with similar products from natural oil. Pyrolyzing plant produces toxic wastewater as a by-product of the operation [19]. 

The Blowdec depolymerization process from Slovakia converts waste plastics into low-sulphur diesel fuel [35]. The main principle is the processing of waste plastics in a hot whirling bed of hot sand in the BLOWDEC reactor (Figure 15.19). The plastic is heated to 430°C. The process allows for simultaneous cracking of hydrocarbons and inhibition of coke formation. The fluidized sand bed products three types of cracking reactions mechano-activation thermal and catalytic (Si02/aluminosilicates). The process is covered under the US Patent 6,165,349. The process enables the economical conversion of mixed waste plastics into liquid hydrocarbons, mainly low-sulphur (25 ppm) diesel... 

Styrene is an important monomer of the plastics industry, generally produced from benzene (a known carcinogen) and ethylene (produced from thermal cracking of hydrocarbons). A more desirable process would be to convert toluene to ethylbenzene through a reaction with methane, the primary component of natural gas. In a 2009 BASF patent, they report a new catalyst that allows such a process to occur. Our goal is to identify the temperature at which the unreacted toluene can be recovered as a liquid when the system is operating at 100 psia. The composition of the vapor product contains 80% ethylbenzene and the remainder toluene. What is the liquid composition at the dew point ... 

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