What’s it all about?

Interesting facts on the following key words:

BIOGAS

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What are difficult substrates?

Corn silage with a high share of liquid cattle manure may be referred to as the classical and easy-to-handle substrate blend. This substrate blend is a tried-and-proven solution already used in many NaWaRo biogas plants and does not constitute any challenge at all for Novatech. The more the substrate blends, however, deviate from it, the more the technology used must be precisely considered. Particularly during periods of high substrate prices, alternative feedstock becomes increasingly interesting. Difficult substrates that are more and more frequently used in biogas plants are:

  • High grass silage shares, particularly in combination with thin liquid pig  manure:
    Strong trend to scum layer formation
  • Solid dung:
    high TS content, long fibers, danger of scum layer formation
  • Horse dung:
    very high TS content, scum layer formation
  • Turkey dung:
    high nitrogen content, danger of process inhibition
  • Dry chicken dirt:
    high nitrogen content, danger of process inhibition
  • Clover grass silage:
    high nitrogen content, danger of process inhibition

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Which main components are required for operating a biogas plant?

The following modules are generally used:

  • Pre-pit:
    Here, the liquid feedstock (liquid manure, surface water and seepage) is collected and then fed into the fermentation tanks.
  • Solids feed:
    The solids feed is used to supply solid feedstock to the fermentation tank. Select the input volume of the solids feed so that a sufficient amount of feedstock for a single day’s ration may be input.
  • Reactors:
    Biogas generation occurs under anaerobic conditions in the sealed reactor. Here organic materials will be disintegrated and converted into biogas by various kinds of bacteria. Stirring systems are used to homogenize the feedstock and mix it with the already active fermentation substrate in the reactor. In order for the anaerobic bacteria to work optimally, heating the reactor is required.
  • Post-fermentation store:
    The previously fermented substrate will be stored in the sealed post-fermentation store prior to its distribution on the fields. In case of high reactor loads and short dwell times, a considerable amount of biogas may also be generated in the post-fermentation store.
  • Gas accumulator:
    The biogas generated in the reactor and post-fermentation store must be collected and intermediately stored in order to ensure a high plant utilization rate.
  • Combined heating and power plant:
    Biogas is fed from the gas accumulator to the combined heating and power plant for the generation of heat and electricity. The electrical energy is fed into the local mains and a compensation fee is paid in accordance with the local EEG rates. In order to increase the overall efficiency and profitability of the biogas plant, the excessive heat that is not required for heating the fermentation tanks may be sold for external heating purposes.
  • Gas pipework
    The gas pipework is used to transport the gas from the sealed fermentation tanks to the gas accumulator and further on to the point of utilization.
  • Substrate pipework
    The general term substrate pipework usually refers to the feed line from the pre-pit to the fermentation tanks, the overflow between the individual fermentation tanks and the substrate lines for recirculation.

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What is a local heating network and what is its purpose?

picture local heating supply

When operating a combined heating and power plant, heat will be generated in the cooling water and exhaust gas. Utilization of the waste heat increases the overall degree of energetic utilization of the biogas plant. Part of the heat generated is used within the process in order to heat the fermentation tanks, The largest part, however, may be supplied to external consumers. The heat generated in the biogas plant is then conveyed to the consumer via the local heating network. The revenue generated by selling the heat together with the CHP bonus enhance the profitability of the entire biogas plant.

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Why are the compact liquid manure operated plants offered as standardized plants?

The differences between compact liquid manure operated plants are very small, to where the three different options offered (40, 60 and 100 kWel) are the equivalent of a “tailored” system, which may furthermore be offered at a lower price.

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Why is it essential to have a tailored biogas plant?

Our experience shows that the biogas plant technology used should be defined in accordance with the substrates list and the plant location. We strongly advise against the construction of a predefined and inflexible plant system. This is primarily true for periods during which the substrate prices increase and the search for economic alternatives is intensified. The selection of the proper technology reduces internal energy consumption and maximizes the plant operating time. This is the only way to ensure an economic operation of the plant also in difficult times.

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What will happen after the biogas plant’s completion?

After completion of the biogas plant and accomplished acceptance inspection, the plant will be started up biologically. Our support department will provide assistance during the initial weeks of operation of your biogas plant for your daily work with the plant. The biological process support generally includes the following services:

  • consultation regarding the operation of the biogas plant
  • preparation of a feed plan for the biogas plant
  • analysis of the degree of acidification and buffer capacities of the fermentation tanks
  • recommendations regarding the feeding of the plant provided on the phone

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Does Novatech also guarantee specific kW outputs?

A performance guarantee may be provided in combination with our low-priced intensive process support program “all-round carefree package”. The exact terms depend on the respective project and will be clarified during the preparation of the project.

> Biological process support

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How long is the warranty / guarantee period?

  • four years in accordance with the German regulations for contracts and execution of construction works (VOB) for fixed components
  • one year for revolving parts or limitation of the warranty periods to those of the sub-suppliers (e.g. six months for pumps, stirring mechanisms)

> Download: Performance provided on site

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Is it possible for me to actively participate as a customer?

Every customer may participate in the construction of his biogas plant on request. Construction costs for the biogas plant may be reduced particularly by providing helpers on site to support our assembly team. An individual adjustment will clarify for which components the provision of help on site will be possible or desirable. If a turnkey plant is not desired, the following elements and performance will usually have to be provided on site:

  • excavation work for fermentation tank and pipework
  • foundations for buildings
  • pump basement
  • provision of helpers on site for concrete pouring for the fermentation tanks
  • CHP building and intermediate building
  • gas accumulator building

On request, Novatech will take over parts of the above performance or will deliver turnkey plants.

