초록 ▼

A hydrocarbon conversion catalyst contains at least one silica-alumina having the following characteristics: A content by weight of silica SiO2of between 10 and 60% by weight; an Na content less than 300 ppm by weight; a total pore volume of between 0.5 and 1.2 m/g measured by mercury porosimetry; a

A hydrocarbon conversion catalyst contains at least one silica-alumina having the following characteristics: A content by weight of silica SiO2of between 10 and 60% by weight; an Na content less than 300 ppm by weight; a total pore volume of between 0.5 and 1.2 m/g measured by mercury porosimetry; a porosity of said silica-alumina wherein: the volume of mesopores whose diameter is between 40 ∠st; and 150 ∠st;, and whose mean diameter varies between 80 and 120 ∠st; represents between 30 and 80% of the total pore volume, and (ii) the volume of macropores, whose diameter is greater than 500 ∠st; and preferably between 1000 ∠st; and 10,000 ∠st; represents between 20 and 80% of the total pore volume; a specific surface area greater than 200 m2/g, and at least one hydro-dehydrogenating element selected metals of group VIB and group VIII, and optionally phosphorus, boron, silicon, or elements of group VIIA, VIIB or VB.

대표청구항 ▼

A hydrocarbon conversion catalyst contains at least one silica-alumina having the following characteristics: A content by weight of silica SiO2of between 10 and 60% by weight; an Na content less than 300 ppm by weight; a total pore volume of between 0.5 and 1.2 m/g measured by mercury porosimetry; a

A hydrocarbon conversion catalyst contains at least one silica-alumina having the following characteristics: A content by weight of silica SiO2of between 10 and 60% by weight; an Na content less than 300 ppm by weight; a total pore volume of between 0.5 and 1.2 m/g measured by mercury porosimetry; a porosity of said silica-alumina wherein: the volume of mesopores whose diameter is between 40 ∠st; and 150 ∠st;, and whose mean diameter varies between 80 and 120 ∠st; represents between 30 and 80% of the total pore volume, and (ii) the volume of macropores, whose diameter is greater than 500 ∠st; and preferably between 1000 ∠st; and 10,000 ∠st; represents between 20 and 80% of the total pore volume; a specific surface area greater than 200 m2/g, and at least one hydro-dehydrogenating element selected metals of group VIB and group VIII, and optionally phosphorus, boron, silicon, or elements of group VIIA, VIIB or VB. ontinuously providing the solution containing metal ions to the electrochemical cell from a fluid source and the step of continuously removing the permeate.14. A method according to claim 11 wherein the step of is accomplished with a nanofilter operative to retain said metal ions.15. A method according to claim 11 wherein the solution is agitated in the region proximate to said cathode.16. A method according to claim 11 wherein said metal ions are divalent copper ions.17. A system for reducing metal ions in a solution to their corresponding elementary metals, comprising: (a) a fluid source operative to provide a solution containing metal ions at a selected concentration; (b) a reservoir in fluid communication with said fluid source and operative to receive the solution; (c) an anode disposed in said reservoir; (d) a cathode disposed in said reservoir; (e) a power source operative to supply electric current to said anode and said cathode; (f) a filter in fluid communication with said reservoir and including a membrane, said filter having a first region on one side of said membrane and a second region on an opposite side of said membrane; (g) a retentate of the solution disposed in the first region of the filter, said retentate having a first concentration of metal ions; (h) a permeate of the solution disposed in the second region of the filter, said permeate having a second concentration of metal ions lower than the first concentration; and (i) a return means operative to return said retentate to said reservoir. 18. A system according to claim 17 wherein the solution is constantly drawn from a region proximate said cathode and provided to said filter.19. A system according to claim 18 wherein said fluid source constantly provides the solution.20. A system according to claim 17 wherein said filter is a crossflow membrane filter.21. A system according to claim 17 wherein said membrane is a nanofilter membrane.22. A system according to claim 17 including a pump in fluid communication with said filter and operative to provide the solution to said filter at a selected fluid pressure.23. A system according to claim 17 wherein said retentate includes a first portion of the solution which does not pass through said membrane and wherein said permeate is formed by passing a second portion of the solution through said membrane.24. A system according to claim 17 wherein gravity is operative to return said retentate to said reservoir.25. In an electrowinning cell operative to reduce metal ions at a selected concentration in a solution at a location proximate to a cathode in a reservoir to their corresponding elementary metals, the improvement comprising a filter apparatus in fluid communication with said reservoir and operative to draw the solution from a region proximate to said cathode and to filter the solution into a first portion having a first concentration of metal ions greater than the selected concentration and a second portion having a second concentration of metal ions lower than the selected concentration, said filter apparatus further operative to return the first portion to said reservoir. 26. The improvement according to claim 25 wherein said filter apparatus includes a filter, a valve, a conduit and a pump.27. The improvement according to claim 26 wherein said filter includes a membrane filter of the nanofiltration range.28. An electrowinning cell adapted to recover metal ions from a solution as their corresponding elementary metals, comprising: (a) a reservoir adapted to receive a solution containing metal ions at a selected concentration; (b) an anode and a cathode disposed in said reservoir, said anode and cathode operative to establish an electric potential difference therebetween; (c) a first conduit in fluid communication with said reservoir and having an inlet and an outlet, wherein said inlet of said first conduit is proximate to said cathode and is operative to receive the solution