From E. Boullanger: Distillerie Agricole et Industrielle(Paris: Ballière,1924). Translation from the French by F. Marc de Piolenc(piolenc@archivale.com).

Mariller-Granger Processes

We owe to Mr. Mariller some very remarkable studies on theindustrial production of absolute alcohol. We have alreadynoted, in our first volume (page 53), the industrial applications

implemented by Mr. Mariller of the method of distillation ofazeotropic mixtures discovered by Young in 1902. From 1920on, Messrs Mariller and Coutant have used benzine and gaso-line, which they injected into rectifiers fed with alcohol at 95degrees, to directly produce the mixture of gasoline and abso-lute alcohol constituting the national standard motor fuel. At thebase, a hydrocarbon/absolute alcohol mixture was extractedwhich, diluted with gasoline, provided the fuel, and at the heada stream which, when decanted, gave a dehydrated upper layerto be returned for treatment and a water-bearing lower layer tobe distilled for recovery of the alcohol that it contained. Ifproduction of absolute alcohol was desired, then one need onlyfractionate it from its mixture with the hydrocarbon.

Later Mr. Mariller acknowledged that it is much simpler tooperate in two phases: a first column eliminates water and thesecond, receiving the dehydrated product, yields at the head amixture that is returned to the first column, and at the tailsabsolute alcohol. With everything figured in, with appropriaterecovery, the steam consumption dropped to 200 kilograms perhectoliter, while Young’s batch method led, with recycling, to anexpenditure of at least 600 kilograms.

But according to Mr. Mariller, the use of water-absorbing sub-stances instead of alcohol-absorbing substances [for separat-ing alcohol/water mixtures by absorption] must necessarily bemore economical, because when alcohol absorbents are used,water, the third substance [absorbent] and the alcohol/sub-stance mixture must all be evaporated and the mixture sub-sequently fractionated to recover pure alcohol. This results inadditional evaporation which penalizes the overall cost of themethod. Contrarily, with water absorbents, only water and a littleentrained alcohol (if any) must be subsequently evaporated;steam consumption then falls to 30 kg per hectoliter of alcohol,or approximately frs 0.40 at the current [1924] price of coal.

Figure 108

These considerations led Mr. Mariller to his absolute alcoholproduction process by dehydration using glycerine. Alcoholicvapors passing through pure glycerine yield 99.2 alcohol di-rectly, and merely adding potassium carbonate, for example, tothe glycerine is sufficient for easily obtaining 99.8. The glycerineand the salt that it holds in solution are regenerated and returnedto the circuit./252/

In what follows we will examine the apparatus that can be usedin various situations, but a special analysis should be consid-ered necessary for each factory, to make use of existing equip-ment.

Continuous rectifier case.

Let us imagine first a continuous rectifier (fig. 108) with itsrectifying column B, its condensers C and D, and column Aacting as a stripping column for the reflux of column B. Alcoholat 96.5 is received, after cooling in cooler R, in gauge E1.

To transform this alcohol into absolute alcohol, it is allowed torun continuously into the recuperator U where it is heated, thenit passes into the steam-heated evaporator F where it is entirelyevaporated. The alcohol vapor thus obtained passes throughcolumn G, which is fed glycerine by a float chamber I and a flowmeter J. The dehydrating liquid is contained in a feeder tankshown in the drawing, and can be readily heated or cooled bya serpentine heat exchanger coil.

The dehydrated alcohol vapor escapes from column G to acondenser K, and the anhydrous alcohol is received in gaugeE2. To compensate for the heating effect produced by theabsorption of water in column G, this reflux can be channeledto the feed plate itself, or better to a segment set above the feedplate, in order to retain any absorbing liquid that is accidentallyentrained./253/

If we wish to directly connect the vapor from the rectifyingcolumn B to the concentrating column G, it is only necessary toprovide the pipe I shown dotted in the drawing, and accessorypiping connecting this pipe to condenser C, with a regulatingcock V inserted between them. Inasmuch as the resistance tothe passage of vapor through column G is greater than that ofcondensers C and D, merely opening this cock more or less isenough to automatically regulate the reflux from condensers Cand D. This reflux is not shown in the drawing; it is usuallybrought back to the top of column B, without modification.

