Presentation on theme: "Energy Efficiency in IPPC installations,"— Presentation transcript:
1 Energy Efficiency in IPPC installations, October 2004 in ViennaAustria Trend Parkhotel SchönbrunnInnovative examples of energy efficiency in the German sugar industry - dewatering and drying process for sugar beet pulp -Dipl.-Ing. Christian VoßSüdzucker AG for the GermanAssociation of Sugar IndustryWerk Warburg, D WarburgTel / 9413U MWELTB UNDESA MT, BerlinPostfach , D BerlinTel. 030/Dr.- Ing. Joachim Wieting
2 Structure1. Introduction (targets and development of the specific energy requirement)2. Mechanical dewatering process for sugar beet pulps in the sugar industry as regards energy3. Drying processes (drum drying, low temperature drying and evaporation drying)4. Energy aspects of pulp drying5. Comparison of energy consumption and theeconomics of different types of installations withexamples6. Characterisation of the technology –economic and ecological aspects
3 Background and Motivation With the finalisation of the Council Directive 96/61/EC concerning „Integrated pollution prevention and control“, the so-called „IPPC Directive“, the concept of an integrated approach to reduce environmental pollution is being pursued at European Community level for the first time, with all installations covered by the directive now requiring permits.The EU Commission is supporting the implementation of the directive as part of its exchange of information by having leaflets compiled on the „best available techniques (BAT)“ by the European Integrated Pollution Prevention and Control (IPPC) Bureau in Sevilla, Spain.
4 Background and Motivation The „food, drink and milk“ BREF gives information at community level on the best available techniques in the sugar industry to help promote the use of these techniques and to support the member countries effectively in their efforts to protect the environment.The efficient use of energy in the industry helps avoid and/or control emissions in the air, in water and in the ground as far as possible.The formulation of the directive into a new VDI guideline in Germany will set out primary and secondary control measures and new reduced emission figures for production technology.
5 precautions in the interest of the climate Introductionprecautions in the interest of the climateAgreement between German sugar industry and the government board signed on :Reduction of the specific CO2 emissions of 41 – 45 % by 2005/06Base year 1990: CO2 emissions/beet kg/tTarget year 2005/06: 81 – 87 kg/tachieved 2000/01: 84 kg/twith kWh/ton of beetTarget achievement: almost 100 %
6 Specific energy consumption in the IntroductionSpecific energy consumption in theGerman sugar industrykWh /100 kg beets12510075current 1996:5030,6ABLDDR / NBL25D, gesbasis 1990:target 2005 :35,6291950196019701980199020002010yearABL = old Federal statesNBL = new Federal statesD = Germany as a whole
7 Specific energy consumption in the IntroductionSpecific energy consumption in theGerman sugar industrySince 1990 > 300 Million € have been invested in projects for combined heat and power generation (CHP).Degree of efficiency of heat and power combinations > 90 %re-use of the heat several times normalf = 7 – 8Future: physical limitsincreasing technical expenditure (costs)marginal energy savings______________________________________________________Personal remarks on sugar market regulation
8 Energy conversion in a beet sugar factory IntroductionEnergy conversion in a beet sugar factoryand VDI extra edition 2594Main flows of energy and technical processes are more closely interlinked than in any other sector of industry.Amount of energy used Sugar production : Dried pulp production:VDI-Guideline „Emission reduction in pulp drying plants in the sugar industry“, First printed August 2004
9 of the dewatering process for beet cossettes Energy aspectsof the dewatering process for beet cossettesProduction of dried pulp with 90 % dry substance and10 % water from extracted cossettes with 10 (- 14) % dry substance and 90 % waterin 2 dewatering stages: mechanical thermalAmount of energy usedkWh/t water approx. 30 approx:Target: To remove as much water as possible mechanically.
