ALGAE TO ETHANOL: Using algae fermentation to produce ethanol 4 th AFRICAN BIOFUEL CONFERENCE March 2009

Algae!

Why Algae? Fast growers relative to other plants and animals –can double their weight every day High carbohydrate/low lignin content Gallons of oil per acre per year –corn 18 –soybeans48 –sunflower102 –rapeseed127 –oil palm635 –micro algae

Process Selection Objectives… Must be simple The process itself must be “bullet proof” Must have low maintenance A labourer must be able to look after algae production A semi-skilled labourer must be able to run conversion Must have low operating costs –little or no nutrient cost –little or no energy cost

Why ethanol and not oil for biodiesel?

Why Algae to Ethanol… Wild algae –have to be fast growers to survive in nature –generally contain <10% oil (lipid) –generally contain high carbohydrate >50% –can be grown in open raceways without fear of contamination Equipment –raceways are low cost installations ($75 000/ha) –raceways consume very little power (10 kW/ha) –starch to ethanol conversion plant is relatively expensive and energy intensive (distillation)

Why Algae to Ethanol… High oil producing algae –are slower growers than wild algae – double every 2-3 days –can be selected for maximum oil content – 50% not unusual –need to be grown in protected environment – typically PBR’s –most algae oil can be used for biodiesel production Photobioreactors (PBR’s) –allow tight control of growing environment –optimise light usage –are capital intensive –are generally power intensive (300 kW/ha?)

General Processing Steps Algae to Ethanol

Processing Steps Algae oxygensunlight CO 2

Processing Steps Algae Concentration dlute slurry liquid oxygensunlight CO 2

Processing Steps Algae Concentration dlute slurry liquid Hydrolysis acid concentrated slurry heat oxygensunlight CO 2

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heatcooling dlute slurry acid oxygensunlight CO 2 yeast

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heatcooling Distillation “beer” ethanol dlute slurry acid oxygensunlight CO 2 yeast

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heatcooling Distillation “beer” Digestion stillage ethanol dlute slurry acid oxygensunlight CO 2 yeast

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heat cooling Distillation “beer” Digestion stillage liquid digestate ethanol solid digestate dlute slurry acid oxygensunlight CO 2 biogas yeast

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heat cooling Distillation “beer” Digestion stillage liquid digestate ethanol solid digestate dlute slurry acid oxygensunlight CO 2 biogas yeast

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heat cooling Distillation “beer” Digestion stillage liquid digestate ethanol solid digestate biogas dlute slurry acid oxygensunlight CO 2 yeast

Processing Steps Algae Concentration liquid Hydrolysis concentrated slurry Fermentation alkali heatcooling Distillation “beer” Digestion stillage liquid digestate ethanol solid digestate biogas dlute slurry acid oxygensunlight CO 2 CHP CO 2 ~ yeast

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester –“compost tea” maker

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester –“compost tea” maker –DAF container to make “white water”

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester –“compost tea” maker –DAF container to make “white water” –stainless steel pressure cooker

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester –“compost tea” maker –DAF container to make “white water” –stainless steel pressure cooker –plastic fermenter

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester –“compost tea” maker –DAF container to make “white water” –stainless steel pressure cooker –plastic fermenter –electrically operated stainless steel batch still

Pilot Plant

Components –20m 2 raceway with 0.55 kW paddle drive –solar panels to supply heat to the digester –digester –“compost tea” maker –DAF container to make “white water” –stainless steel pressure cooker –plastic fermenter –electrically operated stainless steel batch still –various tanks, pumps, drums and buckets

Pilot Plant

Pilot Plant Results Main Production Results –algae density 4 gram/litre –growth140 g/m 2 /day –oil recoverynegligible –ethanol production ml ethanol/m 2 /day

Moving Toward Commercialisation

Production Plant Projection ItemUnits500 l/day5000 l/day Pond areaha1.0 Installed powerkW30 Capital cost$600k Variable cost$/litre0.05 Fixed costs$/year17.5k Selling price$/litre0.50 Sales$85k Gross profit$59k

Production Plant Projection ItemUnits500 l/day5000 l/day Pond areaha1.010 Installed powerkW30150 Capital cost$600k2.75m Variable cost$/litre Fixed costs$/year17.5k35k Selling price$/litre0.50 Sales$85k850k Gross profit$59k645k

Commercial Production Physical requirements –relatively level site

Commercial Size Site

Commercial Production Physical requirements –relatively level site –water –power to drive paddles Potential deployment for “emerging farmers” –can be deployed to tribal areas –relatively low cost for ponds ~ R75/m 2 –centralized conversion plant: can use a tanker for moving algae nutrient and concentrate to and from algae ponds to centralized plant better economy of scale for larger plant better process and inventory control

Challenges to Commercialization Oil price stability High capital cost Limited markets at small volumes Theft of product Challenges to tribal area deployment –Power for paddles: solar? –Theft and vandalism – cables, tanks and pumps are vulnerable

Summary Production of algae to produce ethanol is economically viable Wild algae production does not require a lot of attention Can be rolled out for emerging farmers Conversion plant operation requires semi-skilled expertise

Growing algae in the snow!

QUESTIONS?