초록 ▼

The disclosed invention relates to a distillation process for separating two or more components having different volatilities from a liquid mixture containing the components. The process employs microchannel technology for effecting the distillation and is particularly suitable for conducting diffic

The disclosed invention relates to a distillation process for separating two or more components having different volatilities from a liquid mixture containing the components. The process employs microchannel technology for effecting the distillation and is particularly suitable for conducting difficult separations, such as the separation of ethane from ethylene, wherein the individual components are characterized by having volatilities that are very close to one another.

대표청구항 ▼

The invention claimed is: 1. A process for distilling a fluid mixture in a microchannel distillation apparatus, the microchannel distillation apparatus comprising a plurality of microchannel distillation units, each microchannel distillation unit comprising a plurality of microchannel distillation

The invention claimed is: 1. A process for distilling a fluid mixture in a microchannel distillation apparatus, the microchannel distillation apparatus comprising a plurality of microchannel distillation units, each microchannel distillation unit comprising a plurality of microchannel distillation sections, each microchannel distillation unit having one or more unit inlets, the microchannel distillation apparatus having an apparatus inlet and one or more channel inlets connecting the apparatus inlet to the unit inlets, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation units in a first direction; flowing a liquid phase through the microchannel distillation units in a second direction that is counter-current to the first direction; and flowing the fluid mixture through the apparatus inlet, channel inlets and unit inlets into the microchannel distillation units, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase. 2. The process of claim 1 wherein each microchannel distillation unit has a distillate end and a bottoms end, the process further comprises: flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections towards the distillate ends, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; and flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections towards the bottoms ends, the less volatile component rich liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component. 3. The process of claim 1 wherein each microchannel distillation unit comprises at least one heat exchanger. 4. The process of claim 1 wherein each microchannel distillation unit comprises at least one process microchannel, the process microchannel comprising an area to permit flow of the vapor phase and an area to permit flow of the liquid phase. 5. The process of claim 1 wherein each microchannel distillation unit has a distillate end and a microchannel condenser at the distillate end. 6. The process of claim 5 wherein the microchannel condenser is in the form of a microchannel distillation section. 7. The process of claim 1 wherein each microchannel distillation unit has a bottoms end and a microchannel reboiler at the bottoms end. 8. The process of claim 7 wherein the microchannel reboiler is in the form of a microchannel distillation section. 9. The process of claim 1 wherein each microchannel distillation unit has a distillate end and a bottoms end and further comprises a microchannel condenser at the distillate end and a microchannel reboiler at the bottoms end. 10. The process of claim 9 wherein the microchannel condenser and the microchannel reboiler are in the form of microchannel distillation sections. 11. The process of claim 4 wherein a wicking layer separates the area for vapor phase flow and the area for liquid phase flow. 12. The process of claim 1 wherein at least part of the more volatile component rich vapor phase is condensed and withdrawn from the microchannel distillation units. 13. The process of claim 12 wherein the more volatile component rich vapor phase is condensed in a microchannel condenser. 14. The process of claim 1 wherein at least part of the more volatile component rich vapor phase is condensed and flows into the microchannel distillation units. 15. The process of claim 1 wherein at least part of the less volatile component rich liquid phase is withdrawn from the microchannel distillation units. 16. The process of claim 1 wherein at least part of the less volatile component rich liquid phase is vaporized and flows into the microchannel distillation units. 17. The process of claim 16 wherein the less volatile component rich liquid phase is vaporized in a microchannel reboiler. 18. The process of claim 1 wherein each microchannel distillation unit has a height of up to about 3 meters. 19. The process of claim 1 wherein the height of the equivalent theoretical plate ratio for each microchannel distillation unit is less than about one foot. 20. The process of claim 1 wherein the height of the equivalent theoretical plate ratio for each microchannel distillation unit is less than about one inch. 21. The process of claim 1 wherein the time for cooling the microchannel distillation units from room temperature to about-33° C. is less than about 24 hours. 