The 3rd International Cooperation
This presentation is the property of its rightful owner.
Sponsored Links
1 / 35

The administration and performance evaluation of biogas plants in Germany PowerPoint PPT Presentation


  • 94 Views
  • Uploaded on
  • Presentation posted in: General

The 3rd International Cooperation Conference on Biogas Industrialization in China (Organizers: CAAA, DLG, CBS) 19.05.2012 Nanjing, China . The administration and performance evaluation of biogas plants in Germany. Jan Postel, Dr . Britt Schumacher, Dr. Jan Liebetrau.

Download Presentation

The administration and performance evaluation of biogas plants in Germany

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


The administration and performance evaluation of biogas plants in germany

The 3rd International Cooperation Conference on Biogas Industrialization in China (Organizers: CAAA, DLG, CBS)

19.05.2012 Nanjing, China

The administration and performance evaluation of biogas plants in Germany

Jan Postel, Dr. Britt Schumacher, Dr. Jan Liebetrau


Performance evaluation of biogas plants

Performance evaluation of biogas plants

Efficiency: Ratio of actual power output and power input

What is required to evaluate a biogas plant?

  • Mass balance of in- and output

  • Energy balance of the biogas plant, including in- and output

  • Data of the reliability of the equipment (hours/year)

    What is needed for the mass/energy balances and the reliability data?

  • Characterization of substrates

  • Main state of the art technologies (data acquisition)

  • Losses/Emissions

  • Evaluation of the overall biogas plant concept


Performance evaluation of biogas plants process chain

Excrements

Preliminary

tank

Biogas

Energy crops

Biogas-

utilization

Silo

Digester

Substrate-

storage

Substrate-

Feed in

Digestate

Distribution/Application digestate

Gas-

storage

Storage tank (digestate)

Performance evaluation of biogas plants (processchain)

What is required to evaluate a biogas plant?

  • Mass balance of in- and output

  • Energy balance of the biogas plant, including in- and output

  • Data of the reliability of the equipment (hours/year)

e.g. combined heat and power plant (CHP)


Requirements for energy balances as basis for efficiency evaluation

Requirementsforenergybalancesasbasisforefficiencyevaluation

  • Efficiency: Ratio of actual power output and power input

  • What is necessary for a qualified evaluation?

    • Definition oftheoreticalenergyoutput

    • Evaluation, documentation, quantification of mass and energy streams,

      Evaluation of operational hours, (documentation of down times, flaring events, maintenance periods etc. )

    • Calculation of capacity utilization

    • Actual – theoretical comparison

    • Identification of bottlenecks

    • Optimization


Mass balance

Mass balance

Grass silage

Digester

Cattle Manure

Digestate

Inorganic matter

Organic matter

Water

Water vapour

Carbondioxid

Methane

Documentation and quantification of all relevant mass streams


Mass balances evaluation

Mass balancesevaluation

  • Does the quality and amount of input masses realized in practice meet the design assumptions?

  • Is the Biogas production according to the theoretical value?

    (consider the conversion efficiency within the CHP as important factor if no direct quantification of the biogas mass flow is available!!)

    • If not check:

      • Substrate quality (is the assumed biogas potential correct?)

      • Infeedamountcorrect?

      • Quantification of degree of degradation by means of a gas potential test of the digestate

      • Stability of biological process (acid concentration?)

      • Temperature

      • Inhibition effects

      • Leackageofbiogaswithinthe gas collectionsystem


Energy balance

Energybalance

A high degree of utilization of waste heat from the CHP is of enormous relevance for the overall efficiency


Energy balance evaluation

Energybalanceevaluation

  • Istheenergyoutputasexpected?

  • Electrical:

  • If not check:

    • Biogas productionasassumed?

    • CHP unit – conversionefficiencyasassumed?

    • Consumptionofdevices on siteto large?

    • Downtime - whatarebottlenecksoftheprocess?

  • Thermal:

  • If not check:

    • Losses due topoorinsulation?

    • Are thereotheroptionsforheatutilization?


Characterization of substrates

Characterization of substrates


Biomass substrates

Biomass / Substrates

Organic waste

Energy crops

By-products & Residues


Substrate characteristics

Substrate characteristics

  • Gas potential (maximum biogas yield obtainable) measured or calculated (digestion tests, animal nutrition test, elementary analysis)

  • Degradation rate (reduction of the concentration of organic substance)

  • Content of micro (trace) and macro elements

  • Content of potential inhibitory substances as nitrogen, sulphur, antibiotics etc.

