A method of producing a fuel additive includes passing a feed stream comprising C4 hydrocarbons through a hydrogenation unit producing a hydrogenated stream; passing the hydrogenated stream through a distillation unit producing a first stream and a second stream; producing an isobutylene stream by passing the first stream through a molecular sieve unit; passing the isobutylene stream to a hydration unit as a feedstock for the fuel additive; and forming the fuel additive in the hydration unit.

Systems and processes for the flexible production of gasoline and jet fuel via alkylation of C4 and C5 olefins.

Systems and processes for the flexible production of gasoline and jet fuel via alkylation of C4 and C5 olefins.

A process (100, 200, 300) for the production of ethylene is proposed in which a first feed gas (A) and a second feed gas (B) are fed to a reactor (1) and processed therein by vapour cracking to obtain a product mixture (C), the first feed gas (A) comprising more than 90 weight percent saturated hydrocarbons and more than 80 weight percent ethane, and wherein the product mixture (C) or a part thereof is subjected to a treatment (2, 3, 4) and the resulting mixture (F) or a part thereof is subjected to a separation (10) to obtain a resulting mixture (F) containing hydrogen, methane, ethane, ethylene and hydrocarbons having three, four and at least five carbon atoms. The separation (10) being provided in that it comprises an ethylene separation step (7) to which at least the ethane, the ethylene and the hydrocarbons having three carbon atoms from the succeeding mixture (F) or a part thereof are fed unseparated from each other in a common separation insert (S, V, X), in which in the ethylene separation step (7) a light fraction (K) containing more than 95 mole percent ethylene is fed, and a heavy fraction (T, W, Y) containing at least a portion of the ethane from the separation insert (S, V, X) and at least 15% by weight of the hydrocarbons having three and four carbon atoms from the separation insert (S, V, X), and wherein the heavy separation product (T, W, Y) from the ethylene separation step (7) or a portion thereof is used as part or to form the second feed gas (B). A corresponding annex is also the subject of this invention.

A method for recovering paraxylene from a mixture of aromatic hydrocarbons. The process uses a pressure swing adsorption zone followed by a paraxylene recovery zone. The invention provides for lower throughput through the paraxylene recovery zone, resulting in lower capital costs and operating costs.

An object of the present invention is to provide a chemical liquid purification method which makes it possible to obtain a chemical liquid having excellent defect inhibition performance. Another object of the present invention is to provide a chemical liquid. The chemical liquid purification method according to an embodiment of the present invention is a chemical liquid purification method including obtaining a chemical liquid by purifying a substance to be purified containing an organic solvent, in which a content of the stabilizer in the substance to be purified with respect to the total mass of the substance to be purified is equal to or greater than 0.1 mass ppm and less than 100 mass ppm.

Many linear alpha olefin (LAO) syntheses form a range of LAO products when oligomerizing ethylene in the presence of a Ziegler-type catalyst. The range of products typically requires a plurality of distillation columns to separate the LAO products up to a desired carbon count, but such approaches may be energy- and capital-intensive. LAO product separation using at least one dividing wall column may lessen these burdens. Methods for separating LAOs may comprise: providing a pre-processed product stream comprising Cg+ linear alpha olefins (LAOs) to a first of a series of distillation columns, at least one member of the series of distillation columns comprising a dividing wall column; and separating an overhead stream comprising a first LAO from the dividing wall column and one or more side streams from the dividing wall column, each side stream comprising a different LAO that also differs from the first LAO.

Provided is a method for preparing an oligomer including: supplying a monomer stream and a solvent stream to a reactor to perform an oligomerization reaction to prepare a reaction product; supplying a discharge stream from the reactor including the reaction product to a separation device and supplying a lower discharge stream from the separation device to a settling tank; adding an organic flocculant to the settling tank to settle and remove a polymer and supplying the lower discharge stream from the separation device from which the polymer is removed to a high boiling point separation column; and removing a high boiling point material from the lower portion in the high boiling point separation column and supplying an upper discharge stream including an oligomer to a solvent separation column.

Provided is a method for preparing an oligomer including: supplying a monomer stream and a solvent stream to a reactor to perform an oligomerization reaction to prepare a reaction product; supplying a discharge stream from the reactor including the reaction product to a separation device and supplying a lower discharge stream from the separation device to a settling tank; adding an organic flocculant to the settling tank to settle and remove a polymer and supplying the lower discharge stream from the separation device from which the polymer is removed to a high boiling point separation column; and removing a high boiling point material from the lower portion in the high boiling point separation column and supplying an upper discharge stream including an oligomer to a solvent separation column.

Systems and methods for separating a mixture comprising C.sub.4 hydrocarbons and a solvent have been disclosed. The mixture is produced as a bottom stream of a rectifier column. The mixture is processed in at least two heating and flash-evaporating cycles to remove at least some C.sub.4 hydrocarbons as vapor streams. The resulted liquid stream is further degassed in a degasser column to produce a recycle vapor stream and a lean solvent stream.