PROCESS FOR PRODUCING METHANOL AND/OR METHANE

Abstract

It is disclosed a system for producing methanol/methane, said system comprising an electrolysis section (1) producing hydrogen and oxygen from the cleaving of water molecules, and said system further comprising a closed cultivation/breeding container/pond (5) for aquatic organisms creating CO.sub.2 through their metabolism to be liberated into the water surrounding said organisms forming CO2-rich water, said CO.sub.2-rich water being transported to a CO.sub.2-liberating section forming gaseous CO.sub.2 and CO.sub.2-poor water, said liberated gaseous CO.sub.2 being transported to a reactor (6,6) and being combined with said hydrogen from said electrolysis plant (1) for creating methanol and/or methane as an end product, said methanol/methane being isolated and exited from said system.

Claims

1. A system for producing methanol/methane, said system comprising: an electrolysis stage (1) configured to produce hydrogen and oxygen from the cleaving of water molecules; and a closed cultivation/breeding plant (5) for aquatic organisms creating CO.sub.2 through the metabolism of the aquatic organisms and through biodegradation of faeces and unused feed at the bottom of the breeding/cultivation plant to be liberated into the water surrounding said organisms forming CO.sub.2-rich water, wherein said system is configured to transport CO.sub.2-rich water to a CO.sub.2 liberating section forming gaseous CO.sub.2 and CO.sub.2-poor water, wherein said system is configured to transport said liberated gaseous CO.sub.2 to a reactor (6,6) for reaction with said hydrogen from said electrolysis stage (1) for producing methanol and/or methane as an end product, said methanol/methane being isolated and exited from said system, wherein said system is configured to introduce the oxygen liberated from said cleaving of water molecules into the water in the cultivation/breeding plant (5).

2. (canceled)

3. The system according to claim 1, wherein said oxygen is added to the CO.sub.2-poor water originating from said CO.sub.2-liberating section (7) prior to its re-introduction to the cultivation/breeding plant (5).

4. A process for producing methanol/methane by the use of a system according to claim 1, wherein the methanol and/or methane is formed through the overall reactions
CO.sub.2+3H.sub.2=>CH.sub.3OH+H.sub.2O (I)
CO.sub.2+4H.sub.2=>CH.sub.4+2H.sub.2O (II) wherein the methanol/methane is produced through the steps of: a) electrolysis of water for forming hydrogen gas and oxygen gas, b) isolating carbon dioxide (CO.sub.2) from the CO.sub.2-rich water originating from the organisms' breathing of the water in said plant for forming CO.sub.2 to be sequestered from said water to be used in the reactions (I) or (II) supra, and c) returning said sequestered carbon dioxide to a plant for conducting the reaction(s) (I) and/or (II) supra for creating methanol and/or methane by combining said carbon dioxide with the hydrogen originating from said electrolysis of water, wherein the oxygen liberated from the electrolysis of the water is introduced into the water in the cultivation/breeding plant (5) for the aquatic organisms.

5. The process according to claim 4 wherein carbon dioxide-rich water from a land-based breeding plant for aquatic organisms is used for producing methanol and/or methane by combining said carbon dioxide with hydrogen originating from electrolysis of water and returning the oxygen originating from said electrolysis of the water to the water in the breeding plant for said aquatic organisms.

6. The process according to claim 4, wherein said cultivating/ breeding plant (5) is a closed fish farming plant wherein the water is re-circulated after having been liberated for CO.sub.2.

7. (canceled)

8. The process according to claim 4, wherein hot water originating from the electrolysis of water is supplied to the cultivation/breeding plant to be used in disinfection or slaughtering of edible aquatic animals and/or controlling the temperature in the breeding/cultivating plant.

9. The process according to claim 4, wherein the aquatic organisms are fishes raised in a land-based cultivation/breeding plant.

10. The use of CO.sub.2-rich water originating from a plant for cultivating/breeding aquatic organisms for isolating CO.sub.2 to be reacted with hydrogen originating from the electrolysis of water for forming methanol and/or methane in a process according to claim 4.

