Milledge, John J.

Greenwich Academic Literature Archive

The Oil, Finance & Shipping Symposium31st August 2016, University Of Greenwich at MedwayAlgal biofuelsDr John J MilledgeAlgal Biotechnology Research Group, University of GreenwichClimate Change: “The overwhelming majority of scientists agree that the rising concentrations of heat-trapping greenhouse gases in the atmosphere caused by human activities”The Met OfficeCarbon Dioxide levels are Increasing and global temperatures are risingNASA Climate ResourcesUK Policy on increasing the use of low-carbon technologies• 80% reduction in greenhouse gas emissions by 2050.• 15% of the UK’s energy demand from renewable sources by 2020https://www.gov.uk/government/policies/increasing-the-use-of-low-carbon-technologiesRegulations are driving search for cleaner fuels• UN’s International Maritime Organisation -Sulphur oxides (SOx) – Regulation 14Wind, solar and hydro together generated 15% of Britain's electrical demand in 2015.Based on DECC dataUK Renewable energy fuel use 2015Digest of United Kingdom energy statistics (DUKES)  There is a continuing demand for fluid fuelsHeavy HaulageMarine TransportAviationTargets for biofuel energy content in transport fuels•2005 - 2%•2020 - 10%    ???????????Only Sweden and Germany met the 2005 target The EU Renewable Energy Directive (RED) UK Petrol, Diesel & Jet fuel usageDECC 2016Sources of biomass and biofuelsBIOMASSOil cropse.g. rape, sunflower, palmSugar cropse.g. cane, beet, sorghumWoody biomassStarch cropse.g. wheat, maize, potatoAlgaeWaste biomasse.g.  BMW, food waste, animal slurries, sewage sludgeHerbaceous biomasse.g. switchgrassBIOFUEL PROCESSESAnaerobic digestion or fermentationTransesterificationEthanol fermentationPyrolysisGasificationBiorefiningButanol fermentationCombustionBIOFUELSBiodieselBioenthanolBiogasBiomethaneBiohydrogenWoodBiobutanolMethanolSyngasGlycerolHydrothermalFeedstocks for UK Liquid biofuelsUK biodiesel mainly from Waste  Cooking Oil and TullowDECC and UKPIAGallagher Report  (2008) - EU target of 10% of transport fuel used by 2020s unlikely to be met sustainably.The Gallagher Review of the indirect effects of biofuels production, Renewable Fuels Agency , 2008 .http://webarchive.nationalarchives.gov.uk/20110407094507/renewablefuelsagency.gov.uk/reportsandpublications/reviewoftheindirecteffectsofbiofuelsHow “Green” is Biodiesel?Directive (EU) 2015/1513Max 7% contribution by  biofuels from 'food' cropsEmphasis on biofuel from:Waste feedstocks Advanced biofuelsSources of biomass and biofuelsBIOMASSOil cropse.g. rape, sunflower, palmSugar cropse.g. cane, beet, sorghumWoody biomassStarch cropse.g. wheat, maize, potatoAlgaeWaste biomasse.g.  BMW, food waste, animal slurries, sewage sludgeHerbaceous biomasse.g. switchgrassBIOFUEL PROCESSESAnaerobic digestion or fermentationTransesterificationEthanol fermentationPyrolysisGasificationBiorefiningButanol fermentationCombustionBIOFUELSBiodieselBioenthanolBiogasBiomethaneBiohydrogenWoodBiobutanolMethanolSyngasGlycerolHydrothermalWhat are Algae?• Diverse range of aquatic ‘plants’, ranging from unicellular to multi-cellular forms, • Generally possess chlorophyll, but are without true stems and roots.• Two groups: macro-algae commonly known as ‘seaweed’ micro-algae, microscopic single cell organisms Seaweed growing on the Medway Culturing microalgae in flasksWhy Algae?• Algae can be cultivated on non-agricultural land or at sea.• Many species grow in brackish or salt water. • Potential productivity greater than terrestrial crops Microalgae can contain high quantities of lipids (oil)Nitzschia palea 80%Botryococcus braunii 75%Monallantus salina 72%Chlorella protothecoides 55%Scenedesmus dimorphus 40%Prymnesium parvum 38%Source University of Cape Town Microalgal Biodiesel ProcessDilute Algae Conc’ AlgaeGrowthHarvestingconcentrationDrying & Lipid ExtractionOperational Energy InputNutrients RecycledWater &Nutrients CO2Energy OutputO2TransesterificationLipidCurrently UneconomicGlycerol the byproduct of Biodiesel• The glycerol 9 -13% of fats and oils • ~100 kg of Glycerol from 1 ton of oil Croda Glycerine Market BriefTriglyceride + Methanol → Biodiesel + Glycerol• Biodiesel accounted for only 9% of the supply of Glycerol in 1999 but 64% in 