TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The metal halide comprises RhX3 or IrX3. The rhodium halide is rhodium iodide (RhI3). The iridium halide is iridium iodide (IrI3). The reactor also contains zinc halide and/or indium halide.X = Cl, Br and/or I.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: In addition to methanol and/or dimethyl ether reactants, there is also introduced to the reactor additional feedstock components from hydrocarbons, halogenated hydrocarbons or oxygenated hydrocarbons, especially olefins, dienes, alcohols and ethers. The process is operated in a liquid phase. It is operated at 100-300degreesC, and is performed in the presence of hydrogen. It is a continuous or semi-continuous process for the production of branched chain hydrocarbons from methanol and/or dimethyl ethers, comprising contacting, in a liquid phase reaction composition in the reactor, the methanol and/or dimethyl ether with the catalyst and at a temperature of greater than or equal to100degreesC, to produce a product mixture comprising methanol and/or dimethyl ether and a hydrocarbon reaction product comprising branched chain hydrocarbons, and in which process the catalyst is maintained in the reactor in an active form and in an effective concentration. The catalyst comprising metal halide is be maintained in the active form and in the effective concentration in the reactor by recycling to the reactor one or more promoter compounds, from one or more of hydrogen halides and alkyl halides of 1-8C, from downstream product recovery stage(s).Preferred Components: The reactor contains one or more compounds that can act as initiators for the reaction to produce branched chain hydrocarbons; and one or more promoters from one or more of hydrogen halides and alkyl halides of 1-8C. The initiators are one or more compounds from alcohols, ethers, olefins or dienes having greater than or equal to2C. They are olefins, alcohols and ethers having 2-8C. EXAMPLE - In a dry box, RhI3 (0.484 g), methanol (MeOH, 0.12 ml) and octane (10 mul) were loaded in a heavy-walled Schlenk tube. The tube was taken out of the dry box and immersed in a heated oil bath at the temperature and for a reaction time. After the reaction was completed, the tube was removed from the oil bath and allowed to cool down to room temperature. Dodecane (1 ml) was added to the solid mixture and the suspension filtered through Celite. An aliquot of the solution was diluted 5 times and the mixture was analyzed by gas chromatography (GC), using the octane as an internal standard to determine yields. The yields of triptane and hexamethylbenzene, were 9.0% and 0.9%, respectively.