|Title of Invention||
"A CO2 RECOVERY SYSTEM"
|Abstract||The nozzle contains a laminar-separating element, which is streamed by the aerosol-loaded carbon dioxide-gas. The washer (4) is arranged before the nozzle. The gas balloon is arranged between the nozzle and the compressor. An independent claim is included for a procedure of recovering the fermentation resulting carbon dioxide. (Fig 1)|
|Full Text||Field of the Invention:
The present invention relates to a system for the recovery of CO2 and a method for the recovery of CO2 arising in fermentation according to the generic terms of Claims 1 and 8.
Background and prior art:
CO2 recovery systems or the corresponding methods are currently used in breweries to recover CO2 arising during the main fermentation so that it can be used in other processes such as for example prestressing and emptying storage tanks under pressure, carbonating. bottling, etc.
Fig. 2 shows an example of a CO2 recovery system. Here, the CO2 is removed from the fermentation vessels (not illustrated) via appropriate CO2 extraction devices and first passed to a froth separator 15 which is used to retain any froth that has been carried along. The CO2 gas collects in a large CO2 gas container, so-called CO2 gas balloon 1 1. which acts as a buffer for the collection of the gas. The CO2 is cleared of water-soluble contaminants in the gas washer 4. A CO2 compressor 19 compresses the CO2 in a known method manner to a liquefying pressure in a range from 15 to 22 bar. The liquefied CO2 is then subjected to drying and purification (or vice versa), whereby here the CO2 is first passed to a dryer 16 and then to a filter 17. The compressed CO2 then condenses at low temperature in a CO2 liquefaction system and is then temporarily stored in a C02 storage tank 100 from where it can also be taken for immediate use in the brewery.
During the CO2 recovery often damage can be observed in particular with increased use of high gravity methods in the fermentation section, i.e. during brewing with high wort concentrations, and with the optimization of the net content of the fermenters (reduction of the unfilled space). In this respect also massive corrosion phenomena appear on the above-mentioned pipework, apparatus and machinery (usually pitting). The functional capability, in particular of the CO2 compressors, is substantially impaired due to deposits of aerosols and their constituent substances. This leads to a reduction in the service life of the operational valves and to medium-term damage of glands and piston rods, which can lead to the failure of the complete system.
Objects of the invention:
The object of this invention is therefore to provide a CO2 recovery system for the recovery of CO2 arising in fermentation and an appropriate method with which damage in the pipework, apparatus and machinery of the recovery system can be prevented.
The object is solved according to the invention by the features of Claims 1, 8 and 12.
Summary of the Invention:
The aerosol separator, with which the CO2 gas loaded with aerosols is cleared of aerosols, is arranged before the CO2 compressor. As a result it is possible to prevent aerosols, together with constituent substances carried along with them, from settling in the system
parts of the CO2 recovery system. These types of aerosols arise as constituent substances in CO2 gas particularly with the use of the high gravity method in the fermentation section and during the optimization of the net content of the fermenter. Aerosols are the finest drops of liquid with a diameter between 12 µm and almost 0 µm. These aerosols carry along constitutent substances of the fermenting mixture with the CO2 gas flow to the CO2 recovery system. Such constitutent substances include sugar, hydrocarbons, organic components, which carbonize in the compressor, noticeably damaging it and the following components of the recovery system as described above. However, through the use of the aerosol separator before the compressor, this sort of damage can be prevented.
According to a preferred embodiment, the aerosol separator comprises a watering device to water the aerosol-loaded CO2 gas during the separation. Normally, aerosol separators operate "dry". However, since the substances carried along by the aerosols, in particular various sugars, etc. arc sticky, watering is necessary. The water can collect with the separated aerosols and their constituent substances on the floor of the aerosol separator where it can be level-controlled and extracted.
In a preferred type and manner, the watering device comprises at least one nozzle to spray the aerosol-loaded CO2 gas, or the separation elements with water.
The aerosol separator comprises at least one flat separation element through which the aerosol-loaded CO2 gas flows. As this occurs, the watering device wets at least one separation element with water.
