FR2597502A1 - Process for the manufacture of alcohol with recovery of the vinasses derived from the distillation - Google Patents

Abstract

The invention relates to a process for the manufacture of alcohol with reduction and even suppression of the vinasses derived from the distillation. According to the process of the invention, the concentration 2 of the sugar-containing raw material 1 is carried out in order to obtain a syrup 10. According to the invention, this syrup 10 is diluted by vinasses 26 to form a fermentation medium 23 which is then distilled 24 to produce alcohol 25 and vinasses 26 part of which is reintroduced for dilution. The preconcentrated balance is either reusable in place of process water, or can be upgraded more easily. The invention will find its application most particularly in the sugar industry.

Description

 The invention relates to a process for the manufacture of alcohol with recovery of vinasses resulting from distillation.

It will find especially its application in the sugar industry.

 Among the residues of alcohol distillation from wines obtained by fermentation of sweet juice. there is one that occupies an important place, it is the vinasses.

 The vinasses are produced in large quantities and are very polluting because they are hot. acids, and laden with putrescible matter.

 Their volume is considerable since, taking an example of a distillation of a wine with 9-10 alcoholic strengths, more than one cubic meter of vinasse per hectolitre of pure alcohol produced is obtained.

 The concentration of the fermentation alcohol industry in areas of high sugar production. causes in a given place such quantities of vinasses. that it is no longer possible to reduce them by traditional means such as spreading in fields, natural purification in lagoons, or chemical or biological treatments.

 Otherwise. regulations concerning pollutant industrial discharges are becoming more and more severe. and the increasingly heavy rejection fees.

 Particularly in the case of the molasses alcohol distillery, the vinasses have little other possible destination than to be concentrated in the form of syrup. But this concentration requires a very expensive industrial installation in investment, maintenance and big consumer of energy.

 No satisfactory solution has been made so far and in the analysis of the cost of production of alcohol, the share of waste treatment is considerable.

 The main object of the present invention is to present a process for the manufacture of alcohol with recovery of the vinasses which follow the distillation.

 The advantages of the present invention are twofold since, on the one hand, there is a recycling of industrial waste resulting in less pollution and the economy of the taxes relating to the nuisances caused by the discharges, and on the other hand, there is a reuse of the vinasses, that is the use of a material the cost of which can be considered as nil.

 Investments in heavy equipment to ensure the recycling of vinasse can be avoided and this results in a very significant lowering of the cost of production of alcohol.

 It should be noted that the reuse of a material such as vinasse considered until now undesirable has no negative impact in the quality of the alcohol obtained. The overall performance of the facility is not affected as long as certain sugar concentrations are respected in the manufacturing process.

 Another object of the present invention is to obtain during the alcohol manufacturing process, a concentration of vinasses which facilitates their eventual elimination. As will be seen in the following description. different options may be taken with regard to the destination of the vinasse and in particular, total or partial recycling may be considered.

However, whatever the choice made, the surplus of vinasse to extract. is concentrated which reduces the volume and therefore facilitates treatment.

 Other objects and advantages of the present invention will become apparent from the following description, which is however only indicative.

The method of manufacturing fermentation alcohol with significant reduction and sometimes even total suppression of the rejection of the vinasses resulting from distillation, is characterized by the fact that
- Concentrate in syrup form the sweet juice from the raw material. if it is not concentrated enough.

 the syrup or the concentrated material is diluted before fermentation, by adding the vinasses.

The invention will be better understood on reading the following description accompanied by attached drawings among which:
FIG. 1 schematizes the flow diagram of a sugar beet-distilling factory of traditional type,
- Figure 2 illustrates the different phases of the alcohol production process with vinasse recovery according to the present invention.

 FIG. 3 schematizes the operation according to the invention of a beet distillery taken by way of example, in which the vinasses are totally recycled.

 The present invention relates to a process for the manufacture of alcohol with the recovery of vinasses resulting from distillation.

It will find its application in all fermentation alcohol distillery facilities.

 The process of the present invention is particularly applicable in the case of sugar-rich raw materials in order to obtain a fermentation medium having a high proportion of dissolved sugar compared to dissolved unsweetened products.

 Sugar cane. the banana. grapes are well suited to the application of the process of the present invention, however, it is the beet that has been retained in the following examples since it is one of the main sources of sugar in France.

 Figure 1 shows the traditional operation of a beet sugar refinery.

 Following this diagram, the beets 1 once harvested and cleaned are crushed. it is the extraction of sugar 2.

 This diffusion produces a sugar beet juice 3 as well as pulp 4 which is pressed. Pressing gives pulps which will be dehydrated. Pressing 5 also gives press waters 6 which are reintroduced into sugar extraction 2. At this level. an external water supply 7 is also made to facilitate 1 extraction of sugars which are found almost entirely in the juice of beet 3.

 The beet juice 3 is then purified 8 and then concentrated by evaporation 9 to give a syrup 10.

 By crystallization 11 of the syrup 10, sugar 12 is obtained.

This operation is carried out with the fullness of the syrup 10 in pure sweets which do not produce alcohol.

