A method of producing a fuel additive includes passing a feed stream comprising C.sub.4 hydrocarbons through a first hydrogenation unit producing a first process stream; passing the first process stream through a distillation unit; withdrawing a 2-butene stream from the distillation unit: passing the 2-butene stream through a second hydrogenation unit producing a 1-butene stream; passing at least a portion of the 1-butene stream through a separation unit; and passing the 1-butene stream through a hydration unit producing the fuel additive.

A method for eliminating pressure loss (pressure difference) caused by salt derived from impurities in raw materials in a distillation facility during operation without negative effect on the quality of products and production efficiency is provided. The method for eliminating occurrence of pressure difference caused by precipitation of salt in a distillation facility includes using a specific quaternary ammonium compound.

The present invention relates to a process for oligomerization of C2- to C8-olefins in at least two reaction stages, wherein in the last distillation column the reaction mixture is fractionated such that only very small amounts of the reactant olefins and the analogous alkanes remain in the bottom of the distillation column.

A device for manufacturing dimethyl carbonate including a reaction section and a separation section is provided. The reaction section includes a first distillation column, a methanol supply device, a carbon dioxide supply device, a dehydrating agent supply device, and a side reactor. The methanol supply device is connected to the first distillation column. The carbon dioxide supply device is connected to the first distillation column. The dehydrating agent supply device is connected to the first distillation column. A feed nozzle of the side reactor is connected to a gas outlet of a top of the first distillation column. A discharge nozzle of the side reactor is connected to a recycle nozzle of the first distillation column. A catalyst is disposed in the side reactor. The separation section includes a second distillation column. The second distillation column is connected to a liquid outlet of a bottom of the first distillation column.

Embodiments described herein provide a method, comprising reducing pH of a glycol vaporization separator purge stream to form an acid stream; distilling the acid stream to form an overhead stream and a bottoms stream; and recycling the bottoms stream to the vaporization separator.

The invention relates to an apparatus for carrying out mass transfer processes, comprising a column having at least two inlet pipes for introducing a gaseous phase, where separation-active internals are accommodated in the column and a column section extends from the at least two inlet pipes to the separation-active internals, in which section a coverage of a cross-sectional area of the column is less than 25%, based on the total cross-sectional area, and where the at least two inlet pipes have a height offset which corresponds to not more than three times an inlet pipe diameter and the at least two inlet pipes are at an angle (α) of from 60° to 150° to one another and have asymmetry with respect to one another. The invention further relates to a use of the apparatus and also a method for designing the apparatus.

Methods and systems for separating a first metal from a metal-containing feed stream are provided. The method can include applying solar energy, for example, by focusing one or more mirrors in one or more heliostats, to heat a metal-containing feed stream in a heating zone to a first temperature to produce a first vapor including the first metal. The first vapor can be condensed in a condensation zone to produce a first liquid including the first metal, and the first liquid can be collected. The system can include a separation unit include a heating zone in fluid communication with a condensation zone and a means for applying solar energy to heat a metal-containing feed stream disposed in the heating zone.

An alkylation reaction apparatus has n reactors. In the n reactors, there are m reactors including the first reactor that have three reaction zones as defined below. According to the flow direction order of alkylation reaction streams, the three reaction zones are an x reaction zone, a y reaction zone and a z reaction zone respectively; based on the mixing intensity, the mixing intensity of the y reaction zone>the mixing intensity of the x reaction zone>the mixing intensity of the z reaction zone, wherein n≥1 and n≥m. An alkylation reaction system includes the aforementioned alkylation reaction apparatus, and a liquid acid catalyzed alkylation reaction process by using the aforementioned alkylation reaction apparatus or the aforementioned alkylation reaction system.

Methods and systems for separating a first metal from a metal-containing feed stream are provided. The method can include applying solar energy, for example, by focusing one or more mirrors in one or more heliostats, to heat a metal-containing feed stream in a heating zone to a first temperature to produce a first vapor including the first metal. The first vapor can be condensed in a condensation zone to produce a first liquid including the first metal, and the first liquid can be collected. The system can include a separation unit include a heating zone in fluid communication with a condensation zone and a means for applying solar energy to heat a metal-containing feed stream disposed in the heating zone.

A process for the selective dimerization and etherification of isoolefins. The process including feeding a mixed C5 stream to a selective hydrogenation unit to convert dienes to olefins and isoolefins, producing a hydrogenated effluent stream. The hydrogenated effluent stream is fed to a first fixed bed reactor, producing a first reactor effluent. The first reactor effluent is fed to a catalytic distillation reactor system, producing a first overheads including unreacted olefins, isoolefins, oxygenate, and one or more C5 ethers and a first bottoms including dimers of the isoolefins, any produced trimers of the isoolefins, and heavy oxygenates. The first overheads is fed to a second fixed bed reactor, producing a second reactor effluent including dimers of the isoolefins, unreacted C5s, and unreacted oxygenates. The first bottoms stream and the second reactor effluent are combined and fed to a product splitter, producing a second overheads stream including unreacted C5 olefins, isoolefins, and oxygenates and a second bottoms stream including C10+ hydrocarbons.