  • Material handling: pumpability, content of disturbing material (e.g. sand, stones)


Characterization of substrates composition

Characterizationof Substrates - Composition

  • Dry matter content (DM): waterless (anhydrous) share of a mixture after drying at 105 °C.

  • Organic dry matter content (oDM): Mixture free of water (anhydrous) and free of inorganic substances generally per dryingat105 °C and annealing at 550 °C

  • Fractions of fat, protein and carbohydrate analyzed by “Weender” – Animal nutrition analysis

Representativesamplesofthebiomassare essential formeaningfulresults!


Methods of substrate s characterization

Methods of substrate´s characterization

Animal nutrition analysis

Continuous anaerobic digestion

Discontinuous anaerobic digestion


Methods of substrate s characterization1

Methods of substrate´s characterization

Representativesamplesofthebiomassare essential formeaningfulresults!


Biogas potential

Biogas potential


Characterization of substrates conclusion

Characterization of Substrates - Conclusion

  • Substrates differ in energy density, composition and degradability

  • Mostly pre-treatment enhances the degradability of substrates, except for lignin, which is only aerobic degradable

  • High amounts of extreme easy degradable substrates can lead to process failure, due to a excessive acid production

  • Mono-fermentation can lead to an unbalanced nutrient supply, therefore a suitable mixture of substrates or a supply with lacking nutrients are recommendable

  • High concentrations of ammonia can lead to difficulties in the biological process

  • High concentrations of sulphur can cause damage e.g. CHP

  • Sand and stones can lead to technical difficulties


2 main state of the art technologies

2. main state of the art technologies


General technical requirements

General technical requirements

  • high reliability/durability and short maintenance interruptions of all plant components are essential for high operating and full load hours – the overall process has to be reliable!

  • Technology has to match the substrate/biomass, sufficient flexibility for change in substrate

  • Capacityofthe plant as a wholeandthe plant componentshavetomatchtheactualsubstrateandmassflows

  • Low energy consumption

  • Easy to monitor and control


Biomass and reactor type

Biomass and reactor type

  • Digester type is selected according to the substrate characteristics

  • Agricultural application TS between 3 – 12 % continuous stirred tank reactor (CSTR), manure and energy crops

  • plug flow digesters mostly for higher total solid concentrations

  • Box/garage type digestion only for biomass, which is stackable and can be easily saturated by percolate (landscape management material, separately collected biowaste), highly insensitive to sand, rocks, disturbing material


Continuously stirred tank reactor cstr

Continuously stirred tank reactor (CSTR)


Plug flow tank reactor pftr

Plug Flow Tank Reactor (PFTR)

vertical

horizontal

Intake

Discharge


Batch reactor

Batch Reactor

Garage type digester

discontinuous

Prozeßschema Boxenfermenter (Abbildung: BEKON GmbH Co. KG); Fotos: Bekon GmbH (oben), DBFZ (unten)


Process evaluation

Processevaluation

Laboratory tests

Online measurement

Input

Gas production rate

pH-value

Methanecontent

Carbondioxidcontent

Hydrogen content

Temperature

Permanent available,

easy integration to automated process

information content???

  • Degradation of VS, TS, TOC, COD

  • Content oforganicacids(sumparameter)

  • Content oforganicacids (portionofeachacid)

  • not permanent available

  • need of sampling

  • time consuming,

  • difficult to automate,

  • high information content


Technologies conclusion

Technologies - Conclusion

  • Energy output depended on many factors (substrate qualities, stability of biological process, efficiencies and availabilities technical devices)

  • Primary target should be: process stability, reliability of technology

  • Secondary target: gas production rate and energy output

  • The energy consumption of all devices should be kept by a minimum

  • A high degree of utilization of waste heat from the CHP is of enormous relevance for the overall efficiency


Losses emissions

Losses/Emissions


Losses emissions1

Losses / Emissions

  • Losses reduce the energy output and lead to emissions (gaseous, liquid, solid)

  • Need to minimize losses to

    • prevent environmental pollution

    • avoid the release of greenhouse gases

    • prevent the release of toxic substances

    • ensure high energy efficiency

    • ensure economical operation


Sources of emissions within the process chain

Excrements

Preliminary

tank

Biogas

Energy crops

Biogas-

utilization

Silo

Digester

Substrate-

storage

Substrate-

Feed in

Digestate

Distribution/Application digestate

Gas-

storage

Storage tank (digestate)

Sourcesofemissionswithintheprocesschain

Elevated N2O und

NH3-Emissionsdue to crop growing ?

