Biogas and Digestat Treatment

Die Kombination von industrieller Biogasproduktion und der ENTEX Gärrestaufbereitung eröffnet neue Möglichkeiten zur nachhaltigen Energieversorgung von Industrieanalgen und Wohnquartieren.

  • Durch den Einsatz von Biomassereststoffen (Abfällen) wird die gewonnene Energie preiswert.
  • Das hergestellte Biomethan hat Erdgasqualität und läßt sich sowohl für Heizzwecke als auch zur Generierung von elektrischem Strom nutzen.
  • Die Emissionslage verbessert sich, wenn fossile Brennstoffe wie Kohle durch Biomethan ersetzt werden.
  • Der Einsatz schlanker Biogasreaktoren verschlingt erheblich weniger Platz als herkömliche Biogasanlagen bzw. ermöglichen erst die industrielle Biogasproduktion.
  • Durch den Einsatz einer Gärrestaufbereitung gehen sonstige Emissionen gegen Null.
  • Die Biogaserzeugung kann bei Nutzung eines Gasnetzes auch weit entfernt von der Gasnutzung stehen.
  • Auch die Bioabfallaufbereitung kann ausserhalb des Biogasanlage erfolgen.

Wenn sie an einer ökonomischen Alternative zum Einsatz von fossilen Brennstoffen interessiert sind sprechen sie uns an.

Im Folgenden wird das Konzept technisch näher beschrieben:

 

The wide-spread procedure of waste fermentation is quite problematic due to the complex processing of the digestates. Unlike in the NAWARO biogas plants, in most cases the digestates can’t be utilized for agriculture due to their toxic potential.

No GO Grrest 01

Hydrothermal procedures can offer a solution for this problem. ENTEX Group considers hydrothermal procedures as procedures which work under increased pressure and temperature.

The objective is to mineralize the digestate by applying the hydrothermal procedure, i.e. to split up the digestate in smaller molecular fragments like e.g. CH4 , CO2 und H2O.

Zellabbau 01.en

Anorganic pollutants can be transferred outwards as well depending on which type of procedure is applied – they can be removed either physically during the procedure or chemically by adding certain chemicals as moderators.  

The fact that in this procedure increasing pressure or temperatures have to be applied might be a little discouraging at first – but this is only half the story.

The simplest way to explain this is to use an example which everybody is familiar with: lighting a candle. This comparison might be flawed but it is still instructive. If you hold a lighter or a match to the wick of a candle the temperature will rise until the fuel wax (more exact: the volatile substances in the wax) starts to burn. From this point on the redundant energy maintains the reaction until the candle will have burnt low or we blow it out (and end the romantic lighting).

Aktivierungsenergie 01.en

All hydrothermal procedures have in common that molecules are disintegrated by the earlier described high temperatures and pressure and that these molecules react with the added oxidants or that they use accompanying molecules as an oxygen donor.

All this happens in the confined space of the autoclave of the plant. The mutually reacting molecules meet in confined space resulting in a high reaction density (not like in the gas compartment). Contrary to the known thermic procedures, harmful emissions are not released.

If the activation heat is provided by the waste heat from the CHP or the turbines, you have a cost-efficient technology to utilize food waste for biogas production without any hygiene problems. The recycling plant works almost emission-free.

If you combine this technology with the UDR high-performance packed bed fermenter, the implementation for decentralized energy supply in industrial areas or city districts is possible. This generation of fermenters provides the necessary output rate. Besides, there are further value added options at the site of such plants.

The biologically active microorganisms are fixed with this UDR fermenter of our partner Röring Energy Systems. The substrates are introduced to the bottom of the fermenter and are slowly guided through the packed bed. The microorganisms are not exposed here to shear forces by stirring. The symbiotically interacting microorganisms can efficiently decompose the organic substrates and transform them into methane.

The bloating, not yet transformed substrate material will be redirected to the reflow system at the overflow of the reactor and gradually fed in into the upflow reactor. The fragmented organic molecules reach the downflow reactor where they can be transformed further into methane. At the outward transfer of the reactor you have a digestate with a low residual activity which can be documented by means of the already determined concentration of residual acids.

This procedure allows a very high volume load and an efficient decomposition of the digestive ingredients. The new generation of fermenters technologically represents the digestive tract of ruminants.

The UDR packed bed fermenter is a necessary component for the procedure with sojourn times of 5 days compared to 60 or 100 days in the classical stirrer tank fermenter. There are also other value added options.

The combination of procedures suits ENTEX’ concept to industrially implement it. This is another step to the emission-free plant. Needless to say that the described procedure is of high economic interest.

The single technologies have already passed their performance tests!

Hydrothermal technologies have proven their effectiveness, especially with the harmless disposal and utilization of chemical wastes. The special apparatus engineering of the ENTEX Group, GESA GmbH, is realizing such plants and further aggregates for the biogas production.

Today the NEW UDR high-performance fermenters are distributed with performance warranty in agriculture and they surprise with always new performance ratings which exceed the traditional stirring tank fermenters with 20 – 50 %.

The combination of these technologies for energy efficient utilization in food technology, especially regarding abbatoir waste, is NEW.

These plants have shown their effectiveness with the decomposition of petrochemical wastes. Currently we’re adapting these technologies for problematic residual food in demonstration projects.

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