Abstract: A process for monitoring and controlling reactor conditions during the production of acetic acid by the catalyzed carbonylation of methanol is provided. The process of the present invention comprises measuring the density of the heavy phase of the light ends distillation column in the purification system of the carbonylation process. The density measurement is used to adjust the feed of methanol and/or to regulate the temperature in the reaction zone to optimize reactor conditions. The density measurement may also be used to adjust other parameters in the reactor system. The invention is also directed to the system for manufacturing acetic acid based on the process control procedure described.

Abstract: A method and system is provided for producing acetic acid by the catalytic carbonylation of methanol with carbon monoxide to obtain a reaction product stream comprising acetic acid and a minor amount of acetaldehyde. The acetaldehyde content in the reaction product stream is reduced by oxidation to convert at least a portion of the acetaldehyde in the stream to acetic acid or further to CO2 and H2O. The oxidized stream may then be directed to the purification section, the reaction section, or both whereby the deleterious effects of acetaldehyde are reduced. Advantage of the present invention over conventional processes is the reduced need to dispose of acetaldehyde as waste and improved overall system efficiency in the production of acetic acid.

Abstract: A method and system is provided for producing acetic acid by the catalytic carbonylation of methanol with carbon monoxide to obtain a reaction product stream comprising acetic acid and a minor amount of acetaldehyde. The acetaldehyde content in the reaction product stream is reduced by oxidation to convert at least a portion of the acetaldehyde in the stream to acetic acid or further to CO2 and H2O. The oxidized stream may then be directed to the purification section, the reaction section, or both whereby the deleterious effects of acetaldehyde are reduced. Advantage of the present invention over conventional processes is the reduced need to dispose of acetaldehyde as waste and improved overall system efficiency in the production of acetic acid.

Abstract: A method and apparatus for sequestering entrained or volatile catalyst species in a carbonylation process includes contacting the product stream with a vinyl pyridine or a vinyl pyrrolidone resin bed which is operative to sequester entrained or volatile catalytic species. The invention is particularly useful in connection with the iridium catalyzed carbonylation of methanol wherein the loss of entrained or volatile catalyst species depletes the catalytic content of the reactor. The resin may be digested in order to recover the catalytic metals.

Abstract: A process for monitoring and controlling reactor conditions during the production of acetic acid by the catalyzed carbonylation of methanol is provided. The process of the present invention comprises measuring the density of the heavy phase of the light ends distillation column in the purification system of the carbonylation process. The density measurement is used to adjust the feed of methanol and/or to regulate the temperature in the reaction zone to optimize reactor conditions. The density measurement may also be used to adjust other parameters in the reactor system. The invention is also directed to the system for manufacturing acetic acid based on the process control procedure described.

Abstract: An improvement to methanol carbonylation processes utilizing a homogeneous iridium catalyst system comprises adding a rate-promoting amount of an insoluble pyridine ring-containing polymer. Typically, polyvinylpyridine is added to the reactor in amounts of up to about 2 wt. percent.

Abstract: The method of the present invention provides an improvement upon prior art methanol carbonylation methods which substantially reduces the production of carbonyl impurities. The production of carbonyl impurities, particularly acetaldehyde, crotonaldehyde, and 2-ethyl crotonaldehyde, in methanol carbonylation reactions has been found to decrease by maintaining less than about 4.5 wt % methyl iodide in the reaction medium during the course of the reaction.

Abstract: The present invention provides a process for the carbonylation of an alcohol, ether or ester to products comprising a carboxylic acid, the anhydride thereof or coproduction of the carboxylic acid and anhydride. More particularly, the present invention provides a process for the carbonylation of methanol to produce acetic acid by reacting methanol with carbon monoxide in a liquid reaction medium containing a catalyst comprising rhodium, iridium, iodide ion, and said reaction medium further comprising water, acetic acid, methyl iodide, and methyl acetate and subsequently recovering acetic acid from the resulting reaction product.

Abstract: Disclosed is a process to produce paraformaldehyde prills having a low dissolution time and low concentration of insoluble formation. The insolubles are believed to lead to stickiness, tackiness, and loss of flowability of the product, loss of handling, and lead to storage problems of the final prill product. To address this problem, a concentrated formaldehyde solution is prepared having a purity ranging from 37%-99% and may be mixed with an amine additive, an amine and alcohol additive, or amine, alcohol, and caustic additive. Alternatively, the final prill may be sprayed with an amine or amine mixture stabilizer.

Abstract: This invention relates to a process for improving the color of trimethylolpropane (TMP) by extracting color-causing impurities generated in the reaction to produce TMP. This improved color TMP is characterized by a reduced acid wash color and phthalic anhydride color--color measurement tests commonly used in the industry for assessing product quality and suitability of the TMP for certain color sensitive end-uses.