Biomass Energy Decision Making Framework - … · Web viewThe objective of this binder is to define biomass energy, describe the history of the evolution of the technology and provide

Innovative Energy TechnologyBiomass Energy Decision Making Framework

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Biomass Energy Decision Making FrameworkCornell University Sustainable Design

Sustainability Research FacilityInnovative Energy Technology

Contributors: Jason Wright


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TABLE OF CONTENTS

Introduction to the Biomass Energy Decision Making Framework..............................................................3

Objective.................................................................................................................................................3

Introduction to Biomass Energy..............................................................................................................3

Ithaca.......................................................................................................................................................3

Biomass Energy in the Facility.................................................................................................................4

Biomass Energy Metrics Definitions and Discussion....................................................................................5

Specific Technologies...................................................................................................................................8

Wood boiler.............................................................................................................................................8

Anaerobic digestion...............................................................................................................................13

Pyrolysis.................................................................................................................................................15

Works Cited...............................................................................................................................................17


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Introduction to the Biomass Energy Decision Making Framework

Objective

The objective of this binder is to define biomass energy, describe the history of the evolution of the technology and provide a framework for analyzing and grading the proposed technologies. Ultimately this binder should be used to select technologies for use in the facility.

Introduction to Biomass Energy

Biomass energy, or energy derived from the combustion of organic matter, is one of the oldest sources of renewable energy. For quite some time biomass supplied the majority of renewable energy in the United States, more than solar, hydroelectric, geothermal and wind combined.[EIA 2010] Biomass is often considered essential to a transition to a sustainable energy economy. According to the Union of Concerned Scientists,

“If developed properly, biomass can and should supply increasing amounts of biopower. In fact, in numerous analyses of how America can transition to a clean energy future, sustainable biomass is a critical renewable resource.Sustainable, low-carbon biomass can provide a significant fraction of the new renewable energy we need to reduce our emissions of heat-trapping gases like carbon dioxide to levels that scientists say will avoid the worst impacts of global warming. Without sustainable, low-carbon biopower, it will likely be more expensive and take longer to transform to a clean energy economy.” [UCS 2010]

Biomass energy can take many forms. The National Renewable Energy Laboratory describes

“Biomass energy supports U.S. agricultural and forest-product industries. The main biomass feedstocks for power are paper mill residue, lumber mill scrap, and municipal waste. For biomass fuels, the most common feedstocks used today are corn grain (for ethanol) and soybeans (for biodiesel). In the near future—and with NREL-developed technology—agricultural residues such as corn stover (the stalks, leaves, and husks of the plant) and wheat straw will also be used. Long-term plans include growing and using dedicated energy crops, such as fast-growing trees and grasses, and algae. These feedstocks can grow sustainably on land that will not support intensive food crops.” [NREL 2010]

Ithaca

Sustainably managed biomass technology has precedent in the Ithaca area. One example we will draw heavily on is the Cayuga Nature Center’s wood chip boiler:

“In the fall of 2009, the Cayuga Nature Center (CNC) installed a high-efficiency, gasification-type wood chip boiler supplied by ACT Bioenergy, LLC. The boiler will heat the CNC’s 10,000 ft.² building and is intended to serve as a publicly accessible demonstration of environmentally responsible production and utilization of biomass energy. The CNC expects to reduce their heating costs by more than 80% by replacing propane gas with wood chip fuel and part of the estimated 75 tons per year of fuel for the boiler will come from the sustainably managed forest that surrounds the Center.” [ACT 2010]


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New York State in general is also an excellent location for new biomass projects, specifically for wood waste and anaerobic digestion

“The Biomass Resources Program emphasizes the use of low-cost waste biomass such as agricultural and forestry waste streams to products including fuels and chemicals. Projects that convert biomass to fuels and chemicals use methods that include anaerobic digestion, acid or enzyme hydrolysis, and gasification. The largest source of biomass is wood and wood wastes, a renewable and sustainable resource. As a general rule, New York State has an abundance of biomass feedstocks compared to other states.” [NYSERDA 2004]

Biomass Energy in the Facility

In addition to increased energy generation and the promotion of sustainable agricultural and waste management processes, incorporating biomass energy technology into the SRF would well serve the goals of a broader University-wide project, the Cornell University Renewable Bioenergy Initiative (CURBI), which seeks to “implement commercially available technologies along with Cornell-led technologies and utilize campus biomass resources.” [CUAES 1 2010] Contact between CUSD and CURBI has confirmed that there would be substantial university demand for a facility like the SRF to benefit the goals of CURBI.


