1.-11. (canceled)
12. A compound represented by the following structural formula:
13. A solid phase matrix represented by the general formula:
M-SP-L,
wherein M designates the matrix backbone, SP designates a spacer, and L designates a ligand represented by the following structural formulas:
14. The solid phase matrix of claim 2, wherein the matrix backbone is agarose.
15. The solid phase matrix of claim 2, wherein the spacer SP is represented by the following formula:
\u2014(O\u2014CH2CH(OH)\u2014CH2)m\u2014, wherein m is an integer from 1 to 10.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A process for adiabatically prereforming a feedstock, said process comprising:
providing an adiabatic reactor;
providing a catalyst comprising 1 to 20 wt. % nickel and 0.4 to 5 wt. % potassium, wherein the catalyst has an overall catalyst porosity of 25 to 50%, wherein 20 to 80% of the overall catalyst porosity is contributed by pores having pore diameters of at least 500 \u212b;
providing the feedstock comprising natural gas and steam, wherein the natural gas contains an initial concentration of higher hydrocarbons, and a ratio of steam to natural gas in the feedstock is from 1.5:1 to 5:1;
preheating the feedstock to a temperature of 300 to 700\xb0 C. to provide a heated feedstock;
providing the heated feedstock to the reactor; and
producing a product comprising hydrogen, carbon monoxide, carbon dioxide, unreacted methane, and steam, wherein said product contains a reduced concentration of higher hydrocarbons less than the initial concentration of higher hydrocarbons, to prereform the feedstock:
2. The process of claim 1, further comprising feeding the product to a fired steam-methane reformer to further reform the product.
3. The process of claim 1, wherein the natural gas is desulfurized to a sulfur content of less than about 100 ppb before providing the feedstock to the reactor.
4. The process of claim 1, wherein the natural gas is desulfurized to a sulfur content of less than about 30 ppb before providing the feedstock to the reactor.
5. The process of claim 1, wherein the feedstock contains hydrogen gas.
6. The process of claim 5, wherein the feedstock contains more than about 0.2% hydrogen gas.
7. The process of claim 1, wherein the catalyst comprises 5 to 20 wt. % nickel.
8. The process of claim 1, wherein the catalyst comprises 10 to 20 wt. % nickel.
9. The process of claim 1, wherein the catalyst is supported on calcium aluminate.
10. The process of claim 1, wherein the catalyst is supported on magnesium aluminate.
11. The process of claim 1, wherein the catalyst has an overall porosity of 30 to 45%.
12. The process of claim 1, wherein 50 to 80% of the catalyst porosity is contributed by pores having pore diameters of at least 500 \u212b.
13. The process of claim 1, wherein the catalyst has a median pore diameter of 1000 \u212b to 5000 \u212b.
14. The process of claim 1, wherein the catalyst has a median pore diameter of 1500 \u212b to 3000 \u212b.
15. The process of claim 1, wherein the catalyst has a nitrogen BET surface area from 2 to 10 m2g
16. The process of claim 1, wherein the catalyst has a nitrogen BET surface area from 2 to 8 m2g.
17. The process of claim 1, wherein the catalyst contains 0.4 to 2 wt. % potassium.
18. The process of claim 1, wherein the catalyst contains 0.5 to 1.5 wt. % potassium.
19. The process of claim 1, wherein the catalyst has a particle diameter from 1 mm to 50 mm.
20. The process of claim 1, wherein the catalyst has a particle diameter from 6 mm to 50 mm.
21. The process of claim 1, wherein a mixture of nitrogen gas and hydrogen gas is provided to the reactor prior to providing the feedstock to the reactor, to reduce the catalyst inside the reactor.
22. The process of claim 21, wherein the mixture of nitrogen gas and hydrogen gas contains a concentration of hydrogen ranging from 0.5 to 50%.
23. The process of claim 1, wherein a concentration of methane in the natural gas is 85 to 99.9%.
24. The process of claim 1, wherein an initial concentration of higher hydrocarbons in the natural gas is 1 to 15%.
25. The process of claim 1, wherein a concentration of ethane in the natural gas is 0.1 to 10%, a concentration of propane in the natural gas is 0.1 to 5%, and a concentration of butane in the natural gas is 0.1 to 2%.
26. The process of claim 1, wherein the ratio of steam to natural gas in the feedstock ranges from 1.5:1 to 3:1.
27. The process of claim 1, wherein the reduced concentration of higher hydrocarbons is 70% less than the initial concentration of higher hydrocarbons.
28. The process of claim 1, wherein the reduced concentration of higher hydrocarbons is 80% less than the initial concentration of higher hydrocarbons.
29. The process of claim 1, wherein the reduced concentration of higher hydrocarbons is 90% less than the initial concentration of higher hydrocarbons.
30. The process of claim 1, wherein at least one additional prereforming catalyst is included in the reactor in addition to the catalyst of claim 1.
31. The process of claim 30, wherein the additional catalyst is placed in a top portion of the reactor, above the catalyst of claim 1, and the feedstock is preheated to a temperature of 300 to 550\xb0 C. to provide a heated feedstock.
32. The process of claim 30, wherein the catalyst of claim 1 is placed in a top portion of the reactor, above the additional catalyst, and the feedstock is preheated to a temperature of 550 to 750\xb0 C. to provide a heated feedstock.
33. An apparatus adapted to perform the process of claim 1, said apparatus comprising:
an adiabatic reactor;
a feed source containing natural gas and steam;
valves and pipes connecting the feed source and the reactor; and
a catalyst loaded in the reactor and comprising 1 to 20 wt. % nickel and 0.4 to 5 wt. % potassium, having an overall catalyst porosity of 25 to 50%, wherein 20 to 80% of the catalyst porosity is contributed by pores having pore diameters of at least 500 \u212b.
34. A catalyst for adiabatically prereforming a feedstock, said catalyst comprising 1 to 20 wt. % nickel and 0.4 to 5% potassium, on a calcium aluminate support, wherein an overall catalyst porosity is greater than 40% with greater than 70% of the overall catalyst porosity contributed by pores having pore diameters of at least 500 \u212b, a median pore diameter is greater than 2600 \u212b, and a nitrogen BET area is less than 6.5 m2g.
35. The catalyst of claim 34, wherein the catalyst comprises 5 to 20% nickel.
36. The catalyst of claim 34, wherein the catalyst comprises 10 to 20% nickel.
37. The catalyst of claim 34, wherein the catalyst comprises 0.4 to 2% potassium.
38. The catalyst of claim 34, wherein the catalyst comprises 0.5 to 1.5% potassium.
39. The catalyst of claim 34, wherein greater than 80% of an overall catalyst porosity is contributed by pores having pore diameters of at least 500 \u212b.