Waste Energy Solutions Co-digestion for Energy and Environment

Jane Maxwell, Project Consultantwww.fromwastetoenergy.com

What can Danish biogas technology do?

• Handle waste

• Reduce odour

• Increase nutrient accessibility

• Reduce nutrient leaching

• Provide Carbon neutral energy

• Provide added revenue

• Enrich the community

• Reduce GHG emissions

The technology: Anaerobic digestion

• Mesophilic and Thermophilic process

• Fully mixed digester

• Co-digestion concept

• Proven in Denmark

• We have made all the mistakes and learned

What is Biogas?

CH4 production capacity

Methane production of selected substances

0

100

200

300

400

500

Cow slurry

Pig slurry

Pig manure

Stomac content pig

Flotation sludge

Fish waste

Bleach clay

Sewage sludge

Sewage sludge conc.

Household waste

Protein

Victuals old

Sudge from edible fats

Kitchen and canteen waste

Remenatns from

flavouring

Maize silage

Gras silage

Design biogas plant

m3

CH

4 / s

t in

pu

t

Biogas Plant design

Biogas technology

• Pre-treatment– Mixing– Macerating– Hygienisation/ sterilisation– +/- other pre-treatment: e.g.

concentration

• Digestion

• Aftertreatmnet– Store– Separate– Upgrade

• End use– Land application– Move and apply– Transport market / or disposal

Anaerobic Digestion of Wastes

Bacteria digest organic compounds in oxygen free environments and produce

Anaerobic digestion is a naturally occurring process that involves complex biochemical processes carried out by a consortium of

bacteria.

Biogas

Biogas is

Up to 65% methane

35% to 40% Carbon Dioxide

Trace amounts of H2, NH3, and H2S.

Used as fuel in internal combustion engine to produce electricity

Used in boilers

Or

Stripped of CO2 and contaminants and injected into pipeline

LNG – Liquefied Natural Gas CNG - Compressed Natural Gas

• 23 Dairies in the middle Suwannee basin– Manure causing serious environmental concerns

• New regulations - grease trap cleanouts required monthly for restaurants – Land application of grease is an environmental problem

• Local town and prison sewage solids being land applied– Increasing population will cause land application to be

problematic

• Large amounts of food wastes either going to landfills or into municipal waste water– Organic wastes increase cost of waste water treatment and

size of landfill

One of our Potential Florida Projects

One WES digester taking in approx 800 tons per day will fix these problems!

– WES consultant with 30 yrs experience with state and federal funding programs assists farmers in acquiring funds for upgrading manure separation equipment

– Farmers get income for selling nutrients after all financial obligations have been paid

– No out of pocket costs to farmers– Farmers get back nutrients in solution – much easier to

regulate and prevent over applying– WES gets income from tipping fees and selling power– Society wastes converted from a problem to a solution– Nutrient and Odor problem solved– Dairy Farmers stay in business– Florida needs Dairy Farmers!

How our program works

– Importing milk uses fossil fuels– Using fossil fuels increases GHG’s– Dairy Manure very necessary for co-digestion –

this will help clean up wastes from many sources including wastes from other renewables (stillage from ethanol, glycerine from biodiesel)

– Dairies can be important contributors to renewable energy

– Florida dairies keep jobs and money in Florida

Why FLORIDA dairy farms are important for meeting GHG reductions and RPS

Methane very reliable – don’t have to wait for wind to blow or sun to shine

• 4 to 6 digesters• At least 3 days feedstock • Three to four 1.6 MW generators • Located near power users –

DISTRIBUTED POWER• Possibility for a number of plants in

Florida

Advantages of Waste Energy Solutions

biogas for Utility Providers

Removing 1 ton methane from atmosphere = getting rid of 21 tons CO2

Burning methane converts the methane to CO2

CO2 Equivalent for methane is 18

Burning methane does not increase carbon in the carbon cycle.

Methane 21 times worse than CO2 in causing global warming

Why burning methane from biogas is so important for the environment

Atmosphere

CO2

Through Photosynthesis Plants use CO2 make carbon compounds

Contemporary Carbon Cycle

Plants consumed

as food

Animal and plant Respiration produces CO2Much of the

carbon consumed ends up in Manure

Carbon sources

Food Wastes from meat or plant sources, decaying

of organic material

CH4 + 2O2 = CO2 + 2H2O

Forest Fires

Burning of biomass

Methane Burned

Grain, grass, food

CO2

In AtmosphereCrops grown and

harvested over several months

Carbon continually recycled

Manure

Plants consumed

as food

FOOD WASTE

Digester

Methane

Burned as fuel

A NEED FOR SPEED A fast carbon cycle is important in order to prevent even

temporary increase in CO2

CO2

In Atmosphere

Will take another 20 to 50 years for carbon to be

taken out of atmosphere

and

only if enough trees are planted

Slower carbon cycle can increase atmospheric carbon for 20 to 50 years – Burning Forest biomass is a slow cycle

20 to 50 years growth cycle

Seedlings

In states with established RPS methane from anaerobic digestion of organic materials is a

Tier 1 renewable energy

RECs from Tier 1 are given 110% to 140% credits

Renewable Portfolio Standards

What is the value of a REC?Wind generation costs - Coal generation costs = price of

RECIn general it costs 4 to 6 cents more per kW to get wind

generation to a customer

This difference in costs = the value of the REC

The concept of REC’s is to equalize the “real” cost of coal and other fossil fuels with the cost of renewables.

It is difficult to estimate this cost but it would include health care costs incurred from pollution as well as environmental costs and global warming risks.

Reasons that a Tradable Renewable Energy Credit system should be used

toward meeting the RPS goal tREC’s can be used to promote the development of new renewable

resources, not simply benefit existing generation Requiring percentage of Renewable Energy Credits to be Tier 1 will decrease the

time it takes to reach GHG reduction goals -favoring the cleanest and the greenest. Methane destruction makes anaerobic digesters Tier 1

Tradable credits have proven to be a successful system of reducing other pollutants (reducing acid rain and ozone depletion)

Renewable energy producers can sell energy and renewable energy credits separately. An electricity provider that does not own or purchase enough renewable energy capacity may purchase credits instead of capacity

RPS legislation using tRECs can add some security to a market for new renewable energy, thereby encouraging investment

REC have proven to help build new renewable generation (for example - wind generation increasing quickly in Texas)

Trading system should be limited to Florida only or to the Southeastern states

If the trading region is not limited renewable energy suppliers in regions where producing renewable energy is cheaper than in Florida will have a big advantage

Encouraging renewable energy suppliers to locate in Florida to build new generation will help Florida meet GHG goals

Encouraging renewable energy suppliers to locate in Florida will be good for Florida’s economy and energy security

THANK YOU!