Embed Size (px)
Citation preview
AgriCleanDavid C. Palmer, P.E.Managing Partner
Cost-effective Anaerobic Digestion Technologies and Their Role in Green Power
AgriClean, LLC
An emerging leader in the areas of manure management & anaerobic digestion Not an outfit with an answer in search of a
problem Rather, a solutions oriented company that can
provide a least-cost customized method to meet customer needs
Specializing in dairy, swine and agricultural processing wastes
Energy Recovery
AgriClean
AgriClean, LLC
Significant technological solutions AgriJet process can significantly reduce water
volumes used for flushing AgriGas process can provide a tailored AD
solution AgriClean can optimize organic waste
removal and treatment systems plus energy recovery
AgriClean
Types of Digesters Used Depends on…
Type of waste (feedstocks) Feedstock total solids (TS) concentration Facility location Management structure
AgriClean
With Livestock Operations
Manure Management Systems Traditional flushed barns have dilute total solids
(less than 3%) Scraped barns have higher total solids
(greater than 3%)
AgriClean
Flushing Example #1
AgriClean
Flushing Example #2
AgriClean
Anaerobic Digestion (AD) System Options Suspended Growth Systems
Solids Retention Time = Hydraulic Retention Time (SRT = HRT)
Covered Lagoons Complete Mix
Attached Growth Systems SRT ≠ HRT Fixed Film Others in development pipeline
AgriClean
AgriJet
Substitutes pressure for volume in hydraulic flushing operations Can reduce water use by up to 80% in new
facilities and 50% in existing facilities Programmable control system set to flush at user-
specified, such as milking times All pipes, nozzles and gutters positioned to allow
animal movement and to avoid breakage
AgriClean
AgriJet
Depending on design criteria, AgriJet can deliver manure to the digester with up to 6% Total Solids
Greater Total Solids can significantly reduce AD system cost!
More organic loading = higher gas yields and greater energy potential
AgriClean
AgriJet Dairy Farm Example
A 1,000 head dairy using standard hydraulic flushing techniques would use a flush volume of about 100,000 gallons/day Conventional digester would require a volume of
around 2,000,000 gallons AgriJet system on the same farm will require
35,000 gallons/day for flushing Fixed-film digester w/ a volume of 175,000 gallons Other system aspects (pipes, heat exchangers,
pumps, solids separators, etc.) are also made smaller
AgriClean
AgriGas
AgriClean has several types of AD systems with gas capture in its portfolio Covered lagoon Fixed film AD licensed from the patent-holder Continuously stirred (complete mix)
AgriClean
Fixed Film AD System Development
AgriClean
Fixed Film AD System Advantages
Designed for use w/ dairy manure, but also well suited for hog manure
Small footprint 2-6 day HRT v. 20 days for suspended growth
Modular design Deployed at ~30% less cost than suspended growth
High Methane yields Up to 80% Methane v. ~60% for suspended growth
Very high destruction of Volatile Solids (VSd) Up to 65% VSd w/ hog manure
AgriClean
On-Farm Projects Underway
Fixed-film digester and biogas use system on a 400 head dairy (around 560 animal units or AU) near Hillsboro, MS in partnership with the Mississippi Alternative Energy Enterprise
Fixed-film digester and biogas use system on a swine finishing farm producing 30,000 animals/year (around 1600 AU at steady-state) near Greenville, NC in partnership with the Animal and Poultry Waste Management Center of NC State University
Fixed-film digester and biogas use system on a swine farrow-to-finish operation producing 64,000 animals/year (around 3580 AU at steady-state) in Canada
Covered lagoon digester and biogas use system on a 4000 head swine nursery farm in Montpelier, MS
AgriClean
Ag Processing Plant Projects Underway Fixed-film digester and biogas use system at a 1000
head/day beef packing plant
Covered lagoon digester with biogas capture at a 6000 head/day swine processing facility
AgriClean
What is Green Power…?
Solar Wind Geothermal Biomass
AgriClean
What is Biomass…?
Wood, forestry residuals Agricultural waste Industrial waste Municipal waste Food processing residuals Other organic by-products Crops grown for energy production
AgriClean
What is Anaerobic Digestion…?
A biological process that occurs in the absence of dissolved oxygen
Three temperature ranges for AD Psychrophilic (ambient…swamps, sediments of
lakes and ponds, landfills, intestines of animals) Mesophilic (95-105 degrees F) Thermophilic (125-135 degrees F)
AgriClean
How is Biogas Produced?
Microbiological conversion of organic wastes into methane, carbon dioxide and trace elements like hydrogen sulfide
Amount and quality of biogas depends on the composition and biodegradability of the feedstock
AgriClean
How is the biogas used to create energy?
Most efficient use is to replace other fuel sources like natural gas or propane
The gas can also be used to fuel engine generators or microturbines to produce electricity
In some cases the gas is used to fuel vehicles
AgriClean
Utility Issues
Interconnection agreements System and generation protection
requirements Normal and emergency operating provisions Metering Cost and ownership Power sales agreements
AgriClean
Harris Farm Project Overview
Under contract from the NCAG Smithfield/Premium Standard Farms Agreement for Environmentally Superior Technologies through NCSU’s Animal and Poultry Waste Management Center
Projected economics to be at or below the costs of current lagoon/sprayfield-based treatment systems
Farm owner agreement allows for the retained ownership of the system by AgriClean
AgriClean
AgriClean
Harris Farm Project Overview
12,000 head finishing farm Animals are added in two barns every two weeks
LAW remains fairly constant; w/ tank heated @ 35°C, biogas production should not vary significantly
Barns use a pit recharge, pull plug flushing system Flushing schedule is every 3 days
Daily flow now in excess of 240,000 gpd 20,000 g/barn/day
Changed flush schedule & AgriJet system indicates the use of 30,000 gpd for flushing and 18,000 gpd of flow from the animals 4,000 g/barn/day
AgriClean
Harris Farm Project Overview
Organic loading used to establish initial volume COD is controlling factor
Based on the lab analyses, digester loadings at 48,000 gpd will be:
Component Concentration (mg/l) PoundsTS 25,216 10,079VS 21,490 8,589COD 40,227 16,079TKN 2,880 1,151
AgriClean
Harris Farm Project Overview
Farm connected to the electrical grid Sales agreement to sell peak power to Greenville
Utilities from existing diesel engine/generators Current plan is to offset the increased farm load
resulting from the waste treatment facility Present utility rates and standby charges in North
Carolina make it uneconomical to sell excess power Exploring using the biogas to meet farm’s existing
peaking contract May provide an economical sales structure to sell peak
power from the biogas
AgriClean
What are the economics of producing Green Power from Anaerobic Digestion?
It costs about 6.5 cents per KWh to produce electricity from AD
In most parts of the country, the price utilities will pay for this renewable energy is about half what it costs to produce it
Currently the environmental benefits of AD (odor control, water, air and land pollution reduction) are the driving factors in selecting this as a preferred waste treatment option
AgriClean
How can utilities encourage the development of this source of Green Power?
Progress Energy has a target of 5% of its load from Green Power (about 1,100 MW)
Some others have targets as high as 25% TVA and its distributors offer a Green Power
Switch program including solar, wind and biomass
AgriClean
AgriClean Contacts
Nashville TN, David Palmer @ 615-279-9797
Scott Pogue @ 615-594-8657
Pierre SD, Phil Lusk @ 605-224-4334
AgriClean
