Open n Wo Workshop shop on Micr croalgae oalgae Market ket - PowerPoint PPT Presentation

Open n Wo Workshop shop on Micr croalgae oalgae Market ket Robert Reinhardt AlgEn, algal technology centre, Slovenia robert@algen.si AlgaeBio eBioGas as

Agenda • Introduction to Algae • Algae and biogas: recycling ling nutrients rients and CO CO 2 • Algal-bacterial treatment ment of biogas digestate • Algae as biogas feedst stock ock with 3-5 times better efficiency compared to energy crops • Biogas digestate as algal nutrient rient - higher value products • AlgaeBioGas project AlgaeBio eBioGas as 2

Algae • very large and diverse group of simple organisms • mostly aquatic • typically autotrophic - photosynthetic • from unicellular to multicellular • not organized into distinct (plant) organs • cyanobacteria, microalgae, macroalgae • taxonomy ≠ technology AlgaeBio eBioGas as 3

Modern (microbial) taxonomy AlgaeBio eBioGas as

Macroalgae Ulva sp. Macrocystis pyrifera Sargassum natans Laminaria digitata Lattissima saccharina Laminaria hyperborea AlgaeBio eBioGas as

Microalgae & cyanobacteria Chlorella vulgaris Arthrospira (Spirulina) sp. Heomatoccoccus pluvialis Scenedesmus quadricauda Nannochloropsis Botryococcus braunii Dunaliella salina AlgaeBio eBioGas as

Photosynthesis Sun Algae Nutrients Biomass O 2 CO CO 2 N, P, … AlgaeBio eBioGas as

Algae uses • Energy use – Lipids -> biodiesel – Sacharids (carbohydrates) -> bioethanol Increasing value – Biogas feedstock • Organic fertilizers • Animal food, fish food High protein • Human food content • Nutriceuticals (antioxydants, vitamines, PUFA – poly-unsaturated fatty acids ) • Many more (mostly unknown) bio-active compounds AlgaeBio eBioGas as 8

Algal Technology • How to gr grow and d use e alg lgae • Biology – species, content, growth conditions • Technology – nutrients, CO 2 , light • Economy – energy and cost efficiency • Biorefinery – separation and down-stream processing AlgaeBio eBioGas as 9

Open systems Cyanotech, Hawaii Sapphire Energy, USA Sunchlorella, China Seambiotic, Israel AlgaeBio eBioGas as

Large open production AlgaeBio eBioGas as

Closed systems - photobioreactors Algomed, Germany Provirion, Belgium Kibutz Kitura, Israel AlgaeBio eBioGas as

A large closed system • Roquette Klötze: Chlorella for food & feed • 500 km glass tubes (600m 3 ) • 130 t/year AlgaeBio eBioGas as

AlgaeBioGas Basic Cycle Bio Produc ucts ts from algal biomass ass Refine finery ry the remaining biomass is algal gal returned to biomas mass biogas production digestate as source of nutrients CO 2 , heat Electr ectric ical al power er AlgaeBio eBioGas as

AlgaeBioGas – model 1MWe plant For 1MW of To reuse CO 2 from 1MW electrical power we biogas plant we need need 340 ha of 50 50-85 85 ha of algal ponds energy crops – (not necessarily appropriate for agricultural production) Area for biogas Bio installation, Produc ucts ts from algal biomass ass Refine finery ry silage storage and digestate storage: 5-6 ha the remaining biomass is returned to algal gal biogas biomas ass production digestate as source of nutrients To treat digestatefrom Electr ectric ical al CO 2 , heat 1MW biogas plant we power er need 3-5 ha of algal 1MW ponds AlgaeBio eBioGas as

Anaerobic digestion Biogas Substrate Organic Nutrients O 2 CH 4 CH CO CO 2 Biogas matter N, P, … Feedstock Archaea Bacteria Biogas digestate AlgaeBio eBioGas as

Possible optimizations • Digestate treatment • Feedstock production • Algae production AlgaeBio eBioGas as 17

Digestate as Fertilizer Warning: This topic may be politically controversial • By spreading the digestate we return exactly the same minerals that we removed by harvesting the energy feedstock • Assumption: SAME area • YES, but in liquid form: – highly diluted – high logistic cost (storage, transportation) – flushing the CEC of the soil • Separation into solid and liquid phase – solid phase is useful as fertilizer – better logistics – same machinery – no liquid flush AlgaeBio eBioGas as 18

Unterfrauner, 2010 • 40 weeks trial, 50 m 3 /ha • Application of biogas fermentation residues can adversely affect soil fertility • High content of free K ions -> acidification, overloading of the sorption complex, destruction of the aggregates • Addition of CaCO 3 , MgCO 3 , CaSO 4 , Al silicate improved the results significantly • Unterfrauner, H, et al. 2010, Auswirkung von Biogasguelle auf Bodenparameter , 2. Umwelt oekologisches Symposium 2010, 59-64, Raumberg-Gumpenstein. AlgaeBio eBioGas as 19

