NOVELTY - Recovering (P1) a volatile organic compound from a feed mixture involves: introducing feed mixture into a fractional condensation apparatus; fractionally condensing the feed mixture in the fractional condensation apparatus to form a first condensed fluid and a first vapor, where the feed mixture having temperature of 30-60 degrees C before fractional condensing; condensing the first vapor in a top condenser to form a second condensed fluid and a second vapor, where the top condenser having a temperature of 6-11 degrees C; and condensing second vapor in a product condenser to form a cold product stream.    USE - For recovering a volatile organic compound from a feed mixture, where the volatile organic compound is ethanol (claimed).    ADVANTAGE - The process recovers volatile products from highly diluted liquid and vapor feed mixtures with high purity and recovery yield, both in batch and continuous distillation; provides low-cost and efficient recovery process; provides high productivity and substantially reduced energy costs so that lowering capital and operational cost; provides reducing energy consumption to 1 MJ/Kg product by energy integration; provides recovering volatile products at a savings of primary energy unit (PEU) 1.36 MJ/Kg product for mesophiles and 1.05 MJ/Kg product for thermophiles; and reduces water loss so that maintaining the water level during operation by recirculation of the water that has been separated from the volatile organic product for renewed use e.g. in the photobioreactor(s).    DETAILED DESCRIPTION - Recovering (P1) a volatile organic compound from a feed mixture involves: introducing the feed mixture into a fractional condensation apparatus; fractionally condensing the feed mixture in the fractional condensation apparatus to form a first condensed fluid and a first vapor, where the feed mixture having a temperature of 30-60 degrees C before fractional condensing; condensing the first vapor in a top condenser to form a second condensed fluid and a second vapor, where the top condenser having a temperature of 6-11 degrees C; and condensing the second vapor in a product condenser to form a cold product stream, where the product condenser having a temperature that is below the temperature of the top condenser, where the feed mixture contains the volatile organic compound (1-5 mol.%), water (5 mol.%), and gases (90 mol.%) selected from N2, O2 and/or CO2, where a concentration of the volatile organic compound in the cold product stream of 80 wt.% and a recovery of 60 wt.% is obtained. INDEPENDENT CLAIMS are included for following:    (1) a fractional condensation apparatus (A1) for recovering a compound from a feed mixture;    (2) a multi-sectional modular distillation system (S1) for recovering a compound from a feed mixture having several apparatuses (A1) connected to allow flow of the feed mixture through the apparatuses;    (3) a fractional condensation column (C1) for recovering a compound from a feed mixture comprising a column jacket; a fluid tube positioned centrally within the column and along the length of the column; and first packing material between the column jacket and the fluid tube;    (4) a multi-sectional modular distillation system (S2) for recovering a compound from a feed mixture having several column (C1) connected to allow flow of the feed mixture through the apparatuses;    (5) recovering (P2) a compound from a feed mixture;    (6) recovering (P3) a compound from a feed mixture;    (7) recovering (P4) a compound from a feed mixture;    (8) recovering (P5) a compound from a feed mixture involving flowing the feed mixture through a bottom inlet of the multi-sectional modular distillation system (S2) into a fractional condensation volume of a first fractional condensation column; controlling, independently, temperature profiles of the column jackets and the fluid tubes of the fractional condensation columns of the multi-sectional modular distillation system to provide an internal temperature profile within the fractional condensation volumes within several columns, extending from the bottom inlet of the first fractional condensation column to a top outlet of a last fractional condensation column, which is effective to recover the compound from the feed mixture at the top outlet with improved purity; and collecting the compound at the top outlet;    (9) producing (P7) carbon-based products of interest involving culturing microorganisms in a photobioreactor under suitable conditions using light, CO2 and water to produce carbon-based products of interest; and recovering the products from the photobioreactor by (i) introducing a feed mixture comprising the products of at least 1.5 wt.% into a fractional condenser, (ii) separating the volatile products at optimal operating conditions, and (iii) withdrawing the product at a concentration of 90.4% recovery yield and 90 wt.% concentration;    (10) an apparatus (A2) for recovering volatile products comprising a unit for introducing a feed mixture comprising at least one volatile product of 1.5 wt.% into a fractional condenser; a unit for separating the volatile products at optimized operating conditions; and a unit for withdrawing the product at a concentration of 90.4% recovery yield and 90 wt.% concentration;    (11) a solar biofactory system (S3) comprising a photobioreactor apparatus; organisms adapted to convert light, water and carbon dioxide into carbon-based products of interest; optimized media; and apparatus (A2), where the organisms are cultured in the optimized media under suitable conditions in the photobiorector to produce the products and the products are recovered using the apparatus for recovering products;    (12) a reactive distillation apparatus (A3) comprising an enclosure providing a fractional condensation volume and a reactive zone, where the enclosure having an internal surface in contact with the fractional condensation volume, where the temperature of the internal surface is controllable, and the enclosure having an inlet adapted for receiving a feed mixture and an outlet for providing a recovered product; a second surface positioned centrally within the fractional condensation volume, where the temperature of the second surface is controllable; and first packing material between the internal surface and the second surface;    (13) a multi-sectional modular reactive distillation comprising several apparatuses (A3), where each apparatus is modular, and the apparatuses are connected in series to form a fractional condensation volume extending substantially throughout the connected apparatuses, where thefractional condensation volume containing a reaction zone.