MANUFACTURE OF VINYL CHLORIDE MONOMER FROM RENEWABLE MATERIALS, VINYL CHLORIDE MONOMER THUS-OBTAINED, AND USE

1 . Process for the manufacture of vinyl chloride monomer comprising the following stages:

a) preparation of acetylene from one or more renewable starting materials, then

b) reaction of the acetylene with hydrogen chloride to form vinyl chloride monomer.

2 . Process according to claim 1 , characterized in that the acetylene is prepared according to the following stages:

a) reduction of calcium oxide by carbon resulting from one or more renewable starting materials, in order to form calcium carbide, then

b) hydrolysis of the calcium carbide in order to form acetylene.

3 . Process according to claim 2 , characterized in that the renewable starting material or materials are chosen from wood charcoal, wood tar, in particular from pine or from straw, heavy residues from the pyrolysis of biomass, in particular of straw, cellulose, straw, wood and lignin.

4 . Process according to claim 2 , characterized in that the reduction of calcium oxide by carbon in order to form calcium carbide is carried out in a closed furnace equipped with three electrodes.

5 . Process according to claim 2 , characterized in that the hydrolysis of calcium carbide in order to form acetylene comprises the following stages:

calcium carbide is introduced into a perforated cylinder, then

water is sprayed into the said cylinder, then

the acetylene formed is subjected to a further spraying with water in a washing tower, then

the acetylene is cooled to a temperature of less than 0° C., preferably of between −5° C. and −15° C., better still of the order of −10° C., in order to condense most of the water, then

the acetylene is purified by contact with sulphuric acid and then with sodium hypochlorite, then

the acetylene is cooled, preferably to 0° C., in order to carry out a further separation of the water.

6 . Process according to claim 1 , characterized in that the acetylene is produced from one or more hydrocarbons resulting from one or more renewable starting materials by a process comprising a stage of transfer of energy to the said hydrocarbon(s) and then a stage of quenching.

7 . Process according to claim 6 , characterized in that the transfer of energy takes place by direct transfer of heat by means of an electric arc or of a plasma, or else by indirect transfer of heat by means of contact bodies or of steam, or else by an autothermal process.

8 . Process according to claim 6 , characterized in that the renewable starting material or materials are chosen from biomass pyrolysis tars and biogases.

9 . Process according to claim 1 , characterized in that the reaction of the acetylene with hydrogen chloride is carried out in the presence of a catalyst based on mercury chloride on a support.

10 . Process according to claim 1 , characterized in that the reaction of the acetylene with hydrogen chloride is carried out in the presence of a liquid catalytic system comprising at least one compound of a metal from Group VIII, a fatty amine hydrochloride, the melting point of which is greater than 25° C., and an organic solvent chosen from aliphatic, cycloaliphatic and aromatic hydrocarbons and their mixtures.

11 . Process according to claim 10 , characterized in that the fatty amine hydrochloride comprises from 10 to 20 carbon atoms.

12 . Process according to claim 10 , characterized in that the compound of a metal from Group VIII is chosen from palladium compounds and platinum compounds.

13 . Process according to claim 10 , characterized in that the ratio by volume of the solvent to the fatty amine hydrochloride varies from 0.1 to 20.

14 . Process according to claim 10 , characterized in that the content of compound of a metal from Group VIII, expressed in millimoles per litre of the catalytic system, is greater than or equal to 1 mmol/l and less than or equal to 200 mmol/l.

15 . Process according to claim 1 , characterized in that the reaction of the acetylene with hydrogen chloride is carried out at a temperature of between 80° C. and 180° C.

16 . Process according to claim 1 , characterized in that the hydrogen chloride and the acetylene are employed in a molar ratio of approximately 0.5 to 3.

17 . Process according to claim 1 , characterized in that it comprises a stage of preparation of vinyl chloride monomer from ethylene obtained from one or more renewable starting materials.

18 . Process according to claim 17 , characterized in that the preparation of vinyl chloride monomer is carried out by conversion of the ethylene to dichloroethane by direct chlorination and then cracking of the dichloroethane in order to form vinyl chloride monomer.

19 . Vinyl chloride monomer, in which at least a portion of the carbon atoms is of renewable origin.

20 . Vinyl chloride monomer, capable of being obtained by the process as defined in claim 1 .

21 . Vinyl chloride monomer according to claim 19 , characterized in that it comprises an amount of carbon resulting from renewable materials of greater than 20%, preferably of greater than 50%, better still of greater than 70%, by weight with respect to the total weight of carbon of the vinyl chloride monomer.

22 . Composition comprising the vinyl chloride monomer according to claim 19 .

23 . Use of the vinyl chloride monomer according to claim 19 in the manufacture of polymers, in particular of polyvinyl chloride.