KR19990008041A - Treatment of coffee flavored gas - Google Patents

Abstract

Coffee gas gas drying method. The stream of coffee-flavored gas is contacted with a molecular sieve containing zeolite that has a pore size that minimizes the coffee-flavored gas coffee component but removes water molecules. Thus, water is removed from the coffee aroma gas. The coffee aroma gas can be dried to such an extent that the loss of flavor components is reduced.

Description

Treatment of coffee flavored gas

1 is a schematic flow diagram of a drying process;

2 is a partial cross sectional view of a drying column;

3 is a partial cross-sectional view taken along the line 2-2 of FIG. 2.

Referring to FIG. 1, the coffee fragrance obtained from the coffee extraction system (not shown) is introduced via the fragrance line 58. Coffee aroma gas can be obtained from any suitable source of aroma upon coffee extraction; The coffee flavor gas disperses fresh ground roasted coffee as an inert gas, washes the grinder while grinding roasted ground coffee, stirs the roasted ground coffee with water vapor, and collects the gas released during coffee extraction. , Coffee extract is obtained by gas dissipation and the like.

Depending on its source, the coffee flavor gas is typically prepared as a mixture of inert dissipating gas (eg nitrogen, helium or carbon dioxide or a mixture of nitrogen and helium or a mixture of carbon dioxide), coffee flavor, carbon dioxide and moisture.

Through incense line 58, depending on factors such as the source of the coffee aroma gas, the amount of water used in the quenching of the roasting process, the grain size of the coffee, the treatment of the coffee and the ratio of the mass of the inert gas to the mass of the coffee incense line 58 The water content of the coffee flavor gas entering can be very wide; For example, from about 3 to about 10 g-water / kg-dry gas.

Incense line 58 goes to the first four-way valve 60. Four-way valve 60 connects incense line 58 to either of the two incense inlets lines 21a, 21b.

The other of the two fragrance inlet lines 21a, 21b is connected to the gas outlet 64.

The figure illustrates that the incense inlet line 21b is connected to the gas outlet 64 while the incense line 58 is connected to the incense inlet line 21a. Turning properly to the four-way valve 60, the incense line 58 may be connected to the incense inlet line 21b while the incense inlet line 21a is connected to the gas outlet 64.

The incense inlet line 21a leads to the first dry column 20a while the incense inlet line 21b is connected to the second dry column 20b. Thus, the coffee fragrance gas entering through the fragrance line 58 moves to the first drying column 20a.

Drying columns 20a and 20b are the same and are best described in FIGS. 2 and 3 when the drying column is equal to the reference numeral 20. Referring now to FIGS. 2 and 3, drying column 20 forms a tubular shell 29 having an upper flange 32b at its top and a lower flange 32c at its lower end. The plurality of tubes 27 are located perpendicular to the tubular shell 29 extending from the upper end to the lower end of the tubular shell 29.

Each tube 27 is filled with zeolite beads. Zeolite beads are commercially available and can be obtained, for example, from Degussa GmbH of Germany and CU Chemie Uetikon of Uetikon, Switzerland.

The upper closure 25 is located over the upper end of the tubular shell 29 to seal the closure 25. The upper closure 25 has a flange 32a that can be secured to the bolt 32b, for example, to the bolt, thereby securing the upper closure 25 on the tubular shell 29.

The upper closure 25 has an inlet gap 30 for introducing coffee flavored gas from the gas inlet line 21.

Similarly, the lower closure 26 is located over the lower end of the tubular shell 29 to enclose the closure 25. The lower closure 26 has a flange 32c, for example a flange 32d which can be fixed by a bolt. The perforated plate 28 protrudes in the lower closure 26 at the upper opening face to be positioned below so that it contacts the tube 27 when the lower closure 26 is sealed on the tubular shell 29. In this way, the loss of zeolite from tube 27 can be prevented. The lower closure 26 has an outlet gap 31 with respect to the inlet of the coffee flavor gas via the flavor outlet line 22.