Humus balance?

methane losses of the plant?

Nutrition balance?

No data available - preliminary tank

Leakages?

Methane losses –

Biogas upgrading?

Emissions- from the Co generation unit ?

Coverage?

Relief pressure valve?

Silage losses5-20% ?

Emissions not extensivelyinvestigatedyet

dependend on substrates, moisturecontentofthesoil,

climate, time andperiodofapplication

Large variations in N2O emissions

e.g. Methane emissions from open storage tanks;

Dependend on processing + substrates

Emissions influenced by distribution techniques


Possible losses i

Possible losses I

  • Silage storage facilities

    • Respiration and decomposition of organic matter

  • Hopper/ preliminary tank/ open hydolysis

    • Hopper used for mixing of substrate with digestate

      • Methane (CH4), Hydrogen (H2)

    • Solid material feed in device

      • Respiration and decomposition of organic matter

  • Digester

    • Permeability of rubber membrane, leakages and pressure relief valves

      • Mainly Methane (CH4)


  • Possible losses ii

    Possible losses II

    • Storage tank (digestate)

      • Methane (CH4), nutrients (fertilizer value) (NH3,(N2O))

  • Gas utilization

    • Co generation unit

      • Mainly Methane (CH4) and unburnthydrocarbon (CnHm)

    • Upgrading facilities (Feed in with natural gas quality)

      • Methane slip (CH4)


  • Gas potential of digestates

    Gas potential of digestates

    Specific biogas yield (l*kgVS-1)

    Time (d)

    Low retention times lead to incomplete substrate utilization

    For comparison: 18-70 m³/t digestate


    3 losses emissions conclusion

    3. Losses / Emissions - Conclusion

    • due to environmental and economic reasons losses should be avoided

    • Plant design, substrate and operation of the plant affect the amount of losses

    • Frequent check of the plant and operational management should be self-evident

    • Actual – theoreticalcomparisonisneededforpreciseidentificationoflosses!


    4 evaluation of the overall biogas plant concept

    4. Evaluation of the overall biogas plant concept


    Evaluation for optimization

    Evaluation for Optimization

    Aim: Achievingof a definedtargetstate (optimum) by well-directedmodificationofcurrentsituation

    Noindependentoptimizationofisolateditemspossible, due to mutual dependency

    • Availability

    • Capacityutilization

    • Efficiency

    • Procedure

    • Processcontrol

    • Investment costs

    • Operational costs

    • Income

    • Greenhouse gas emissions

    • Odouremissions

    • Noise emissions

    Source: Leitfaden Biogas; www.fnr.de


    4 evaluation of the overall biogas plant concept conclusion

    4. Evaluation of the overall biogas plant concept - Conclusion

    • Are technology and substrates (texture/amount) a good match?

    • Which ratio of energy production to energy consumption is achievable? (electricity and heat)

    • Fits the plant to operational needs, infrastructure and consumers - gas, electricity and/or heat grid?

    • Are collection and documentation of data appropriate to avoid malfunction?

    • Are the losses reduced to a minimum?

    • Which climatic conditions are to consider? Are insulation or cooling needed?

    • Are the distances between biogas plant and substrates source respectively between biogas plant and residues application short enough? (logistics, costs)

    • Are aspects of environmental protection to consider?


    The administration and performance evaluation of biogas plants in germany

    Contact:

    Dr.-Ing. Jan Liebetrau

    Jan Postel

    Dr. Britt Schumacher

    Deutsches BiomasseForschungsZentrum German Biomass Research Centre

    Torgauer Straße 116

    D-04347 Leipzig

    www.dbfz.de

    Tel./Fax. +49(0)341 – 2434 – 112 / – 133

    Thank you very much for your attention!

    Research for the Energy of the Future


  • Login