TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst comprises a transition metal comprising one or more of palladium, platinum, ruthenium, chromium, nickel, copper, zinc, iron, rhodium, manganese and/or molybdenum, deposited on a support substrate.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The product stream from the secondary reactor is brought to a combined cooling and gas/liquid separation device. The separated gas from the gas/liquid separation device is further treated in a gas separation device. The separation device contains molecular sieve or polymer gas membrane separation unit. The lean gas fraction is recycled to the secondary reactor.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process further comprises feeding at least one of the reactant components (a)-(c) through a two-way recuperator which receives as counter stream the product stream from the reactor, to heat one of the reactant components and to cool the product stream. The reactor operates at a pressure below of 3.45 MPa gauge, and a temperature below 210 degrees C. The process further comprises: separating the cooled product stream into a liquid phase fraction which comprises the major products components and minor products components, a gas phase fraction; feeding the gas phase fraction to a purification unit bringing it in contact with water, for removal of undesired gas component from the gas phase fraction, leaving a purified gas phase effluent comprising one or more organic gas phase components and unreacted hydrogen gas; separating components of the liquid phase fraction; recycling the purified gas phase effluent into the reagent mix; separating the cooled product stream into a liquid phase fraction which comprises the major products components and minor products components, a gas phase fraction; and raising the temperature and pressure of the gas phase fraction and feeding to a separate gas phase secondary reactor containing fixed bed catalyst. The purified gas phase effluent is used as a feedstock for hydrogen production, combustion, fed to a gas distribution network or compressed for automotive fuel application. In the method, no gas from the gas phase fraction is recycled back to the reactor. The additional hydrogen is mixed to the gas phase fraction. The gas phase fraction is led through a two-way recuperator which receives the product stream from the reactor as counter stream, to pre-heat the reactant components and to cool the product stream. The organic gas phase components from the product stream from the secondary reactor are concentrated and rejected from the process, leaving a lean gas fraction with enriched concentration of inorganic gas components. The concentrated organic gas fraction containing one or more inorganic gas component impurities, is used as a feedstock for hydrogen production, combustion, fed to gas distribution network or compressed for automotive fuel application. The reactant feedstock is obtained as a side product from biodiesel production. The operating temperature of the reactor is 170-220 degrees C. The reactor charged with catalyst has trickle bed configuration. The step of heating and liquid product separation isolation is realized by means of applying thermal energy and no use of ion exchange or membrane separating devices. Preferred Components: The minor product components comprise at least 3 wt.% of the total combined amount of the obtained major components and the minor components. The molar ratio of the feed hydrogen gas to the reactant feedstock, converted, is below 1:2. The reagent mix further comprises an alkali metal hydroxide as co-catalyst. The solvent comprises water. The reactant feedstock is in a mixture with a solvent, where the solvent has a concentration of more than 50 wt.%. The product stream from the secondary reactor contains at least one mono-hydroxy alcohol. The minor product components consist of one or more of methanol, ethanol, isopropanol, n-propanol, acetone and hydroxyacetone. The reactant feedstock comprises one or more of glycerin, sorbitol, mannitol, arabinitol, xylitol, erythritol, maltitol, and lactitol. The source of thermal energy is geothermal.