11. The process according to claim 4 further utilizing the produced methane and/or methanol for producing fish feed.

12. The process according to claim 5 wherein the land-based breeding plant for aquatic organisms are fish farms.

13. The process according to claim 4 wherein said aquatic organisms are different from fish.

14. The process according to claim 9 wherein the fishes are one or more of carp, mullet, bass, pike, abbor and trout.

15. The process according to claim 13 wherein the aquatic organisms are crustaceans or mollusks.

16. The process according to claim 13 wherein the aquatic organisms are one or more of fresh water crayfish, fresh water pearl clams, and fresh water scallops.

17. The use according to claim 10 wherein the produced methane and/or methanol is used to produce fish feed.

Description

[0034] The present invention will become better understood with reference to the enclosed FIGURE showing an embodiment of a system according to the present invention combining the formation of oxygen 2 and hydrogen 3 from electrolysis 1 of water wherein CO.sub.2 is isolated 4,4 from the water taken from used water including entrained CO.sub.2 from a cultivation/breeding tank/pond 5 for aquatic animals/fish. The isolated CO.sub.2 is reacted with hydrogen originating from the electrolysis 1 of water forming methane and/or methanol 6,6 as explained supra. In one embodiment the methane may be supplied to a bacterial culture 8 as a growth substrate for creating protein to be used in e.g. fish feed. Such protein may in one embodiment constitute about 30% of protein included in such fish feed.

[0035] In an alternative embodiment methanol created by the process according to the invention may be used as a starting material for making more complex substances (e.g. plastics, oil, etc.) or may be used as a fuel or a fuel additive.

[0036] In one embodiment hot water used in the system according to the invention may be supplied from an external source or may be water recirculated from the cultivation/breeding tank 5. In an alternative the CO.sub.2-poor water from the carbon dioxide-extracting section 4 may be supplied with oxygen 2 originating from the electrolysis section 1 of the system according to the invention and be returned in an oxygen-rich state back to the cultivation/breeding tank/pond 5. This is indicated by a dotted line 7 running from the carbon dioxide removal stage 4 to the supply line 2 carrying oxygen from the electrolysis stage 1 to the cultivation/breeding tank/pond 5.

[0037] The energy in the hot water from the electrolysis stage 1 may be heat-exchanged into cooling of the water in closed plants (not shown). Hot water (exceeding 80 C.) being collected as a by-product from the production stages of methanol and methane 6,6, may be used for disinfection or directly for slaughtering fish, and may additionally and optionally be used for drying sludge collected from the cultivation/breeding tank/pond 5. Such sludge may in one embodiment be used as e.g. fertilizer.

[0038] In a closed cultivation system for aquatic animals/fish excess CO.sub.2 should be removed from the water for maintaining acceptable pH values, and the CO.sub.2 is also considered as a waste product with negative environmental effects such as e.g. acidification of the water through the formation of H.sub.2CO.sub.3 and HCO.sub.3. A too high content of CO.sub.2 in the water will also have as a consequence that it will become difficult for the aquatic animals to breathe (the water becomes CO.sub.2-poisoned). Several other environmental consequences, e.g. the prevention and/or treatment of diseases and parasites (e.g. salmon lice), escape, no effect on the environment through medication, removal of waste (feces, dead animals, over-feeding, etc.) is easily taken care of in closed cultivation/breeding systems.

[0039] Regular feed or feed/protein produced from the bacterial fermentation of CH.sub.4 in the fermentor 8 may be introduced into the fish farming tank/pond 5 through lines 9,9.

[0040] 3. The addition of extra oxygen (O.sub.2) to fish cultivation/breeding/farming plants has been recommended in studies performed by IRIS (previously Rogalands-forskning), but integration with a methanol or methane production plant is a new concept. The new concept is to capture CO.sub.2 created by cultivated/bred organisms/fish and process this as a raw material in the methanol/methane plant. This idea is new probably because the technology for producing methanol, as disclosed supra, is rather new. The use of CO.sub.2 in this way reduced the capital expenses with about 30% and the production costs with about 14% for the methanol production and free oxygen and heat assists in making land-based fish raising and breeding plants very profitable. By utilizing CO.sub.2 for producing methane and fish feed about 30% of the expenses may be saved for necessary feed.

