The present disclosure relates to a catalyst for dehydration of glycerin, a preparation method thereof, and a production method of acrolein using the catalyst. Particularly, the catalyst according to an embodiment of the present disclosure is used in a dehydration reaction of glycerin to exhibit high catalytic activity, a high yield, and high selectivity to acrolein and acrylic acid, and has a longer lifetime compared to the conventional catalysts due to a characteristic that coke carbon cannot be easily deposited on the surface of the catalyst.

A process for continuous, on-demand production of dilute acrolein liquid on-site, at or near the point of acrolein injection, by the liquid dehydration of glycerol in an improved tubular reactor where non-aqueous glycerol is combined with a heteropolyacid catalyst, including silicotungstic acid, phosphotungstic acid, or phosphomolybdic acid. The acid catalyst is evenly dissolved and dispersed in the glycerol upstream of the reactor vessel. The reaction is conducted in a tubular reactor which is heated to an elevated reaction temperature. The dilute acrolein produced in the tubular reactor is directed downstream, optionally through a liquid-liquid heat exchanger and then an air-liquid heat exchanger to reduce temperature, and then diluted prior to being injected into sulfide contaminated systems (such as oil & gas water floods, water disposal systems, producing oil wells, and fuel oil storage) via a pressure conduit.

A process for continuous, on-demand production of dilute acrolein liquid on-site, at or near the point of acrolein injection, by the liquid dehydration of glycerol in an improved tubular reactor where non-aqueous glycerol is combined with a heteropolyacid catalyst, including silicotungstic acid, phosphotungstic acid, or phosphomolybdic acid. The acid catalyst is evenly dissolved and dispersed in the glycerol upstream of the reactor vessel. The reaction is conducted in a tubular reactor which is heated to an elevated reaction temperature. The dilute acrolein produced in the tubular reactor is directed downstream, optionally through a liquid-liquid heat exchanger and then an air-liquid heat exchanger to reduce temperature, and then diluted prior to being injected into sulfide contaminated systems (such as oil & gas water floods, water disposal systems, producing oil wells, and fuel oil storage) via a pressure conduit.

The invention pertains to a process for preparing a compound of formula (1)

##STR00001## wherein R.sub.1 is independently chosen from C.sub.1-C.sub.6 alkyl, cycloalkyl, aralkyl and aryl, and R.sub.2, R.sub.3 and R.sub.4 are independently chosen from hydrogen and C.sub.1-C.sub.6 alkyl, cycloalkyl, aralkyl and aryl; which process comprises the steps of: a) contacting a compound of formula (2)

##STR00002## wherein R.sub.1 and R.sub.2 are as above and M.sup.+ is a monovalent metal ion, with a compound of formula (3)

##STR00003## wherein R.sub.3 and R.sub.4 are as above, to form a compound of formula (4)

##STR00004## and b) followed by contacting the compound of formula (4) with an acid to give a compound of formula (1), wherein step (a) and/or step (b) are conducted in continuous mode.

The invention pertains to a process for preparing a compound of formula (1)

##STR00001## wherein R.sub.1 is independently chosen from C.sub.1-C.sub.6 alkyl, cycloalkyl, aralkyl and aryl, and R.sub.2, R.sub.3 and R.sub.4 are independently chosen from hydrogen and C.sub.1-C.sub.6 alkyl, cycloalkyl, aralkyl and aryl; which process comprises the steps of: a) contacting a compound of formula (2)

##STR00002## wherein R.sub.1 and R.sub.2 are as above and M.sup.+ is a monovalent metal ion, with a compound of formula (3)

##STR00003## wherein R.sub.3 and R.sub.4 are as above, to form a compound of formula (4)

##STR00004## and b) followed by contacting the compound of formula (4) with an acid to give a compound of formula (1), wherein step (a) and/or step (b) are conducted in continuous mode.

Disclosed herein is a method useful in the process of contacting a first product that includes ethylene glycol, propylene glycol, and glycerol with the catalyst composition, thereby producing a second product that includes acrolein and acetaldehyde.

Disclosed herein is a method useful in the process of contacting a first product that includes ethylene glycol, propylene glycol, and glycerol with the catalyst composition, thereby producing a second product that includes acrolein and acetaldehyde.

Disclosed herein is a method useful in the process of contacting a first product that includes ethylene glycol, propylene glycol, and glycerol with the catalyst composition, thereby producing a second product that includes acrolein and acetaldehyde.

The present invention relates to a method for preparing acrylic acid from glycerin. More specifically, the present invention provides a method which can improve the selectivity of acrolein by applying a specific catalyst composition and process conditions to minimize the generation of coke carbon of the catalyst, and can prepare acrylic acid with higher productivity for a longer duration of time because a dehydration reaction can be performed for a longer working period while maintaining catalyst activity at a high level during the reaction.

The present invention relates to a method for preparing acrylic acid from glycerin. More specifically, the present invention provides a method which can improve the selectivity of acrolein by applying a specific catalyst composition and process conditions to minimize the generation of coke carbon of the catalyst, and can prepare acrylic acid with higher productivity for a longer duration of time because a dehydration reaction can be performed for a longer working period while maintaining catalyst activity at a high level during the reaction.