A reactor shell for producing olefins via steam cracking from a fed reactive mixture stream composed of steam and hydrocarbons comprising: at least one reactive stream duct formed within said reactor shell, at least one structured ceramic bed having a plurality of hollow flow paths, at least one electrical resistance heating element for heating the reactive mixture stream up to a predetermined reaction temperature and a coating provided on a surface contacting with the reactive mixture stream is provided. The reactor shell is characterized by that said electrical resistance heating element that is arranged inside at least some of said hollow flow paths in a manner that there still remains a flowing passage inside the hollow flow paths.

A process for performing high temperature reactions includes introducing reactants into a reactor vessel, generating a high temperature within the reactor vessel, exposing a first portion of the reactants to the high temperature, and reacting the first portion of the reactants based on contact with the high temperature to produce one or more products. The high temperature is higher than a lower temperature of a wall of the reactor vessel, and a temperature gradient is generated between the high temperature and the lower temperature of the wall. A second portion of the reactants are not exposed to the high temperature, and the second portion of the reactants do not react.

Systems and methods are provided for performing ethane steam cracking at elevated coil inlet pressures and/or elevated coil outlet pressures in small diameter furnace coils. Instead of performing steam cracking of ethane at a coil outlet pressure of ˜22 psig or less (˜150 kPa-g or less), the steam cracking of ethane can be performed in small diameter furnace coils at a coil outlet pressure of 30 psig to 75 psig (˜200 kPa-g to ˜520 kPa-g), or 40 psig to 75 psig (˜270 kPa-g to ˜520 kPa-g). In order to achieve such higher coil outlet pressures, a correspondingly higher coil inlet pressure can also be used, such as a pressure of 45 psig (˜310 kPa-g) or more, or 50 psig (˜340 kPa-g) or more.

The invention relates weldments useful as heat transfer tubes in pyrolysis furnaces. The invention relates to tubes that are useful in pyrolysis furnaces. The weldments include a tubular member and at least one mixing element. The tubular member comprises an aluminum-containing alloy. The mixing element comprises an aluminum-containing alloy. The mixing element's aluminum-containing alloy can be the same as or different from the tubular member's aluminum-containing alloy. Other aspects of the invention relate to pyrolysis furnaces which include such weldments, and the use of such pyrolysis furnaces for hydrocarbon conversion processes such as steam cracking.

The present invention relates to the field of fluid heat transfer, and discloses a heat transfer enhancement pipe as well as a cracking furnace and an atmospheric and vacuum heating furnace including the same. The heat transfer enhancement pipe (1) includes a pipe body (10) of tubular shape having an inlet (100) for entering of a fluid and an outlet (101) for said fluid to flow out; the internal wall of the pipe body (10) is provided with a fin (11) protruding towards the interior of the pipe body (10), the fin (11) spirally extends in an axial direction of the pipe body (10), wherein at least one of a heat insulator (14) and a heat insulating layer (17) is provided at the outside of the pipe body (10). The heat transfer enhancement pipe can reduce thermal stress of itself, thereby increasing service life of the heat transfer enhancement pipe.

The present invention relates to the field of fluid heat transfer, and discloses a heat transfer enhancement pipe as well as a cracking furnace and an atmospheric and vacuum heating furnace including the same. The heat transfer enhancement pipe (1) includes a pipe body (10) of tubular shape having an inlet (100) for entering of a fluid and an outlet (101) for said fluid to flow out; internal wall of the pipe body (10) is provided with a fin (11) protruding towards interior of the pipe body (10), wherein the fin (11) has one or more fin sections extending spirally in the axial direction of the pipe body (10), and each fin section has a first end surface facing the inlet (100) and a second end surface facing the outlet (101), at least one of the first end surface and the second end surface of at least one of the rib sections is formed as a transition surface along spirally extending direction. The heat transfer enhancement pipe can reduce thermal stress of itself, thereby increasing service life of the heat transfer enhancement pipe.

A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr.sub.2O.sub.4 having a thickness up to 5 microns.

A pass or tube or a section thereof or U bend in a coil in a paraffin cracker having section having a pore size in the metal substrate from about 0.001 to 0.5 microns over coated with a dense metal membrane permits the permeation of one or more of H.sub.2, CH.sub.4, CO and CO.sub.2 from cracked gases moving the reaction equilibrium to the production of ethylene and reduces the load on the down-stream separation train of the steam cracker.

A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr.sub.2O.sub.4 having a thickness up to 5 microns.

A substrate steel of the comprising from 0.01 to 0.60 wt. % of La, from 0.0 to 0.65 wt. % of Ce; from 0.06 to 1.8 wt. % of Nb up to 2.5 wt. % of one or more trace elements and carbon and silicon may be treated in an oxidizing atmosphere to product a coke resistant surface coating of MnCr.sub.2O.sub.4 having a thickness up to 5 microns.