22. The process of claim 1 wherein each microchannel distillation unit has a distillate end and a bottoms end, the fluid mixture being introduced into at least one microchannel distillation section positioned between the distillate end and the bottoms end. 23. The process of claim 1 wherein the microchannel distillation sections have heat exchange channel zones thermally communicating with the microchannel distillation sections, each of the heat exchange channel zones comprising at least one heat exchange fluid loop. 24. The process of claim 23 wherein heat exchange fluid flows from one heat exchange fluid loop to another heat exchange fluid loop. 25. The process of claim 23 wherein at least two heat exchange fluid loops are nested. 26. A process for distilling a fluid mixture in a microchannel distillation apparatus, the microchannel distillation apparatus comprising a plurality of microchannel distillation units, each microchannel distillation unit comprising a plurality of microchannel distillation sections, each microchannel distillation unit having one or more unit inlets, the microchannel distillation apparatus having an apparatus inlet and one more more channel inlets connecting the apparatus inlet to the unit inlets, each microchannel unit having a distillate end and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through each microchannel distillation unit towards the distillate end of each microchannel distillation unit; flowing a liquid phase through each microchannel distillation unit towards the bottoms end of each microchannel distillation unit; flowing the fluid mixture through the apparatus inlet, channel inlets and unit inlets into the microchannel distillation units, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in each microchannel distillation unit towards the distillate end of each microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in each microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component. 27. The process of claim 26 wherein each microchannel distillation unit comprises at least one process microchannel and at least one heat exchanger. 28. The process of claim 26 wherein each microchannel distillation unit comprises at least one process microchannel, the process microchannel comprising an open area to permit flow of the vapor phase and a wicking region to permit flow of the liquid phase. 29. The process of claim 28 wherein each microchannel distillation section comprises a liquid inlet for permitting liquid to flow into the open area from the wicking region, a liquid outlet for permitting liquid to flow out of the open area into the wicking region, an interior wall extending from the liquid inlet to the liquid outlet, and a capture structure, the liquid outlet being downstream from the liquid inlet. 30. The process of claim 29 wherein the liquid phase flows on the surface of the interior wall, the liquid phase being in the form of a thin film. 31. The process of claim 28 wherein part of the wicking region forms a wall for the open area of the process microchannel. 32. The process of claim 31 wherein the liquid phase flows in the wicking region and the vapor phase flows in the open area of the process microchannel and contacts at least part of the liquid phase in the wicking region. 33. The process of claim 27 wherein the process microchannel has an internal dimension of width or height of up to about 10 mm. 34. The process of claim 27 wherein the process microchannel has an internal dimension of width or height of up to about 2 mm. 35. The process of claim 27 wherein the process microchannel is made of a material comprising: steel; monel; inconel; aluminum; titanium; nickel; copper; brass; an alloy of any of the foregoing metals; a polymer; ceramics; glass; a composite comprising a polymer and fiberglass; quartz; silicon; or a combination of two or more thereof. 36. The process of claim 27 wherein the heat exchanger comprises at least one heat exchange channel having an internal dimension of width or height of up to about 10 mm. 37. The process of claim 27 wherein the heat exchanger comprises at least one heat exchange channel having an internal dimension of width or height of up to about 2 mm. 38. The process of claim 27 wherein the heat exchanger comprises at least one heat exchange channel, the heat exchange channel being made of a material comprising: steel; monel; inconel; aluminum; titanium; nickel; copper; brass; an alloy of any of the foregoing metals; a polymer; ceramics; glass; a composite comprising polymer and fiberglass; quartz; silicon; or a combination of two or more thereof. 39. The process of claim 28 wherein the wicking region comprises a wick. 40. The process of claim 39 wherein the wick comprises one or more sintered metals, metal screens, metal foams, polymer fibers, or a combination of two or more thereof. 41. The process of claim 28 wherein the wicking region comprises a wicking surface. 42. The process of claim 41 wherein the wicking surface comprises grooves in one or more interior walls of the process microchannel. 43. The process of claim 42 wherein the grooves are aligned parallel to the direction of flow of the vapor phase in the process microchannel. 44. The process of claim 42 wherein the grooves are aligned tangentially to the direction of flow of the vapor phase in the process microchannel. 45. The process of claim 42 wherein the grooves provide a flow path for the liquid phase to flow between microchannel distillation sections. 46. The process of claim 42 wherein the grooves are etched into at least one wall of the process microchannel using a laser. 47. The process of claim 28 wherein the wicking region comprises a wire mesh that is welded to at least one wall of the process microchannel. 