WO2012056432A1

WO2012056432A1 - Gas processing system

Info

Publication number: WO2012056432A1
Application number: PCT/IB2011/054815
Authority: WO
Inventors: Remo Crosato
Original assignee: L.A.S.I S.R.L.
Priority date: 2010-10-27
Filing date: 2011-10-29
Publication date: 2012-05-03
Also published as: EP2633023A1; ITVR20100205A1

Abstract

To avoid polluting emission problems and costly disposal, a processing method is proposed for gaseous products of a crushed vegetable product (M) contained in one or more fermentation or processing tanks (12, 112, 212, 312), characterized by recycling the gaseous products without substantially dispersing them into the atmosphere.

Description

GAS PROCESSING SYSTEM

The present invention relates to a processing system and method for the purpose of recycling the gases produced by alcoholic fermentation of a crushed vegetable product. In the following the CO2 generated during winemaking is taken as an example.

The latest available data estimated the world production of wine in about 290 million hectoliters. During wine-making the alcoholic fermentation produces about 45 liters of CO2 per liter of produced wine. This means 2,600,000 tons of CO2 produced by fermentation alone, to which adds the technical CO2 normally bought in cylinders and used as an inert gas and anti-oxidant during the pressing, maceration of crushed grapes, storage and bottling. The technical CO2 is dispersed into the environment too, along with that generated by or used in the fermentation of beer and all other alcoholic beverages.

The release in atmosphere of CO2 is a data increasingly guarded by modern science and ecology, that with concern correlates it with the greenhouse effect and global wanning on Earth.

Even if the CO2 generated by fermentation is mostly that captured earlier from the atmosphere through vegetal photosynthesis, every re-entry must be approached carefully and considered a polluting activity. If one could somehow avoid it the net extraction/ emission balance into the atmosphere would be favorable, and, given the increasingly alarming reports on climate, every step towards safeguarding the environment can only be appreciated and supported.

The traditional winemaking considers the CO2 generated by the fermentation process as a by-product that is simply expelled into the environment.

Only a minority of fermenters uses CO2 for fermentation processes: either as an inert gas, or to transform malic acid into lactic acid even before the alcoholic fermentation, or to facilitate the transition of the anthocyanins from the peel to the pulp, coloring the must that derives from it, or extracting the flavourings present in musts and skins.

Fermenters as in EP 2058384 trap and accumulate the fermentation CO2 in an auxiliary tank, and then re-enter it into the must which has generated it. Or, as in EP 1314778 too, the CO2 is used under pressure to make pumping-over thereby eliminating the use of pumps.

However, the exploitation of CO2 is restricted to the tank that produced it, and after some recirculation is released in the atmosphere just the same.

The main object of the invention is to improve the state of the art by making the traditional fermenters more ecological. Other preferential objects are:

- to reduce the emission of CO2 in the atmosphere and/or

- to reduce winemaking costs by limiting the use of commercial CO2 cylinders, and/or

- to produce low cost CO2, and/ or

- to use stored and compressed CO2 to achieve energy savings, and/or

- to improve the cooling system in heat exchangers, e.g. refrigeration pockets, located on the storage and winemaking tanks. Hie objects are achieved by a processing method for gaseous products of a crushed vegetable product contained in one or more fermentation tanks, characterized by recycling the gaseous products without substantially dispersing them into the atmosphere.

Hie recycling of gases, mainly CO2. not only prevents the emission and the need to safely evacuate the gases, but also reduces the needs for technical gases by reusing the recovered ones, particularly if the gaseous products are captured and processed to put them in the form of usable gas outside of the one or more tanks.

During the fermentation and/or the processes of movement of liquid in the cellar the CO2 under pressure can be used as a driving force to move wines, musts, or liquids, i.e. as a replacement of conventional pumps with electric motor, with considerable energy savings.

One can also take advantage of the heat generated in the expansion process of CO2. from compressed to expanded, e.g. from 25 bar and 20 °C to 1 to 8 bar. One can, for example, cool the coolant used to cool the heat exchangers (cooling pockets) placed on storage and winemaking tanks.

