The present invention relates to a process for preparing a terephthalic diester by reacting terephthalic acid with at least one alcohol, wherein terephthalic acid is suspended in the alcohol in a dispersing tank, the preliminary suspension is passed from the dispersing tank into a reactor and converted in the presence of an esterification catalyst, and water of reaction is distilled off together with the vapor as alcohol-water azeotrope, the vapor is at least partly condensed, the condensate is separated into an aqueous phase and an organic phase and the organic phase is conducted through a column in which the organic phase is run counter to at least a portion of the vapor, and the organic phase is collected in the lower region of the column and at least partly passed into the dispersing tank.

The present invention relates to a process for preparing a terephthalic diester by reacting terephthalic acid with at least one alcohol, wherein terephthalic acid is suspended in the alcohol in a dispersing tank, the preliminary suspension is passed from the dispersing tank into a reactor and converted in the presence of an esterification catalyst, and water of reaction is distilled off together with the vapor as alcohol-water azeotrope, the vapor is at least partly condensed, the condensate is separated into an aqueous phase and an organic phase and the organic phase is conducted through a column in which the organic phase is run counter to at least a portion of the vapor, and the organic phase is collected in the lower region of the column and at least partly passed into the dispersing tank.

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

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

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

The present invention relates to a production process of a 4-hydroxy-benzoic acid long chain ester, that includes a step of reacting a 4-hydroxy-benzoic acid short chain ester with an aliphatic alcohol in the presence of a metal catalyst. The present invention also relates to a purification process of a 4-hydroxy-benzoic acid long chain ester, that includes a step of adding an acid aqueous solution to a crude composition including the 4-hydroxy-benzoic acid long chain ester, separating the crude composition to an organic phase and a water phase and extracting the organic phase.

The present invention relates to a production process of a 4-hydroxy-benzoic acid long chain ester, that includes a step of reacting a 4-hydroxy-benzoic acid short chain ester with an aliphatic alcohol in the presence of a metal catalyst. The present invention also relates to a purification process of a 4-hydroxy-benzoic acid long chain ester, that includes a step of adding an acid aqueous solution to a crude composition including the 4-hydroxy-benzoic acid long chain ester, separating the crude composition to an organic phase and a water phase and extracting the organic phase.

The present invention relates to a production process of a 4-hydroxy-benzoic acid long chain ester, that includes a step of reacting a 4-hydroxy-benzoic acid short chain ester with an aliphatic alcohol in the presence of a metal catalyst. The present invention also relates to a purification process of a 4-hydroxy-benzoic acid long chain ester, that includes a step of adding an acid aqueous solution to a crude composition including the 4-hydroxy-benzoic acid long chain ester, separating the crude composition to an organic phase and a water phase and extracting the organic phase.

There is described a process and an apparatus for purifying a mixture and related products. In particular, there is described a process and an apparatus for purifying a mixture comprising fats, oils and greases as are typically found in sewer waste. The process involves heating, acidifying and separating the mixture. The apparatus used includes a heating and separation device for separating into a solid fraction, an organic liquid fraction and an aqueous liquid fraction. Apparatus such as a three phase separation unit and a rotary vacuum filter may also be used.

There is described a process and an apparatus for purifying a mixture and related products. In particular, there is described a process and an apparatus for purifying a mixture comprising fats, oils and greases as are typically found in sewer waste. The process involves heating, acidifying and separating the mixture. The apparatus used includes a heating and separation device for separating into a solid fraction, an organic liquid fraction and an aqueous liquid fraction. Apparatus such as a three phase separation unit and a rotary vacuum filter may also be used.