Adsorption of water by the zeolite is an exothermic process and therefore energy is released during the process. However, the adsorption capacity of zeolite decreases with increasing temperature. Thus, cooling of the zeolite can be described during the adsorption process, especially when the temperature is above 10 ° C. The tubular shell 29 thus has a coolant inlet 33 near its lower end and a coolant outlet 34 near its upper end.

The coolant inlet line 23 is connected to the coolant inlet 33 and the coolant outlet line 24 is connected to the coolant outlet. In this method, a cooling material is introduced into the tubular shell 29 and flows around to cool the tube 27 containing the zeolite.

Baffle 38 and the like are placed in the tubular shell 29 to obtain optimum flow conditions.

As described above, even if the coolant flow is countercurrent to the coffee flavored gas, the system can be easily switched to cocurrent. Any suitable fluid, gas or liquid may be used as the cooling material. Water is particularly non-expandable and suitable for easy adjustment. The temperature of the cooling material should be such that the temperature of the adsorption process is maintained between 20 ° C and 80 ° C. In particular, the zeolite is preferably kept at a temperature above the dew point of the coffee-flavored gas to prevent condensation, a non-selective method of removing water.

The water content of the dried fragrance gas leaving the drying column 20 through the fragrance outlet line 22 is determined by the length of the zeolite layer in tube 27, the rate of the coffee fragrance gas in tube 27, the temperature of the zeolite, the brew pressure, and the coffee entering the drying column 20 It is a function of the moisture content of the fragrance gas. Thus, the above parameters can be adapted to obtain the desired water content of the dried fragrance gas. This can be done by one skilled in the art.

Typically, however, the water content of the dried fragrance gas varies from about 0.1 to about 2 g-water / kg-dry gas.

The column pressure drop in the zeolite layer can be easily maintained without any restriction: for example, about 4 kPa to about 6 kPa. In most commercial applications, the dry column is preferably about 0.5 m to about 2 m in length. Drying column 20 also preferably contains about 5 kg to about 20 kg of zeolite for each kilogram of water to be removed.

Referring back to FIG. 1, incense outlet line 22a from first drying column 20a and incense outlet line 22b from second drying column 20b respectively go to second poway valve 62. The second four-way valve 62 is connected to either the incense supply line 66 or the regeneration line 68 at either of the two incense outlet lines 22a, 22b. The figure illustrates that the incense outlet line 22b is connected to the regeneration line 68 while the incense outlet line 22a is connected to the incense supply line 66. By properly turning the second four-way valve 62, the incense outlet line 22a can be connected to the regeneration line 68 while the incense outlet 22a is connected to the incense supply line 66.

The incense feed line 66 extends to the cryogenic incense condenser 70 where the dried incense gas will condense. Many suitable fragrance condensers 70 are known and reported in the literature.

Preferably, however, the fragrance condenser 70 has a housing in the form of an upper cylindrical portion and a lower cone shaped portion. The lower end of the cone-shaped portion terminates upon opening release. Some cylindrical 72 preferably extends vertically within the porous stainless steel, upper cylindrical portion. The inner diameter of each cylindrical filter is connected to the gas manifold 74.

In liquid form, an inert gas is sprayed from the gas source of liquid (if squeezed) into the housing via gas introduction line 76. The liquid inert gas is preferably the same as the inert gas in the fragrance line 58, more preferably nitrogen. Sufficient liquid inert gas is sprayed into the housing to maintain the housing at a temperature of about −80 ° C. or less, but high enough to vaporize the liquid inert gas in the housing.

Thus, the fragrance component of the mostly dried fragrance gas introduced into the cryogenic fragrance condenser 70 condenses into ice, while the inert gas carrying the dried fragrance is not the same as carbon dioxide. The fragrance freeze falls off the bottom of the housing and exits into the directional opening. Inert gas flows through the cylindrical filter 72 to the manifold 74. Some entrained fragrance freeze can be collected on the cylindrical filter 72, but it can be removed by vibrating the back of the inert gas through the cylindrical filter 72 at regular intervals to remove the freeze. Freezing falling through the discharge opening can be recovered by mixing with a suitable material such as, for example, coffee oil.