In other words, the endothermic power of stored gases is exploited when they evaporate. E.g. when the CO2 evaporates and expands, it cools the environment a lot, and making it evaporate in a condenser or coil installed e.g. on a coolant tank. By recirculating such liquid in the cooling pockets of fermentation and storage tanks one can refrigerate several batteries of tanks. Another possibility is to mount the CO2 condenser directly on one or more winemaking apparatuses: the gas is directly exploited as a cooler. It can therefore be hypothesized that recovered CO2 becomes, with a simple expansion plant, a cooling unit operating by recovered CO2. The winemaking apparatuses usually are constructed with circulating-fluid thermo- regulating pockets, the fluid being cooled by traditional cooling units that are environmentally polluting and have huge energy consumption. The result is costly and challenging- to-build structures. The increased cooling power of the gases and their availability in the storage tanks make them a convenient substitute for the normal refrigeration and temperature control plants.

It must be considered that during winemaking the fermentation processes on one hand produce CO2. but on the other they produce heat that must be lowered and controlled, otherwise ''tnermo- winemaking'¹ is triggered, resulting in destruction of the fermentative yeast strains and fermentation stops. The energy expended in the process of pressurized storage of fermentation CO2 is compensated by the energy saved for cooling. The CO2 stored under high pressure and then converted to CO2 at low pressure can then be used in the cellar for moving liquids, to inertize, and more.

The recovered gas can also be compressed and liquefied, so as to store them easily in cylinders.

Preferably the one or more tanks are connected with an accumulation environment to accumulate therein the gaseous products generated in each tank; as an alternative e.g. one can recover the gas tank by tank, emptying one at a time with a movable collecting means.

Preferably the gaseous products are separated in the gases that compose them in order to retrieve them individually, thereby increasing the flexibility and opportunities of use for the recovered gases. Preferably the separation takes place directly in the accumulation environment, for better efficiency and less complexity.

A gas very suitable for separation, when present, is CO2.

To adjust the flow of recovered gas, the amount of the chosen separated gas is controlled in an accumulation environment, e.g. the CO2. in an accumulation environment and over a given threshold the gas is drawn and compressed in cylinders or containers.

To increase the recovering capability, from the gaseous products the flavors are extracted. Such extraction can occur in the accumulation environment for better practicability.

The invention generally contemplates also a method for the exploitation of the fermentation gaseous products of a (preferably crushed) vegetable product, comprising:

- putting the product to ferment into a tank;

- drawing the gaseous products from the tank, compressing and storing them under pressure in cylinders or containers. From the gaseous products also the flavourings can be distilled and purified.

The economical impact of this method and its capability to save a lot of gas supplies are noticeable.

Note that the fermentation facilities or apparatus herein described and claimed, as well as the methods, can process not only crushed or vegetal material but biomass as well, such as sewage, drains, biological waste, etc.

In cellars or biomass plants recovery and storage of gases, especially CO2. reduces costs and bulk for activities such as:

- inerting the products being processed, by exploiting the recycled inert gases;

- the injection of gases in winemaking apparatuses, such as the one described in WO 2010105675;

pressuring storage tanks whose internal pressure is used to move liquid or fluid masses;

additivation and integration during the fermentation and/ or maceration processes e.g. on grape must.

For each method a phase can be added of: making CO2 recovered from fermentation expand to refrigerate tanks directly and/ or indirectly, for example by using the expansion of recovered CO2 in special plants that replace the traditional cooling and temperature control systems unit of tanks, living and working environments as homes and offices, or other temperature-controlled environments such as actual refrigerators for cold storage, and/or

using CO2 recovered from fermentation to inert tanks, and/or

- using CO2 recovered from fermentation as an additive in fermentative processes (e.g. the breaking of the cap) or for the movement of liquids and/or crushed material.

To carry out the method a complex can be used for the treatment of gaseous products of a fermenting crushed vegetable, comprising

- one or more tanks for the fermentation of the crushed vegetable,

- a network of ducts for connecting the one or more tanks to an accumulation environment, in order to accumulate in the latter the fermentation gaseous products generated in each tank.

The system is not complicated to put into practice and guarantees an almost zero-cost performance, as well as savings on gas supplies and safety evacuation systems.

The accumulation environment can advantageously comprise a separator for the introduced gaseous products adapted to separate the fed gas mixture into the primary gases that compose it.

To store the recycled gases the complex can comprise a compressor connected to the accumulation environment to fill cylinders or containers with a gas isolated inside the accumulation environment. The direct, on-site packing of the gas in a form usable simply advantages the activity of e.g. a cellar and avoids movements. The outflow from the accumulation environment can be facilitated and monitored easily if the environment comprises a quality and/or quantity sensor of a specific gas, capable of detecting whether the specific gas exceeds or is below a certain threshold. Hie complex can also comprise, in the accumulation environment, storage means for extracting the flavors from the gaseous products. It is then created a second recycling process, parallel to that for the gas.

