Hydrogen production naphtha treatment

Application To produce high yields of benzene, toluene, xylenes and hydrogen from naphthas via the CCR Aromizing process coupled with RegenC continuous catalyst regeneration technology. Benzene and toluene cuts are fed directly to an aromatics extraction unit. The xylenes fraction, obtained by fractionation and subsequent treatment by the Arofining process for diolefins and olefins removal, is ideal for para-xylene and orthoxylene production. 

Impurities in natural gas are usually simple sulfur compoimds such as hydrogen sulfide and mercaptans and are easily removed. Where the gas supply is also used for domestic purposes a stenching agent such as a thioether or thiophene may have been added. These less-reactive compoimds have to be subjected to a hydrogenolysis treatment before they can be removed. Naphthas contain several hundred parts per million of more complex organic sulfur compounds and may be pre-treated in a hydrofiner before use in ammonia or hydrogen production. Variation in the sulfur content of feed does not affect the performance... 

We cite isomerization of Cs-Ce paraffinic cuts, aliphatic alkylation making isoparaffinic gasoline from C3-C5 olefins and isobutane, and etherification of C4-C5 olefins with the C1-C2 alcohols. This type of refinery can need more hydrogen than is available from naphtha reforming. Flexibility is greatly improved over the simple conventional refinery. Nonetheless some products are not eliminated, for example, the heavy fuel of marginal quality, and the conversion product qualities may not be adequate, even after severe treatment, to meet certain specifications such as the gasoline octane number, diesel cetane number, and allowable levels of certain components. 

Most industrial hydrogen is manufactured by the following hydrocarbon-based oxidative processes steam reforming of light hydrocarbons (e.g., NG and naphtha), POx of heavy oil fractions, and ATR. Each of these technological approaches has numerous modifications depending on the type of feedstock, reactor design, heat input options, by-product treatment,... 

A typical steam cracker consists of several identical pyrolysis furnaces in which the feed is cracked in the presence of steam as a diluent.The cracked gases are quenched and then sent to the demethanizer to remove hydrogen and methane. The effluent is then treated to remove acetylene, and ethylene is separated in the ethylene fractionator. The bottom fraction is separated in the de-ethanizer into ethane and C3, which is sent for further treatment to recover propylene and other olefins. Typical operating conditions of ethane steam cracker are 750-800°C, 1-1.2 atm, and steam/ethane ratio of 0.5. Liquid feeds are usually cracked at lower residence time and higher steam dilution ratios compared to gaseous feeds. Typical conditions for naphtha cracking are 800° C, 1 atm, steam/hydrocarbon ratio of 0.6-0.8, and a residence time of 0.35 sec. Liquid feedstocks produce a wide spectrum of coproducts including BTX aromatics that can be used in the production of variety of chemical derivatives. 

This result is of fundamental importance in the preparation of supported catalysts from chlorides, which are commonly used due to their low price and easy solubilization in water. In fact, the presence of chloro species in a supported catalyst can be responsible for a low activity in many industrial reactions such as CO hydrogenation to hydrocarbons (Fischer-Tropsch synthesis) and to oxygenated products, and reforming reactions (naphtha reforming and post-regeneration due to coke deposits) Usually a calcination treatment is sufficient to... 

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