Further details of the operation of the cryogenic fragrance condenser 70 can be obtained from US Pat. Nos. 5,182,926 and 5,323,623, which are disclosed by reference. Obviously other cryogenic fragrance condensers can be disclosed and used, for example, in US Pat. No. 5,030,473.

The inert gas flowing to manifold 74 relies on the compressor 84, which exits the cryogenic fragrance condenser 70 through the outlet channel 78 and induces gas circulation through the system. Compressing the gas in the stage is not removed in the cryogenic fragrance condenser 70 and is therefore not damaged. From compressor 84, the inert gas is sent to a flow splitter 80. Flow splitter 80 directs a portion of the inert gas to heater 82 to heat a temperature suitable for zeolite regeneration, such as from about 180 ° C to about 220 ° C. The heated inert gas exiting heater 82 is fed to regeneration line 68 to second drying column 20b via second poway valve 62. Purge the residue of inert gas leaving flow splitter 80 in inert gas 56 or recover for further use or disperse coffee flavor from a suitable source.

Prior to introducing the heated inert gas into the second drying column 20b, the cooling material is conveniently expelled from the tubular shell 29 to allow for faster heating of the zeolite. The heated inert gas flows through the second drying column 20b to extract moisture adsorbed by the zeolite and to regenerate the zeolite. Moisture inert gas exiting the second drying column 20b flows through gas line 21b to the first four-way valve 60 and to the gas outlet 64.

In use, the first drying column 20a containing the coffee fragrance gas may be operated until the moisture content of the dried fragrance gas exiting the first drying column 20a occurs rapidly over time. This is referred to as breakthrough time. At this point, the zeolite has begun to reach its maximum water capacity and can no longer perform suitably as a molecular sieve. The time taken for breakthrough depends on many factors such as the initial moisture content of the zeolite and incoming coffee flavor gas, the amount of zeolite, the mass flow rate of the coffee flavor gas, and the like. However, it's easy to decide which one to apply. Suitable detectors are also located at the directional exit line 22 to detect at the onset of breakthrough time. Typically, under industrial conditions, drying column 20 may be operated for about 3 to about 10 hours before breakthrough time.

The time taken for breakthrough time in the first drying column 20a is sufficient for the time at which the zeolite should be regenerated in the second drying column 20b. Once regenerated, the zeolite in the second drying column 20b is theoretically cooled at a temperature of about 20 ° C to about 80 ° C. This can be accomplished by turning off heater 82 and allowing the cooling inert gas to flow through second drying column 20b. Also, if desired, the cooling material can be flowed through the tubular shell 29 of the second drying column 20b.

The system can thus be operated in semi-continuous form. Once the first drying column 20a containing the incoming coffee fragrance gas has reached its breakthrough time, the first four-way valve 60 is switched so that the incoming coffee fragrance gas is directed to the second drying column 20b. In addition, the second four-way barb 62 is switched to connect the second drying column 20b to the fragrance supply line 66 and the regeneration line 68 to the first drying column 20a. The incoming coffee flavor gas is then dried in the second drying column 20b and the first drying column 20a is regenerated as described above.

Obviously numerous modifications have been made by the described embodiments without departing from the scope of the invention. For example, it is not necessary to have two dry columns 20.

If it is easy to operate in batch form, one drying column 20 can be used. Similarly, two or more dry columns 20 can be used.

It is also not necessary to assign the drying column vertically; It can be leveled or assigned to the desired angle. In addition, the drying column 20 need not be a shell type tubular column; Any type of fixed bed system can be used. In addition, under selected flow rate drying, the temperature rise of the zeolite during drying is small and the need for cooling is reduced or completely eliminated.