Preferably the complex comprises a compressing station comprising a compressor, a filtering unit and a refrigerating unit, the station being connected downstream the accumulation environment. Hie advantage is to compress and liquefy e.g. the CO2 in a very fast and efficient way.

Hie invention also refers to a refrigerating apparatus or heat remover, with the features described herewith in the following, which exploits, through means adapted for that, the expansion or condensation of the recovered gases, e.g. CO2. Particularly the apparatus can comprise a volume for storage or cold maintenance to which heat is subtracted by means of said expansion or condensation.

Additional features and advantages of the invention will be more clear from the description of an exemplary CO2 recycling system, along with the annexed drawing in which:

Figure 1 shows a plan diagram of a cellar;

Figure 2 shows a side view of two components of the cellar of Fig. 1;

Figures 3-5 show variants of the system according to the invention.

Figure 1 shows a plan of a cellar organized according to the invention. There are many winemaking apparatuses 12, e.g. such as those in EP 2058384 or EP 1314778, containing fermenting must.

The winemaking apparatuses 12 are all reached by a duct or pipe 14 to which they are connected. The duct 14 collects the gases produced by fermentation in each winemaking apparatus 12, mostly CO2. The gases are conveyed in the duct 14 after they have terminated their enological function, e.g. as a means to break the cap (see EP 2058384), or instead of being dispersed in the environment.

The branches of the duct 14 that draw gas from the winemaking apparatuses 12 converge on a section 18 that conveys the gases to a metal gas accumulation tank 20. In the tank 20 are thus stored all the gases produced in the apparatuses 12, and flavorings can also be distilled.

A conduit 22 puts into communication the tank 20 with a compressor 24, from which a conduit 26 extends to a regulator or dispensing station 28 (preferably constituted of a compressor, and in case of a cooling unit too).

Such unit serves to lower the temperature of the gas to be stored so as to reach the proper temperature/pressure combination for the gas for its liquefaction and cryogenic storage in special cryogenic tanks. There can be a filtering unit, useful for removing unwanted organic and inorganic particles contained in the CO2 and expelled during the fermentation processes. Or the filtering unit can be used to selectively remove other gases which, being by-product of physical/ chemical processes that occur during fermentation or injected in the musts from outside (air, oxygen, nitrogen, argon, etc.), are mixed with the fermentation CO2.

At the station 28 are connected cylinders 30 to be filled. Another duct 32 puts into communication the tank 20 with an auxiliary tank

34, in which flavorings extracted from the gas are stored.

Shown in Figure 2 is part of the storage and gas recovery system, limited for the explanation to one single apparatus 12.

The winemaking apparatus 12 has e.g. two wine-making cells 80, 82 (in dotted lines), of which one is usually optional. The cells 80, 82 are communicating between each other by means of a conduit 40, which also connects them to the collecting duct 14. Valves 42, 44, 46 allow to interrupt the gas flow to the duct 14, or between the cells 80, 82.

The CO2 weighs about twice the air and nitrogen, so in a volume saturated with these gases it tends to stratify at the bottom. One can then separate the CO2 from the lighter gases e.g. by providing a storage tank 20. Alternatively it can be envisaged to use several small tanks connected in series, each of which has the function of separating a given gas and to distill some different type of flavorings at different condensation temperatures.

Hie storage tank 20 comprises an internal diaphragm or dividing means 50 and two CO2 sensors 52, 54, placed at two different heights. The diaphragm 50 serves to vertically partition the interior of the tank 20 into two sub-volumes 90, 92 communicating between each other only through one or two passages 60, 61 having an aperture much lesser than the section of the tank 20.

The duct 14 leads to the roof or top portion of the tank 20, in any case above the diaphragm 50. Inside the tank 20, near the bottom, there is a level sensor 56 for condensed and distillated flavorings. The condensation of these flavors is promoted e.g. by a cooling pocket 58, which affects the lateral band of the tank 20 near the bottom, and/or with special heat exchangers; the band or coil external to the tank, however, could also be placed inside the same and/or a tube bundle or a combination of these different technical solutions can be envisaged.

The system works as follows.