According to a preferred embodiment of the invention a gas washer is arranged before the aerosol separator. A conventional washer of this type, i.e. a spray washer, washer with integral structured packages (e.g. Sulzer Mella Pach, etc.) or washer with packed bed fillings (e.g. Pall rings, Rasching rings, etc.) cannot remove aerosols from the CO? gas flow, but they prevent excessive loading of the aerosol separator through an appropriate preliminary purification. In particular the gas washer clears the CO2 of water-soluble contaminants.
According to a special embodiment, a CO2 gas balloon, which provides temporary storage, is arranged between the aerosol separator and the CO2 compressor. The arrangement of the CO2 gas balloon between the aerosol separator and the CO2 compressor enables gas which has already been purified to be temporarily stored.
The invention is explained in more detail in the following with reference to the following figures:
Fig. 1 shows the schematic layout of an embodiment of the invention.
Fig.2 shows a CO2 recovery system as is known from the state of the art.
The CO2 recovery system according to the invention is used during the brewing of beer.
With the CO2 recovery system according to the invention initially, as in the state of the art, aerosol-loaded CO2 gas is removed from the fermentation tun via a CO2 extraction device (not illustrated). The extracted CO2 gas is loaded with aerosols. The exact location at which the aerosols are produced has not been scientifically determined, it Is assumed however that they arise during sudden changes of pressure caused by gas bubbles as they pass through the surface of the liquid in the fermenter.
With the increased use of the high gravity method in the fermentation section, i.e. with the use of high percentage wort (greater than 12 %) these sorts of aerosols occur more frequently in the CO2 gas. Also increased aerosols have been observed during the optimisation of the net content of the fermenter (reduction of the unfilled space).
According to the invention, the aerosol-loaded CO2 gas is initially fed to a conventional preliminary washer 4 via an appropriate feed line 9. A conventional gas washer is taken to be for example a spray washer, a washer with integral structured packages (e.g. Sulzer-Mella Pach, etc.) and washers with packed-bed fillings (e.g. Pall rings, Raschig rings, etc.). The gas washer 4 removes water-soluble contaminants from the CO2. The contaminants which are washed out can be extracted through the valve 13 from the lower end of the gas washer 4. The washed-out contaminants can be extracted, controlled in level by appropriate level sensors / switches LSH (high level - valve 13 open) and LSI (low level - valve 13 closed). A mechanical floatation valve (WC flushing principle) is also possible.
From the output 10 of the gas washer 4 the prepurified CO2 gas, which is still however loaded with aerosols, is passed to the aerosol separator 1 via the feed line 5. Aerosol separators are in widespread use in chemical engineering, e.g. in the cleaning of flue gases or in the removal of solvents from airflows. This type of aerosol separator consists at least of one flat separator element 2, which is arranged in a container 20. With the embodiment illustrated in Fig. 1 two tubular elements 2a, 2b are, for example, arranged in the container. The element walls here consist of a synthetic fabric. The elements are fitted upright in the container 20. The C02 gas to be purified is passed into the elements 2a, b and leaves the elements in a radial direction.
When flowing through the elements, due to specific mechanisms, such as for example the diffusion effect, medial separation and inhibiting effects, the aerosols, including the substances carried along with them, are removed from the CO2 gas. The CO2 gas can leave the separator 1 more or less free of aerosols via the outlet 6. The aerosol separator facilitates the removal of almost 100 % of all droplets > 3 urn to 99 % of all droplets The embodiment described in connection with Fig. 1 for an aerosol separator is only an example. The elements do not have to be formed tubular, but rather they can be formed, for example, as filter mats through which the aerosol-loaded CO2 gas flows. The separator element also does not have to be formed
from a synthetic fabric, but can for example be formed from a glass fibre fabric or a synthetic needle felt, for example a polyester needle felt or from a fleece, etc.