If the moisture content of the coffee flavor gas is very high, for example, if the coffee flavor gas is obtained by steam dissipating the coffee extract, the coffee flavor gas may be partially condensed from the coffee flavor gas prior to introduction into the drying column. It is preferable. In this method, it is desirable to avoid rapid saturation of the drying column with water. Some fragrance is lost in the condenser, but it can be kept within acceptable limits.

The present invention relates to a method of drying coffee-flavored gas and an apparatus for use in drying coffee-flavored gas.

Instant coffee powders obtained from commercial methods involving extraction, concentration and drying are typically substantially fragrant. However, it is important for a coffee product to have a fragrance because consumers prefer a good coffee product. If a coffee product lacks coffee aroma, it adversely affects consumer perception of the product.

For this reason, it is common to recover coffee aromas emitted during processing of instant coffee and to later incorporate them into instant coffee powder.

Coffee flavored gas may be recovered at several points during the processing of the intact coffee. However, most coffee-flavored gases are typically recovered by steam dissipating the coffee extract prior to concentration and drying the coffee solids during grinding of the roasted coffee. The recovered coffee flavor gas typically contains a degree of moisture that, if not reduced, causes stability problems and complexity in processing the downstream stream of flavor. For this reason, it is common to try to remove as much moisture as possible from the coffee flavor gas.

Typically the moisture is removed from the coffee flavor gas by purifying the coffee flavor gas through one or more condensers operated at a temperature low enough to condense the moisture but not so low that the entire flavor gas is condensed or frozen.

Temperatures in the range of 0 ° C to 20 ° C are commonly used. Condensers are most effective at removing moisture, but upon removal of moisture, the condenser also removes many of the fragrance components soluble in the aqueous solution. This may ultimately lead to some imbalance in the recovered fragrance.

U. S. Patent No. 5,342, 639 discloses a method in which coffee flavor gas is further passed through a dry layer containing calcium sulfate granules to further remove water content. Collect and mix the fragrance gas exiting the bed. The moisture content of the fragrance gas leaving the bed is 1000 ppm. Before this, the process is terminated once the granular water content is 4.3% by weight. The granules must then be regenerated. The collected fragrance gases should ensure that the moisture content does not exceed about 200 ppm.

The process has three main drawbacks: first, the adsorption capacity of the bed is low; Secondly, the pressure drop across the bed is high, and thirdly, the regeneration of the granules is energetic and requires a long period of time. This drawback raises another problem. In particular, since the adsorption capacity is low, the process requires a large amount of desiccant and therefore expensive equipment. In addition, to provide a suitable operating time, the US patent proposes to remove most of the water using a condenser prior to contacting the fragrance gas with calcium sulfate. As mentioned above, this means that any flavor component is lost. In addition, the high pressure drop means that the gas must be compressed, so that the unstable fragrance may be damaged.

It is an object of the present invention to provide a method of drying the fragrance which can selectively remove moisture from the fragrance gas.

Accordingly, the present invention consists in contacting a stream of coffee aroma with a molecular sieve containing a zeolite having a pore sized to remove water molecules while minimizing the coffee aroma component from the coffee aroma gas. To provide a way.

Surprisingly, the present invention allows the coffee flavor gas to be dried to such a level that it reduces the loss of flavor component. For example, at least 80% by weight of moisture in the coffee aroma gas is removed to such an extent that up to 20% by weight of flavor components are lost. The water removal counter loss ratio is much better than what can be obtained using a condenser.

The aromas obtained are also of high quality and do not produce adverse effects such as cracked traces or incomplete aroma distribution. In addition, the molecular sieve has a high water load capacity, and thus can be used to remove moisture from the coffee flavor gas for an extended period of time without the need to regenerate the molecular sieve.

Preferably, up to about 20% by weight of the coffee flavor component in the coffee flavor gas is removed by molecular sieve; More preferably, about 15% or less by weight of the fragrance component is removed, for example about 10% by weight or less.