 Since beet harvesting is carried out for a relatively short period of time, some sweets store a portion 13 of the syrup 10 to spread the production of sugars 12 by crystallizing the syrup subsequently stored.

 In molasses sweeteners-distilleries molasses 14 from the syrup 10 and forming the uncrystallized portion is fermented after dilution with water 16 to obtain a wine 17.

This wine 17 is distilled 18 to extract the molasses alcohol 19.

 Distillation residues form molasses vinasse 20 which are concentrated by evaporation 21 to form a vinasse syrup 22.

 The vinasses molasses 20 have enough dry matter to be evaporated which allows the marketing of vinasse syrup 22.

 In sugar beet distilleries, at the outlet of the sugar extraction 2, part of the beet juice 3 is fermented directly 23 and then distilled 24 to give alcohol 25. The distillation residues 24 form the vinasses of the sugar beet. beets 26.

 In a pure beet distillery, all of the beet juice 3 is used to produce alcohol after fermentation 23 and distillation 24. In this type of installation, beet vinasse 26 represents a very large volume which can not be used. be totally recycled and can not easily be discarded as they can not be concentrated due to their low solids content and the presence of colloids.

 The present invention specifically proposes to provide a solution for producing alcohol 25 and recovering vinasse 26 from distillation 24.

 FIG. 2 schematizes the various stages of the alcohol production process with recovery of the vinasses resulting from the distillation according to the present invention.

 In the example chosen, beets 1 are chosen as sweet raw material, however, other sugar-rich materials can be used perfectly. The beet 1 undergoes extraction of the sugar 2 which decomposes them into a sweet juice 3 and pulp 5. The pulps 5 undergo a pressing operation which gives pressed pulps 5 and the press water 6 is reincorporated at the level of the extraction sugar 2.

 The sweet juice 3 is purified and then concentrated by evaporation 9 and then takes the form of a syrup 10. This syrup 10 is the basic element of a fermentation 23 followed by a distillation 24 which makes it possible to harvest alcohol 25.

 As in the traditional process, the distillation residues 24 are constituted by vinasses 26.

 The fermentatien of a concentrated medium is more delicate to realize too. according to the main feature of the alcohol manufacturing process of the present invention, the concentrated syrup 10 is diluted with a portion of the vinasses 26 from distillation 24.

 To re-use the majority of residual vinasse 26 distillation, it is also possible to reincorporate part of the extraction of sugar 2.

 The recycling of the vinasses 25 are shown diagrammatically in FIG. 2 by the arrows 27.

 In the example chosen. all the vinasses 26 obtained from the distillation 24 of the syrup 10 are reintegrated into the process for the manufacture of the alcohol 25.

 The method described above makes it possible to reduce considerably and even in certain cases to completely remove the effluent from vinasses to the outside.

 In case of volume reduction, the rate of dissolved solids increases thereby the subsequent processing for recovery or purification is greatly facilitated. In case of total cancellation. the concerns of rejection and related taxes are avoided and in addition the consumption of water according to this process is reduced.

 This has been stated previously. the manufacturing method according to the present invention applies more particularly to the medium rich in dissolved sugar, also, it is sometimes desirable to preconcentrate or purify the raw material.

These preliminary treatments are, on the whole, much easier and less expensive than the subsequent treatments of the vinasse. In many cases, they are not necessary for example for dried fruits, saccharified starchy materials, concentrated sugar residues, etc.

 In other cases, cases are already being carried out where the distillery is an annex to another industry, such as in the adjoining distilleries of sugar factories. The main purpose of the purification is to facilitate the concentration of the juice in syrup. It can consist, as traditionally in candy, a calco-carbonic treatment. However, simpler and less expensive methods can be used physically, chemically or biologically. Indeed the elimination of the non-sugar, 1 inversion of sucrose in reducing sugars. the coloring, etc ... oozes here These secondary considerations.

 In the example described below. it is shown that a beet candy which desires to make alcohol with a portion of beets treated to advantage according to the process of the invention, to produce syrup and to send it in fermentation, rather than ferment directly juice The cost of purifying and concentrating the juice intended for the distillery is offset by the total removal of the vinasse and removes any investment and any expense for the processing thereof.

 However. the limit of the recycling in fermentation is reached when the accumulation of the non-sugar in the circuit gene the microorganism used for the fermentation. The total dry sugar ratio will therefore decrease to reach an equilibrium when all the non-sugar entering the system will evacuate in the part of non-recycled vinasse fermentation.

The total recycling of the fermenting vinasse is not possible since the ratio above would tend to zero, due to the incessant increase of its denominator. Hence the interest of directing a fraction of the obtained vinasse towards diffusion. In the absence of diffusion, it is also possible to find another outlet for excess vinasse. Moreover, this surplus can easily be converted into syrup at a lower cost since it is already pre-concentrated and purified.

 In general, the ratio of sugars sugar tolerable by yeasts of the genus Saccharomyces can decrease to 0.6 or even 0.5. Schizosaccharomyces yeasts or bacteria support even weaker dry sugar ratios.

 However, water must be returned to the system and it will be advantageous to do so by washing the yeast cream if the method used is of the yeast recovery type as described in the following example.

