EXAMINATION ON THE UTILIZATION OF BY-PRODUCTS OF DISTILLERY
1NAGY Valéria – 2Dr MEGGYES Attila
1college assistant lecturer, 2professor
1 Szolnok College Technical and Agricultural Faculty, Department of Research and Development 5400 Mezőtúr (Hungary), 1 Petőfi tér, valinagy@mfk.hu
2Budapest University of Technology and Economics, Department of Energy Engineering 1111 Budapest (Hungary), 3 Műegyetem rkp, meggyes@energia.bme.hu
NAGY Valéria Dr MEGGYES Attila
Summary
The methods trying to decrease the waste caused by different kind of production technologies and products are directed towards utilising the energy of waste and making environmental pollution harmless, but at the same time these are environment-saving researches as well. In every case the purpose is the establishment of finishing production cycle in the processes.
Pressing residues and distillery wastes arose in the course of technology for ethanol from sorghum. In the frame of the environmental protection researches directed to development we make experiments of biogas production with its admixture to the thin manure of fermentation residues. The fermentation residues and the technological residue after obtaining artichoke liquid can be utilised excellently as organic matter additive in the biogas factories. Other micro-organisms, however, take part in the decomposing process just as at the un-doped decomposition (biodegradation), therefore, the analysis and multiplication of bacterium-breeding intensifying the decomposing is, in any case, desirable from the point of the economical running of the biogas factories.
This utilization technological developments offer practical solution variants in the field of biogas plant stock supplying. The applied solutions can be spread to more different kind of biomass stock energetic purpose utilisation.
Introduction
By-products and wastes of agricultural origin were used in the near past in the establishments producing biomass energy for renewable energy production, or arborescent vegetation was burned up. The primary objective was to dispose the wastes, the rational economical renewable energy production and utilization were the secondary viewpoints. Economic viewpoints of energy production have come into prominence at the new energy production establishments.
The treatment of the inputs of the renewable energy production, of the production and the utilization as a complex system is a closing cycle, which brings about a competitive technology by recycling the technological wastes and by-products.
Our objective is to determine further possible utilization way of the by-products and/or wastes of the ethanol/alcohol production in the biogas production and which factors and how they influence the utilization.
Utilization of by-products of distillery in biogas works
The biomass plants are suitable for production of the renewable energy carriers (amongst the biogas) as well as the by-products and wastes originating on the course of plant cultivation and animal breeding, too. The production and utilization of energy obtainable from these are not only important in the viewpoint of energy production, but further utilization of by- products is also an indispensable condition of environment protection, and of sustainable farming, as well as the reduction of the quantity and danger of wastes, too.
On the course of the technological experiments on biogas production carried out at the Technical and Agricultural Faculty of Szolnok College, Mezőtúr, we have had several opportunities for examining the utilization of various plants and animal by-products as the possible basic and additive agents for biogas workshops.
Besides the biologically active thin manure in high concentration and quantity, which is a source of potential environment pollutant in animal breeding, the residues of distillation (stillage) can also serve as the basic material of biogas production, which takes form on the course of the production of 1 hectoliter of alcohol strength, the reaction of which is acidic.
In biogas workshops we usually apply various admixtures to enhance biogas output, for instance, the pressing residues of sorghum. The residues after pressing especially build up from lignocelluloses. The cellulose – as skeleton material – plays an important role in the building up of plants, the most important and greatest natural polymer which can be found in every plant. Almost half of the bound carbon dioxide of the atmosphere changes to cellulose.
In fact, cellulose is a long chain building up from the units of sugar, while sugar is an excellent carbon source for methane bacteria. The great molecules of starch also consist of – similarly to cellulose – building units of sugar.
The above listed by-products can also serve as admixtures and basic materials utilizable in biogas workshops according to the accepted practice in the EU, that is to say, recycling of wastes is the most efficient environment protection investment.
Figure 1 shows the pressing residues of sorghum, while figure 2 presents the wastes of distillery.