The dehydrated liquid collected at the base of column G flowsinto column M, formed by stacked plates having steam heatingcoils. In addition, the base of this column is heated by aserpentine coil or tubular heater N. The vapor that is released,consisting of water and alcohol retained by the adsorbent,returns directly to the rectifying column B.

To avoid entrainment, a serpentine condenser is used, locatedin the upper part of column M, or a condenser of any other typewhose condensate is collected in washing plates in which thevapor bubbles up before escaping to rectifying column B.

In many cases, and notably when the intent is to produce alcoholthat is not completely anhydrous, the liquid obtained at the baseof column M can be directly taken up by a pump and send to thefeeder tank. On the other hand, to obtain alcohol at 99.8-100degrees with glycerine with dehydrating salts added, it is vital tocomplete the total dehydration of the product, an operationwhich can only be accomplished under vacuum to avoid anydegradation of the absorbent./254/

Concentration under vacuum must be carried out on a liquid thatis completely free of alcohol, in order to avoid alcohol losseswhich always take place in vacuo when operating on a liquidthat contains any appreciable quantity of it.

It has been recognized that total alcohol extraction can beaccomplished in column M by completing the heating processwith a slight direct injection of steam in the sub-base of thecolumn.

From column M, the liquid passes automatically into a concen-trator O which, being under vacuum, provides suction.

Upon arrival, the liquid undergoes evaporation; it is then con-centrated in stacked plates similar to those of column M, and

finally in a sub-base chamber equipped with powerful coils inwhich steam flows under pressure.

The liquid must be brought to a temperature such that it iscompletely rid of water. For glycerine that is carbonated by theaddition of potassium carbonate, the correct temperature isapproximately 160 to 170 degrees. At the base of this column,the regenerated absorbing liquid is taken up by a pump anddelivered to a tank for return to the circuit.

The upper portion of the concentrator is so constructed as toavoid any entrainment taking place. It can for instance beequipped with diffusers, with labyrinths or with a column withflow splitters, that column receiving a stream of a washing liquidfor retaining entrained matter in solution.

Finally, the vapor passes to a condenser P, and the liquid isreceived in reservoirs R. This liquid must be extracted using aspecial pump./256/

The gases aspirated by vacuum pump T are delivered to asecond condenser Q and all the liquid obtained is assembled intank S. This liquid is water that is completely free of alcohol, butas it takes up very little volume it is perfectly possible, if we wantto avoid any loss, however minimal, to add this liquid to thefermented mash to be distilled.

It is also possible to use part of the rectifying column forproducing absolute alcohol, thus eliminating column G. In thiscase, the rectifying column B is partitioned into two stackedportions. The vapor from the lower segment goes to the con-denser and returns to the base of the upper segment; the refluxfrom the condenser feeds the lower segment, and the uppersegment is fed by a stream of absorbent liquid. The apparatusfor regenerating the absorbent is identical to that describedearlier.

Figure 109

Continuous direct rectifier case.

Figure 109 represents a continuous direct rectifier for fermentedmash, directly producing absolute alcohol with the smallestpossible expenditure of steam. In this apparatus, the liquid tobe distilled enters through 5 into column A1, which is chargedwith removing head products more volatile than alcohol. Theliquid then enters column A2 which is an extension of thepreceding one, where it is completely stripped of alcohol. Thealcohol vapor passes through pipe 7 into a concentrating col-umn Z of a few plates. Another part of the vapor passes intocolumn A1 and evaporates the head products which are con-centrated in plates G1 and whose flow is regulated by a cock

placed in drainpipe 6 of this column. They are then condensedin condensers X and Y./257/

The head products are then delivered to a special gauge viapipe 13.

The alcohol vapor, upon leaving column Z, passes into anevaporator W, which is fed pure water by a tank V and aregulating cock 11. In evaporator W, the alcohol vapor partiallycondenses while evaporating a certain quantity of water andthus supplying the vapor which will be taken up by thermo-com-pressor 13 to participate in the heating of column A2 andeventually of column A1.

