Patent GB-792757-A (GB)
Title: Improvements in hydroforming
IPC: C10G69/08
Filed: 1956-04-25
Abstract: In a fixed bed hydroforming process the naphtha feed is hydrodesulphurized, for example in the presence of a cobalt molybdate catalyst, to give a naphtha with a sulphur content of 0.0005-0.0015 wt. per cent, the water content is then adjusted to 5-20 parts per million and the chlorine content to 1-10 parts per million and the naphtha is hydroformed in a plurality of separate reaction zones in series in the presence of a fixed bed of a catalyst comprising platinum on alumina, preferably eta-alumina.  In a preferred embodiment the desulphurized naphtha is stripped with an inert gas, such as hydrogen or nitrogen, prior to adjusting the water and chlorine contents which latter process may be carried out by adding water and a chlorine-containing naphtha.  Sulphur may also be added if the content is below 0.0005 wt. per cent.  The inlet temperature to each hydroforming zone is in the range 900-965 DEG  F. and may be gradually raised over a period of time to compensate for gradual catalyst deactivation. In an example a naphtha is hydrodesulphurized over a catalyst containing 12 per cent cobalt molybdate and 85 per cent alumina at 550-700 DEG  F., 400 p.s.i.g. and a WHSV of 2 lb./lb./hr. in the presence of 500-1000 SCF/barrel of feed of hydrogen.  The sulphur content was adjusted to 0.001 wt. per cent. chlorine to 2 parts per million and water to 7 parts per million. This feed was hydroformed at 900-210 DEG  F., 400 p.s.i.g., a WHSV of 1.3 in the presence of 6000 SCF of hydrogencontaining gas per barrel of feed, the hydrogencontaining gas containing 70-90 mol. per cent hydrogen, over a catalyst containing 0.6 wt. per cent platinum and 0.65 wt. per cent chlorine on eta-alumina to give a 86.5 volume per cent yield of a hydroformate having a research octane number of 95. Specification 761,058, [Group III], is referred to.ALSO:In a fixed bed hydroforming process the naphtha feed is hydrodesulphurized, for example in the presence of a cobalt molybdate catalyst, to give a naphtha with a sulphur content of 0.0005-0.0015 wt. per cent, the water content is then adjusted to 5-20 parts per million and the chlorine content to 1-10 parts per million and the naphtha is hydroformed in a plurality of separate reaction zones in series in the presence of a fixed bed of a catalyst comprising platinum on alumina, preferably eta-alumina.  In a preferred embodiment the desulphurized naphtha is stripped with an inert gas, such as hydrogen or nitrogen, prior to adjusting the water and chlorine contents which latter process may be carried out by adding water and a chlorine-containing naphtha.  Sulphur may also be added if the content is below 0.0005 wt. per cent.  The inlet temperature to each hydroforming zone is in the range 900-965 DEG  F. and may be gradually raised over a period of time to compensate for gradual catalyst de-activation. In an example, a naphtha is hydrodesulphurized over a catalyst containing 12 per cent cobalt molybdate and 88 per cent alumina at 550-700 DEG  F., 400 p.s.i.g. and a WHSV of 2 lbs/lb./hr. in the presence of 500-1,000 SCF/barrel of feed of hydrogen.  The sulphur content was adjusted to 0.001 wt. per cent, chlorine to 2 parts per million and water to 7 parts per million.  This feed was hydroformed at 900-910 DEG  F., 400 p.s.i.g., a WHSV of 1.3 in the presence of 6000 SCF of hydrogen-containing gas per barrel of feed, the hydrogen-containing gas containing 70-90 mol. per cent hydrogen, over a catalyst containing 0.6 wt. per cent platinum and 0.65 wt. per cent chlorine on eta-alumina to give an 86.5 volume per cent yield of a hydroformate having a research octane number of 95.  Specification 761,058 is referred to.