Disclosed is a process for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce two extract streams—one rich in paraxylene and a paraxylene-rich extract stream that is lean in ethylbenzene and an ethylbenzene-rich extract stream that is lean in paraxylene- and a paraxylene-depleted raffinate stream. A significant amount of the ethylbenzene is removed in the ethylbenzene-rich extract stream (at least enough to limit buildup in the isomerization loop), so the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy and capital intensive hydrogen recycle loop.

Disclosed is a process for recovering paraxylene in which a first simulated moving bed adsorption unit is used to produce two extract streams—one rich in paraxylene and a paraxylene-rich extract stream that is lean in ethylbenzene and an ethylbenzene-rich extract stream that is lean in paraxylene- and a paraxylene-depleted raffinate stream. A significant amount of the ethylbenzene is removed in the ethylbenzene-rich extract stream (at least enough to limit buildup in the isomerization loop), so the paraxylene-depleted raffinate stream may be isomerized in the liquid phase. Avoiding vapor phase isomerization saves energy and capital, as liquid phase isomerization requires less energy and capital than the vapor phase isomerization process due to the requirement of vaporizing the paraxylene-depleted stream and the use of hydrogen, which requires an energy and capital intensive hydrogen recycle loop.

PROBLEM TO BE SOLVED:

In an apparatus for synthesizing methane from carbon dioxide and hydrogen, a device which is capable to remove the reaction heat and lower the reaction temperature as the reaction progresses in order to increase the conversion ratio to methane has been desired.

SOLUTION:

In the present invention, powders of magnesium hydroxide and magnesium carbonate, which are chemical heat storage agents, are used as part of the fluidizing medium of the multi-stage fluidized bed in the temperature range where the methanation reaction proceeds. The heat generated during the methanation reaction can be absorbed and stored in the powder. At this time, carbon dioxide generated from magnesium carbonate can be used as a raw material gas for the methanation reaction. Furthermore, after discharging the magnesium oxide generated by endotherm, the powder can be regenerated with an external regenerating facility and then the storage heat can be released and recovered. The regenerated powder can be fed to the uppermost stage of the multi-stage fluidized bed at a temperature lower than the internal temperature of the reactor to lower inside temperature. This made it possible to lower the reaction temperature of ascending reaction gas in the reactor along with the reaction progress, and to increase the conversion ratio to the produced methane by this lowered temperature.

A method of converting one or more alkanes to one or more alkenes that includes providing a first stream containing one or more alkanes and oxygen to an oxidative dehydrogenation reactor; converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor containing one or more alkanes, one or more alkenes, and one or more of oxygen, carbon monoxide and acetylene; and providing the second stream to a second reactor containing a catalyst that includes CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor containing one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.

A method of converting one or more alkanes to one or more alkenes that includes providing a first stream containing one or more alkanes and oxygen to an oxidative dehydrogenation reactor; converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor containing one or more alkanes, one or more alkenes, and one or more of oxygen, carbon monoxide and acetylene; and providing the second stream to a second reactor containing a catalyst that includes CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor containing one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.

A method of converting one or more alkanes to one or more alkenes that includes providing a first stream containing one or more alkanes and oxygen to an oxidative dehydrogenation reactor; converting at least a portion of the one or more alkanes to one or more alkenes in the oxidative dehydrogenation reactor to provide a second stream exiting the oxidative dehydrogenation reactor containing one or more alkanes, one or more alkenes, and one or more of oxygen, carbon monoxide and acetylene; and providing the second stream to a second reactor containing a catalyst that includes CuO and ZnO and reacting the second stream to provide a third stream exiting the second reactor containing one or more alkanes, one or more alkenes, and lower or undetectable levels of oxygen and acetylene compared to the second stream.

Methods for producing olefins through hydrocarbon steam cracking include passing a hydrocarbon feed that includes one or more hydrocarbons to a hydrocarbon cracking unit and passing one or more sulfur-containing compounds to the hydrocarbon cracking unit. The sulfur- containing compounds include at least hydrogen sulfide gas, and a flow rate of the sulfur- containing compounds to the hydrocarbon cracking unit is sufficient to produce a molar concentration of elemental sulfur in the hydrocarbon cracking unit of from 10 ppm to 200 ppm. The methods include cracking the hydrocarbon feed in the hydrocarbon cracking unit to produce a cracker effluent and contacting the cracker effluent with a quench fluid in a quench unit to produce at least a cracked gas and a first pygas. The first pygas has a concentration of carbon disulfide less than 50 ppmw based on the total mass flow rate of the first pygas.

The present invention relates to a process for treating an effluent obtained from an oligomerization step in a vaporization step. In particular, the oligomerization step is a step for dimerization of ethylene to 1-butene with a nickel-based catalytic system.

In a process for the catalytic conversion of lower hydrocarbons to aromatic compounds comprising benzene, toluene and xylenes, a process stream containing lower hydrocarbons is contacted with a zeolitic catalyst having an MFI framework and containing 0.1 to 10 percent by weight of a zinc compound. The process stream further contains one or more sulfur compounds, especially hydrogen sulfide, for improving the selectivity.

A volume of natural gas including a volume of methane and a volume of other alkanes may be cleaned of the other alkanes using a steam reformer system to create synthesis gas.