The alcohol vapor, upon leaving the evaporator W, enter columnAB whose vapor escapes to a mash preheater C. At the upperpart of this column, the vapor arrives at a strength of approxi-mately 90-92 degrees; they are then directed to dehydrationcolumn G, which is supplied with the absorbing liquid.

The rest of the apparatus is identical to what was describedearlier. The higher alcohols are extracted from column ABthrough one or more taps 8, in the usual fashion. Residual waterobtained at the base of column A flows through pipe 9 to a pumpthat delivers it by pipe 10 to a tank V.

Adaptation of the Mariller-Granger process to an existingcontinuous direct rectifier.

Figure 110 represents a rectifier of the usual type modified forthe production of absolute alcohol./258/

Let us consider an existing apparatus comprised of: a distillationcolumn A, a purifying column G and a rectification column IJ.The distillation column is equipped, as we saw earlier, for heatrecovery by the use of a closed thermal circuit. For this purpose,

Figure 110

the alcohol vapors escape to an evaporator B, which receivesthe spent distilled water coming from the rectifier I. This water,which arrives boiling in the evaporator, undergoes boiling thereat a temperature of 85 degrees under partial vacuum. Theexcess water flows through a standpipe which drains it to a tankin such a way as to form an hydraulic trap. The steam for heatingthe column passes into a thermo-compressor G, which providessuction to aspirate the vapor from the evaporator and deliver itto the column, where it will contribute to heating. It is necessary,

of course, to heat the beer especially with the residues from thedistillation column or by any other means so as to free thegreatest possible amount of heat at the evaporator. It is, how-ever, possible to connect a small beer pre-heater for the vaporleaving the purifier.

Alcohol from the distillation column passes into the purifier,which eliminates ethers and aldehydes.

Finally, the alcohol passes into the rectifying column usuallyequipped with a condenser and a cooler L at its top. It is notnecessary to obtain 96 degree alcohol from this column, and alower strength is quite tolerable. Hence the top of the plates Jis usually connected to the condenser by a closed plate and alateral pipe. This condenser supplies the plates J with thenecessary reflux. The usual extraction of higher alcohols occurson plates I and J. The vapor, on leaving the condenser, isbrought to the plates R, plates currently belonging to the recti-fying column which are no longer receiving alcohol but a streamof glycerine coming from the feeder tank. The absolute alcoholleaving this column goes directly to a cooler and from there tothe gauge./260/

The regeneration of the glycerine is obtained in two stages: 1st,alcohol stripping in column M, 2nd, complete dehydration incolumn O which operates under vacuum. A float chamber Vautomatically drains the alcohol-stripped liquid to introduce itinto vacuum column O. The water vapor that escapes from thecolumn is condensed in a condenser P, and from there thegasses pass to an ejector Q which provides vacuum for theentire plant. Water from the vacuum column is extracted by ahydraulic lock or by a pump T.

The regenerated glycerine absorbent is taken up by pump Swhich delivers it to a feeder tank.

Figure 111

Adaptation of the Mariller-Granger process to a batchrectifier.

The batch rectifier (fig. 111) is represented by boiler B, columnC, condenser E and cooler W. The production of absolutealcohol must obviously not take place using the bad-tastingfractions and the medium fractions, for we would then obtain analcohol rich in aldehydes, ethers or higher alcohols. Further, itwould not be suitable to run a batch process for absolute alcohol.To avoid these drawbacks, the absolute alcohol apparatus iscalculated such that the good-tasting fraction produced over 24hours can pass continuously into the part of the plant thatdehydrates it. For this purpose, a tank is provided which re-ceives a certain quantity of this alcohol while the good-tastingfraction is distilling over, so as to allow it to be evaporated in theevaporator V during the periods of the medium and bad-tastingfractions. To economize steam used in partially evaporating thealcohol, a recuperator VR is used which receives the residualboiling water from column C2. While the good-tasting fraction iscoming over, a system of cocks allows the vapor to pass directlyto the dehydration column D which receives the stream ofabsorbent liquid, which is stored in a feeder tank G. The cockconnected ot the column is fully open and the cock on cooler Wis opened just enough to obtain the supplementary stream ofgood-tasting alcohol in to tank A; this alcohol is treated duringthe medium and bad taste periods./262/

The absolute alcohol, upon leaving column D, is condensed inF, then sent to a cooler T and gauge X.

