Patent ID: 8535487

Claim:
A process for the purification of an aqueous reaction stream coming from a Fischer-Tropsch reaction which comprises (a) feeding the aqueous reaction stream containing one or more organic by-products of the Fischer-Tropsch reaction in a quantity ranging from 0.5 to 7% by weight, to a system consisting of a distillation column, equipped with a partial condenser and a total condenser; (b) vaporizing a part, ranging from 5 to 40% by weight of the aqueous reaction stream inside the distillation column; (c) collecting the vaporized stream from the head of the distillation column in a quantity ranging from 5 to 40% by weight of the aqueous reaction stream, containing the by-products of the Fischer-Tropsch reaction at a concentration ranging from 20 to 80% by weight, and a minimum quantity of water obtainable in relation to the composition of the feeding and operating conditions; (d) condensing a quantity ranging from 0.5 to 15% by weight of the vaporized stream leaving the head of the distillation column in the partial condenser and collecting a first distillate containing water at a concentration varying from 10 to 50% by weight and one or more heavy organic by-products of the organic by-products at a concentration ranging from 30 to 60% by weight; then (e) completely condensing the remainder of the vaporized stream leaving the partial condenser in the total condenser so as to obtain a first liquid stream containing one or more low molecular weight by-products of the organic by-products and water at a concentration ranging from 20% to 50% by weight; (f) sending a portion of the first liquid stream corresponding to 75-98% by weight of the first liquid stream leaving the total condenser back to the distillation column as reflux and collecting a remainder of the first liquid stream, corresponding to 2 to 25% by weight of the first liquid stream leaving the total condenser, as a second distillate; (g) removing a purified aqueous stream from the bottom of the distillation column, containing a residual quantity of one or more non-acid organic compounds lower than 1,000 ppm.