US4652374A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for anaerobic fermentation of solid wastes in water in two phases
Assignee: Paques BV
•
Filing: 1984-09-07
•
Granted: 1987-03-24
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Expires: 2004-09-07
Abstract
Abstract A solid organic waste is fermented in water in two phases, a hydrolysis/acidification phase and a methane fermentation phase. Solid organic waste is introduced in the first phase, of which waste at least 80% of the volume has a particle size larger than x mm, x being between 0.25 and 1.5 mm dependent on the introduced solid organic waste. The waste in the first phase is continuously or periodically stirred and is screened for the removal of particles smaller than x mm with liquid, whereafter the smaller particles are separated from the liquid and the so-separated liquid is at least mainly supplied to the methane fermentation space, while the separated smaller particles are recirculated to the first phase reactor and/or discharged.
Inventors
- 👤 Alberto Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:33
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/02; C02F11/04; C12; C12M; C12M21/00; C12M21/04; C12M45/00; C12M45/04; C12M45/06; C02F3/00; C02F3/28; C02F3/286; Y; Y02; Y02E; Y02E50/00; Y02E50/30
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
129 words
A process for the anaerobic fermentation of solid organic wastes in water in a first hydrolysis/acidification phase and a second methane fermentation phase, said process comprising the steps of: introducing said solid organic waste into a reaction space of the first phase, at least 80% of the volume of said organic waste having a particle size larger than X mm, X being between 0.25 and 1.5 mm depending on the solid organic waste introduced; continuously or periodically stirring said organic waste; screening said organic waste for the removal of particles smaller than X mm with liquid; separating the particles smaller than X mm from the liquid; supplying said liquid from said separation step to said methane phase; and recirculating said separated smaller particles to said first phase reaction space.
Claim 2
Dependent Claim
129 words
A process for the anaerobic fermentation of solid organic wastes in water in a first hydrolysis/acidification phase and a second methane fermentation phase, said process comprising the steps of: introducing said solid organic waste into a reaction space of the first phase, at least 80% of the volume of said organic waste having a particle size larger than X mm, X being between 0.25 and 1.5 mm depending on the solid organic waste introduced; continuously or periodically stirring said organic waste; screening said organic waste for the removal of particles smaller than X mm with liquid; separating the particles smaller than X mm from the liquid; supplying said liquid from said separation step to said methane phase; and recirculating said separated smaller particles to said first phase reaction space.
Claim 3
Dependent Claim
26 words
Process according to claim 1, characterized in that the solid organic waste to be treated is continuously introduced in the reaction space of the first phase.
Claim 4
Dependent Claim
35 words
Process according to claim 1 characterized in that the waste, which has to be fermented, is successively transported through at least one reaction space wherein at least a part of the first phase is performed.
Claim 5
Dependent Claim
20 words
Process according to claim 1, characterized in that in the reaction space of the first phase aqueous liquid is added.
Claim 6
Dependent Claim
28 words
Process according to claim 4, characterized in that the solid organic waste is mixed with at least a part of that aqueous liquid before entering the first phase.
Claim 7
Dependent Claim
24 words
Process according to claim 4, characterized in that the aqueous liquid is totally or partly originating from the effluent of the methane fermentation phase.
Claim 8
Dependent Claim
29 words
Process according to claim 4, characterized in that the aqueous liquid is totally or partly waste water of organic origin containing no inhibiting substance for the methane fermentation phase.
Claim 9
Dependent Claim
30 words
Process according to claim 1, characterized in that particles smaller than x mm separated from the liquid are at least partly recirculated to the reaction space of the first phase.
Claim 10
Dependent Claim
37 words
Process according to claim 1, characterized in that at least in the first reaction space of the first phase the volume percentage of aqueous liquid added to this reaction space is 0-150% per volume of bulk waste.
Claim 11
Dependent Claim
26 words
Process according to claim 9, characterized in that this volume percentage of aqueous liquid added to this reaction space is 25-100% per volume of bulk waste.
Claim 12
Dependent Claim
48 words
Process according to claim 9, characterized in that the effluent of the methane fermentation phase is recirculated at least partly in such a way, that recirculated effluent is introduced in the reaction space of the first phase and the organic waste content is maintained in that reaction space.
Claim 13
Dependent Claim
28 words
Process according to claim 1, characterized in that the screening of the waste takes place on the screen surface situated mainly above the waste in that reaction space.
Claim 14
Dependent Claim
69 words
Process according to claim 12, characterized in that a transporter transports the waste over a screen surface, over an opening variable in size through which a determined part of the waste or the total waste, transported by that transporter, is recirculated in that reaction space, dependent on the size and/or the periodes of opening of that opening, and removes at the same time the remaining part of the waste.
Claim 15
Dependent Claim
31 words
Process according to claim 1, characterized in that the collecting space for the liquid which is separated during the screening of said organic waste, is periodically or continuously flushed by liquid.
Claim 16
Dependent Claim
24 words
Process according to claim 14, characterized in that said collecting space for the liquid is flushed by the effluent from the methane fermentation space.
Claim 17
Dependent Claim
41 words
Process according to claim 14, characterized in that said collecting space for the liquid is flushed by liquid which, during the separation of the smaller solid particles and the liquid, is separated from the material that has passed the screen surface.
Claim 18
Dependent Claim
13 words
A process according to claim 1 wherein said separated smaller particles are discharged.
Claim 19
Dependent Claim
21 words
A process according to claim 1 wherein said separated smaller particles are recirculated to said first phase reaction space and discharged.
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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) | 1990-03-23 | 1990-09-22 | 1991-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-23 | 1994-09-22 | 1995-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-23 | 1998-09-22 | 1999-03-24 | $7700.00 | Window Closed / Lapsed |