Solvent pulping of biomass
First Claim
1. A method of solvent pulping cellulose-containing biomass comprising substantially continuously and sequentially:
- a) gradually stepping up the pressure and temperature of particulate, crushed or shredded biomass from substantially atmospheric and ambient to above about 350 psig and above kraft cooking temperature, in a plurality of different stages of increasing pressure and temperature;
b) delignifying the particulate biomass in an aqueous slurry of solvent at a pressure above about 350 psig and a temperature above kraft cooking temperature;
c) simultaneously removing solvent while continuing delignification of the biomass in the slurry, at a pressure above about 350 psig and at a temperature above about 140 deg. C., preferably above about 180 deg. C.;
d) substantially instantaneously greatly reducing the pressure of the slurry; and
then e) washing the slurry.
1 Assignment
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Accused Products
Abstract
An apparatus and process for solvent pulping of cellulose-containing biomass utilizes at least one steaming vessel, a plug screw feeder or compression screw device, at least one super-atmospheric impregnation vessel, a solvent delignification reactor capable of operating at a pressure of 350 psig or more, and a solvent containing line for introducing solvent-containing liquor at the plug screw feeder outlet or compression screw device outlet. The process and system can also include at least one series connected pressure diffuser and optionally a retention tube downstream of each pressure diffuser to provide sufficient retention time to substantially preclude re-deposition of lignin on the cellulose fibers of the biomass, a blow tank connected to the last of the pressure diffusers and retention tubes, and vessels for multistage alcohol washing. The method steams the biomass and impregnates it with solvent to produce an aqueous slurry of biomass and solvent, delignifies the particulate biomass in the slurry, removes solvent while continuing delignification of the biomass in the slurry and while substantially precluding re-deposition of lignin on the cellulose of the biomass, reduces the pressure of the slurry; and then washes the slurry.
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Citations
46 Claims
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1. A method of solvent pulping cellulose-containing biomass comprising substantially continuously and sequentially:
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a) gradually stepping up the pressure and temperature of particulate, crushed or shredded biomass from substantially atmospheric and ambient to above about 350 psig and above kraft cooking temperature, in a plurality of different stages of increasing pressure and temperature;
b) delignifying the particulate biomass in an aqueous slurry of solvent at a pressure above about 350 psig and a temperature above kraft cooking temperature;
c) simultaneously removing solvent while continuing delignification of the biomass in the slurry, at a pressure above about 350 psig and at a temperature above about 140 deg. C., preferably above about 180 deg. C.;
d) substantially instantaneously greatly reducing the pressure of the slurry; and
thene) washing the slurry. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A solvent pulping system for a cellulose containing biomass, comprising:
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a) at least one steaming vessel having a first outlet;
b) at least one impregnation vessel operatively connected to the first outlet, and having a second outlet;
c) a blow-back preventing, upon upset conditions, device;
d) a solvent delignification reactor operatively connected to b) and capable of operating at a pressure of 350 psig or more; and
wherein c) is capable of withstanding the operating pressure of d). - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A solvent pulping system for a cellulose containing biomass, comprising:
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a) at least one steaming vessel having a first outlet;
b) at least one super-atmospheric impregnation vessel operatively connected to the first outlet, and having a second outlet;
c) a solvent delignification reactor operatively connected to b) and capable of operating at a pressure of 350 psig or more, and having a third outlet; and
d) a plurality of series connected pressure diffusers operatively connected to the third outlet and operating at 350 psig or more, and optionally a retention tube downstream of each pressure diffuser to provide sufficient retention time to substantially preclude re-deposition of lignin on the cellulose fibers of the biomass. - View Dependent Claims (28, 29, 30, 31)
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32. A solvent pulping system for a cellulose containing biomass, comprising:
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a) at least one steaming vessel having a first outlet;
b) at least one super-atmospheric impregnation vessel operatively connected to the first outlet, and having a second outlet;
c) a solvent delignification reactor operatively connected to b) and capable of operating at a pressure of 350 psig or more, and having a third outlet; and
wherein b) includes a plug screw feeder and a fluffer at its outlet; and
further comprising a solvent containing line for introducing solvent-containing liquor at the plug screw feeder outlet or between the plug screw feeder and fluffer, or in the fluffer.
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33. A solvent pulping system for a cellulose containing biomass, comprising:
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a) at least one super-atmospheric steaming vessel having a first outlet;
b) at least one super-atmospheric impregnation vessel operatively connected to the first outlet, and having a second outlet;
c) a solvent delignification reactor operatively connected to b) and capable of operating at a pressure of 350 psig or more, and having a third outlet; and
d) a plug screw feeder or compression screw device between a) and b); and
e) a solvent containing line for introducing solvent-containing liquor at the plug screw feeder outlet or compression screw device outlet. - View Dependent Claims (34, 35, 36, 37, 38, 39, 40)
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41. A method of solvent pulping cellulose-containing biomass comprising substantially continuously and sequentially:
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a) steaming the biomass and impregnating it with solvent to produce an aqueous slurry of biomass and solvent;
b) delignifying the particulate biomass in the slurry at a pressure above about 350 psig and a temperature above about 140 degrees C., preferably above about 180 degrees C.;
c) simultaneously removing solvent while continuing delignification of the biomass in the slurry, at a pressure above about 350 psig and a temperature above about 180 degrees C. in a series of stages, and to substantially preclude re-deposition of lignin on the cellulose of the biomass;
d) substantially instantaneously greatly reducing the pressure of the slurry; and
thene) washing the slurry. - View Dependent Claims (42, 43, 44, 45, 46)
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Specification