2009Courtesy SRS Engineering Corporation Biodiesel is the Main Driver of Glycerol SupplyQuispe CAG, Coronado CJR, Carvalho Jr JA (2013) Glycerol: Production, consumption, prices, characterization and new trends in combustion Renew and Sustain Energy Rev 27:475-493 dGlycerol• Water-soluble• Non-flammable• Non-volatile• High boiling point• Bio-production• Bio-degradableCCCOOOHHHHHHHHGlycerol emissions on combustionGlycerolGas Engine, natural gasEPA-Tier 4CO2, g Kwh-1NOx, g Kwh-1864200 1 2 3 4DieselGlycerol with catalytic abatement Independently verifiedUniversity of Greenwich has installed a glycerol-fired Combined Heat and Power plant at the Medway CampusThis is the first building retro-fit in the world.Glycerol -CHPCombined Heat and Power410 kW of Electricity 450 kW  of Heating2600 tonnes per annumReduction in Carbon FootprintProblemsCrude RefinedQualityCostly to refine crude glycerolFuture Sustainable supply Limited waste cooking oilDunaliella salinaMicroalga>80% glycerolCommercially grownβ Carotene >14 %Salt tolerantGrows in salt-pansDunaliella Glycerol CHPDilute Algae Conc’ AlgaeGrowthHarvestingconcentrationAlgal BiorefineryNutrients RecycledWater &Nutrients CO2GlycerolCo-productsO2CHP PowerOperational Energy InputHeatCO2 RecyclingEstimate of annual glycerol productionAverage Biomass  dry matter yield gm-2d-1 16Glycerol % in dry matter % 80Days per year operational days 350annual production 44.8 tonnes ha y-1annual energy production 850          gJ ha-1Algal glycerolpalm oilrape  8,000 hrs operation 1,800 t glycerol yr-1 ~40 HectaresThe D-Factory for glycerolKBBE.2013.3.2 (No: 613870)1. 10 million Euro FP7-funded project 2. 13 partners from 8 countries – 2 universities 3. Flexibly and sustainably produce suites of compounds and fuel from Dunaliella to meet market requirements. 4. Showcase a sustainable biorefinery:  demo  - 2017/8Macroalgal (Seaweed)  Biofuels Research at Greenwich UniversityAlgal BiofuelsMethod Utilises entire algal biomassUtilises wet biomass Primary energy productDirect combustion ✓ ✕ HeatPyrolysis ✓ ✕ Primarily liquid by fast pyrolysisGasification ✓ ✕ b (conventional) Primarily GasBiodiesel production ✕ ✕ c LiquidHydrothermal treatments ✓ ✓ Primarily LiquidBioethanol production ✕ a ✓ LiquidBiobutanol production ✕ a ✓ LiquidAnaerobic digestion ✓ ✓ Gasa Polysaccharides require hydrolysis to fermentable sugars. Some of the sugars produced from the breakdown of seaweed polysaccharides are not readily fermented; b Supercritical water gasification (SCWG) an alternative gasification technology can convert high moisture biomass; c No current commercial process for the wet  trans-esterification of wet macroalgal biomassSargassum muticum feedstockSeason Ash C H O N S HHV% total wt. % dry weightKJ g-1dwSpring 29.5 30.7 4.0 29.6 4.9 1.5 16.3Summer 33.3 30.1 4.2 28.1 3.6 0.8 12.0• High moisture ~85%• High ash• High Sulphur • HHV lower than terrestrial energy cropsMaintaining Year Round Supply• Harvesting is seasonal • Need to preserve and store for a continuous supplyEnsilage• Used to store forage for animal feed• Naturally-present bacteria • Lactic acid fermentation under anaerobic conditions • pH decreases to preserve copEnsiled seaweed composition  Moisture C H O N S Ash Salt HHV% total wt. % dry weight % of ash KJ g-1 dwUnensiled 85.4 30.1 4.2 28.1 3.6 0.8 33.3 46.1 12.05Ensiled whole 85.5 30.0 4.2 29.3 3.3 <0.1 33.1 43.6 12.13Ensiled chopped 85.2 29.4 3.9 29.8 3.5 <0.1 33.3 45.9 12.36• No sig difference in CHON, ash and HHV• Ensiling results in a significant reduction in salt• Ensiling results in virtual total loss of organic sulphurEnergy Losses due to Ensiling<8 % original Higher Heating Value Effect of Ensilage on CH4 YieldMethane productionL CH4 g-1 VSAverage StdVUntreated 0.10 0.05Ensiled whole 0.11 0.08Chopped prior to ensiling 0.06 0.01No statistically significant effect on methane yields Acknowledgements• The Engineering and Physical Sciences Research Council EPSRC EP/K014900/1 – MacroBioCrude• EU FP7 KBBE.2013.3.2 (No: 613870) D-factory • High Value Chemicals from PlantsThank you

Algal biofuels

http://gala.gre.ac.uk/15750/1/15750_Milledge_Algal%20biofuels%20%28presentation%29%202016.pdf

Algal biofuels

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