Patent ID: 8809601
Filing Date: 2014-08-19
Classification: C01F,C01P,C07C

Abstract:
1. A process for the continuous or semicontinuous manufacture of a (hydro)fluoroolefin compound comprising (i) bringing at least one compound comprising from three to six carbon atoms, at least two fluorine atoms and at least one hydrogen atom, provided that at least one hydrogen atom and one fluorine atom are situated on adjacent carbon atoms, into contact with potassium hydroxide in an aqueous reaction medium in a stirred reactor equipped with at least one inlet and with at least one outlet, to yield the (hydro)fluoroolefin compound and potassium fluoride, wherein the (hydro)fluoroolefin compound is separated from the reaction medium in the gaseous form, (ii) bringing the potassium fluoride formed in stage (i) into contact in an aqueous medium with calcium hydroxide in a second reactor to yield potassium hydroxide and calcium fluoride precipitate, (iii) separating the calcium fluoride precipitated in stage (ii) from the reaction medium in stage (ii), wherein potassium hydroxide present in the reaction medium of stage (ii) represents between 10 and 35% by weight, with respect to the weight of the water and potassium hydroxide mixture of the reaction medium; and (iv) optionally recycling the reaction medium from stage (ii) to stage (i) after optional adjustment of the concentration of potassium hydroxide.