Disclosed are processes and systems for removing water from a polyether polyol that employs a controlled temperature and pressure profile.

A method for precisely predicting phase equilibrium from existing phase equilibrium data on the basis of a wide range of phase equilibrium data including binary vapor-liquid equilibrium data; a method or apparatus for designing or controlling a component separator or a refiner using the prediction method; and a program for designing this design or control apparatus. Binary phase equilibrium measurement data is used to calculate an index of proximity ratio to critical points and infinite dilution pressure gradients. The obtained index is correlated with the infinite dilution pressure gradients to newly calculate infinite dilution activity coefficients from the respective index to infinite dilution pressure gradients correlations. The obtained infinite dilution activity coefficients values are used to predict phase equilibrium. Thus, the obtained values are used to design or control a component separator or a refiner, such as a distillation column.

A method for precisely predicting phase equilibrium from existing phase equilibrium data on the basis of a wide range of phase equilibrium data including binary vapor-liquid equilibrium data; a method or apparatus for designing or controlling a component separator or a refiner using the prediction method; and a program for designing this design or control apparatus. Binary phase equilibrium measurement data is used to calculate an index of proximity ratio to critical points and infinite dilution pressure gradients. The obtained index is correlated with the infinite dilution pressure gradients to newly calculate infinite dilution activity coefficients from the respective index to infinite dilution pressure gradients correlations. The obtained infinite dilution activity coefficients values are used to predict phase equilibrium. Thus, the obtained values are used to design or control a component separator or a refiner, such as a distillation column.

A hybrid mint plant characterized by an essential oil composition profile, methods of cultivating the hybrid mint plant, and methods of producing an essential oil composition with the essential oil composition profile using the hybrid mint plant are disclosed.

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.

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 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 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.

The present invention discloses a gas distribution structure for a distillation column. Pressure drop adjusting column tray assemblies are arranged in a left mass transfer region and a right mass transfer region along a column height direction. The gas distribution structure includes column trays, gas-rising pipes, downcomers and cover hoods, wherein a gas flow meter is arranged in a pipe of any gas rising pipe; a feeding port and a liquid collecting port are formed in a column wall; a liquid flow meter, an adjusting valve and a circulation pump are arranged on a circulation pipeline between each liquid collecting port and each feeding port; technological parameters are transmitted to a control system; and the circulation pumps and the adjusting valves are controlled by the control system