To my opinion, it will depend on your catalyst and your desired product, i.e. if you want to use homogeneous catalysis (Ru, Rh, Ir or the recently developed Fe-based catalysts), which is up to date better suited for formaldehyde production) or heterogeneous catalysis for the production of methanol, which requires relatively harsh conditions. There are also promising developments using homogeneous catalysts for methanol when you chose indirect routes to methanol from carbonates carbamates etc. (see Han Z, Rong L, Wu J, Zhang L, Wang Z, et al. (2012) Catalytic  Angew. Chem. Int Ed. Engl. 51: 13041-5. Balaraman E, Gunanathan C, Zhang J, Shimon LJ, Milstein D (2011)  Nat. Chem. 3: 609 - 614.). By using homogeneous catalysis high-pressure autoclaves (Parr or similar) are usually suitable for gas-liquid-phase reactions.

Dear Imre Toth.

thank you for the kindness o replying to my eralier request. Within a process scheme we are assuming fixed bed or bubble-bed reactors which are very common in industrial CO-based FT synthesis,

Our present objectives were short chain and fuel-type hydrocarbons as are usually obtained in industrial FT synthesis. This can be also achieved  by carbon dioxide hydrogenation as we have recently shown (Baerns and associates(ChemCatChem 2013 and Chem.Ing.Techn. 2014). A respective patent is presently pending.

Thanks again for your kind interest.

Manfred Baerns