METHOD OF PRODUCING ACRYLIC ACID FROM HYDROXYPROPIONIC ACID Russian patent published in 2020 - IPC C07C51/04 C07C51/377 C07C59/08 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing acrylic acid, involving bringing a stream of incoming gaseous materials containing water vapour and hydroxy propionic acid, hydroxy propionic acid derivatives or mixtures thereof, in contact with catalyst in single-layer reactor at certain values of temperature, steam water partial pressure, gas hourly space velocity (GHSV) and weight hour space velocity (WHSV) for dehydration of said hydroxypropionic acid, hydroxypropionic acid derivatives or mixtures thereof with subsequent production of acrylic acid; wherein said catalyst contains a phosphate salt containing a cation and an anion represented by the empirical formula: [H_2(1-x)PO_(4-x)]^-, where x is any real number greater than or equal to 0 and less than or equal to 1; wherein said steam water partial pressure is greater than or equal to 13 bar; wherein said single-layer reactor comprises a wall, an outer surface and an inner surface; wherein said wall is made of wall material, has wall thickness and extends from said outer surface to said inner surface; wherein said wall material contains aluminium in an amount of about 1 wt. % to approximately 50 wt. %; wherein said inner surface is in contact with said catalyst; and wherein the corrosion rate of said single-layer reactor during said dehydration is less than about 1.3 millimeters a year (mm/year).

EFFECT: disclosed is a method of producing acrylic acid from hydroxypropionic acid.

15 cl, 4 dwg, 1 tbl, 11 ex