Provided is a solvent separation method and a solvent separation apparatus in which a vaporized solvent is collected at one internal side of a solvent separation unit by attracting the vaporized solvent based on electric field, while the vaporized solvent is prevented from coming into contact with electrodes, and the collected solvent is discharged from the solvent separation unit. Different electric fields are alternately applied to a pair of first electrodes and a pair of second electrodes present at predetermined locations inside a tetragonal tubular solvent separation unit to attract a vaporized solvent toward the second electrodes. Thus, the vaporized solvent is collected in a space between the second electrodes inside the solvent separation unit, and the collected solvent is discharged from the solvent separation unit, together with a portion of the exhaust atmosphere present around the collected solvent.

The invention relates to a method for producing isocyanates, according to which exhaust flows provided for the combustion are guided through an adsorption device before being supplied into the exhaust gas combustion process, and are thereby depleted of solvent, the adsorption device comprising at least two adsorption units connected in parallel, which are alternately (i) exposed to the at least one exhaust flow and (ii) regenerated with water vapor, where, during method step (i), an exhaust flow depleted of solvent is obtained, and during method step (ii), a flow containing water and solvent is obtained, the solvent proportion of which is recycled into a method for producing isocyanates.

The invention relates to a method for producing isocyanates, according to which exhaust flows provided for the combustion are guided through an adsorption device before being supplied into the exhaust gas combustion process, and are thereby depleted of solvent, the adsorption device comprising at least two adsorption units connected in parallel, which are alternately (i) exposed to the at least one exhaust flow and (ii) regenerated with water vapour, where, during method step (i), an exhaust flow depleted of solvent is obtained, and during method step (ii), a flow containing water and solvent is obtained, the solvent proportion of which is recycled into a method for producing isocyanates.

In a method for the reduction of methanol emission from an ammonia plant, a chilled methanol-containing feed gas is fed to a methanol absorber, carbon dioxide is separated from the gas phase leaving the methanol absorber, the methanol-containing gas is fed to a final separator, and the chilled, methanol-free process condensate from the final separator is used to wash out the methanol in a scrubbing column. By cooling the streams to the column and inserting a number of individual wash trays in the column, a practically quantitative removal of methanol is possible.

A method for separating organic solvents from solvent-containing process exhaust air, where the process exhaust air is directed through a separation zone of a separating device, and the separating device is regenerated by passing a regeneration stream through a regeneration zone of the separating device. The regeneration stream passing through the separating device is divided into a first partial stream having an impurity concentration less than a first predetermined limit, and a second partial stream having an impurity concentration equal or greater than a second predetermined limit, by a divider, where the second predetermined limit is equal to or greater than the first predetermined limit, to return the first partial stream generated during regeneration to the separating device and direct the second partial stream generated during regeneration to a cleaning device.

Provided are a solvent separation method, a solvent separation apparatus, and a solvent separation system that make it possible to easily collect a solvent removed from an exhaust atmosphere and that make it possible to easily carry out maintenance of exhaust gas pathways. An impeller placed in a storage space of a casing is rotated to introduce a gas including a volatilized solvent from an inlet of the casing into the storage space, and the volatilized solvent is cooled and devolatilized by a collection face that has been cooled so as to have a surface temperature lower than the temperature of the gas, to thereby separate the solvent from the gas.

In the method for scrubbing a chemical from a medium, wherein the improvement comprises the steps of using a carbide derived carbon to adsorb the chemical which may later be released by heating. The carbide derived carbon may be a powder, a fiber, a solid foam, a mesh, or other solid form. The carbide derived carbon can adsorb a chemical in the gaseous, liquid, particulate, or aerosol phase.

A feedstock processing system extracts a product from a solid using a CTSE system comprising a plurality of continuous stirred tank extraction stages arranged in fluid communication with each other in series such that effluent from one stage flows to a next stage in the series. One of the stages has an inlet to allow a measured amount of liquid solvent and the solid to be introduced to the continuous stirred tank extraction stage. The stage mixes the solid with the introduced solvent to form a homogeneous slurry to enable the product associated with the solid to be extracted with the solvent. A solid-liquid separator is arranged in fluid communication with the continuous stirred tank extraction stages, and receives an effluent from one of the stages and separates the liquid solvent containing the product from the solid to form a product-containing liquid and a product-depleted solid.

Provided is a gas detector which has a high durability to silicone poisoning and of which power consumption is reduced. The gas detector includes a contact combustion-type gas sensor and detects a paraffinic hydrocarbon gas, a solvent gas, and a hydrogen gas. The contact combustion-type gas sensor is configured to include two gas detection elements that are disposed in two detection chambers partitioned from each other, respectively, and the gas inlet of one detection chamber is provided with a silicone removal filter. The paraffinic hydrocarbon gas is detected by one gas detection element disposed in the one detection chamber which is provided with the silicone removal filter. Furthermore, the solvent gas is detected by the other gas detection element which is disposed in the other detection chamber. Still furthermore, the hydrogen gas is detected by either the one gas detection element or the other gas detection element.

With the invention a washing apparatus and a process for the efficient separation and recovery of methanol from waste gases loaded with methanol is proposed, wherein the invention also can be used in an integrated flow chart for the production and processing of methanol. The methanol fractions separated from the waste gases are recovered within the already existing, distillative processing of the crude methanol to pure methanol, so that no separate apparatuses are required for the recovery of the methanol from the loaded scrubber waste waters. The valuable substance methanol is recovered and the impact on the environment is reduced. By particular aspects of the invention the total degree of methanol separation can be adapted according to the locally applicable emission limit values.