Figure 1 Sorghum pressing residue Figure 2 Waste of alcohol production Different microbiological inoculating materials (cellulose decomposer, biogas formation assisting agent, N bounder) comes to utilization.
Examination on the utilization of bio-ethanol/alcohol by-products of distillery
We have chosen the indicators amongst which there may be relations, or rather some more important conclusions can be drawn from the changes of their tendencies, the given values of parameter, on the basis of which the basic and additive agents of biogas production can be chosen.
Table 1 shows the apparatus, instruments for determining the characteristics of further utilizable materials for biogas production at bio-ethanol workshops and distillery.
Table 1 The characteristics of bio-ethanol by-products
characteristics and
unit of measurement pig thin manure
Sorghum pressing residues
distillation residues of
alcohol production type of applied apparatuses,
instruments grape
rape
fruit rape pH
[unit] 6,8-7,2 - ~3,91 ~4,3 HydroLab Quanta
C/N ratio 5-10 31-33 20-22 19-22 Vario MAX CN
element analyser dry material content
[%] ~4 ~42 ~17,9 ~10 LP 321/3 drying
cabin organic dry material
content [%]
~3,8 ~39 ~16,5 ~8,91 annealing furnace
The size and the pre-treatment have determining role beyond parameters that are listed in table 1. The significance of the size lies in the assurance of the proper solid matter. The greater the specific surfaces of the materials are, the easier the bacteria reach the alimentary substances, which can be ensured – in the case of grape rape and fruit rape with homogenization – via pre-treatment. The necessity of pre-treatment explains why the biogas production was higher with 20-25 % in the case of homogenized rape additive than the utilized additive without pre-treatment.
The rape is inclined to compression on its own (anaerob surroundings evolve as a result of compression), however, its utilization as additive is advantageous to biogas production. Its volume mass is 450-500 kg/m3, with which an appropriate quantity of dry material content can be assured.
Conclusions
Our examinations have proved that great attention should be paid to the composition of the basic materials participating in fermentation, since more meaningful biogas may be produced specifically in the case of better C/N ratio and greater dry material content. The C/N ratio of the pig thin manure used in our experiments is 5-10:1, however, it may be optimised by adding plant tissues turned into various C/N proportioned wastes. The suitable range of C/N ratio is 20-30:1. Too high C/N ratio should be avoided, because this, however, shows that the partial ratio of difficult to decompose materials is high.
The fermentation residues turning up on the course of bio-ethanol/alcohol production technology can be the admixtures of biogas production, namely that the sugar degree of the juice obtained through pressing after cutting the sorghum is 13-16%, which means that the C/N ratio of the pressing residue from the point of view of biogas production moves towards the optimum range. The favourable characteristics of the distillation residues of alcohol production and by means of their bio-decomposition (bio-degradation) are excellent nutrients for methane bacteria.
The micro-organisms participating in the decomposition (degradation) – towards the formation of their appropriate metabolism activities – are in need of settlement surface, which can be provided by optimising the dry material content. Should there be enough surfaces at disposal for creating life conditions of bacteria, it will be realised in a quantity form of more favourable specific biogas.
As what regards the reaction, we have established that the mash residues are acidic, that is why it cannot be utilised as the basic material of biogas production, but as admixtures – approximately 30 % – it can be excellently utilised after the formation of anaerobic environment.
All in all, it can be ascertained that biomass energy production has been of technology centred, however, nowadays the object is the realization of the closed technologies, as a result of which the environment burden will be the least possible. The by-products of renewable energy producing technologies can be, for example, the ferment residues of ethanol and biogas production as well. In the interest of the realization of “waste free” technologies, the potential contaminant content of input, output and additive agents of renewable energy production should be examined.
Of course, there are several renewable energy production models, the point of which lies in its approach and complexity. The characteristics of biomass varieties resulting in the renewable energy production as well as animal and plant by-products and wastes for energetic are the planned input of the (resulting renewable energy production) models. While that of its output are formed by the produce-able and utilizable energy. The models, so beyond the energy production and starting from the local needs focus over the utilization of renewable energy as well.
References
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