Since the substances carried along by the aerosols during the C02 recovery are sticky (the various sugars, etc. already quoted), it is advantageous if, as illustrated in Fig. 1, a watering device 3 is provided. The watering device 3 is provided in the housing 20 of the aerosol separator 1. Here, the watering device 3 exhibits a feed 8 for water, and a number of nozzles, which spray water onto the separator elements 2a, 2b. The water then collects with the separated aerosols and their constituent substances on the floor of the container and can be extracted under level control from there via a drain 7 and a suitable valve 14. As described in connection with the gas washer 4, here appropriate level sensors / switches LSH (high level - valve 14 open) or LSI (low level - valve 14 closed) can be provided.
CO2 gas, cleared of aerosols, can be passed to a CO2 intermediate store, here a CO2 balloon 11, via the outlet 6. The purified CO2 gas can then be passed to the CO2 compressor 19, which compresses the CO2 gas as described in conjunction with the state of the art, from the outlet 6 of the aerosol separator 1 or alternatively from the CO2 balloon 11. Furthermore, the device can also as described in conjunction with the state of the art, comprise a device for purifying and drying the compressed, cooled CO2 gas, as well as a C02 liquefaction system and a CO2 storage tank. As can be seen from Fig. 1, the device here also comprises over- and underpressure protection 12 for the CO2 balloon operation.
Through t he u se o f t he a erosol s eparator 1 i n a ddition t o t he g as washer 4, t he C O2 g as, c leared o f water-soluble constituents, can also be cleared of aerosols and the constituent substances carried along with them, so that no aerosols and constituent substances transported with them can settle in the recovery system. In particular, it is possible to prevent damage occurring due to the deposition of such constituent substances in the following parts of the CO2 recovery system. Examples of such damage are massive corrosion phenomena in pipework, apparatus and machinery (usually pitting), impairment of the functional capability of the CO2 compressor 19, drastic reduction in the service life of the operating valves and medium-term damage to glands and piston rods, which can lead to a total breakdown.
1. A system for the recovery of CO2 arising during fermentation with a CO2 compressor (19), characterized in that an aerosol separator (1) is arranged before the CO2 compressor (19) to clear the CO2 gas of aerosols.
2. The CO2 system as claimed in claim 1, wherein the aerosol separator (1) comprises a watering device (3).
3. The CO2 recovery system as claimed in claim 2, wherein the watering device (3) comprises at least one nozzle.
4. The CO2 recovery system as claimed in any one of claims 1 to 3, wherein the aerosol separator (1) comprises at least one flat separation element (2a/2b) through which the aerosol loaded CO2 gas flows.
5. The CO2 recovery system as claims in one of the claims 2 to 4, wherein the watering device (3) waters the atleast one separation element (2).
6. The CO2 recovery system as claimed in one of the claims 2 to 4, wherein a gas washer (4) is arranged before the aerosol separator (1).
7. The CO2 recovery system as claimed in atleast one of the claims 1 to 6, wherein a CO2 gas balloon (11) is arranged between the aerosol separator and the CO2 compressor 09).
8. A method of recovering CO2 arising from the fermentation as clamed in claim 1, wherein the aerosol-loaded CO2 gas is fed to an aerosol separator (1) before being compressed.
9. The method of recovering CO2 arising from the fermentation as claimed in claim 8, wherein the aerosol-loaded CO2 or atleast one separation element (2) watered during the aerosol separation.
10. The method as claimed in claim 8 or 9, wherein the CO2 gas loaded with the aerosol is passed through a gas washer (4) before the aerosol separation.
11. The method as claimed in claims 8 to 10, wherein the CO2 gas is passed to a CO2 balloon before being compressed.
12. Use of an aerosol separator before a CO2 compressor in the recovery of CO2 arising from fermentation.
|Indian Patent Application Number||53/DEL/2006|
|PG Journal Number||21/2005|
|Date of Filing||05-Jan-2006|
|Name of Patentee||KRONES AG|
|Applicant Address||BOEHMERWALDSTRASSE 5,93073 NEUTRAUBLING, GERMANY.|
|PCT International Classification Number||B01D 45/02|
|PCT International Application Number||N/A|
|PCT International Filing date|