Biohydrogen production Unit of Functional Bionanomaterials School of Biosciences Prof Lynne E Macaskie Rafael Orozco Dr Mark D Redwood

Why bio-hydrogen? Unique combination of advantages: Renewable/sustainable energy sources Organic matter and sunlight Inherently free of fuel cell poisons CO, H2S Waste disposal food waste agricultural residues Simple/cheap process Ambient temperature & pressure

Solar energy means large Method Net energy / area kWh/day/hectare Source UoB’s bio hydrogen (UK) (+ gate fees) Biowaste2energy Photovoltaics (PV) 665 (Bavaria) Bavaria Solarpark Wind 480 (UK, on shore) MacKay (2009) Anaerobic Digestion (AD) 425 (+ gate fees) Vagron, Netherlands* Plant-derived bio-fuels ~120 (UK) Algae-derived bio-diesel Purportedly better than plants * Including parasitic energy and total site area. Published values use the raw energy generated and only the space occupied by the digester.

Recycle excess bacterial cells for metal recovery and catalysis Biohydrogen at UoB Recycle excess bacterial cells for metal recovery and catalysis H2 Dark Fermentation Photo- Fermentation Sugary waste Clean water Organic acids We focus on 2 methods Dark fermentation Photofermentation

E. coli fermentation Bench scale (1ml-20L) Pilot scale (120 L)

Dark fermentation in E. coli Ideally: 1 Glucose  2 H2 + 1 acetate + 1 ethanol + 2 CO2 We select E. coli because Fast aerobic growth Tolerance to O2 during anaerobic fermentation Best tolerance to H2 partial pressure No sporulation Best-characterised genetic background for GM E.g. removal of uptake hydrogenases

Fermentation with product separation Anion Cation Anion-selective membrane +/- Fermentation Concentrated organic acids - + Electrodialysis uses an anion selective membrane and direct current OAs cross the membrane due to negative charge

Photofermentation Organic acids  H2 + CO2 Purple non-sulphur bacteria Rhodobacter spp. Anoxygenic photosynthesis High yield, broad substrate range e.g. Lactate  6 H2 e.g. Butyrate  10 H2 H2 produced by Nitrogenase enzyme Very sensitive to NH4+ Select wastes with high C/N Light conversion efficiency Up to ~5%

Solar hydrogen production in Birmingham March, June and even October Logging equipment for light intensity and temperature. Water heater pumps 30 °C water to the jackets

Photobioreactors

Solar simulation PBR at Birmingham Tubular array Simulates 0.5 m2 of sunlit area Variable volume up to 50 L Lamps deliver programmed light patterns Simulates any location or season

Commercialising biohydrogen Spin-out company: Biowaste2energy Ltd Formed in 2008 Startup investment from Modern Waste Purpose: to commercialise waste to hydrogen Business model Gate fees for disposal of biodegradable waste Biodegradable waste restricted from landfill Generate electricity from H2 Renewables Obligation Certificate. Route to market Add-on to anaerobic digestion www.bw2e.com

Thank you for your time

How much bioH2 can we make from biowaste? How much hydrogen energy could be regained? UK [food industry + domestic] = 24 M tpa Potential to produce 280 M kg of bio-H2 Energy value: 5.6 TWh (terawatthour) and heat UK’s electricity usage: ~350 TWh pa ~2% of UK’s total electricity demand Not including agricultural and non- food industry wastes

Elimination of uptake hydrogenase Mol of H2 equivalent 1.5 1 0.5 2