[0041] The liberated oxygen expelled from the electrolysis plant 1 may also be used for other purposes than the addition to a fish cultivation/breeding plant, e.g. for combustion systems/plants for garbage, from which further CO.sub.2 may be introduced into the methanol/methane production plant 6,6 (not shown).

[0042] The balance for the methanol production related to fish farming/breeding (per 1000 kg methanol) is: [0043] produced O.sub.2 from H.sub.2O: 1541 kg [0044] 75% of O.sub.2 introduced in the fish farming: 1157 kg [0045] CO.sub.2 available from the fish: 1157.Math.1.2=1388 kg [0046] CO.sub.2 required for producing methanol: 1380 kgbalance

[0047] Some extra oxygen may be provided to the fish because the fish may not be able to assimilate it all. The extra oxygen originating from the electrolysis covers this requirement.

[0048] The enclosed FIGURE depicts a possible flow chart for a system for producing methanol/methane according to the invention, wherein said system includes an electrolysis section 1 producing hydrogen and oxygen from the cleaving of water molecules, and said system further including a closed cultivation/breeding container/pond 5 for aquatic organisms creating CO.sub.2 to be liberated into the water surrounding said organisms forming CO.sub.2-rich water, said CO.sub.2-rich water being transported to a CO.sub.2-liberating section forming gaseous CO.sub.2 and CO.sub.2-poor water, said liberated gaseous CO.sub.2 being transported to a reactor 6,6 and being combined with said hydrogen from said electrolysis plant 1 for creating methanol and/or methane as an end product, said methanol/methane being isolated and exited from said system.

[0049] Technology for harvesting CO.sub.2 from water in an industrial scale is available as explained supra, and the system according to the invention will, in one embodiment, capture the formed CO.sub.2 as well and thereby avoid accumulation. If this security measure should fail, there exist methods for removing CO.sub.2 from water without capturing the CO.sub.2, e.g. like bubbling air through the water in an aquarium.

[0050] The loops for transporting oxygen, hydrogen and carbon dioxide between a methanol/methane production plant and a plant for cultivating/breeding aquatic organisms/fish improve both to a large extent by: [0051] 1. Reducing both capital and production expenses for the methanol/methane production. [0052] 2. Providing a continuous supply of oxygen and energy to the fish raising/breeding plant. [0053] 3. Replacing parts of the need for fish feed.

[0054] In summary the present invention may be presented by the following features:

[0055] The process according to the invention is conducted by producing methanol and/or methane by the reactions (I) and/or (II)

CO.sub.2+3H.sub.2=>C.sub.3OH+H.sub.2O (I)

CO.sub.2+4H.sub.2=>CH.sub.4+2H.sub.2O (II)

wherein the methanol/methane is created through the steps

[0056] a) electrolysis of water for forming hydrogen gas and oxygen gas,

[0057] b) transferring the oxygen gas from step a) to a plant for breeding aquatic animals for oxygenating the water in said plant to be used for the animal's breathing of the water in said plant for forming CO.sub.2 to be sequestered from said cultivation/breeding water to be used in the reactions (I) or (II) supra, and

[0058] c) returning said sequestered carbon dioxide to a plant for conducting the reaction(s) (I) and/or (II) supra for creating methanol and/or methane by combining said carbon dioxide with the hydrogen originating from said electrolysis of water.

[0059] Alternatively the invention may be viewed as using carbon dioxide-rich water originating from a cultivation plant/container/pond for aquatic animals/fish, after the liberation of said carbon dioxide from said cultivation/breeding water, to be combined with hydrogen originating from electrolysis of water for forming methanol and/or methane.

[0060] The aquatic animals such as fish that may be cultivated/bred in a closed cultivation/breeding plant comprises fish types such as e.g. carp, mullet, bass, abbor, pike, trout, etc. The water used for cultivating/breeding the aquatic animals may be salt or fresh, fresh water being preferred. Organisms thriving in fresh water other than fish, and that may be cultivated in a land-based closed cultivation/breeding plant either alone or together with the different fish types, may be fresh water crawfish, fresh water clams, pearl fresh water oysters, etc.