When in one or both of the two cells 80, 82 there is fermentation gas no longer useful to the winemaking, the valve 46 and the valve 42 or 46 are opened. The gas under pressure rises in the conduit 40 and is pushed into the duct 14, up to inside the tank 20. The valves 46 of the other apparatuses 12 are preferably closed to prevent backflow or interference in the control of winemaking pressure.

The jet of gas coming into the tank 20 is tumultuous and instantaneous, and forms turbulences F above the diaphragm 50. After the initial agitation, the gas in the tank 20 stabilizes and by gravity stratifies. The

CO2 is the heaviest of the components of the injected gas (usually nitrogen and air), and slipping on the diaphragm 50 accumulates on the bottom, see reference MC. During the subsequent injection of gas, the diaphragm 50 also protects against turbulence F the sedimented and isolated CO2, avoiding the mixing thereof.

The minimum and maximum level of CO2 on the bottom is controlled by the two sensors 52, 54. Only when the level reaches a maximum indicated by the upper sensor 52 the compressor 24 activates to store the CO2. while it is off when the level is minimal, reported by the sensor 54.

These sensors 52, 54 could be pressure detectors capable to detect the increased pressure of the CO2 pre- accumulation tank(s) 20 at the moment in which the CO2 comes from the fermentation tanks. When the pressure in the tank 20 reaches a set value (e.g. 100 mbar), the compressor 24 activates until the pressure in the tank 20 will drop to a minimum set level (e.g. 30 mbar).

This allows the compressor 24 to work in optimal conditions with a constant and prolonged load, without fluctuations. In addition, the pressure inside the tank 20 is well controlled to avoid structural damage, e.g. implosion.

At the bottom of the tank 20 (or of the tanks battery) all flavorings AR contained in the gases condense. By a conduit 32 the flavorings can accumulate into a dedicated tank 34, or can be sent to a filling station of supply containers. The sensor 56 serves to control the level of flavorings and stop the discharge below a certain threshold or until emptying.

If the diaphragm 50 is arranged inclined with respect to the horizontal axis of the tank 50 two passages are more preferable than two. The CO2 coming from the fermenters 12 will flow in the lower sub-volume 92 via the lower passage 61, while through the upper passage 60 can raise and accumulate in the upper volume 90 any other residual gas.

The advantage of this gas filtration and separation system is evident, being very selective but at zero cost.

One could use, instead of the tank 20, one or more normal winemaking or storage tanks with heat exchangers ("refrigeration pockets") having, for the sole duration of the winemaking, function of buffer tank to receive CO2 and distiller of flavors. This way the plant cost will be remedied for one or more special buffer tanks. At the end of alcoholic fermentation, said the tank(s) can be reused in their primary storage function.

When the diaphragm with respect to the support plane of the winemaking apparatus is horizontal (e.g. with conical or flat shape), the passage for the gases can also be one, allowing a simultaneous rising gas flow for lighter gases, and a descending one of the CO2.

The function of the diaphragm and of the gas passages is to divide the volume inside the tank 50 into two sub-volumes: the top sub-volume to contain whirling flows in the inlet gas, the bottom sub-volume to collect CO2 for dewatering flavors and to be pumped into the dispensing station 28.

The invention also contemplates, when it proves beneficial to improve the separation of gases, to use more than one diaphragm inside the tank 50. The optimal choice must be made in relation to the type of gases to be separated.

The system of the invention works well with fermenter that recover the CO2 and exploit it internally, e.g. as in EP 2,058,384, or that simply convey outside that generated by the must. In the first case to the tank 20 arrive impulsive releases of CO2, in the second a regular but lower flow.

To avoid a pressure control in the tank 20, or a triggering for the compressor that evacuates the CO2, (Fig. 3) as a means for storing the gases a bag or inflatable membrane 188 can be used, e.g. made of FVC, coupled to the roof of a rigid tank 120. From a fermenter 112, with must M in it which created a cap CP, through a conduit 114 the gas produced by the fermentation comes whirling in the bag 188. CO2 falls by gravity and sediment in the tank 120, and from here it is drawn through a conduit 122 (as before). The condensated flavorings AR are recovered by a conduit 132 (as before).

The advantage of the bag 188 is that its volume variations compensate both the gas inlet by the fermenters 112, which are, if uncontrolled, with random rates of flow, and the decrease of CO2 due to the flow in the duct 122.

The inflatable bag can be at the input of the rigid tank (Fig. 3) or at its output (Fig. 4).