Regeneration of the absorbent is obtained as before in a systemof two devices in series: 1st alcohol stripping (column JK,condenser L2 and tubular heater M); 2nd, concentration undervacuum with column OP condenser q, vacuum tank R andejector S.

In this apparatus, the alcohol obtained at the outlet of the alcoholstripping column could be condensed and returned in the liquidstate to boiler B of the batch plant to have its strength increased,but we would thus lose the benefit of the latent heat of this vaporwhich allows it to be brought up to 95 degrees almost free ofcharge. In this case, it is enough to direct the vapor to a rectifyingcolumn C1 with stripper C2 and a condenser, at the outlet ofwhich the vapor goes to column D.

Application of the Mariller-Granger process to a high-proof column.

When the plant already has a high-proof column, oil extractionhas to be provided for in the lower plates if it doesn’t alreadyexist, and the apparatus must be completed with a purifier thatthe beer goes through coming out of the preheater. The purifiedbeer then enters the high-proof column. The vapor leaving thepreheater are directed to the column for dehydration by glycerin,whose regeneration is accomplished by the components de-scribed earlier.

Economy of the method

Dehydration by glycerine gives rise to extreme reductions inreflux. Mr. Mariller has shown for example that one can proceedfrom vapor at

65° GL to 99.5° with 3.7 reflux/263/

83° GL to 99.8° with 2.85 reflux

93° GL to 99.9° with 0.53 reflux

95° GL to 99.9° with 0.35 reflux

96° GL to 99.9° with 0.27 reflux.

We thus arrive at absolute alcohol with much lower reflux ratesthan the current ones, and this result is obtained with only 12plates instead of the 40 or more plates of current rectifiers.

In these circumstances, is is obvious that the cost of the processper hectoliter of alcohol will be highly variable, depending on thestarting strength of the alcohol, disposition of the equipment,etc. The process does not result in any loss of alcohol, any lossof absorbent, any supplementary labor requirement. As for theexpenditure of steam: from 45 degrees on it is less than 25kilograms per hectoliter of alcohol, which corresponds to 4kilograms of coal at 100 francs per tonne, or frs 0.40. Evencounting in 1 franc per hectoliter to take into account smallabsorbent leaks through joints and slightly increased consump-tion of steam, and by adding in 2 francs per hectoliter forroyalties, we reach a cost price of 3 francs. This cost can beconsiderably reduced in an apparatus that ensures a reducedreflux rate and uses a closed thermal circuit, with a thermo-com-pressor. We do, however, need to add in the amortization of thespecial equipment, which varies with plant capacity. For a plantcapacity of 200 hectoliters, counting 200,000 francs for equip-ment, amortization over 100 days would give a figure of 10francs per hectoliter. Total cost in this case, then, would be near13 francs per hectoliter, which would still leave a daily profit of400 francs based on an added value of 15 francs per hectoliter.After this very short amortization period, the cost would drop to3 francs, which would still leave an additional 7 francs perhectoliter assuming that added value would drop to 10 francs./264/

Other processes for preparing absolute alcohol

Besides the Ricard-Allenet process and the Mariller-Grangerprocess described above, we find the chemical dehydrationprocesses that subject either alcoholic liquors or alcoholic va-pors to the action of extremely hygroscopic substances formingfixed hydrates with water.

The principal substances employed for this purpose are quick-lime, calcium chloride, potassium carbonate, etc. Deininger ranvapor leaving the rectifier into a cylinder containing calciumchloride. Wolkoff sent alcohol vapor into an apparatus chargedwith potassium carbonate; the vapor, in passing through thissalt, gave up its water vapor, which in turn dissolved the salt.The saline solution obtained in this fashion was then concen-trated in a Porion furnace to regenerate potassium carbonate.

The only method that survives today consists of dehydratingalcohol vapor by passage over quicklime. The lime dehydratesthe alcohol, stops acids and ethers and allows absolute alcoholto be obtained with a loss of 2 to 3%.