The average diameter of the pore openings in the crystalline lattice of the zeolite is preferably equal to or less than 0.5 nm, for example 0.4 nm or 0.3 nm. Zeolites having an average pore diameter of 0.3 nm are preferred. Since water molecules are estimated to have a diameter of about 0.26 nm, zeolites having an average pore diameter of about 0.3 nm can be used to adsorb water molecules to a size of less than aromatic molecules. In this way, the loss of fragrance components can be minimized.

Preferably, the zeolite is A-type zeolite. A-type zeolite is an aluminosilicate of the formula _{M 2 O · Al 2 O ·} xSiO 2 · yH 2 O, wherein x is 2; When fully hydrated, y is 4.5 and M is a metal ion; Preferably from Na, K, Mg, Ca, Sr and Ag. Particular preference is given to 3A type zeolites having an average pore diameter of 0.3 nm. Type 5A zeolites with an average pore diameter of 0.5 nm may have a greater amount of odor removed than would be unacceptably high, but will operate fully suitably.

The molecular sieve may be in the form of powder, beads, shaped form, or sintered form.

Preferably the molecular sieve is bead type. The diameter of the beads is preferably about 1 to about 5 mm. More preferably about 2 mm to about 3 mm. Conveniently, the molecular sieves are arranged in the form of a packed bed in which a stream of coffee flavored gas flows.

Preferably the stream of coffee flavor gas is contacted with the molecular sieve at a temperature in the range of about 20 ° C to about 80 ° C, more preferably 20 ° C to 60 ° C.

The molecular sieve can be cooled during contact with the coffee fragrance to maintain the molecular sieve at a substantially constant temperature. This has the advantage of preventing a decrease in molecular capacity to adsorb water; Water adsorption capacity decreases with increasing temperature.

The stream of coffee-flavored gas preferably has a time to stay in contact with the molecular sieve for about 0.5 seconds to about 20 seconds, for example, about 1 second to about 5 seconds. Particularly preferred is a residence time of about 1 second to about 2 seconds.

The pressure drop across the molecular sieve is preferably from about 2 kPa to about 100 kPa, for example from about 4 kPa to about 6 kPa. The pressure drop of this magnitude is small enough to avoid substantial compression of the fragrance gas.

In a preferred embodiment, a stream of coffee flavor gas is flowed through the molecular sieve for less than the required time to saturate the molecular sieve with water and then terminate the flow of the stream of coffee flavor gas through the molecular sieve. Then, the hot dry sieve is flowed through the molecular sieve to regenerate the molecular sieve to extract water from the molecular sieve.

The stream of coffee-flavored gas preferably flows through the molecular sieve for a sufficient time to allow about 10% to about 20% by weight; For example, from about 15% to about 20% by weight of the molecular sieve. The time is about 1 hour to about 12 hours; Preferably from about 6 hours to about 10 hours; For example, it may be about 8 hours.

The molecular sieve is preferably regenerated using a gas heated to about 180 ° C to about 220 ° C. The time required to regenerate the molecular sieve can be from about 3 hours to about 6 hours. Regeneration of the molecular sieve ends when the water content of the molecular sieve is reduced to about 2% by weight or less.

Preferably two or more molecular sieves and arranged in pairs in parallel; The stream of coffee-flavored gas passes through each pair of molecular sieves, while the hot, dry gas passes through the other pair of molecular sieves to regenerate the molecular sieves.

In this way, the process can be operated in a continuous form.

In another aspect, the present invention provides a system for removing moisture from a stream of coffee flavored gas, consisting of:

A pair of dryers each containing at least one layer of molecular sieves of zeolite having a pore sized to adsorb water molecules, but minimizing the coffee component, and the pair of dryers having an inlet end and an outlet end; A cryogenic flavor condenser for condensing coffee flavor from a stream of coffee flavor gas and separating the coffee flavor from the non-condensable gas in the stream, wherein the cryogenic flavor condenser is configured to provide an inlet and a non-condensable gas for receiving a stream of Has an outlet to discharge; Means for selectively sending the stream to one or the other of the pair of dryers for flowing the stream through the dryers at the inlet end of the pair of dryers, the first flow direction means connecting the other dryers to the exhaust device; And receiving condensate gas from the stream and the cryogenic condenser outlet from the stream flowing dryer at the outlet end of the pair of dryers, optionally directing the stream to the inlet of the cryogenic condenser, and sending the non-condensable gas to another dryer for flow through the dryer. Second flow direction means for.