 The example of application illustrated in Figure 9 is my limitative. the process can be applied to different materials susceptible to fermentation such as starch or cellulosic materials or juices containing materials other than sugars to be fermented such as: alcohol.

acids and others.

 The fermentation can be alcoholic (by yeast or bacteria) or intended to produce any metabolite resulting from a microbial or enzymatic action.

 Finally, the alcohol, or metabolite formed, can be extracted by distillation or any other separation process.

 In any case, the process of the present invention envisages the resorption by recycling or simplified treatment of the final extraction residue, by the correct writing of the balance sheet saving the flow of the alcohol production process.

 FIG. 3 illustrates the operation according to the invention of a candy factory having an annex distillery, which uses as beet raw materials. Depending on the case examined, all production is transformed into alcohol with complete recycling of vinasses.

 A thousand kilograms of sugar beet are introduced at the level of the extraction of sugar 2, which produces 1,189 kilos of sweetened diffusion juice 3 and 800 kilos of pulp 4 which, after pressing, give 584 kilos of press water 6 reintroduced into sugar extraction. 2.

 The remaining 216 kilograms of pressed pulp are recovered and dried for secondary use.

 The sweetened diffusion juice 3, the composition of which is given in FIG. 3 in table 28, undergoes a purification and dilution operation 29, the result of which is a juice before evaporation containing 156 kg of sugar for a total weight of 1,250 kg. .

 This juice is concentrated by evaporation or any other method and gives a sweet syrup at 60% by weight.

 According to the method of the present invention, this syrup undergoes a dilution 32 before being fermented in a tank 23.

 The fermentation yeasts are introduced into the tank 23 from an auxiliary tank 33, or they have been washed by an external water supply 34. It should be emphasized that this is the only entry of pure water used in the process described.

 Once the diluted syrup has been fermented, the resulting wine is directed to a distillation column from which alcohol is extracted which is about 195 liters at 50 degrees.

 Fermentation 23 produces 1,355 liters of fermented medium at 8 alcoholic strengths. A fraction, about 136 liters of the fermented solution containing yeasts separated by centrifugation is introduced into the yeast tank 33 and will be used to carry out the subsequent fermentation.

 Distillation produced 1.023 liters of vinasse. This vinasse is fully recycled in the process of manufacturing the alcohol at the rate of 618 liters used for the dilution 32 of the syrup 31 and 505 liters used as diffusion liquid at the diffusion level 2 of the beets 1.

 The advantages of such a process are obvious, on the one hand there is no effluent polluting vinasse and thus reduction of the costs of rejection. The heating of the apparatus to be distilled is possible by the evaporation samples which could also serve for the crystallization in the case of work in sugar refinery. The process does not involve any additional cost of steam. On the other hand, the facility is very flexible and can move quickly from producing sugar to producing alcohol and vice versa.

 The possible recovery of vinasse compounds is facilitated because of its concentration. there is a saving of water and the fermentation is also facilitated by the use of heated products (syrup-vinasse) thus sterilized. There is also a less dirty appliances with purified products.

 Other implementations of the present invention, within the reach of those skilled in the art, could also have been considered without departing from the scope thereof.

Claims (5)

 1. Process for the manufacture of fermentation alcohol with significant reduction and sometimes even complete suppression of the rejection of vinasses resulting from distillation, which will notably find its application in the sugar industry for the recycling of residues, according to which the extraction is carried out sugar (2) of the sweet raw material (1Z, such as beets, sugar canes or others. with press water (6> to obtain a sweet juice (3) which once fermented (23) is distilled to extract the alcohol (25> and obtain the vinasses (26), characterized in that  - Concentrating in the form of syrup (10) the sweet juice (3> from the raw material (1X, if it is not sufficiently concentrated,  the syrup (10) or the concentrated material before fermentation (23) is diluted by addition of vinasses (26).  2. A method of manufacturing alcohol according to claim 1, characterized in that one reincorporates the vinasses (26) at the extraction of the sugar (2) of the sweet raw material (1>.  3. Process for the manufacture of alcohol according to claim 1, in which the syrup (10) is fermented by introduction of yeasts from an auxiliary tank (33), characterized in that one introduces deconcentration water (34) in the auxiliary tank (33> for washing the yeast cream and 1 this deconcentration water (34> is then introduced into the fermentation medium.  5. Process for the manufacture of alcohol according to claim 1, in which saccharomyces fermentation yeasts are used, characterized in that the vinasses (26) for distillation are recycled to the fermentation medium (23> so that this The latter has a dry sugar ratio close to 0.5.  5. Process for the manufacture of alcohol according to claim 2, characterized in that the distillation vinasses (26) are reintroduced at the level of the sugar extraction (2> of the sugar raw material (1) in a ratio 400 kg of vinasse (26) for 160 kg of sugar or 1,000 kg of beet.  6. Process for the manufacture of alcohol according to claim 1, characterized in that the vinasses (26> in the syrup (10) are reintroduced at a ratio of about 618 liters of vinasse to 260 kg of sweet syrup at 60%. in weight.