An apparatus and process doubles the number of trays in a single fractionation column. A dividing wall is used to isolate a first side from a second side and fractionation on trays on each side is independent of the other. A transition vapor stream is ducted from a top of a first side to the bottom of the second side, and a transition liquid stream is ducted from a bottom of the second side to the top of the first side.

A process for stably and safely producing acetic acid without increasing an internal pressure of a distillation column is provided. The process comprises (1) a carbonylation reaction step for allowing methanol to react with carbon monoxide; (2) a flash step for separating the reaction mixture into a volatile phase and a less-volatile phase; (3) a first distillation step for separating the volatile phase into a first overhead and a crude acetic acid stream rich in acetic acid; and (4) a separation step for separating at least acetaldehyde from the first overhead. The separation step (4) comprises (6) a second distillation step for distilling the first overhead while controlling an internal pressure of a distillation column provided with a pressure control unit 68 to form a second overhead rich in acetaldehyde and methyl iodide and a bottom or lower stream, and (7) an extraction step for extracting acetaldehyde from the second overhead to form an extract rich in acetaldehyde and a raffinate rich in methyl iodide.

The present invention relates to a method of controlling a concentration of a first component of a rectification column for separating a binary mixture of the first component with a second component on the basis of temperature measurements, wherein a control path defined by temperature sensors (T3, T2, T6) arranged in the longitudinal direction of the column is linearized with the aid of an estimated temperature profile, wherein a real temperature profile T*(h), determined by means of the temperature sensors, is approximated by a function T(h) in dependence on a column height h, wherein the column id divided into two sections along the column height h and the function T(h) is defined section by section on the basis, in each case, of a logistical function.

An onsite purification plant/system to delivery high and ultra high purity product, such as, process chemicals, industrial and specialty gases to manufacturing processes within the onsite plant turndown ratio from 0% to 100% while preserving the predetermined purity of the supplied substances within a predefined specification range is provided. Preserving liquid/vapor ratio in at least one of the purification means/units ensuring that product purity range stays unchanged is achieved by redirecting the product back into the onsite purification plant/system.

Fouling of an MMA process is reduced by strategically removing an aqueous slip stream.

The present invention relates to evaporation apparatus (100) comprising manifolds provided with at least one nozzle (102), a tank unit (103) for a liquid, and a sample holder configured to be inserted into the tank unit. The sample holder is configured to hold at least sample in a defined position relative the at least one nozzle a control unit (104) an inlet port (105) configured to be connected to a gas supply, a pressure regulator (106) arranged downstream the inlet port (105). A set value of the pressure regulator (106) is controlled by the control unit (104), a control valve (107) arranged downstream the pressure regulator (106), wherein each of the at least one manifold (101a-d) is connected to a corresponding output port of the control valve. The control valve is controlled by the control unit (104), and the control unit is configured to set the set value of the pressure regulator to a value that causes a predetermined gas flow from each of the at least one nozzle.

A process for the separation of monoethylene glycol (MEG) and 1,2-butanediol (1,2-BDO) from a first mixture including MEG and 1,2-BDO, the process including providing the first mixture of MEG and 1,2-BDO as a feed to a distillation column. The process also includes providing a feed comprising glycerol to the distillation column above the first mixture. The process also includes operating the distillation column at a temperature in the range of from 50 to 250? C. and a pressure in the range of from 0.1 to 400 kPa. The process also includes removing a stream comprising MEG and glycerol as a bottoms stream from the distillation column and removing a stream comprising 1,2-BDO above the point at which the feed comprising glycerol is provided to the distillation column.

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.

In a process for the epoxidation of propene, comprising the steps: reacting propene with hydrogen peroxide in the presence of a titanium silicalite catalyst and a methanol solvent; separating non-reacted propene and propene oxide from the resulting reaction mixture to provide a solvent mixture comprising methanol and water in a combined amount of at least 90% by weight; and feeding this solvent mixture as a feed stream to a continuously operated methanol distillation column at a feed point in the middle section of said column to provide an overhead product comprising at least 90% by weight methanol and a bottoms product comprising at least 90% by weight water; the addition of a liquid defoamer, having a solubility in the feed stream of less than 10 mg/kg at 25 C. and a surface tension at the liquid air interface of less than 22 mN/m at 20 C., at or above the feed point in an amount exceeding the solubility of the liquid defoamer in the feed stream suppresses foam formation in the methanol distillation column.

A process for stably and safely producing acetic acid without increasing an internal pressure of a distillation column is provided. The process comprises (1) a carbonylation reaction step for allowing methanol to react with carbon monoxide; (2) a flash step for separating the reaction mixture into a volatile phase and a less-volatile phase; (3) a first distillation step for separating the volatile phase into a first overhead and a crude acetic acid stream rich in acetic acid; and (4) a separation step for separating at least acetaldehyde from the first overhead. The separation step (4) comprises (6) a second distillation step for distilling the first overhead while controlling an internal pressure of a distillation column provided with a pressure control unit 68 to form a second overhead rich in acetaldehyde and methyl iodide and a bottom or lower stream, and (7) an extraction step for extracting acetaldehyde from the second overhead to form an extract rich in acetaldehyde and a raffinate rich in methyl iodide.