The present invention relates to the production of light (meth)acrylic esters by direct esterification of acrylic acid by methanol or ethanol. The invention more particularly relates to a process for the recovery/purification of C1-C2 alkyl acrylate comprising the azeotropic distillation of the crude reaction mixture using a distillation column comprising a sidestream drawing off of a fraction rich in alkyl alkoxypropionate byproduct, the boiling point of which is close to that of acrylic acid, and therefore problematic in the purification process.

The present invention relates to the production of light (meth)acrylic esters by direct esterification of acrylic acid by methanol or ethanol. The invention more particularly relates to a process for the recovery/purification of C1-C2 alkyl acrylate comprising the azeotropic distillation of the crude reaction mixture using a distillation column comprising a sidestream drawing off of a fraction rich in alkyl alkoxypropionate byproduct, the boiling point of which is close to that of acrylic acid, and therefore problematic in the purification process.

The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.

The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C.sub.5-C.sub.20 oleophilic alcohol compounds, C.sub.5-C.sub.20 alkanes and/or C.sub.4-C.sub.20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.

Embodiments described herein relate generally to systems, apparatus, and methods for using graphene oxide-containing membranes for separation and concentration processes. In some embodiments, a fluid component having a first concentration in a fluid mixture can be concentrated using a first distillation process to a second concentration. In some embodiments, the fluid component can be concentrated from the second concentration to a third concentration using a graphene oxide-containing membrane. In some embodiments, the fluid component can be concentrated from the third concentration to a fourth concentration using a second distillation process. In some embodiments, the fluid component can have an azeotropic concentration between the second concentration and the third concentration.

Embodiments described herein relate generally to systems, apparatus, and methods for using graphene oxide-containing membranes for separation and concentration processes. In some embodiments, a fluid component having a first concentration in a fluid mixture can be concentrated using a first distillation process to a second concentration. In some embodiments, the fluid component can be concentrated from the second concentration to a third concentration using a graphene oxide-containing membrane. In some embodiments, the fluid component can be concentrated from the third concentration to a fourth concentration using a second distillation process. In some embodiments, the fluid component can have an azeotropic concentration between the second concentration and the third concentration.

The present disclosure provides azeotrope or azeotrope-like compositions including trifluoroiodomethane (CF.sub.3I) and trifluoroacetyl chloride (CF.sub.3COCl), and a method of forming an azeotrope or azeotrope-like composition comprising the step of combining trifluoroacetyl chloride (CF.sub.3COCl) and trifluoroiodomethane (CF.sub.3I) to form an azeotrope or azeotrope-like composition.

The present disclosure provides azeotrope or azeotrope-like compositions including trifluoroiodomethane (CF.sub.3I) and trifluoroacetyl chloride (CF.sub.3COCl), and a method of forming an azeotrope or azeotrope-like composition comprising the step of combining trifluoroacetyl chloride (CF.sub.3COCl) and trifluoroiodomethane (CF.sub.3I) to form an azeotrope or azeotrope-like composition.

A method for evaporatively concentrating a radioactive metal nuclide, including: a first evaporative concentration process in which a radioactive solution formed by dissolving a radioactive metal nuclide in an acidic aqueous solution is heated to evaporate a solvent in the radioactive solution so as to obtain a concentrated liquid containing the radioactive metal nuclide; and a second evaporative concentration process in which a low-boiling organic solvent having a lower boiling point than water is added to the concentrated liquid, and the concentrated liquid is heated to induce azeotropic boiling of the concentrated liquid and the low-boiling organic solvent so as to obtain an evaporative concentrate of the radioactive metal nuclide.

A method for evaporatively concentrating a radioactive metal nuclide, including: a first evaporative concentration process in which a radioactive solution formed by dissolving a radioactive metal nuclide in an acidic aqueous solution is heated to evaporate a solvent in the radioactive solution so as to obtain a concentrated liquid containing the radioactive metal nuclide; and a second evaporative concentration process in which a low-boiling organic solvent having a lower boiling point than water is added to the concentrated liquid, and the concentrated liquid is heated to induce azeotropic boiling of the concentrated liquid and the low-boiling organic solvent so as to obtain an evaporative concentrate of the radioactive metal nuclide.