PATENTS

2808.  ROELEN, O., AND FEISST, W.  Catalysts for Benzine Synthesis.  United States Patent 2,447,029, Aug. 17, 1948.  Chem. Abs., vol. 42, 1948, p. 9126.

Improved catalytic materials for reaction of CO and H₂ are provided.  Also means of regenerating these catalysts following a material reduction in activity.  In large-scale benzine synthesis from CO and H₂ the catalysts employed are metals of the Fe group (Fe, Co, Ni), whose active constituents have been precipitated on kieselguhr.  It has been found that certain drawbacks are eliminated by use of CO₂ compounds of Mg as carrier substances insoluble in alkaline solutions for precipitating catalysts of the Fischer-Tropsch benzine synthesis, more particularly for the production of catalysts containing Mg, it having  been found that basic MgCO₃ is particularly suitable.  Method of preparing catalysts involves addition of the carrier mass, that consists of 1 of the Mg compounds previously referred, immediately after precipitation of the metal catalysts, and this is stirred with the precipitant.  Advantage of using MgCO₃ as carrier substance consists in the facility of procuring raw materials.  Furthermore, it is advantageous to work up spent catalysts produced from MgCO₃.  Use of the carrier substances.  according to the invention. is particularly advantageous because no other chemicals are required to dissolve them except the cheap CO₂ that is available in large quantities as waste gas and which.  moreover, may be used in circulation.  Unlike kieselguhr, Mg can be used as often as desired, so that there is practically no loss in carrier mass.  Furthermore, no foreign substances find their way into the catalyst or into the solution from which the catalyst is precipitated.