10 of the dewatering process for beet cossettes Energy aspectsof the dewatering process for beet cossettesState of the art: Spindle presses horizontal/verticalpulp inlet screenring, axially relocatable for pressing pressure variationpress water collectorpulp outlet
11 of dewatering process for beet cossettes Energy aspectsof dewatering process for beet cossettesQuantity of material pressed out depends on capacity of presses - Hardening with calcium ions (gypsum), Development by Südzucker (SZ):343,4323,2303282,8Dry-substance content inWater carrying in kg Water/Press-pulps in %kg Dry-substance content262,6242,4222,2202808284868890929496980002CampaignDry-substance content in %Watercarying in kg Water/kg Dry-substance contentSZ-Pressing target before drying: 32.5 % dry substance in the pressed pulp
12 of dewatering process for beet cossettes Energy aspectsof dewatering process for beet cossettesOther mechanical dewatering processes % dry substance in the pressed pulpDiffusive dewatering:in combination with evaporation plant to concentrate the press waterDisadvantage: no suitable separation of solids/liquidsHigh-pressure, multi-layer pressing: Filter band press: 300 bar; 15 min. pressing time Disadvantage: no suitable filter cloth quality no reliable control of the 300 hydrauliccontrol loopsExtraction under alkaline conditions – 50Pilot installations in France, Germany and England
13 of dewatering process for beet cossettes Energy aspectsof dewatering process for beet cossettesCombination of electroporation and alkaline extractionAlkaline extraction results in increased deposits of calcium ions and thus to a definite increase in the pressability of the extracted cossettes Dry substance (DS) content of extracted cossettes : % (an increase of approx. 10 % DS)Opening the cells by electroporation to prepare for deposit of calcium ions opening the cell membranes by high voltage impulseshigh voltage impulses: a voltage of several hundred kV for the duration of approx. 1 µsec• low energy demand: approx. 1 kWh/t beet
14 of dewatering process for beet cossettes Energy aspectsof dewatering process for beet cossettesChanges in the mechanical properties of beet due to electroporationElectroporation increases the flexibility of the cossettes considerably and enables them to stand up to heavier mechanical stress.
15 of dewatering process for beet cossettes Energy aspectsof dewatering process for beet cossettesbeetsPossibleconfigurationofelectroporationandextraction*electroporationelectroporatedbeetselectroporatedandalkalinedcossettesslicingmachinelimemash*patent applied forjuicetowardsjuicepurification
16 Steam system of a sugar factory with steam drying Drying processSteam system of a sugar factory with steam drying
17 Steam system of a sugar factory with Drying processSteam system of a sugar factory withsteam drying
18 Energy aspects of cossettes drying In order to consider the energy aspects of the installations described, the general data of thefactories with both direct and indirect dewatering systems have been standardised as follows:· Beet processing tons/day· Length of „campaign“ (season) 90 days p.a.· Mass flow of pressed pulp: 160 kg/t beet processed = 66,7 tons/h· Dry substance content of the pressed pulp 31 %· Dry substance content of the dried pulp 90 %· Steam consumption of a sugar factory for 200 kg/t processed beet = 83.4 t/h· Live steam pressure 85 bar· Live steam temperature 525 °C· Thermal value of the fuel kJ/kg.
19 Energy aspects of cossettes drying · Electrical energy demand of the sugar factory without drying 10.4 MW = kWh/t beet processed· Complete crystallisation of the thick juice in the beet campaignThese norms pre-suppose that the factories have the following technical installations:· A steam generator with 85 bar and 525 °C.· A corresponding back pressure turbine bar back pressure to supply the evaporation station or 3 bar back pressure and 25 bar extraction pressure to supply the steam dryer.· A gas turbine to reduce the use of electric energy when using a steam dryer.· A effluent treatment plant which can process the condensed vapours from the evaporation dryer..
20 Summary of the examples of installations Steam dryerHigh temperature dryerLow/high temperature dryerFactory without a dryerTotal electric energy demandMW11.5511.2012.1010.40Total fuel energy73.72111.83104.8067.13Total electric energy obtained11.4811.66Total energy costs€/h1,1821,7801,6951,048Total energy costs per campaign103€/a2,5323,8453,6612,264
21 Summary of the examples of installations Additional energy costs in comparison to a factory without dryers for the individual variations:High temperature dryers €Low/high temperature dryers €Steam dryers €Operation related costs (higher investment costs of installations in comparison to lower fuel costs in operation)High temperature dryers € p.a.Low/high temperature dryers € p.a.Steam dryers € p.a.
22 Summary of the examples of installations Investment costs plus net running costs of the dryer for the individual variations:High temperature dryers Mio. €Low/high temperature dryers Mio. €Steam dryer Mio. €Characterisation of the technology:At the present time steam drying is the best available technique for new sugar factory construction or for complete reconstruction of energy production and heat control systems. However, it cannot be integrated easily into a normal existing factory.
23 Advantages achieved by steam dryingMain achievement - Improvements for the environment with regard to emissions and energy consumption:Emissions are avoided by direct primary use of energy for drying.No application of steam-volatile and odorous vapours.Energy consumption 30% less than in a factory with direct drying.Inter-media effectsTransfer of the exhaust fumes into the effluent (approx m3 effluent with a chemical oxygen requirement of mg/l and a NH4-content of 25 mg/l).
24 THANK YOUIn conclusion we should like to thank all those who participated -the members of the VDI working group 2594,the participating companies in the Sugar Associationand all of you for your attention.THANK YOU