Electrohydrodimerization process improvement and improved electrolyte recovery process

In a continuous process for hydrodimerization of an olefinic compound having the formula R.sub.2 C.dbd.CR--X wherein --X is --CN, --CONR.sub.2 or --COOR', R is hydrogen or R' and R' is C.sub.1 -C.sub.4 alkyl, to form a dimerized product, which comprises electrolyzing in a reaction cell an aqueous electrolyte solution having dissolved therein at least 0.1% by weight of the olefinic compound, at least 10.sup.-5 gram mol per liter of quaternary ammonium cations of a directive salt and at least 0.1% by weight of conductive salt, the aqueous solution having an organic phase and an aqueous phase, being in contact with the cathodic surface having a cathode potential sufficient for hydrodimerization of the olefinic compound, purging the aqueous solution, recovering dimerized product by extracting with the olefinic compound the dimerized product from the aqueous phase of the purged aqueous solution thereby producing a product extraction comprising the dimerized product and the olefinic compound and leaving a product extraction residue comprising conductive salt;

• extracting with water quaternary ammonium salt from the organic phase of the aqueous solution thereby producing a directive salt extraction comprising quaternary ammonium salt and water and a directive salt extraction residue comprising the dimerized product, and thereafter crystallizing the product extraction residue to recover the conductive salt, and reconstituting the aqueous solution employing the recovered conductive salt and the recovered quaternary ammonium salt, the improvement comprising evaporating the product extraction residue, in an amount not to exceed process water gain, to a conductive salt concentration of 10-30% before crystallizing, thereby minimizing conductive salt loss in the crystallizing step, making up process water balance by substantially reducing water gained in the process including water gained in extracting the quaternary ammonium salt.