US4897497A
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US
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Lignocellulose degradation to furfural and levulinic acid
Assignee: BIOFINE TECHNOLOGIES LLC
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Filing: 1988-04-26
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Granted: 1990-01-30
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Expires: 2008-04-26
Abstract
Abstract A process for producing furfural and levulinic acid from lignocellulose includes subjecting a sample of lignocellulose to acid degradation at an elevated temperature for a minute or less, during which time at least fifty percent of the furfural that theoretically can be derived from the sample is generated. The resulting mixture is then subjected to a second acid degradation at an elevated temperature to produce levulinic acid. During the second acid degradation, furfural vapors are continuously collected from the mixture.
Inventors
- 👤 Stephen W. Fitzpatrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 02:20
CPC Classifications
C; C07; C07C; C07C51/00; C07D; C07D307/00; C07D307/02; C07D307/34; C07D307/38; C07D307/40; C07D307/46; C07D307/48; C07D307/50
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
150 words
A process for producing furfural and levulinic acid from lignocellulose, said method comprising (1) in a first reactor having an entrance and an exit, subjecting a sample comprising lignocellulose to acid degradation at an elevated temperature for a time less than a minute to yield a degradation mixture comprising at least fifty percent of the furfural that theoretically can be derived from said sample: (2) continuously supplying a volume of said sample to said first reactor through said entrance of said first reactor and continuously removing through said exit of said first reactor a corresponding volume of said degradation mixture and supplying said corresponding volume to a second reactor; (3) in said second reactor, subjecting said degradation mixture to further acid degradation at elevated temperature to produce levulinic acid; and (4) during step (3), continuously collecting furfural from said degradation mixture by condensation of furfural vapors arising from said mixture.
Claim 2
Dependent Claim
150 words
A process for producing furfural and levulinic acid from lignocellulose, said method comprising (1) in a first reactor having an entrance and an exit, subjecting a sample comprising lignocellulose to acid degradation at an elevated temperature for a time less than a minute to yield a degradation mixture comprising at least fifty percent of the furfural that theoretically can be derived from said sample: (2) continuously supplying a volume of said sample to said first reactor through said entrance of said first reactor and continuously removing through said exit of said first reactor a corresponding volume of said degradation mixture and supplying said corresponding volume to a second reactor; (3) in said second reactor, subjecting said degradation mixture to further acid degradation at elevated temperature to produce levulinic acid; and (4) during step (3), continuously collecting furfural from said degradation mixture by condensation of furfural vapors arising from said mixture.
Claim 3
Dependent Claim
18 words
The process of claim 1 further comprising continuously collecting levulinic acid from said degradation mixture during step (3).
Claim 4
Dependent Claim
22 words
The process of claim 2 wherein said levulinic acid is collected by drawing off liquids containing levulinic acid from said degradation mixture.
Claim 5
Dependent Claim
23 words
The process of claim 1 wherein said degradation mixture further comprises lignin, said method further comprising collecting said lignin from said degradation mixture.
Claim 6
Dependent Claim
90 words
The process of claim 1 wherein step (1) is carried out in a first reactor having an entrance and an exit and step (3), is carried out in a second reactor having an entrance connected with said exit of said first reactor, said method further comprising continuously supplying a volume of said sample to said first reactor through said entrance of said first reactor and continuously removing through said exit of said first reactor a corresponding volume of said degradation mixture and supplying said corresponding volume to said second reactor.
Claim 7
Dependent Claim
26 words
The process of claim 1 wherein said first reactor is a tubular reactor and said sample is passed through said tubular reactor without significant axial mixing.
Claim 8
Dependent Claim
15 words
The process of claim 1, further comprising mixing said degradation mixture in said second reactor.
Claim 9
Dependent Claim
21 words
The process of claim 1 further comprising adding a sulfite salt to said sample to prevent clogging of said first reactor.
Claim 10
Dependent Claim
21 words
The process of claim 1 wherein in step (1) said sample is subjected to acid degradation for at least three seconds.
Claim 11
Dependent Claim
22 words
The process of claim 9 wherein in step (1) said sample is subjected to acid degradation for between 7 and 30 seconds.
Claim 12
Dependent Claim
19 words
The process of claim 1 wherein in step (1) said elevated temperature is between 180° C. and 265° C.
Claim 13
Dependent Claim
19 words
The process of claim 11 wherein in step (1) said elevated temperature is between 210° C. and 250° C.
Claim 14
Dependent Claim
23 words
The process of claim 1 wherein in step (1) the aqueous portion of said sample comprises 1 to 10% by weight mineral acid.
Claim 15
Dependent Claim
23 words
The process of claim 13 wherein in step (1) said aqueous portion of said sample comprises 2 to 7% by weight mineral acid.
Claim 16
Dependent Claim
27 words
The process of claim 1 wherein in step (3) said degradation mixture is subjected to acid degradation for an average time of between 1 and 60 minutes.
Claim 17
Dependent Claim
27 words
The process of claim 15 wherein in step (3) said degradation mixture is subjected to acid degradation for an average time of between 2 and 30 minutes.
Claim 18
Dependent Claim
19 words
The process of claim 1 wherein in step (3) said elevated temperature is between 130° C. and 250° C.
Claim 19
Dependent Claim
19 words
The process of claim 17 wherein in step (3) said elevated temperature is between 150° C. and 200° C.
Claim 20
Dependent Claim
24 words
The process of claim 1 wherein in step (3) the aqueous portion of said degradation mixture comprises 1 to 15% by weight mineral acid.
Claim 21
Dependent Claim
24 words
The process of claim 19 wherein in step (3) said aqueous portion of said degradation mixture comprises 3 to 10% by weight mineral acid.
Claim 22
Dependent Claim
43 words
The process of claim 1 wherein in step (1) said elevated temperature is between 210° C. and 250° C.; said sample is subjected to acid degradation for between 7 and 30 seconds; and said sample comprises 2 to 7% by weight mineral acid.
Claim 23
Dependent Claim
53 words
The process of claim 21 wherein in step (3) said elevated temperature is between 150° C. and 200° C.; said degradation mixture is subjected to acid degradation for an average time of between 2 and 30 minutes; and the aqueous portion of said degradation mixture comprises 3 to 10% by weight mineral acid.
Claim 24
Dependent Claim
53 words
The process of claim 1 wherein in step (3) said elevated temperature is between 150° C. and 200° C.; said degradation mixture is subjected to acid degradation for an average time of between 2 and 30 minutes; and the aqueous portion of said degradation mixture comprises 3 to 10% by weight mineral acid.
Claim 25
Dependent Claim
28 words
The process of claim 1 wherein in step (1) said degradation mixture comprises at least sixty percent of the furfural that theoretically can be derived from said sample.
Claim 26
Dependent Claim
28 words
The process of claim 24, wherein in step (1) said degradation mixture comprises at least seventy-five percent of the furfural that theoretically can be derived from said sample.
Claim 27
Dependent Claim
28 words
The process of claim 1 wherein said degradation mixture from step (3) contains at least 30% of the levulinic acid that theoretically can be derived from said sample.
Claim 28
Dependent Claim
28 words
The process of claim 26 wherein said degradation mixture from step (3) contains at least 55% of the levulinic acid that theoretically can be derived from said sample.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |