Biomass catalytic conversion process and apparatus for use therein
View Patent ↗Disclosed is a process for small-scale operation of biomass catalytic cracking. The process is suitable for lab scale and pilot plant operation, as well as for small-scale commercial operation. The process is suitable for simulating a continuous biomass catalytic cracking (BCC) process. The process comprises a biomass conversion cycle and a catalyst regeneration cycle. A fluid bed reactor and a reaction feed fluidizer suitable for use in the process are also disclosed.
1. A cyclic process for catalytically converting a solid particulate biomass material, said process comprising (i) a biomass conversion cycle comprising contacting a stream of solid biomass particles with a fluidized catalyst bed; and (ii) a catalyst regeneration cycle comprising contacting said fluidized catalyst bed with an oxygen containing gas at a temperature in the range of from about 500 to about 800° C.
2. The process of claim 1 further comprising a stripping cycle, carried out after said biomass conversion cycle and before said catalyst regeneration cycle.
3. The process of claim 1 wherein the catalyst-to-biomass ratio during said biomass conversion cycle is in the range of from 2 to 80.
4. The process of claim 1 wherein said biomass conversion cycle is carried out at a temperature in the range of from about 250° C. to about 600° C.
5. The process of claim 1 wherein said biomass conversion cycle is carried out at a temperature in the range from about 350° C. to about 550° C.
6. The process of claim 1 wherein said biomass conversion cycle is preceded by a biomass mixing step, during which said solid biomass particles are mixed with an inert carrier gas.
7. The process of claim 6 wherein said solid biomass particles are heated during said biomass mixing step to a temperature between ambient and about 150° C.
8. The process of claim 6 wherein said solid biomass particles are heated during said biomass mixing step to a temperature between ambient and about 100° C.
9. The process of claim 1 wherein said solid biomass particles and said catalyst have a contact time of from about 0.5 seconds to about 120 seconds.
10. The process of claim 1 wherein cycles (i) and (ii) are carried out in a fluid bed reactor having a removable top head.
11. The process of claim 10 wherein said fluid bed reactor further comprises a conical bottom head or a porous plate at the end of the cylindrical portion for fluidization from the bottom.
12. The process of claim 10 wherein said fluid bed reactor is provided with a heat source designed and configured to maintain said fluidized catalyst bed at a predetermined temperature.
13. The process of claim 1 wherein said fluidized catalyst bed is stripped with an inert gas at a point in time which is after said biomass conversion cycle and before said catalyst regeneration cycle.
14. The process of claim 13 wherein reaction products are passed through a condenser during said biomass conversion cycle and/or during said stripping step.
15. The process of claim 14 wherein uncondensed gases from said condenser are recycled at least in part to said biomass conversion cycle.
16. The process of claim 1 wherein said biomass conversion cycle comprises a first conversion step conducted at a first temperature in the range of from about 150 to about 400° C. and a second conversion step conducted at a second temperature in the range of from about 350 to about 500° C., whereby said second temperature is higher than said first temperature.
17. The process of claim 16 wherein the reaction time of said first conversion step is longer than the reaction time of said second conversion step.
18. The process of claim 16 wherein the reaction time of said first conversion step is at least twice the reaction time of said second conversion step.
19. The process of claim 16 whereby reaction products are stripped off the catalyst after said first conversion step and before said second conversion step.
20. The process of claim 6 wherein said biomass mixing step is carried out in a reaction feed fluidizer comprising a removable top head, a gas inlet, and a fluidized feed outlet.
21. The process of claim 20 wherein said reaction feed fluidizer further comprises a heat source designed and configured for maintaining a predetermined temperature in said reaction feed fluidizer.
22. The process of claim 20 wherein said biomass particles are loaded into said reaction feed fluidizer by gravity, by pressure surge, by means of a syringe, or by means of a screw feeder.
23. The process of claim 20 wherein said reaction feed fluidizer further comprises an inlet for introduction of a liquid solvent or diluent.