Digestate separation 1MWe model case • Loss of nutrients • High energy Volume 80-95% consumption Biolog logica cal treatm tmen ent Enviro ronmen ent Liquid phase (anaero erobi bic / / (cen entrate) trate) aerobi bic) 65-90 m 3 /day Sludge Diges esta tate te 80-100 m 3 /day 30.000 m 3 /yr • Simpler and less costly Fertili tilizer er logistics (storage, Solid phase (Incinera eratio tion if if transport, spreading) waste te) 5- 20 m 3 /day • Existing spreading 6000 m 3 /yr technology • Mixing with other Volume 5-20% components (adjusted nutritional and soil conditioning value) AlgaeBio eBioGas as 20

Digestate centrate • What do we do with the liquid phase? – classical biological WWT is the most frequent answer – high cost: • investment, • aeration power • bacterial sludge disposal – Nutrients are lost • C, N-loss = energy • P-loss = substance, eutrophication – GHG emissions • Aerobic treatment mostly converts biomass to CO 2 AlgaeBio eBioGas as 21

Biological Wastewater Treatment Aeration GHG Treated water Waste Organic Nutrients water O 2 CO 2 matter N, P, … Removed in polishing process - Tertiary treatment Bacteria Bacterial sludge AlgaeBio eBioGas as

Photosynthesis Sun Algae Nutrients Biomass O 2 CO CO 2 N, P, … AlgaeBio eBioGas as

Algal Bacterial (ALBA) Wastewater Treatment Sun Treated water Algae Waste Organic Nutrients water O 2 CO 2 matter N, P, … Bacteria Algal Bacterial sludge AlgaeBio eBioGas as

Digestate treatment Biogas Sun Treated water Algae Substrate Organic Nutrients Organic Nutrients O 2 CH CH 4 CO CO 2 O 2 CO 2 matter N, P, … matter N, P, … Biogas Feedstock Archaea Bacteria Bacteria Biogas Algal Bacterial digestate sludge Fertilizer AlgaeBio eBioGas as

Algal bacterial WWT (ALBA WWT) ideas • at least 55 years old (e.g. Oswald 57) • lagoon treatment • shifting objectives in the past • purpose of algal biomass • algae : bacteria - C : N • more diverse microbial community  less sensitive to sudden changes (antibiotics, biocides, salt, …) AlgaeBio eBioGas as 26

A research topic of today • No state of the art universal solutions • Algae bacterial community is unstable • Needs to be tightly controlled • Digestate may be black – no light for algae • Removal of heavy metals, endocrine disruptors, accumulated toxic substances, … • Should be independent of weather AlgaeBio eBioGas as 27

The ALBA pilot (Cornet Albaqua 2011) AlgaeBio eBioGas as

Hybrid ALBA WWT primary treatment secondary & tertiary treatment secondary clarifier clean water light part algae-bacterial treatment dark aeration by algae part pretreatment inoculation PBR bioproducts bio- refinery aeration when needed electrical biogas power gas nutrients anaerobic motor digestion CO 2 CO 2 CO 2 fertilizer AlgaeBio eBioGas as

Many open issues • dark – light sections • how long good oxygenation lasts? • floc ecology • Auto-flocculation • how to control the microbial composition (algae- bacteria balance) AlgaeBio eBioGas as 30

Expected performance (digestate treatment) • Model biog iogas as CHP wit ith 1 MW MWe • to recycle major part of nutrients • area 3 - 5 ha • volume 3000 – 17000 m 3 • 60 – 200 t algae bacterial biomass p.a. • use approx the same amount of waste paper pulp • replacing 120 – 400 t dry mass of corn = 360 – 1200 t of corn silage • replacing 8 – 26 ha of corn fields AlgaeBio eBioGas as 31

Optimization for biomass production • Larger area • Longer retention time • More diluted digestate • CO 2 introduction • More algae, less bacteria AlgaeBio eBioGas as 32

Algae as biogas substrate • Hard to digest • C : N ratio – high C substrate should be added (i.e. cellulose) • Pretreatment required – Heating, enzymatic, fungal, bacterial, ultrasonification, pressure shock, … • Thermophilic process optimal • If done properly biogas productivity comes close to corn silage (based on dry weight) • Depends on species & composition AlgaeBio eBioGas as 33

Economy • More expensive than corn • Makes sense: – if we have substantial non agricultural area available – if we leverage on energy crop subsidies – if we are co-producing high value products • Digestate treatment makes sense: – always when the required area is available AlgaeBio eBioGas as 34