Preferably the system further comprises heating means for heating the non-condensable gas to a temperature of about 180 ° C. to about 220 ° C. before the non-condensable gas is directed to the dryer.

The system also consists of cooling means for maintaining the molecular sieve of the dryer receiving a stream of coffee flavored gas at a temperature in the range of about 20 ° C to about 80 ° C.

Embodiments of the present invention will now be described by way of example only with reference to the following drawings:

Example 1

270 g of roasted ground coffee batches are placed on a bench-scale tumbler.

The tumbler's drum is maintained in a water bath at about 38 ° C. (100 ° F.). Nitrogen gas is introduced into the tumbler at a flow rate of 0.5 liters / minute to dissipate the coffee flavor from the roasted ground coffee. The resulting gas is passed through a cartridge containing 1 g or 2 g of type 3A zeolite. The zeolite is maintained at a temperature of about 22 ° C. (72 ° F.) to about 88 ° C. (190 ° F.). Gas from the incoming and outgoing cartridges is taken to separate the moisture content every 10 minutes and the perfume content every 5 minutes. The process continues for about 1 hour.

The dry fragrance gas exiting the cartridge is collected and smelled.

Undried gas leaving the tumbler is also collected and smelled as a control. No difference is detected and the dried fragrance gas has a well balanced fragrance distribution.

The test was repeated with type 4A zeolite and the results are similar despite slightly more water removal and more loss of fragrance.

Example 2

A drying column 50 mm in diameter and 800 mm in length is burned with 1 kg of 3A type zeolite. The drying column is insulated and placed vertically. The coffee flavor gas is collected by dissipating fresh ground roasted coffee as nitrogen gas. The coffee aroma gas has a moisture content of about 20 g-water / kg dry gas.

Coffee flavor gas is sent to the drying column for about 4 hours at a flow rate of about 4.4 kg / hr. Samples are taken from the coffee flavor gas entering the drying column and the coffee flavor gas leaving the drying column.

The amount of water removed from the coffee aroma is about 65% by weight. Fragrance loss cannot be measured.

Example 3

The process of Example 2 is repeated with various forms of zeolite and at various different time periods. The results are as follows:

The fragrance loss value is an integrated value. For each run, the fragrance loss initially decreases rapidly over time before reaching steady-state asymptotes. In Runs 1 to 3, steady-state asymptotes arrive quickly, which means that the numbered results are higher than what would actually be obtained if the run was run for a longer time. In run 4, breakthrough time reached after about 350 minutes, which reduced the water removal value. Prior to breakthrough time, water removal is at least 90% by weight.

Example 4

Two dry columns 40 nm in diameter and 1000 mm in length were filled with 10 kg of 3A type zeolite, respectively. Insulate the drying column and place it vertically.

Coffee-flavored gas with a moisture content of 4 g-water / kg dry gas was in two drying columns at a flow rate of 30 Nm ³ / hr at 7 kPa inlet gauge pressure (Nm ³ represents volume at normal conditions of 0 ° C. and 101.3 kPa). Send to the first drying column. Coffee-flavored gas has a speed of 0.6 m / s in the drying column; It has a residence time of about 1.7 seconds.

The dried coffee aroma gas exiting the first drying column has from about 82% to about 93% by weight of the initial moisture removed. The amount of fragrance lost in the drying column decreases over time as the selectivity of the zeolite improves. The dried coffee flavor gas is sent to the cryogenic condenser as described above and in US Pat. No. 5,182,926. Condensed coffee aroma is taken vertically and taken from coffee oil. The non-condensing gas is heated vertically at about 200 ° C. and then directed to the second drying column of the two drying columns at a flow rate of about 32 Nm ³ / hr and an inlet gauge pressure of 8 kPa. At the moment of leaving the second drying column, the gas is discharged.