48. The process of claim 26 wherein the flow of the liquid phase is driven by gravitational forces. 49. The process of claim 26 wherein the flow of the liquid phase is driven by gravitational force and/or a pressure differential. 50. The process of claim 26 wherein the fluid mixture comprises ethane and ethylene. 51. The process of claim 26 wherein the fluid mixture comprises styrene and ethylbenzene. 52. The process of claim 26 wherein the fluid mixture comprises oxygen and nitrogen. 53. The process of claim 26 wherein the fluid mixture comprises cycohexane and cyclohexanol or cyclohexanone. 54. The process of claim 26 wherein the fluid mixture comprises hexane and cyclohexane. 55. The process of claim 26 wherein the fluid mixture comprises isobutane. 56. The process of claim 26 wherein the fluid mixture comprises naptha. 57. The process of claim 27 wherein the heat exchanger comprises a heat exchange channel, an endothermic or exothermic process being conducted in the heat exchange channel. 58. The process of claim 27 wherein the heat exchanger comprises a heat exchange channel, a heat exchange fluid being in the heat exchange channel. 59. The process of claim 58 wherein the heat exchange fluid undergoes a phase change in the heat exchange channel. 60. The process of claim 58 wherein the heat exchange fluid undergoes partial boiling in the heat exchange channel. 61. The process of claim 27 wherein the heat exchanger comprises a heat exchange channel, the vapor phase flows through the process microchannel in a first direction, and a heat exchange fluid flows through the heat exchange channel in a second direction, the second direction being co-current, cross-current or counter-current relative to the first direction. 62. The process of claim 27 wherein the heat exchanger comprises a heat exchange channel, a heat exchange fluid flows through the heat exchange channel, the heat exchange fluid comprising one or more of air, steam, liquid water, carbon dioxide, gaseous nitrogen, liquid nitrogen, a gaseous hydrocarbon or a liquid hydrocarbon. 63. The process of claim 27 wherein the heat exchanger comprises a heat exchange channel, the pressure within the process microchannel is in the range from about 30 to about 100 atmospheres, and a heat exchange fluid flows in the heat exchange channel, the temperature of the heat exchange fluid being in the range from about-30 to about 200° C. 64. The process of claim 26 wherein at least part of the more volatile component rich vapor phase is condensed and withdrawn from each microchannel distillation unit. 65. The process of claim 64 wherein the more volatile component rich vapor phase is condensed in a microchannel condenser. 66. The process of claim 26 wherein at least part of the more volatile component rich vapor phase is condensed and flows into each microchannel distillation unit. 67. The process of claim 26 wherein at least part of the less volatile component rich liquid phase is withdrawn from the microchannel distillation unit. 68. The process of claim 26 wherein at least part of the less volatile component rich liquid phase is vaporized and flows into each microchannel distillation unit. 69. The process of claim 68 wherein the less volatile component rich liquid phase is vaporized in a microchannel reboiler. 70. The process of claim 26 wherein each microchannel distillation unit has a height of up to about 3 meters. 71. The process of claim 26 wherein the height of the equivalent theoretical plate ratio for each microchannel distillation unit is less than about one foot. 72. The process of claim 26 wherein the height of the equivalent theoretical plate ratio for each microchannel distillation unit is less than about one inch. 73. The process of claim 26 wherein the time for cooling each microchannel distillation unit from room temperature to about-33° C. is less than about 24 hours. 74. The process of claim 26 wherein a distillate product is formed, the distillate product being treated in another microchannel distillation unit. 75. The process of claim 74 wherein another distillate product is formed in the another microchannel distillation unit, the another distillate product being treated in a third microchannel distillation unit. 76. The process of claim 26 wherein a bottoms product is formed, the bottoms product being treated in another microchannel distillation unit. 77. The process of claim 76 wherein another bottoms product is formed in the another microchannel distillation unit, the another bottoms product being treated in a third microchannel distillation unit. 78. The process of claim 26 wherein a distillate product is removed from each microchannel distillation unit at the distillate end. 79. The process of claim 26 wherein at least one product is removed from each microchannel distillation unit downstream from the distillate end. 80. The process of claim 26 wherein a bottoms product is removed from each microchannel distillation unit at the bottoms end. 81. The process of claim 26 wherein at least one product is removed from each microchannel distillation unit upstream from the bottoms end. 82. The process of claim 26 wherein at least one feed stream is introduced into each microchannel distillation unit in at least one microchannel distillation section positioned between the distillate end and the bottoms end. 83. The process of claim 26 wherein the microchannel distillation sections have heat exchange channel zones thermally communicating with the microchannel distillation sections, each of the heat exchange channel zones comprising at least one heat exchange fluid loop. 84. The process of claim 83 wherein heat exchange fluid flows from one heat exchange fluid loop to another heat exchange fluid loop. 85. The process of claim 83 wherein at least two heat exchange fluid loops are nested. 86. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, each microchannel distillation section comprising a vapor region and a capture structure, the process comprising: flowing a liquid stream in the capture structure, flowing a vapor stream in the vapor region, the capture structure comprising a first depth and a second depth, wherein the second depth is less than the first depth and the second depth comprises surface features that create a perpendicular velocity component in the liquid stream in at least a portion of the first depth that is greater than in the second depth. 87. The process of claim 1 wherein the fluid mixture comprises a gas. 88. The process of claim 1 wherein the fluid mixture comprises a liquid. 89. The process of claim 1 wherein the fluid mixture comprises a two-phase mixture. 90. The process of claim 1 wherein the fluid mixture comprises a homogeneous feed. 91. The process of claim 1 wherein the inlet feed channels comprise at least one micromanifold for providing for the flow of the fluid mixture to the microchannel distillation units. 92. The process of claim 1 wherein the direction of flow of the fluid mixture into the at least one microchannel distillation section in each microchannel distillation unit is orthogonal to the direction of flow of the vapor phase. 93. The process of claim 1 wherein the flow of the fluid mixture into each microchannel distillation section traverses the width of each microchannel distillation section. 94. The process of claim 1 wherein each microchannel distillation unit comprises at least one process microchannel, each process microchannel comprising an inlet feed channel that is adjacent to the process microchannel, the process microchannel containing one or more openings to permit the fluid mixture to flow from the inlet feed channel into the process microchannel. 95. The process of claim 1 wherein the inlet feed channels comprise grooves to direct the flow of the fluid mixture into the at least one microchannel distillation section of each microchannel distillation unit. 96. The process of claim 1 wherein the inlet feed channels comprise one or more wicks to direct the flow of the fluid mixture into the at least one microchannel distillation section of each microchannel distillation unit. 97. The process of claim 1 wherein the microchannel distillation apparatus comprises a plurality of feed inlets and inlet feed channels, each feed inlet and inlet feed channel providing for the distribution of the flow of the fluid mixture into different microchannel distillation sections in each microchannel distillation unit. 98. The process of claim 1 wherein the fluid mixture comprises a multiphase mixture, the multiphase mixture being separated to form a liquid phase feed stream and a vapor phase feedstream, the liquid phase feedstream flowing into contact with the liquid phase, the vapor phase feedstream flowing into contact with the vapor phase. 99. The process of claim 1 wherein the fluid mixture comprises a multiphase mixture, the multiphase mixture flowing into contact with the vapor phase. 100. The process of claim 1 wherein the fluid mixture comprises a multiphase mixture, the multiphase mixture comprising a liquid containing gas bubbles. 101. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising at least one process microchannel and a plurality of microchannel distillation sections in the process microchannel, the process microchannel comprising an area to permit flow of the vapor phase and an area to permit flow of the liquid phase, the process microchannel having an interior wall in the area for vapor phase flow and an interior wall in the area for liquid phase flow, each of the walls being opposite each other and having surface features to enhance the mixing of the vapor phase with the liquid phase, the microchannel distillation unit having at least one feed inlet, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit in a first direction; flowing a liquid phase through the microchannel distillation unit in a second direction that is counter-current to the first direction; and flowing the fluid mixture through the feed inlet into at least one microchannel distillation section, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase. 102. The process of claim 101 wherein the surface features comprise grooves and/or protrusions on each wall. 103. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having at least one feed inlet, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit in a first direction; flowing a liquid phase through the microchannel distillation unit in a second direction that is counter-current to the first direction; and flowing the fluid mixture through the feed inlet into at least one microchannel distillation section, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; the microchannel distillation sections having heat exchange channel zones thermally communicating with the microchannel distillation sections, a heat exchange fluid flowing in the heat exchange channel zones, the heat exchange fluid undergoing partial boiling in the heat exchange channel zones, the pressure of the heat exchange fluid in each of the heat exchange channel zones being different. 104. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having at least one feed inlet, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit in a first direction; flowing a liquid phase through the microchannel distillation unit in a second direction that is counter-current to the first direction; and flowing the fluid mixture through the feed inlet into at least one microchannel distillation section, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; the microchannel distillation sections having heat exchange channel zones thermally communicating with the microchannel distillation sections, a heat exchange fluid flowing in the heat exchange channel zones, the heat exchange fluid undergoing partial boiling in the heat exchange channel zones, the temperature in each microchannel distillation section being different. 105. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having at least one feed inlet, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit in a first direction; flowing a liquid phase through the microchannel distillation unit in a second direction that is counter-current to the first direction; and flowing the fluid mixture through the feed inlet into at least one microchannel distillation section, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; wherein the microchannel distillation unit is in a microchannel distillation assembly comprising a plurality of microchannel distillation units, some of the microchannel distillation units being active and some of the microchannel distillation units being inactive. 106. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein each microchannel distillation section comprises a liquid region, a vapor region positioned above the liquid region, and a bubble cap tray positioned above the vapor region. 107. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein each microchannel distillation section comprises a tray, the tray comprising a capture structure for collecting liquid and an opening for permitting the flow of the vapor phase through the tray. 108. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the microchannel distillation unit comprises at least one process microchannel, the process microchannel comprising an open area to permit flow of the vapor phase and a wicking region to permit flow of the liquid phase; wherein each microchannel distillation section comprises a liquid inlet for permitting liquid to flow into the open area from the wicking region, a liquid outlet for permitting liquid to flow out of the open area into the wicking region, an interior wall extending from the liquid inlet to the liquid outlet, and a capture structure, the liquid outlet being downstream from the liquid inlet; and wherein the capture structure comprises wire mesh. 109. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the microchannel distillation unit comprises at least one process microchannel, the process microchannel comprising an open area to permit flow of the vapor phase and a wicking region to permit flow of the liquid phase; wherein each microchannel distillation section comprises a liquid inlet for permitting liquid to flow into the open area from the wicking region, a liquid outlet for permitting liquid to flow out of the open area into the wicking region, an interior wall extending from the liquid inlet to the liquid outlet, and a capture structure, the liquid outlet being downstream from the liquid inlet; and wherein the capture structure comprises one or more inverted cones, liquid-nonwetting porous structures, liquid-wetting porous structures, perforated foils, fibers, or a combination of two or more thereof. 110. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the microchannel distillation unit comprises at least one process microchannel and at least one heat exchange channel; wherein an exothermic process is conducted in the heat exchange channel, the exothermic process comprising a water-gas shift reaction, a methanol synthesis reaction or an ammonia synthesis reaction. 111. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the microchannel distillation unit comprises at least one process microchannel and at least one heat exchange channel; wherein an endothermic process is conducted in the heat exchange channel, the endothermic reaction comprising a steam reforming process or dehydrogenation process. 112. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the microchannel distillation sections have heat exchange channel zones thermally communicating with the microchannel distillation sections, a heat exchange fluid flows in the heat exchange channel zones, the heat exchange fluid undergoes partial boiling in the heat exchange channel zones, the pressure of the heat exchange fluid in each of the heat exchange channel zones being different. 