There is provided a method for producing a C.sub.2-C.sub.20 fluorine-containing organic acid with reduced fluorine-free organic compound. A method for producing a C.sub.2-C.sub.20 fluorine-containing organic acid, the method including contacting a mixture containing a C.sub.2-C.sub.20 fluorine-containing organic acid and a fluorine-free organic compound with a concentrated sulfuric acid and then separating a C.sub.2-C.sub.20 fluorine-containing organic acid phase from a concentrated sulfuric acid phase. The contacting is conducted such that an amount of water present in the concentrated sulfuric acid phase is 10% by mass or less, and the C.sub.2-C.sub.20 fluorine-containing organic acid is obtained in the form of the C.sub.2-C.sub.20 fluorinated organic acid phase having a reduced content ratio of the fluorine-free organic compound compared with said mixture.

There is provided a method for producing a C.sub.2-C.sub.20 fluorine-containing organic acid with reduced fluorine-free organic compound. A method for producing a C.sub.2-C.sub.20 fluorine-containing organic acid, the method including contacting a mixture containing a C.sub.2-C.sub.20 fluorine-containing organic acid and a fluorine-free organic compound with a concentrated sulfuric acid and then separating a C.sub.2-C.sub.20 fluorine-containing organic acid phase from a concentrated sulfuric acid phase. The contacting is conducted such that an amount of water present in the concentrated sulfuric acid phase is 10% by mass or less, and the C.sub.2-C.sub.20 fluorine-containing organic acid is obtained in the form of the C.sub.2-C.sub.20 fluorinated organic acid phase having a reduced content ratio of the fluorine-free organic compound compared with said mixture.

Methods for making acrylic acid, acrylic acid derivatives, or mixtures thereof by contacting a feed stream containing lactic acid, lactic acid derivatives, or mixtures thereof with a molten salt catalyst comprising an ionic liquid (IL) and an acid in liquid phase are provided.

Methods for making acrylic acid, acrylic acid derivatives, or mixtures thereof by contacting a feed stream containing lactic acid, lactic acid derivatives, or mixtures thereof with a molten salt catalyst comprising an ionic liquid (IL) and an acid in liquid phase are provided.

There is provided a method for producing a C2-C20 fluorine-containing organic acid with reduced fluorine-free organic compound. A method for producing a C2-C20 fluorine-containing organic acid, wherein the method comprises contacting a mixture containing a C2-C20 fluorine-containing organic acid and a fluorine-free organic compound with a concentrated sulfuric acid and then separating a C2-C20 fluorine-containing organic acid phase from a concentrated sulfuric acid phase, wherein the contacting is conducted such that an amount of water present in the concentrated sulfuric acid phase is 10% by mass or less, and the C2-C20 fluorine-containing organic acid is obtained in the form of the C2-C20 fluorinated organic acid phase having a reduced content ratio of the fluorine-free organic compound compared with said mixture.

There is provided a method for producing a C2-C20 fluorine-containing organic acid with reduced fluorine-free organic compound. A method for producing a C2-C20 fluorine-containing organic acid, wherein the method comprises contacting a mixture containing a C2-C20 fluorine-containing organic acid and a fluorine-free organic compound with a concentrated sulfuric acid and then separating a C2-C20 fluorine-containing organic acid phase from a concentrated sulfuric acid phase, wherein the contacting is conducted such that an amount of water present in the concentrated sulfuric acid phase is 10% by mass or less, and the C2-C20 fluorine-containing organic acid is obtained in the form of the C2-C20 fluorinated organic acid phase having a reduced content ratio of the fluorine-free organic compound compared with said mixture.

A treatment method of at least partially removing impurities from a composition containing a fluorine-containing organic acid having the carbon number of 2 to 7 and impurities, the method including a flocculant mixing step of mixing the composition and a flocculant; and a separating step of separating a mixed phase obtained at the mixing step into a solid phase and a liquid phase.

A treatment method of at least partially removing impurities from a composition containing a fluorine-containing organic acid having the carbon number of 2 to 7 and impurities, the method including a flocculant mixing step of mixing the composition and a flocculant; and a separating step of separating a mixed phase obtained at the mixing step into a solid phase and a liquid phase.

Catalysts for the dehydration of lactic acid, lactic acid derivatives, or mixtures thereof to acrylic acid, acrylic acid derivatives, or mixtures thereof in liquid phase comprising an ionic liquid (IL) and an acid are provided.

Catalysts for the dehydration of lactic acid, lactic acid derivatives, or mixtures thereof to acrylic acid, acrylic acid derivatives, or mixtures thereof in liquid phase comprising an ionic liquid (IL) and an acid are provided.