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How much experience does Novatech possess in building biogas plants?

Until the end of 2007, Novatech has been involved in the construction and planning of biogas plants with a total output power of 19,000 kW. Under the assumption of 8,000 operating hours per annum (max. possible: 8,760 hours), these plants consequently produce 150 million kWh of electrical energy per annum. In mathematical terms, 40,000 households of four are thus supplied electricity in an environmentally compatible way. Assuming an average production of 670 g/kWh CO2, more than 100,000 tons of the greenhouse gas CO2 are thus “saved” every single year. In 2011 Novatech has put into operation over 40 biogas plants nationwide and one plant in France.

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How safe are biogas plants?

The following aspects are essential for the safety of our biogas plants:

  • concrete vessel with a wall thickness of between 20-22 cm (0.8 – 0.9“)
  • vessel height usually 6 m ((20’), partially sunk in the ground
  • pure biogas in the gas accumulator is not combustible
  • no fixed connection between vessel cover and walls. The cover would rise in case of a possible overpressure condition and the excess pressure would be reduced 
  • construction of the plant in accordance with the respective safety regulations that apply to agricultural biogas plants
  • acceptance inspection by an external expert of every single biogas plant built

The fact must be mentioned that there is no such thing as absolute safety for biogas plants. Proper qualification of the operator as well as of the plant manufacturer is thus essential. Novatech may look back on 17 years of experience in the construction and building of biogas plants. Since 1996, Novatech has furthermore gathered experience by operating a company-owned biogas plant on site at the corporate premises.

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Which motivation is the driving force for the biogas team?

Responsibility towards the next generations, ideology and compassion

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Which certificates does Novatech possess in the biogas sector?

Novatech is certified as a specialist company in accordance with WHG §19 (Water Ecology Act). This act includes regulations for the protection of water and soil including numerous ordinances and technical regulations. Only craft enterprises in the possession of the quality seal are authorized to install, erect, maintain, repair, and clean plants that are sensitive regarding the environment.
> Water Ecology Act

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Low-priced credits from KfW for “compact plants” or partial debenture waiver

> KfW
Apparently lacking development programs are realized in the form of performance subsidies. Consequently a plant with a higher performance will also received higher subsidies.

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Legal basis

Link list

Please adhere to the following legal bases for the construction of a biogas plant:

> EEG (Renewable Energies Act)
> Baugesetzbuch (Federal Building Code)
> Bundes-Immissionsschutzgesetz (BImSchG) (Federal Emissions Act)
> Bioabfallverordnung (biowaste ordinance)
> Tierische Nebenprodukte-Beseitigungsgesetz (Animal by-Products Disposal Act)

Additionally:

  • Landesbauordnung (State Building Regulations)
  • EU-Hygieneverordnung (EU Hygiene Ordinance)
  • Technical instructions, such as TI Air, TI Noise etc.

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Feed fee - current / expected?

(valid as of July 2004)

 

 

up to 150 kWel

up to 500 kWel

up to 5 MWel

more than 5 MWel

Basic fee

existing plants

as before

from 1/112006

11.16

9.6

8.64

8.15

from 1/1/2007

10.99

9.46

8.51

8.03

from 1/1/2008

10.83

9.32

8.38

7.91

from 1/1/2009

10.67

9.18

8.25

7.79

NawaRo bonus

existing plants

6

6

4

-

new plants

6

6

4

-

CHP Bonus

existing plants

-

-

-

-

new plants

2

2

2

2

Technology bonus (only if CHP requirements are met)

existing plants

-

-

-

-

new plants

2

2

2

-

 > current fees

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Why was the EEG amended?

A verification of the efficiency and – if required – an adaptation of the ecologic and economic parameters is made.

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What is the EEG?

The “”Priority of Renewable Energies Act” (“Gesetz für den Vorrang Erneuerbarer Energien”), in short EEG, came into force on 29 March 2000. It is the objective of the EEG to promote the expansion of the use of renewable energies for the generation of electricity as a central element for the protection of climate and environment, a sustainable development and the increase of the share of renewable energies in domestic electricity generation. It proved to be – also compared within the European Union – as a particularly efficient instrument for the expansion of renewable energies. The last amendments that affect the biogas industry came into force in July 2004.

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What can biogas do for me?

Personal benefits:

  • Active contribution to the protection of our climate
  • Utilization of renewable locally available raw materials
  • Enhanced fertilizer quality contrary to raw liquid manure
  • reduced odor intensity and etching during application
  • the plants may exploit the nutrient content better and faster than is the case for raw liquid manure
  • Profit created from the feed fee or the sales of heat
  • Independence from price increases for fuel oil or natural gas

Social benefit / environmental benefit:

  • Climatic protection and independent energy supply
  • biogas is used and does not escape as a gas that is harmful to the climate
  • heating energy from biomass instead of fossil fuels
  • decentralized energy supply
  • energy autarky of the FRG is increasing

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What is biogas?

The production of biogas is not a technical achievement, but rather a natural process that has been around for millions of years. The existing biomass is converted into its source materials under the exclusion of oxygen and is thus again available for new biomass to be created. In scientific terms this means: Biogas is the result of the anaerobic fermentation of biomass. The gas blend thus created – dependent on the substrate used - features a methane share (CH4) of about 50 - 70 percent and a carbon dioxide share (CO2) of approx. 30 - 50 percent. A low concentration of hydrogen (H2), hydrogen sulfide (H2S), ammonia (NH3) and other trace gases may furthermore be found in the blend.

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