113. A process for distilling a fluid mixture in a microchannel distillation assembly, the microchannel distillation assembly comprising at least one microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having a feed inlet, a distillate end, and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit towards the distillate end of the microchannel distillation unit; flowing a liquid phase through the microchannel distillation unit towards the bottoms end of the microchannel distillation unit; flowing the fluid mixture through the feed inlet for the microchannel distillation unit into at least one microchannel distillation section within the microchannel distillation unit, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the distillate end of the microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in the microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich vapor liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the microchannel distillation sections have heat exchange channel zones thermally communicating with the microchannel distillation sections, a heat exchange fluid flows in the heat exchange channel zones, the heat exchange fluid undergoes partial boiling in the heat exchange channel zones, the temperature in each microchannel distillation section being different. 114. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising at least one microchannel distillation section, the microchannel distillation unit having at least one feed inlet, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing the fluid mixture through the feed inlet into the microchannel distillation unit; flowing a vapor phase of the fluid mixture through the microchannel distillation unit in a first direction; flowing a liquid phase of the fluid mixture through the microchannel distillation unit in a second direction that is counter-current to the first direction; flowing the vapor phase and the liquid phase in the at least one microchannel distillation section and changing the direction of flow of either the vapor phase or the liquid phase in the microchannel distillation section to provide for the flow of the vapor phase and the liquid phase in the same direction; and contacting the vapor phase and the liquid phase in the microchannel distillation section, part of the more volatile component transferring from the liquid phase to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the vapor phase to the liquid phase to form a less volatile component rich liquid phase. 115. A process for distilling a fluid mixture in a microchannel distillation unit, the microchannel distillation unit comprising a plurality of microchannel distillation sections, the microchannel distillation unit having at least one feed inlet, the feed inlet comprising a feed inlet channel positioned adjacent to and parallel to the microchannel distillation unit, the microchannel distillation unit comprising a plurality of feed openings to permit the flow of the fluid mixture from the feed inlet channel through the feed openings into at least one microchannel distillation section, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through the microchannel distillation unit in a first direction; flowing a liquid phase through the microchannel distillation unit in a second direction that is counter-current to the first direction; and flowing the fluid mixture from the feed inlet channel through the feed openings into the at least one microchannel distillation section, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; wherein a barrier wall is positioned in the at least one microchannel distillation section, the fluid mixture flowing into the microchannel distillation section contacting the barrier wall, the direction of flow of the fluid mixture changing from being orthogonal to the flow of the vapor phase to being aligned with the flow of the vapor phase. 116. A process for distilling a fluid mixture in a microchannel distillation apparatus, the microchannel distillation apparatus comprising a plurality of microchannel distillation units, each microchannel distillation unit comprising a plurality of microchannel distillation sections, each microchannel distillation unit having one or more unit inlets, the microchannel distillation apparatus having an apparatus inlet and one more more channel inlets connecting the apparatus inlet to the unit inlets, each microchannel unit having a distillate end and a bottoms end, the fluid mixture comprising a more volatile component and a less volatile component, the process comprising: flowing a vapor phase through each microchannel distillation unit towards the distillate end of each microchannel distillation unit; flowing a liquid phase through each microchannel distillation unit towards the bottoms end of each microchannel distillation unit; flowing the fluid mixture through the apparatus inlet, channel inlets and unit inlets into the microchannel distillation units, part of the more volatile component transferring from the fluid mixture to the vapor phase to form a more volatile component rich vapor phase, part of the less volatile component transferring from the fluid mixture to the liquid phase to form a less volatile component rich liquid phase; flowing the more volatile component rich vapor phase through a plurality of the microchannel distillation sections in each microchannel distillation unit towards the distillate end of each microchannel distillation unit, the more volatile component rich vapor phase contacting the liquid phase in each microchannel distillation section and becoming enriched with the more volatile component; flowing the less volatile component rich liquid phase through a plurality of the microchannel distillation sections in each microchannel distillation unit towards the bottoms end of each microchannel distillation unit, the less volatile component rich liquid phase contacting the vapor phase in each microchannel distillation section and becoming enriched with the less volatile component; wherein the gas to liquid Reynolds number is in the range from about 500×(Suratmann Number)-0.67 to about 4500×(Suratmann Number)-0.67.