The food industry:
new energy possibilities
IES FOOD INDUSTRY
Aerobic and anaerobic:
a perfect synergy
The constant efficiency of production processes has led the food industry to dispel on average only 2% of the processed product. These are mostly residues transported by the water used to clean machinery and premises.
The enormous food production makes this small percentage a great source of pollution by organic compounds such as carbon, nitrogen and phosphorus.
Biological technologies have long been developed to purify these waters before they are released into water bodies.
Years of experience
Sustainable energy for the food industry
The biological purification strategy is based on the natural metabolism of a number of bacterial species that digest organic pollutant compounds to grow in turn. Nature has developed an enormous variety of bacteria suitable for the most different environmental conditions. In biological purification plants, are applied techniques that intensify the growth of the desired bacterial species, replying the conditions best suited to them.
ACTIVATED SLUDGE TECHNIQUE
The most widespread biological technique, known as the activated sludge technique, uses bacterial species whose metabolism (similar to that of higher living beings) is based on the carbon oxidation and, for this reason, they breathe oxygen taking the name of aerobic species, which efficiently metabolize carbon over a wide range of temperatures. With them, have been developed techniques that break down also nitrogen.
The intensification of this technique involves high energy consumption, since it is necessary to supply oxygen to the bacteria. Experience, now almost one hundred years old, shows that no less than 1 kWh must be used to treat the carbon correspondent to 1 kg of COD; the metabolic efficiency means that from this treatment, no less than 200 grams of bacteria (sludge) to dispose are obtained.
Less common, especially because efficient in a narrower temperature range (30-55 °C), are the families of bacterial species called anaerobic, whose metabolism is based on carbon reduction and which, for this reason, do not need to breathe oxygen. Their metabolism is much less efficient, so much that with the same amount of carbon they grow up less than one tenth of it in comparison to the aerobic ones; from their metabolism results, however, an interesting quantity of methane.
The application of the anaerobic technique is less widespread, because it requires temperatures higher than 30°C and a sufficient concentration of carbon, but above all because in the past the low cost of energy, the low sensitivity for its efficient use together with the low cost of sludge disposal, has favoured the less expensive technique in terms of the initial investment.
Today, however, the rising operating costs make it increasingly necessary to minimize the use of aerobic techniques for carbon abatement. Today it is fundamental, in biological purification, to use all the plant strategies, which make it possible to apply anaerobic technology to lowering carbon.
In anaerobiosis, the abatement of carbon corresponding to 1 kg of COD (which requires at least 1 kWh) involves irrelevant electricity consumption, while it produces a quantity of methane corresponding to almost 3.5 kWh of chemical energy.
The energy balance is also extremely profitable for the production of biomethane: net of heat requirements, energy consumption is less than one fifth of the energy produced.
An integrated system for energy production
Large companies in the food industry have a lot of waste that cannot be recovered easily and economically, and by-products, which reuse involves considerable costs.
IES Biogas technologies for anaerobic digestion offer highly customized and case-studied solutions to enhance these substrates, through the perfect integration of a biogas plant in the business economic model.
An opportunity to achieve energy efficiency in the production process, reducing energy supply costs and generating a new source of income.
Here is your company, 100% integrated with biogas
In the food and beverage sector, biogas and biomethane plants are used very well: thanks to the IES FoodIndustry division, by-products and waste from food processes are enhanced and transformed into energy, offering a new source of income.
Our anaerobic fermentation technologies perfectly fit to the food industry, because:
1) they produce by-products, which use can be enhanced form an economic and environmental point of view;
2) they consume heat and electricity: the waste, through the production of biogas, allows to create energy and so provides new income in the perspective of a circular economy;
3) the use of by-products finds a great opportunity in the promotion of biomethane.
We have the best anaerobic solutions for:
- Beverage industry
- Potato and tuber industry
- Confectionery industry
- Brewing industry
- Biodiesel production
- Meat and fish industry
- Dairy industry
Infusion techniques produce a considerable waste, partly hydrolysed by the process itself. These matrices can always be used in anaerobic digestion. The factories, which process fruit for the production of purees and juices, release effluents with a strong dissolved sugars pollution. There is a specific anaerobic technology based on biomass, which conforms in granular colonies: this technology allows a 90% reduction of purification costs.
POTATO AND TUBER INDUSTRY
Waste and wastewaters from potato processes are particularly suitable for anaerobic treatment. On the one hand, the solid fractions discarded from the preparation of the tubers and, on the other hand, the starch dissolved in the effluent, make the purification process highly advantageous through anaerobic treatments. In these processes, the anaerobic digestion of waste and residues, combined with cogeneration techniques, can generate renewable energy at a rate of 20-30% of electricity consumption.
The emptying residues of the packaging lines, those coming from the preparation of raw materials, the creams and pastes remaining from the machinery cleaning, the non-compliant product, the fats and sugars transported by the washing water are matrices which, treated anaerobically, lead to the self-production of between 10 and 20% of the electricity consumption of these factories.
The effluents from the breweries contain starches and dissolved sugars, 90% of which can be broken down using granular mud anaerobic technology. In this case, it is an initial treatment of the effluent, which is then refined in an aerobic activated sludge system. The synergy between anaerobic and aerobic technologies allows to reset costs of the effluents treatment.
The production of biodiesel is obtained from ethanol derived from the distillation of fermented cereals: in addition to being used in fertigation, the distillation residues, called borlande, can be used in anaerobic digestion to produce biogas, which quantity can be used not only for electricity or biomethane production, but also to cover a portion of the high internal thermal consumptions of the production plants.
MEAT AND FISH INDUSTRY
Slaughterhouses and factories processing fish emit effluents, which organic load can be greatly reduced by simple coagulation and separation of solid fractions processes in the form of primary sludge. These sludges can represent a significant disposal cost, but can become a significant resource, if treated with anaerobic technology. In slaughterhouses, faecal and ruminal residues from bovines also represent eligible matrices for biogas production. In the meat sector, the application of these strategies, combined with cogeneration techniques, obtain the total reduction of purification costs.
Dairy production generates waste and by-products that contain an organic pollutant mass that cannot be handled with aerobic techniques. These are enormous quantities of material that must be daily disposed to avoid production shutdowns. For this reason, dairies are often forced to dispose this waste in specialised centres, enduring considerable costs, especially in the South Italy. An anaerobic technology has been developed to treat this kind of waste as well, transforming the costs into incomes for energy production.
Medium-sized dairies (>200 quintals of milk per day) can eliminate electrical costs and halve thermal costs.
Our Case History
A biogas and biomethane plant is an important choice for a company.
It means converting to renewable energy and adopting new green business strategies, seizing all the opportunities offered by the circular economy.
A sustainable choice, that produces profits for the company and protects the environment.