Abstract: The present disclosure relates generally to solid/liquid separation processes. One aspect of the disclosure is a process including filtering a solid/liquid mixture comprising a solid crude aromatic carboxylic acid, a monocarboxylic acid solvent, and minor amounts of an oxidation catalyst in a feed zone of a rotary filter (e.g., a rotary pressure filter), the feed zone having at least two filter zones to form a first feed filtrate comprising monocarboxylic acid solvent and solids; and a second feed filtrate separate from the first feed filtrate, the second feed filtrate comprising monocarboxylic acid solvent and solids, the second feed filtrate being lower in solids than the first feed filtrate; and transferring at least a portion of the first feed filtrate to the reactor zone as recycle.

Abstract: Solid/liquid separation processes using a large pore filter. One aspect of the disclosure is a process comprising filtering a solid/liquid mixture of a collection of solid aromatic carboxylic acid particles in a solvent in a first zone of a rotary pressure filter apparatus to form a filter cake on a filter surface, and removing the filter cake from the filter surface.

Abstract: Processes for recovering a purified aromatic carboxylic acid include contacting a crude aromatic carboxylic acid with hydrogen in the presence of a catalyst in a hydrogenation reactor to form a purified aromatic carboxylic acid; crystallizing the purified aromatic carboxylic acid to form a solid/liquid mixture comprising purified aromatic carboxylic acid solids; filtering the solid/liquid mixture in a rotary pressure filter apparatus to remove a liquid filtrate, washing the solid/liquid mixture in the rotary pressure apparatus with a wash fluid to form a washed solid/liquid mixture, and drying the washed solid/liquid mixture in the rotary pressure apparatus with an inert gas to form a filter cake comprising purified aromatic carboxylic acid solids and a wet gas stream; withdrawing the wet gas stream from the rotary pressure filter apparatus while maintaining the wet gas stream at a pressure above ambient; and recovering the purified aromatic carboxylic acid solids from the filter cake.

Abstract: A rotary pressure filter apparatus, a sealing device for use with the rotary pressure filter apparatus, and a process of using the apparatus. The rotary pressure filter apparatus is designed to treat a solid-liquid mixture under pressure in successive work zones. A rotary drum moves compartments containing the solid-liquid mixture through the successive zones. The zones are separated by a sealing member, which is designed to reduce pressure fluctuations as the compartments enter a successive zone.

Abstract: Processes for recovering a purified aromatic carboxylic acid include contacting a crude aromatic carboxylic acid with hydrogen in the presence of a catalyst in a hydrogenation reactor to form a purified aromatic carboxylic acid; crystallizing the purified aromatic carboxylic acid to form a solid/liquid mixture comprising purified aromatic carboxylic acid solids; filtering the solid/liquid mixture in a rotary pressure filter apparatus to remove a liquid filtrate, washing the solid/liquid mixture in the rotary pressure apparatus with a wash fluid to form a washed solid/liquid mixture, and drying the washed solid/liquid mixture in the rotary pressure apparatus with an inert gas to form a filter cake comprising purified aromatic carboxylic acid solids and a wet gas stream; withdrawing the wet gas stream from the rotary pressure filter apparatus while maintaining the wet gas stream at a pressure above ambient; and recovering the purified aromatic carboxylic acid solids from the filter cake.

Abstract: A rotary pressure filter apparatus, a sealing device for use with the rotary pressure filter apparatus, and a process of using the apparatus. The rotary pressure filter apparatus is designed to treat a solid-liquid mixture under pressure in successive work zones. A rotary drum moves compartments containing the solid-liquid mixture through the successive zones. The zones are separated by a sealing member, which is designed to reduce pressure fluctuations as the compartments enter a successive zone.

Abstract: This invention relates to control or removal of amounts of dissolved iron that may be present in liquid process streams in the manufacture of aromatic acids. The present invention further relates to the control or removal of dissolved iron contaminants present in liquid streams during the manufacture of a crude aromatic acid. The present invention also further relates to the control or removal of dissolved iron contaminants present in liquid streams during the purification of a crude aromatic acid. The present invention also further relates to controlling of decreasing the formation of iron oxides on the surfaces of equipment used during the manufacture of crude aromatic acid and/or purification of crude aromatic acid.

Abstract: This invention relates to control or removal of amounts of dissolved iron that may be present in liquid process streams in the manufacture of aromatic acids. The present invention further relates to the control or removal of dissolved iron contaminants present in liquid streams during the manufacture of a crude aromatic acid. The present invention also further relates to the control or removal of dissolved iron contaminants present in liquid streams during the purification of a crude aromatic acid. The present invention also further relates to controlling of decreasing the formation of iron oxides on the surfaces of equipment used during the manufacture of crude aromatic acid and/or purification of crude aromatic acid.