After about 6 hours, about 98% of the water is removed from the second drying column. The dry column is then cooled for about 2 hours.

The system is operated in this form for one cycle of about eight hours. The incoming coffee flavor gas is then sent to the second drying column and the non-condensing gas is heated from the cryogenic condenser to the first drying column. The system is operated in the cycle method for a total of 48 hours; Each drying column has an adsorption period of 8 hours before being regenerated.

The average fragrance loss during each cycle is measured by gas chromatography, which should be about 10% by weight or less. Note that the fragrance loss decreases over time as the selectivity of the zeolite improves during each cycle and from one cycle to the next.

Example 5

The method of Example 4 is repeated except that 5A zeolite is used in a drying column. The process proceeds with an 8 hour adsorption cycle followed by 48 hours with each drying column for regeneration and cooling.

The dried coffee flavored gas leaving the first drying column has from about 65% to about 78% by weight of the initial moisture removed (average about 77.8%). Compared to zeolite 3A, the water load capacity of zeolite 5A is reduced (86-76%). The average fragrance loss is about 20% by weight or less.

Claims (10)

A method of drying coffee-flavored gas, comprising contacting the stream of coffee-flavored gas with a water molecule containing zeolite that has a pore size that minimizes the coffee flavor component but removes water molecules. The method of claim 1 wherein the molecular sieve removes up to about 20% by weight of the coffee flavor component from the coffee flavor gas. The method of claim 1, wherein the zeolite has pores of average diameter of about 0.3 nm to about 0.5 nm. The method of claim 1 wherein the zeolite has the formula _{M 2 O · Al 2 O 3} · xSiO 2 · yH A -type zeolite of O _2, wherein x is 2; When fully hydrated, y is 4.5 and M is a metal ion selected from Na, K, Mg, Ca, Sr, and Ag. The method of claim 1, further comprising cooling the molecular sieve during contact with the coffee fragrance gas to maintain the molecular sieve at a substantially constant temperature. The method of claim 1, wherein the stream of coffee flavor gas has a residence time for contacting the molecular sieve for about 0.5 seconds to about 20 seconds. The method of claim 1, wherein the stream of coffee flavored gas is allowed to flow through the molecular sieve for less than the time required to saturate the molecular sieve with water, and then terminate the flow of the stream of coffee gas through the molecular sieve, The hot and dry gas flows through the molecular sieve to regenerate to extract water from the molecular sieve. 8. The method of claim 7, wherein the stream of coffee aroma is flowed through the molecular sieve for a time sufficient to increase the water content of the molecular sieve by from about 10% to about 20% by weight. The method of claim 7, further comprising at least two molecular sieves arranged in pairs in parallel; Wherein the stream of coffee-flavored gas flows through the other sieve of each pair while hot dry gas flows through the molecular sieve of one pair to regenerate the other molecular sieve. A system for removing moisture from a stream of coffee flavored gas, consisting of: A pair of dryers each containing at least one layer of molecular sieves of zeolite having a pore sized to adsorb water molecules, but minimizing the coffee component, and the pair of dryers having an inlet end and an outlet end; Cryogenic flavor condenser for condensing coffee flavor from a stream of coffee flavor gas and separating coffee flavor from condensed gas within the stream, wherein the cryogenic flavor condenser releases an inlet and a non-condensable gas for receiving a stream of coffee flavor gas Having an outlet for; First flow direction means for selectively directing the stream to one or the other of the pair of dryers for flowing the stream through the dryers at the inlet end of the pair of dryers, the first flow direction means connecting the other dryers to the exhaust device; And Receive streams from the dryer and condensate gas from the outlet of the cryogenic condenser where the stream flows at the ends of the pair of dryer outlets, optionally directing the stream to the inlet of the cryogenic condenser and sending the non-condensable gas to the other dryer to be fed through the dryer. Second flow direction means.