An inflatable bag or membrane 288 is coupled via a conduit 222 to the bottom of a rigid tank 220. Through a conduit 214, the gas produced in a fermenter 212, with must M in it which has formed a cap CP, comes whirling into the tank 220. CO2 by gravity sediments and expands into the bag 288, and from here it is aspired through a conduit 226. The condensed flavors AR at the bottom of the tank 220 are retrieved by a conduit 232. This configuration can be beneficial when the pulses of gas from the fermenters are very violent and it is advisable to have metal walls that will withstand the impact waves. Note that the inflatable bags or membranes are less expensive than metallic tanks and easily displaceable. In Fig. 5 it is shown a variant in which the means for collecting and recovering the fermentation gases consist of an inflatable bag 388. The bag 388 is coupled via a conduit 314 to the roof of a fermenter 312, with must M in it which formed a cap CP. The gas produced by the fermentation comes whirling in the bag 388, makes it swell and then by gravity the CO2 sediments downwards.

A conduit 326 allows to suck up the CO2. while the condensed flavors AR at the bottom of the bag 388 are retrieved by a duct 332.

This configuration can be advantageous when the entire volume of collected gas, although perhaps still with CO2 mixed and not separated, must be moved in the cellar or brought to a different user. Note that the bag filled with a gas is still very light and easily transportable.

As an addition, one can arrange into one of the described bags a diaphragm analogous to the internal diaphragm 50, preferably foldable.

A further advantage of the invention is that the conveyance of the CO2 solves the problem of exhalations in the cellar. During the fermentation the cellar should be ventilated by expensive equipment, in order to prevent the accidental death of operators for CO2 poisoning, which can very quickly reach concentrations at ground level very dangerous to humans. And to work with closed tank constantly emptied of CO2 prevents workers to die by asphyxia (as has happened in recent cases) when they open the manhole for maintenance or wine control.

Claims

1. Processing method for gaseous products of a crushed vegetable product (M) contained in one or more fermentation or processing tanks (12, 112, 212, 312), characterized by recycling the gaseous products without substantially dispersing them into the atmosphere.

2. Method according to claim 1, wherein the gaseous products are captured and treated to put them in form of gas usable outside the one or more tanks.

3. Method according to claim 1 or 2, wherein the one or more tanks are connected with an accumulation environment (20, 188, 288, 388) to accumulate therein the gaseous products generated in each tank.

4. Method according to any one of the preceding claims, wherein the gaseous products are separated in the gases that compose them in order to retrieve them individually.

5. Method according to an one of the preceding claims, wherein from the gaseous products the present CO2 is separated.

6. Method according to claim 5, wherein

- in an accumulation environment (20, 188, 288, 388) the amount of a given separated gas is controlled, and

- over a certain threshold it is taken and is compressed in cylinders or containers (30).

7. Method according to one of the preceding claims, wherein the flavors are extracted from the gaseous products.

8. Method for the exploitation of the fermentation gaseous products of a vegetable or biomass product, comprising:

- putting the product (M) or biomass to ferment into a tank (20, 112, 212, 312),

- drawing the gaseous products from the tank, compressing and storing them under pressure in cylinders or containers (30).

9. Method according to one of the preceding claims, wherein the CO2 recovered from fermentation is made to expand to refrigerate tanks or environments, such as e.g. offices, houses or working places.

10. Method according to one of the preceding claims, wherein the CO2 recovered from fermentation is used to inert tanks.

11. Method according to one of the preceding claims, wherein the CO2 recovered from fermentation is used as an additive in fermentative processes or for the movement of liquids and/or crushed material.

12. Complex (10) for the treatment of gaseous products of a fermenting pressed vegetable or biomass, comprising

- one or more tanks (12) for the fermentation of the pressed vegetable or biomass,

- a network of ducts (14, 18) for connecting the one or more tanks to an accumulation environment (20), in order to accumulate in the latter the fermentation gaseous products generated in each tank.

13. Complex according to claim 12, wherein the accumulation environment comprises a separator (50) for the introduced gaseous products adapted to separate the fed gas mixture into the primary gases that compose it.

14. Complex according to claim 12 or 15, comprising a compressing station comprising a compressor, a filtering unit and a refrigerating unit, the station being connected downstream the accumulation environment.

15. Refrigerating apparatus or heat remover comprising means for making expand or condensate the gases recovered according to the methods in the preceding claims.