A hydrocarbon production system capable of efficiently producing hydrocarbon containing a high-calorie gas by securing hydrogen and carbon monoxide required for hydrocarbon synthesis using water and carbon dioxide as raw materials is obtained. The hydrocarbon production system includes an electrolytic reaction unit that converts water and carbon dioxide into hydrogen and carbon monoxide through an electrolytic reaction, a catalytic reaction unit that converts a product generated by the electrolytic reaction unit into hydrocarbon through a catalytic reaction, and branch paths and that branch a portion of an outlet component of the catalytic reaction unit.

A hydrocarbon production system capable of efficiently producing hydrocarbon containing a high-calorie gas by securing hydrogen and carbon monoxide required for hydrocarbon synthesis using water and carbon dioxide as raw materials is obtained. The hydrocarbon production system includes an electrolytic reaction unit that converts water and carbon dioxide into hydrogen and carbon monoxide through an electrolytic reaction, a catalytic reaction unit that converts a product generated by the electrolytic reaction unit into hydrocarbon through a catalytic reaction, and branch paths and that branch a portion of an outlet component of the catalytic reaction unit.

The invention is concerned with a method for producing a conjugated diene including a reaction step of subjecting a raw material gas containing a monoolefin having a carbon atom number of 4 or more to an oxidative dehydrogenation reaction with a gas containing molecular oxygen in the presence of a catalyst, to obtain a reaction product gas containing a conjugated diene; and a cooling step of cooling the reaction product gas, wherein in the cooling step, a cooling agent is supplied into a cooling column and brought into contact with the reaction product gas; the cooling agent discharged from the cooling column is then cooled by a heat exchanger; a precipitate dissolved in the cooling agent is precipitated within the heat exchanger and recovered; and the cooling agent from which the precipitate has been recovered is circulated into the cooling column.

The present invention relates to a plant and a process for producing propylene at least one oxygenate, comprising a reactor for converting the reactant mixture into a product mixture which comprises propylene and also aliphatic and aromatic C.sub.5+ hydrocarbons, at least one distillation column for removing a C.sub.5+ stream, the C.sub.5+ stream comprising at least 90 wt % of the aliphatic and aromatic C.sub.5+ hydrocarbons of the product mixture, an extractive distillation column for separating the C.sub.5+ stream into an aromatics stream and an aliphatics stream, the aliphatics stream comprising at least 90 wt % of the aliphatics of the C.sub.5+ stream, and the aromatics stream comprising at least 90 wt % of the aromatics of the C.sub.5+ stream, and an aliphatics recycle line for at least partial recycling of the aliphatics stream to the reactor. According to the invention, an aromatics recycle line is provided which returns the aromatics stream at least partially as extractant into the extractive distillation column.

The present invention relates to a plant and a process for producing propylene at least one oxygenate, comprising a reactor for converting the reactant mixture into a product mixture which comprises propylene and also aliphatic and aromatic C.sub.5+ hydrocarbons, at least one distillation column for removing a C.sub.5+ stream, the C.sub.5+ stream comprising at least 90 wt % of the aliphatic and aromatic C.sub.5+ hydrocarbons of the product mixture, an extractive distillation column for separating the C.sub.5+ stream into an aromatics stream and an aliphatics stream, the aliphatics stream comprising at least 90 wt % of the aliphatics of the C.sub.5+ stream, and the aromatics stream comprising at least 90 wt % of the aromatics of the C.sub.5+ stream, and an aliphatics recycle line for at least partial recycling of the aliphatics stream to the reactor. According to the invention, an aromatics recycle line is provided which returns the aromatics stream at least partially as extractant into the extractive distillation column.

A process is presented for the recovery of solvent used in an alkylation process. The solvent removes heavy hydrocarbons from a C4 stream. The C4 stream is passed to an alkylation unit to generate an alkylate product. A portion of the solvent is carried over with the C4 stream and needs to be recovered to reduce the aromatics content in the C4 stream, to reduce any deleterious effects of the aromatics in downstream processing.

A process is presented for the recovery of solvent used in an alkylation process. The solvent removes heavy hydrocarbons from a C4 stream. The C4 stream is passed to an alkylation unit to generate an alkylate product. A portion of the solvent is carried over with the C4 stream and needs to be recovered to reduce the aromatics content in the C4 stream, to reduce any deleterious effects of the aromatics in downstream processing.

The invention generally relates to processes for reducing fouling in amine systems and to equipment useful in such processes. Such amine systems are useful for removing one or more acidic gases such as CO.sub.2 or H.sub.2S from olefin containing hydrocarbon streams. The invention generally relates to minimizing residence time of foulant and foulant precursors at the relatively high temperature found in the amine regenerator and/or to purging the foulant and foulant precursors from the regenerator system. This is accomplished by operating the regenerator column as a stripper (no reflux) and re-routing reflux liquid containing foulant or foulant precursors to a processing location that is less prone to fouling or, optionally, by replacing the reflux liquid with fresh make-up amine or water.

The invention generally relates to processes for reducing fouling in amine systems and to equipment useful in such processes. Such amine systems are useful for removing one or more acidic gases such as CO.sub.2 or H.sub.2S from olefin containing hydrocarbon streams. The invention generally relates to minimizing residence time of foulant and foulant precursors at the relatively high temperature found in the amine regenerator and/or to purging the foulant and foulant precursors from the regenerator system. This is accomplished by operating the regenerator column as a stripper (no reflux) and re-routing reflux liquid containing foulant or foulant precursors to a processing location that is less prone to fouling or, optionally, by replacing the reflux liquid with fresh make-up amine or water.

The invention removes oxygenate from an olefin rich gas stream, the process comprising: (a) reacting an oxygenate, in a reaction zone in the presence of a molecular sieve catalyst, at a temperature from 350 to 1000° C., to produce an effluent stream, comprising at least oxygenate, olefin, water and acidic by-products; (b) cooling the effluent stream and contacting it with a first aqueous stream in a quench zone to produce an aqueous stream and an olefin rich gas stream; (c) compressing the olefin rich gas stream in one or more compressors in series to produce a compressed gas stream, (d) cooling the compressed gas stream and separating condensed material from said gas stream after each of the one or more compressors.