Thermal hydrocracking

Catalytic Reforming. Worldwide, approximately 30% of commercial benzene is produced by catalytic reforming, a process ia which aromatic molecules are produced from the dehydrogenation of cycloparaffins, dehydroisomerization of alkyl cyclopentanes, and the cycHzation and subsequent dehydrogenation of paraffins (36). The feed to the catalytic reformer may be a straight-mn, hydrocracked, or thermally cracked naphtha fraction ia the... 

Kerosine, a distillate fraction heavier than naphtha, is normally a product from distilling crude oils under atmospheric pressures. It may also he obtained as a product from thermal and catalytic cracking or hydrocracking units. Kerosines from cracking units are usually less stable than those produced from atmospheric distillation and hydrocracking units due to presence of variable amounts of olefinic constituents. 

Van Driesen and Stewart (V4) have reported temperature measurements for various locations in commercial gas-liquid fluidized reactors for the large-scale catalytic desulfurization and hydrocracking of heavy petroleum fractions (2500 barrels per day capacity). The hydrogenation was carried out in two stages the maximum and minimum temperatures measured were 774° and 778°F for the first stage and 768° and 770°F for the second. These results indicate that gas-liquid fluidized reactors are characterized by a high effective thermal conductivity. 

The present state of technology is reviewed (mainly from German literature of 1993 -4) in the Add of three principal thermal methods used for plastics wastes, namely pyrolysis (high-temperature carbonisation, coking), hydrocracking and gasification. 36 refs. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. 

Details are given of the thermal methods of recycling plastics. Emphasis is given to pyrolysis, hydrocracking, and gasification. 36 refs. 

Dieselmax A petroleum cracking process which combines mild hydrocracking with thermal cracking to maximize the production of middle distillate without using more hydrogen than hydrocraking alone. Developed by UOP. 

Hydrocracking, 30 48-52 behavior, thermal, 29 269 catalytic, 26 383 deethylation, 30 50 demethylation, 30 50 metallocarbene formation, 30 51-52 of f -decane, 35 332-333 primary coal liquids, 40 57 procedure, 40 66-67 product distribution, 30 49 reactions, over perovskites, 36 311 suppression by sulfur, 31 229 zeolite-supported catalysts, 39 181-188... 

Other reactions may also occur. These include carbon formation, hydrocracking or thermal cracking, dehydrocyclization of paraffins to naphthenes, and dehydrogenation of naphthenes to aromatics. These have been discussed in the deactivation of reforming catalysts, in Section 2. 

Bitumen is a hydrogen-deficient oil that is upgraded by carbon removal (coking) or hydrogen addition (hydrocracking) (2,4). There are two methods by which bitumen conversion can be achieved by direct heating of mined tar sand and by thermal decomposition of separated bitumen. The latter is the method used commercially, but the former has potential for commercialization (see Fuels, synthetic). 

Cracking is effected by one of three general methods thermal cracking, catalytic cracking, or hydrocracking. Each process has its own characteristics concerning operating conditions and product compositions. 

The preheated coal slurry (essentially liquefied) is sent to the reactor, where thermal and catalytic cracking, hydrogenation, and hydrocracking take place. These reactions occur rather slowly because fewer reactive bonds are involved in this stage, which produces distillate range small molecules. 

A study is presented of the synthesis and properties of the novel synthetic zeolite omega. The synthesis variables and kinetics of formation are discussed, as well as the ion exchange, sorption, and thermal properties. By decomposition of imbibed tetra-methylammonium ions and exhaustive treatments of the zeolite with ammonium ions, a pure hydrogen form can be obtained which is a suitable substrate for the preparation of hydrocarbon conversion catalysts. Several catalysts were prepared and utilized to isomerize n-hexane, and to hydrocrack a heavy gas oil. 

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