Economic aspects of control: Harvesting water hyacinth for

renewable biofuels and fertilizer

Mike E. Cox, CEOLaura M. Cox, PhD

Robert Hungate: Anaerobic Microbiology Pioneer

Expansion of an invasive species, water hyacinth

(Photo credit: Wes Rhea, Visit Stockton)

Floating boat bridge, Bangladesh

Economic impact of water hyacinth

• Loss of revenue for marinas and surrounding businesses

• Damage to boats

• Cost of spraying and removal by State employees

• Cost of mechanical removal

Methods of removal

Proposed previously by congress to combat water hyacinth in 1910

Handpicking: 100 acres/year

Herding: 500-1,000 acres/year

Susan Tripp Pollard

Spraying: up to 3,500 acres/year

Mechanical removal

Water Hyacinth CollectionClean Lakes Inc.

Disposal of invasive water hyacinthClean lakes Inc.

Statewide challenges in water hyacinth disposal

• Water hyacinth decomposing in water depletes dissolved oxygen and destroys habitats

• One acre can weigh up to 200 tons

• Must find disposal sites for mechanically harvested plants

• Water hyacinth decomposing on land releases CO2 and other greenhouse gases

Vision for the future: Anaerobic Fermentation

• Generate hydrogen and fertilizer from water hyacinth

• Economically incentivize mechanical removal

• Develop a disposal process that does not release greenhouse gas

• Conserve all water throughout the process

Traditional anaerobic digestion

• Group A Organisms:

– Convert carbohydrates to hydrogen, carbon dioxide and organic acids

• Group B Organisms

– Convert hydrogen and carbon dioxide to methane

• Group C Organisms

– Convert organic acids to methane

Sergei Winogradsky

1856-1953

Modern Winograsky Column, Anaerobe Systems

Grass Winogradsky Window

Summer 2006

Jennifer Conrey

Ashley Fetterman

Mike Cox

`

Day 1

Day 2

Day 6

Day 9

Day 12

Day 30

Day 43

Anaerobe Systems Process

Convert plant-based waste into high value products

Evaluatesubstrates

Optimize organism

Optimize operational

dynamics

Making the media

Optimizing biogas production

Water hyacinth

132 PB CB 1210

4

8

12

16

Organism

PS

I

No supplements

Water hyacinth

None A B A + B0

4

8

12

16

PB

CB

121

132

Supplements

PS

I

Effect of Supplementation

Preparing the fermenter

Fermentation process – building reliability

Sterile processingControlled at many levels• Organism inoculated• Temperature• pH• Pressure• Osmotic pressure• Sugar content• Atmospheric conditions

Water Hyacinth Batch Fermentation

Fermentation end productsBiogas composition Organic acid composition

48% H248% CO23.5% N20.5% O2

All CO2 is captured

Fermentation End Products

Hydrogenfor fuel cells

Liquid Fertilizer Soil amendment

Economic Benefits

Products

• Each ton of water hyacinth can produce 2 kilograms of hydrogen

• Each ton can produce 1000 kilograms of liquid fertilizer

Environmental Cost Reduction

• Credits for CO2 captured and H2 produced

• Reduce land needed for dumping

Local Business Benefits

• Clear the waterways for commerce

• Permit recreational activities in the delta

Invasive Arundo donax

Arundo donax environmental impact

• 10,000 acre infestation in Orange County

• Uses an estimated 57,000 acre feet of water

• Clogs waterways

• Competition with native species

• Fire danger

• Alter hydrological regimes

Scalable, Adaptable, and LocalLocal processing plantSourced Materials

Invasive Species

Agricultural Waste

Products

Hydrogen

CO2 + KOH = potassium carbonate fertilizer

Liquid Fertilizer

Solid Soil Amendment

Current Hydrogen Applications

Hydrogen Gas Stations

Birth of Industrial Fermentation

Chaim Weizmann1874-1952

Commercial Solvents(Photo credit MargaretBourke-White)

Thank You