Thermolytic fragmentation of sugars using resistance heating
A process for large scale and energy efficient production of oxygenates from sugar is disclosed in which a sugar feedstock is introduced into a thermolytic fragmentation reactor comprising a fluidized stream of heat carrying particles which are separated from the reaction product and directed to a reheater comprising a resistance heating system.
1. A reactor system for thermolytic fragmentation of a sugar into C 1 -C 3 oxygenates comprising:
a fragmentation reactor comprising heat carrying particles for supplying heat to the thermolytic fragmentation of the sugar into C 1 -C 3 oxygenates, said fragmentation reactor being equipped with a fragmentation particle inlet for introducing heated heat carrying particles into the fragmentation reactor, a fragmentation particle outlet for collecting spent heat carrying particles from the fragmentation reactor, a feedstock inlet for introducing the sugar into the fragmentation reactor, a fragmentation riser comprising a fragmentation zone and allowing thermolytic fragmentation of the sugar, and a product outlet for recovering the C 1 -C 3 oxygenates;
a reheater, said reheater comprising:
a first reheater gas inlet
a reheater particle inlet
a reheater particle outlet
a reheater gas outlet
a resistance heating system
first flow means for conveying spent heat carrying particles from the fragmentation particle outlet to the reheater particle inlet; and
second flow means for conveying heated heat carrying particles from the reheater particle outlet to the fragmentation particle inlet;
wherein the resistance heating system comprises a heating structure of electrically conductive material, said heating structure being configured such that an electrical current is imposed between two points to supply resistive heat between the two points,
wherein said heating structure is arranged in a heating zone within the reheater to provide heat to the heat carrying particles within the reheater.
2. The reactor system according to claim 1 , wherein the heating structure of electrically conductive material is connected to an electrical power supply, wherein said electrical power supply is configured to heat the heat carrying particles to a reheater exit temperature of at least 300° C.
3. The reactor system according to claim 1 , wherein the electrically conductive material of the heating structure is a material having an electrical resistivity in the range of from 10 −7 Ω·m to 10 −5 Ω·m at 20° C.
4. The reactor system according to claim 1 , wherein the electrically conductive material of the heating structure is a material providing a heat flux from the heating structure to the heat carrying particles in the range of from 500 to 500,000 W/m 2 .
5. The reactor system according to claim 1 , wherein the electrically conductive material of the heating structure is an electrically conductive metal or metal alloy comprising one or more of copper, silver, aluminum, chromium, iron and nickel.
6. The reactor system according to claim 1 , wherein the electrically conductive material of the heating structure is an electrically conductive ceramic material.
7. The reactor system according to claim 1 , wherein the resistance heating system further comprises a protective layer covering at least 50% of the surface of the heating structure.
8. The reactor system according to claim 7 , wherein the protective layer comprises a material having an electrical resistivity above 10 9 Ω·m at 20° C.
9. The reactor system according to claim 7 , wherein the protective layer comprises a ceramic material.
10. The reactor system according to claim 1 , wherein the heat carrying particles are selected from the group consisting of sand, silica, glass, alumina, steel, and silicon carbide.
11. The reactor system according to claim 1 , wherein the Sauter mean particle size of the heat carrying particles is in the range of from 20-400 μm.
12. The reactor system according to claim 1 , wherein the reheater has a reactor wall and the heating structure is connected to the electrical power supply through said reactor wall in fittings electrically insulating the heating structure from the reactor wall.
13. The reactor system according to claim 12 , wherein the heating zone is arranged vertically below the reheater gas outlet.
14. The reactor system according to claim 12 , wherein the fittings are arranged vertically above the reheater particle outlet.
15. The reactor system according to claim 1 , wherein the reheater particle outlet is arranged vertically above the fragmentation particle inlet.
16. The reactor system according to claim 1 , wherein the first and or second flow means are equipped with fluid control means.
17. The reactor system according to claim 1 , wherein the fragmentation reactor further comprises:
a fluidization gas inlet for introducing a fluidization gas; and/or
a first fragmentation particle separator for separating a fraction of the spent heat carrying particles from the C 1 -C 3 oxygenates; and/or
a cooling section for quench cooling the C 1 -C 3 oxygenates; and/or
a second fragmentation particle separator for separating any remaining spent heat carrying particles from the C 1 -C 3 oxygenates; and/or
fragmentation stripping zone equipped with baffles or other internals to improve mixing of any fluid passing it.
18. The reactor system according to claim 17 , wherein the first fragmentation particle separator is arranged within a separator vessel and the separator vessel further comprises a fragmentation stripping zone equipped with baffles or other internals to improve mixing of any fluid passing it and a separator fluidization gas inlet; wherein the stripping zone is arranged vertically below the first fragmentation particle separator and the separator fluidization gas inlet is arranged vertically below the separator stripping zone.
19. The reactor system according to claim 18 , wherein the fragmentation particle outlet is arranged vertically below the fragmentation stripping zone and vertically above the reheater particle inlet.
20. The reactor system according to claim 1 , wherein the reheater further comprises:
a reheater stripping zone equipped with baffles or other internals to improve mixing of any fluid passing it; and/or
a second reheater gas inlet for providing an oxidizing gas to the stripping zone of the reheater; and/or
a reheater particle separator; and/or
a reheater compressor.
21. The reactor system according to claim 20 , wherein the reheater stripping zone is arranged vertically below the heating zone and vertically above the reheater particle outlet.
22. The reactor system according to claim 1 , wherein the reheater does not utilize a combustion gas.
23. The reactor system according to claim 2 , wherein said electrical power supply is configured to heat the heat carrying particles to a reheater exit temperature of 400-700° C.
