Embodiments described herein relate to methods and systems for dewatering alcoholic solutions via forward osmosis, where the concentration of alcohol in the draw stream is equal to or greater than the concentration of the alcohol in the feed stream. As the feed stream is concentrated the alcohol is retained in the feed stream.

A method and system for membrane-assisted production of high purity concentrated dimethyl carbonate by the reaction of carbon dioxide and methanol is provided. Carbon dioxide is recovered from flue gas or other dilute streams from industrial processes by a membrane and subsequent conversion takes place to an intermediate methyl carbamate by reacting of carbon dioxide with ammonia and methanol. For high-purity carbon dioxide obtained by one of the carbon capture technologies or by a process (such as, for example, ethanol fermentation process) the membrane reactor is replaced with a catalytic reactor for direct conversion of carbon dioxide to methyl carbamate by reacting with ammonia and methanol. The methyl carbamate is further reacted with methanol for conversion to dimethyl carbonate. An integrated reactive distillation process using side reactors is used for facilitating the catalytic reaction in the subject method for producing high purity dimethyl carbonate.

A distillation and dehydration system is provided that produces an anhydrous organic solvent. The provided system includes vapor recompression (e.g., a mechanical or thermal vapor recompression unit) to recover heat from a rectification-distillation section (e.g., a rectifier/stripper column). The addition of vapor recompression enables further heat recovery within a stream by increasing the condensation temperature and pressure of that stream and later using its latent heat by condensing it.

In an embodiment is provided a process to re-refine used oil that includes introducing a used oil and a solvent to a separation unit under separation conditions selected to produce a purified oil product, the separation unit comprising a porous membrane, a semiporous membrane, or both; and separating the used oil to obtain an effluent comprising a purified oil product. In another embodiment is provided an apparatus for re-refining used oil that includes a separation unit comprising a porous or semiporous membrane; a used oil feed coupled to an inlet of the separation unit; and an inlet of a diffusate collection unit coupled to an outlet of the separation unit. In another embodiment is provided a composition generated from a membrane separation process that includes a base oil, the composition having a soot content of about 0.05% or less.

Provided is a method for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water in an energy-efficient manner. The method, which is for producing purified acetic acid from a mixed solution containing acetic acid, an organic solvent, and water, includes: a distillation step in which the mixed solution is distilled and separated into a purified liquid rich in acetic acid and a separated liquid rich in an organic solvent; and a membrane separation step in which the water is separated from the purified liquid by a separation membrane. The purified liquid has a water concentration of 4 wt.% or less.

A distillation station for separating components of a liquid mixture, comprising a vertical distillation column split into individual separation stages by fittings and which is further split by the liquid mixture feed into a stripping chamber and an enriching chamber, wherein in the stripping chamber the lower boiling fraction of vapor from the fluid mixture rising from a column sump comprising an evaporator is stripped, and in the enriching chamber the vapor is enriched with the lower-boiling fraction, which is withdrawn from a return fluid produced due to the vapor drawn from the column head being precipitated at least partially in a condenser and returned to the rectifier column, and the return liquid and the liquid mixture preferably fed between two separating stages being routed to the fittings vertically connected in sequence. In the process, each of the fittings comprise at least one liquid channel, which is separated at least partially from the vapor chamber of the distillation column by a two-sided vapor-permeable, liquid-tight membrane wall.

A process of purifying 1,4-butanediol (1,4-BDO) from a fermentation broth including separating solid materials, salts and water, and subjecting the resulting material to a two, three or four column distillation system, that can include a wiped film evaporator to produce a purified 1,4-butanediol.

A process is described for making acrylic acid from dextrose, which comprises fermenting dextrose; removing solids from the resulting fermentation broth; removing lactic acid from the clarified broth by extraction into an organic solvent; separating out the lactic acid-loaded organic solvent while recycling at least a portion of the remainder back to the fermentation step; reacting the lactic acid with ammonia to provide a dehydration feed comprising ammonium lactate while preferably recycling the organic solvent; carrying out a vapor phase dehydration of the ammonium lactate to produce a crude acrylic acid product; and purifying the crude acrylic acid by distillation followed by melt crystallization, chromatography or both melt crystallization and chromatography.

An energy saving and emission reduction system for chemical separation and purification process is disclosed. The chemical separation and purification process includes a synthesis section and/or a distillation section and/or a recovery section. The energy saving and emission reduction system includes an energy comprehensive utilization maximizing energy saving module. The energy comprehensive utilization maximizing energy saving module comprehensively evaluates the chemical separation and purification process, and acquires a lowest energy consumption value according to initial and final material flow parameters. Then energy integration optimization and energy saving technical modification are performed on the synthesis section and/or distillation section and/or recovery section according to the lowest energy consumption value. The disclosure involves a comprehensive and extensive energy saving and emission reduction system for chemical separation and purification process, and has achieved good environmental benefits.

A process and a preparation plant prepares methacrolein from formaldehyde and propionaldehyde, in presence of water and a homogeneous catalyst based at least on an acid and a base. A reaction mixture is introduced into a methacrolein workup plant and separated in a first distillation column, into a first distillation mixture in a gas phase at the top and a second distillation mixture in a liquid phase at the bottom. The first distillation mixture is condensed and, in a first phase separator, the organic phase and the aqueous phase of the condensate are separated from one another. The aqueous phase is introduced into a second distillation column, that is not part of the methacrolein workup plant, and is separated into a third distillation mixture in a gas phase at the top and a fourth distillation mixture at the bottom. The third distillation mixture is introduced into the methacrolein workup plant.