Abstract: A heat transfer tube includes a twisted baffle arranged in an inner wall of the tube. The twisted baffle extends spirally along an axial direction of the heat transfer tube. The twisted baffle is provided with a non-through gap extending along an axial direction of the heat transfer tube from an end to the other end of the twisted baffle. A cracking furnace uses the heat transfer tube. The heat transfer tube and cracking furnace have good heat transfer effects and small pressure loss.

Abstract: The present invention relates to a process for separating the isoprene, 1,3-pentadiene and dicyclopentadiene from a C5 cuts, comprising dimerization of the cyclopentadiene and selective catalytic hydrogenation. The second extractive rectification step can be omitted, because the alkynes are removed through selective catalytic hydrogenation prior to the extractive rectification. As a result, the solvent-recovering units can be simplified, and thus the process as a whole can be optimized. Correspondingly, the investment and energy consumption, the operation cost, and finally the production cost can be substantially reduced.

Abstract: A catalyst component for the (co)polymerization of olefins is provided. The catalyst comprises titanium, magnesium halogen and a mixed electron-donor and a catalyst for the (co)polymerization of olefins comprising:(A) the catalyst component; (B) an organic aluminum compound; and (C) an organic silicon compound. A polymer with high and adjustable stereospecificity and broad molecular weight distribution can be prepared by using the catalyst.

Abstract: The present invention relates to a highly active titanium based supported catalyst suitable for olefin (co)polymerization, preparation and use of the same. The catalyst according to the present invention is obtained by supporting a titanium based catalyst component containing a halide promoter on spherical silica. The resultant catalyst is excellent in its particle morphology and flowability, has highly catalytic activity, has excellent hydrogen response and has superior comonomer incorporation, the polymer prepared by using such a catalyst has its particle morphology further improved.

Abstract: A selective hydrogenation catalyst system, and a process for its preparation and its use. The catalyst system of the invention comprises a support material, a Pd-containing catalyst component and a Bi-containing cocatalyst component. The catalyst system of the invention is manufactured by impregnating the support material simultaneously or separately with Pd-containing solution, Bi-containing solution or/and one or more other cocatalyst solutions, and then drying and calcining. The activity and selectivity of the catalyst system of the invention, in selective hydrogenation of acetylenic and diolefmic compounds in hydrocarbon feeds, are significantly improved, while the green oil formation and carbon deposit on the catalyst reduced, and the service life increased and production costs decreased.

Abstract: The present invention provides a fully vulcanized powdery rubber having a particle size of from 20 to 2000 nm, its preparation and use. The vulcanized powdery rubber is obtained by irradiating a rubber latex having a particle size of from 20 to 2000 nm with a high-energy irradiation. The vulcanized powdery rubber is very easily to be dispersed into various plastics, and thus can be mixed with various plastics to prepare toughened plastics and fully valcanized thermoplastic elastomers.

Abstract: The present invention provides a compound catalyst system useful for synthesizing polyethylenes or copolymers of ethylene having bimodal or broad molecular weight distributions, prepared by incorporating an organic alcohol as an electron-donor compound and an aluminoxane compound into the prior art compound catalyst systems, thereby promoting the activities of the two active centers, which leads to not only a large improvement in the activity of the catalyst system, but also the formation of polyethylenes and copolymers of ethylene having bimodal or broad molecular weight distributions, which in turn gives polymers having excellent processability and mechanical properties. A process for preparing the solid catalyst component used in the compound catalyst system according to the present invention and use of the compound catalyst system are also disclosed.