24. The reactor system according to claim 6 , wherein the electrically conductive ceramic material is a material comprising one or more of silicium carbide, molybdenum carbide, wolfram carbide, titanium nitride, molybdenum disilide, wolfram disilide, mixtures thereof.
25. The reactor system according to claim 1 , wherein the reheater further comprises a reheater stripping zone equipped with baffles or other internals to improve mixing of any fluid passing it.
26. The reactor system according to claim 1 , wherein the system is configured to fluidize the heat carrying particles within the reheater using a reheater fluidization gas, wherein the system is configured to operate with a ratio (a:b) of a) m3/hour of the reheater fluidization gas to b) kg/hour on a dry basis of the sugar composition of 10 to 1000.
27. The reactor system according to claim 26 , wherein the ratio (a:b) is 100 to 300.
28. The reactor system according to claim 1 , wherein the electrically conductive material has a surface area, wherein the system is configured to operate with a ratio (c:d) of c) the surface area (m2) to d) kg/hour on a dry basis of the sugar composition of 1 to 1000.
29. The reactor system according to claim 28 , wherein the ratio (c:d) is 10 to 100.
30. The reactor system according to claim 1 , wherein the reheater has a mean diameter, wherein the system is configured to operate with a ratio (e:f) of e) the mean diameter (m) to f) kg/hour on a dry basis of the sugar composition of 0.01 to 1.
31. The reactor system according to claim 30 , wherein the ratio (e:f) is 0.05 to 0.5.
32. The reactor system according to claim 1 , wherein the system has a process heating efficiency measured as percentage of energy (kW) supplied to the resistance heating system to energy (kW) supplied to the heat carrying particles of at least 80%.
33. The reactor system according to claim 32 , wherein the process heating efficiency is 82 to 99.
34. The reactor system according to claim 32 , wherein the process heating efficiency is 90 to 98%.
35. The reactor system according to claim 1 , wherein the system is configured to operate with a ratio (g:h) of g) energy (MW) supplied to the resistance heating system to h) kg/hour on a dry basis of the sugar composition of 800 to 2500.
36. The reactor system according to claim 35 , wherein the ratio (g:h) is 1100 to 2000.
37. The reactor system according to claim 1 , wherein the system is configured to fluidize the heat carrying particles within the reheater using a reheater fluidization gas, wherein the reheater further comprises a compressor to compress the reheater fluidization gas, wherein the system is configured to operate with a ratio (i:j) of i) energy (MW) supplied to the compressor to j) kg/hour on a dry basis of the sugar composition of 1 to 20.
38. The reactor system according to claim 37 , wherein the ratio (i:j) is 2 to 8.
39. The reactor system according to claim 1 , wherein the system is configured to fluidize the heat carrying particles within the reheater using a reheater fluidization gas, wherein the system is configured to operate with a ratio (a:b) of a) m3/hour of the reheater fluidization gas to b) kg/hour on a dry basis of the sugar composition of 10 to 1000,
wherein the reheater has a mean diameter, wherein the system is configured to operate with a ratio (e:f) of e) the mean diameter (m) to f) kg/hour on a dry basis of the sugar composition of 0.01 to 1.
40. The reactor system according to claim 1 , wherein the system is configured to fluidize the heat carrying particles within the reheater using a reheater fluidization gas, wherein the system is configured to operate with a ratio (a:b) of a) m3/hour of the reheater fluidization gas to b) kg/hour on a dry basis of the sugar composition of 10 to 1000,
wherein the system is configured to operate with a ratio (g:h) of g) energy (MW) supplied to the resistance heating system to h) kg/hour on a dry basis of the sugar composition of 800 to 2500.
41. The reactor system according to claim 1 , wherein the system is configured to fluidize the heat carrying particles within the reheater using a reheater fluidization gas, wherein the system is configured to operate with a ratio (a:b) of a) m3/hour of the reheater fluidization gas to b) kg/hour on a dry basis of the sugar composition of 10 to 1000,
wherein the reheater has a mean diameter, wherein the system is configured to operate with a ratio (e:f) of e) the mean diameter (m) to f) kg/hour on a dry basis of the sugar composition of 0.01 to 1,
wherein the system is configured to operate with a ratio (g:h) of g) energy (MW) supplied to the resistance heating system to h) kg/hour on a dry basis of the sugar composition of 800 to 2500,
wherein the reheater further comprises a compressor to compress the reheater fluidization gas, wherein the system is configured to operate with a ratio (i:j) of i) energy (MW) supplied to the compressor to j) kg/hour on a dry basis of the sugar composition of 1 to 20.
42. The reactor system according to claim 1 , wherein the reheater further comprises a reheater stripping zone equipped with baffles or other internals to improve mixing of any fluid passing it,
wherein the system is configured to fluidize the heat carrying particles within the reheater using a reheater fluidization gas, wherein the system is configured to operate with a ratio (a:b) of a) m3/hour of the reheater fluidization gas to b) kg/hour on a dry basis of the sugar composition of 10 to 1000,
wherein the reheater has a mean diameter, wherein the system is configured to operate with a ratio (e:f) of e) the mean diameter (m) to f) kg/hour on a dry basis of the sugar composition of 0.01 to 1,
wherein the system is configured to operate with a ratio (g:h) of g) energy (MW) supplied to the resistance heating system to h) kg/hour on a dry basis of the sugar composition of 800 to 2500,
wherein the reheater further comprises a compressor to compress the reheater fluidization gas, wherein the system is configured to operate with a ratio (i:j) of i) energy (MW) supplied to the compressor to j) kg/hour on a dry basis of the sugar composition of 1 to 20.