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.

The present invention relates to a method of producing and purifying a high-purity anhydrosugar alcohol in high yield by a simple process and apparatus, the method includes the steps of: allowing a sugar alcohol to react in the presence of an acid catalyst in a reactor, and, at the same time, evaporating a product of the reaction; cooling the evaporated product to remove water and obtain a crude anhydrosugar alcohol; and introducing the crude anhydrosugar alcohol into a melt crystallization process to obtain a high-purity anhydrosugar alcohol.

A method produces acetic acid and includes a reaction step, a first purification step, a second purification step, and a third purification step. In the reaction step, a material mixture including methanol, carbon monoxide, a catalyst, and an iodide is subjected to a methanol carbonylation reaction in a reactor (1) to form acetic acid. In the first purification step, a crude acetic acid stream including acetic acid formed in the reaction step is subjected to distillation in a distillation column (3) to give a first acetic acid stream enriched with acetic acid. In the second purification step, the first acetic acid stream is subjected to distillation in a distillation column (5) to give a second acetic acid stream further enriched with acetic acid. In the third purification step, an acetic acid stream is subjected to purification in an additional purification unit (e.g., a distillation column (6)) while controlling the corrosive iodine concentration in the acetic acid stream passing through the unit to 100 ppm or less, to give a third acetic acid stream still further enriched with acetic acid. The method for producing acetic acid is suitable for restraining corrosion of the acetic acid production equipment.

A carbonate ester purification apparatus including a first distillation column in which an alcohol and a first solution containing a carbonate ester and formaldehyde, or a first solution containing a carbonate ester, formaldehyde and an alcohol is supplied to obtain a distillate containing the formaldehyde and the alcohol from a column top part while obtaining a carbonate ester solution with a lower content of formaldehyde than in the first solution from a column bottom part, a reactor having a catalyst for producing an acetal and/or a hemiacetal by reacting the formaldehyde to the alcohol and a reflux part refluxing a fluid containing the acetal and/or the hemiacetal to the first distillation column.

A method for treating a urea aqueous solution includes a first stripping step of steam stripping an aqueous solution containing urea, ammonia and carbon dioxide at 0.2 to 0.6 MPaA in a first stripper to separate ammonia and carbon dioxide from this aqueous solution into a gas phase; a hydrolysis step of hydrolyzing urea in the solution obtained from the first stripping step at an LHSV of 10 to 20 h.sup.−1, at 1.1 to 3.1 MPaA and 180 to 230° C. in a catalytic hydrolyzer; and a second stripping step of steam stripping a liquid obtained in the hydrolysis step in a second stripper to separate ammonia and carbon dioxide from this liquid into a gas phase. The residual urea concentration can be reduced to 1 ppm or lower; the residual ammonia concentration can be decreased; LHSV can be increased; and an increase in apparatus size is minimized.

The present invention relates to a process for preparing chlorinated oligosilanes, wherein chlorinated polysilane having an empirical formula of SiCl.sub.1.0-2.8 and/or a mixture comprising the chlorinated polysilane is reacted with elemental chlorine or a chlorine-containing mixture. Additionally claimed are chlorinated oligosilanes prepared by the process and the use thereof for production of semiconductors and/or hard coatings.

This invention discloses an approach for the separation of the close-boiling mixture of polyols. The raw material is ethylene glycol containing miscellaneous polyols (such as 1,2-propylene glycol and 1,2-butanediol). Over an acid catalyst, these miscellaneous polyols, through (1) a dehydration reaction, (2) pinacol rearrangement, and (3) acetalization or ketalization reaction, are converted into aldehydes (small amounts), acetals, and ketals (trace amount), which are simultaneously and readily separated via distillation. Meanwhile, after the reaction, the mixture is further separated to obtain an ethylene glycol product at a high purity. The invention provides a technique to remove the miscellaneous polyols from ethylene glycol via liquid-phase dehydration reactions under mild conditions, with low energy consumption. In particular, this approach is markedly effective for the removal of 1,2-butanediol that is difficult to be removed via conventional techniques. The purity of the resulting ethylene glycol product is high, and value-added acetals or ketals are co-produced.

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.

The present invention describes a device for supplying the catalytic zone of a reactive distillation column using a liquid stream as the reaction stream, the flow of liquid in the reactive zone being of the upflow type and gas not encountering the liquid in the reactive zone.

A process for recovering an ethylene oxide (EO) enriched product stream from fat absorbent (FA) comprising water, EO, and acetaldehyde. The process comprises passing a feed of FA from a loopgas EO absorber to a multi-stage countercurrent distillation zone, the feed of FA having a concentration of EO in the range of from about 1 to about 15 wt % upon entering the distillation zone; and obtaining from the distillation zone an acetaldehyde enriched stream, a lean absorbent (LA) stream, a vapour stream enriched in light ends, a glycol enriched bottoms stream and an EO enriched product stream. Suitable apparatus is also disclosed.