Food or edible material: processes – compositions – and products – Fermentation processes – Material is mammal or fowl derived
Patent
1980-10-17
1983-01-18
Lander, Ferris H.
Food or edible material: processes, compositions, and products
Fermentation processes
Material is mammal or fowl derived
426807, 426 55, 71 10, 71 21, 48197A, 210603, 210609, 210630, 210903, 435167, 435813, 435819, A23L 131
Patent
active
043691943
DESCRIPTION:
BRIEF SUMMARY
The invention has for its object a method of treating manures, whatever they be, notably bovine, ovine or porcine manures, which consists in diluting the manure, introducing the resulting liquid mixture into a bioreactor in order to produce biogas, separating the solid manure particles from the liquid, and drying the recovered manure particles in a burner-type drier fed with biogas from the bioreactor, at least one fraction of the separated liquid being recycled and utilized for diluting the manure, all the process aiming at producing high-protein residues usable as cattle food and residues usable as fertilizers.
A plant of this character is disclosed in the U.S. Pat. No. 3,838,199. In this plant the liquid mixture containing at least 10% of solid matter, must be kept during 121/2 days in the bioreactor and all the residual liquid is recycled. However, such a plant can only be operated with extremely clean manures, that is, free of straw or other vegetable or mineral waste, but such conditions are not found in actual practice.
On the other hand, the amount of recycled water is too high and causes the plant to be rapidly choked up due to the excess of inorganic salts. This choking effect should take place after about 15 days. Moreover, the dwelling time in the bioreactor is too long. This long dwell not only requires a very large gas-holder, but causes a floating layer of dead bacteria to develop in the bioreactor and choke the system. Finally, the important problem of ammonia treatment is not tackled.
A similar process, but without any recycling of the residual liquid, is disclosed in the U.S. Pat. No. 3,973,043. It is also contemplated therein that the liquid mixture contains at least 10% by weight of solid matter. The dwell in the bioreactor is at least 10 days. It is necessary to discharge the bioreactor periodically, and this implies closing down the plant. It is contemplated to utilize as such, as cattle food, the residue from the anaerobic fermentation, and this is attended by a risk that this residue is not sterile. It is also contemplated to utilize the waste-water as such, as a fertilizer. Now this waste water is likely to cause a nitrification of the soil. In addition, the transport of such waste-water may be prohibited for in many instances waste-water is not sterile.
A water nitrification/denitrification process has been proposed in the French Pat. No. 898,669. However, it is applicable only to drinking water having a low ammonia content. Now, in a plant such as the one constituting the subject-matter of the invention, very high ammonia concentrations are found in waste water. In the plant according to the prior art a sand-filled nitrifier is used, but this is detrimental in that it retains dead matters and must be washed periodically.
It is the object of the present invention to provide a method and a plant for carrying this method, adapted to be utilized under actual service conditions, with a high efficiency, eliminating any risk of choking or jamming by reducing the dwell in the bioreactor and producing sterile residues, notably sterile and denitrified waste-water which can be discharged directly into the town sewage system.
This object can be attained with the method according to the invention.
By combining a fine manure shredding step with the control of the mixture, limiting the concentration to a maximum value of 4% and re-heating the bioreactor by means of the condensate, it has been possible to reduce the dwell in the bioreactor to four days and even less, according to cases, and this four-days dwell gave a gas yield of 200 cu.cm./gr., a result equivalent to 24 days according to the diagrams prepared by Prof. W. Baader, Braunschweig, published by "Biogas in Theorie und Praxis", KTBL. The production of methane begins even on the first day. The thermal drying energy is utilized directly and twice by the water vapor and its condensate, firstly in the bioreactor, then in the nitrification-denitrification subplant, in which the supply of additional heat appears to be necessary.
The inventi
REFERENCES:
patent: 3838199 (1974-09-01), Coe et al.
patent: 3953327 (1976-04-01), Parker
patent: 4198211 (1980-04-01), Shattock
patent: 4252901 (1981-02-01), Fischer et al.
Adams Bruce L.
Burns Robert E.
Lander Ferris H.
Lobato Emmanuel J.
Societe Agricole et Fonciere S.A.F. S.A.
LandOfFree
Process for treating manures does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for treating manures, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for treating manures will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-137279