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Biomass Energy Metrics Definitions and Discussion

I. EFFICIENCY, ENVIRONMENTAL IMPACT AND COST

1. Performance in Ithaca a. Definition: the ability of a biomass energy module to operate at manufacturer

specified efficiencies in Ithaca, NY. b. Units of Measure: ten point scale based on industry standard met belowc. Considerations:

i. Feed Availability (5 point scale): the proximity of the module to necessary biomass inputs.

ii. Temperature (⁰C): the standard operating temperature of the module.iii. Storage Area (m^3): the volume of space available to store excess biomass.

2. Module PerformanceA. Manufacturer Module Efficiency

a. Definition: The ability of a biomass module to convert biomass to heat and/or usable electrical energy as a function of the energy of the biomass input.

b. Units of Measure: percentB. Energy Generation/Module Area

a. Definition: the production of energy per unit area, calculated by dividing the rated module energy output by the area the module.

b. Units of Measure: W/ m2

3. Module Pricea. Definition: the monetary cost per rated watt of capacityb. Units of Measure: $/ Wc. Considerations:

i. Initial Cost ($): manufacturer listing of price per moduleii. Maintenance($/year): cost to maintain the module annually

iii. Government incentives($/W): government rebates or tax incentives per Watt of energy capacity

State Federal

iv. Sponsorship ($): willingness of a corporation to provide a module at a reduced rate or free after the establishment of a mutual relationship with CUSD.

v. Energy saved ($/kWh): the monetary value of energy produced by the module at the local electricity rate per kWh

vi. Payback period (year): the time required for the monetary value of energy produced by the module to breakeven with the cost of the module over its useful life

4. Environmental Impact:a. Definition: the life cycle analysis of the module’s total impact from cradle to graveb. Units of Measure:

i. Manufacturing (produced): g CO2/ W ii. Operation (mitigated): g CO2/ kWh


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c. Considerations:i. Inputs:

- Inventory of energy and materials required for manufacturing and distribution of a module throughout the supply chain

- Inventory of energy and materials required for the operation of a module over its useful life.

ii. Availability of natural resources and material componentsiii. Outputs: associated environmental emissions released from the

manufacturing and operation of a module

II. OPERATION AND INTEGRATION INTO THE FACILITY

5. Maintenance Required/ Ease of Operationa. Definition: the cost and labor required to maintain and operate the moduleb. Units of Measure: 5 point scale (1: high maintenance, 5: no maintenance)c. Considerations:

i. Manual Operation: the labor required to operate machinery, store inputs, etc.

ii. Input Provision: the labor required to acquire and transport necessary biomass inputs.

iii. Upkeep & Repair: the labor required to repair, clean, and upgrade the module.

6. Controllabilitya. Definition: ability to control the generation and distribution of heat and/or

electricity produced by the module in an integrated facility control system.b. Units of Measure: 5 point scale (1: not controllable , 5: effortless to control)

7. Modularitya. Definition: (as defined by the modularity sub-team) the ability to assemble and

disassemble a technology with ease, and reuse or recycle all technology components so there is no waste.

b. Units of Measure: 5 point scale (1: not modular, not reusable 5: assembled/disassembled easily, zero waste)

8. Synergy a. Definition:

i. Ability to operate efficiently and integrate seamlessly with other technology utilized in the facility.

ii. Ability to integrate into the facility with minimal infrastructure modification or addition

b. Units of Measure: 5 point scale (1: stand alone technology, 5: adds value to other technologies in the facility)

c. Considerations:i. Structural Integration: the space required to store the module, the

necessary rooms and exterior space required to operate the moduleii. Visual Effects: the potential impact on the image of the facility

iii. Noise: the potential sound emitted from the operation of the moduleiv. Odor: the potential odor emitted from the operation of the module

9. On-Campus Researcher Support


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a. Definition: the quantity and usefulness of related research currently conducted by Cornell faculty on campus

b. Units of Measure: 5 point scale (1: no campus research, 5: large research initiative)c. Considerations:

i. Laboratory: ability to test on campus research within the limits of the facility and surrounding property

ii. Monitoring: ability to monitor energy output for the benefit of the facility and the enhancement of the technology

iii. Student Involvement: ability for both undergraduate and graduate students to access and maintain the technology for advancement of their research goals as they pertain to the mission of CUSD.

III. FEASIBILITY AND LONGEVITY

10. Current Technological Feasibility and Availabilitya. Definition: is the technology available commercially and is it feasible to produce

adequate energy at reasonable monetary costs. b. Units of Measure: 5 point scale (1: not market ready, 5: commercially common)

11. Useful Lifea. Definition: the predicted life time of the module at the rated efficiencyb. Units of Measure: yearsc. Considerations

i. Degradation: at what rate does the efficiency degrade per yearii. Warranty: the manufacturer defined time period in which a product is

insured. The manufacturer will perform a specified level of service in this time period.

IV. SUBJECTIVE ANALYSIS

12. Subjective Analysisa. Definition: the Innovative Energy Technology Sub-team’s preference for a given

technology based on its “coolness”, novelty, and aesthetic appeal.b. Units of Measure: 5 point scale (1: No Interest, 5: Full Team Interest)c. Considerations:

i. Innovation: the innovative nature of the technology given other commercial solutions in the industry

ii. Novelty: the uniqueness of the technology given other commercial solutions in the industry

iii. Aesthetic Appeal: the visual appearance of the technology as a perception of a viewer

Note: All specified units of measure will be weighted as a function of the specified industry standard (see grading system)


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Specific Technologies

Wood boiler

“Wood pellet boilers have proven to be a reliable and effective way to heat homes and businesses, with one million units now in service throughout Europe. Functioning much like oil and propane boilers, the operation of these boilers is automatic. Typically, an electric ignition coil lights the pellets as needed, while wood pellets are fed to the burner in measured doses via an auger connected to an attached hopper or adjacent storage bin. These systems are convenient enough to be a great alternative to fossil fuel fired boilers.” [EcoHeat 2009]

One add-on technology we should strongly consider is emission gasification, which can significantly improve efficiency and reduce adverse environmental effects. This is the process used by the Cayuga Nature Center’s boiler.

Greenwood (renewable energy company) explains:

“In gasification wood boilers the wood gases don't just go up and out the chimney, as is the case with standard wood boilers. Instead, the reaction is continued and the emitted woodgas is superheated and mixed with air resulting in complete combustion. The heat is then transferred to a boiler for efficient distribution. An additional benefit of the gasification process is that the complete combustion leaves little or no ash.

There are several common schools of thought for applying wood gasification and secondary combustion principles in the design of a residential or small-scale wood boiler, here are two of the most common approaches:

Continuous burn: Dual combustion chambers. Many of the wood gasification models imported from Europe employ this technique. These units are designed to operate properly when they burn a load of wood in one continuous burn and transfer the resulting heat to a water storage container (usually 400 gallons or greater) where it is stored until the heat is needed.

In these systems, the gases flow down through the fire into a secondary chamber where firebrick (or a ceramic material) creates the superheated environment necessary to complete the efficient combustion process. Keeping this secondary chamber at high temperatures is key to the performance of the overall system, hence the need for one continuous burn so that this chamber does not cool and lower the boiler efficiency.

On-demand burn: Single combustion chamber. The Greenwood wood boiler uses a single burn chamber to foster wood gasification. During normal operation, a patented thermal mass maintains the firebox at the extreme temperatures required for complete combustion. This enables the system to operate as an on-demand system, thereby removing the need for the water storage tank outlined above. This design not only simplifies the operation and maintenance of the unit, but also enables a greater variability of fuel composition (e.g. whole log wood and wood moisture content).

Conclusion


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So, if you are researching a purchase of a wood boiler, the bottom line is that wood gasification boilers that provide complete combustion are better than traditional water-jacketed wood boilers. Some key points to take away from this article include:

In general, gasification is very efficient in extracting energy from different types of organic materials, including wood.

Extremely high combustion efficiency is obtained by gasification, thereby creating minimal emissions.

With respect to wood boilers, wood gasification means:

-Less wood is required,

-Significantly lower emissions/smoke, and

-Less ash.” [Greenwood 1 2011]

Building code requirements will likely apply mostly to outdoor wood boilers as opposed to indoor models, in general regulations concerning fire safety, air pollution, and zoning will apply. One important issue that will apply is whether any outdoor wood boiler is classified as residential or commercial--- a commercial-size boiler would likely trigger stricter regulations that would prevent development because of proximity to many other public spaces.

NY State recently published new regulations concerning outdoor wood boilers:

The particulate emission limits, stack height and setback requirements for residential-size new OWBs are set forth in Section 247.5. Residential-size new OWBs will be subject to a weighted average particulate emission limit of 0.32 pounds per million British thermal units (mmBtu) heat output. In addition, the particulate emission rate for any test run conducted pursuant to Test Method 28-OWHH may not exceed 15.0 g/h when the burn rate is 1.5 kilograms per hour (kg/h) or less and 18.0 g/h when the burn rate is greater than 1.5 kg/h. Further, residential-size new OWBs must be located 100 feet or more from the nearest property boundary line (or 100 feet or more from the nearest residence not served by the OWB if the OWB is sited on contiguous agricultural lands of 5 or more acres) and must be equipped with a permanent stack extending a minimum of 18 feet above ground level. Notwithstanding the foregoing, the Department may require that the permanent stack extend up to two feet above the peak of any roof structure within 150 feet of the OWB when necessary to adequately disperse smoke emitted from an outdoor wood boiler.

Commercial-size new OWBs (Section 247.6) will be subject to a weighted average particulate emission limit of 0.32 pounds per million mmBtu heat output. In addition, the particulate emission rate for any test run conducted pursuant to Test Method 28-OWHH may not exceed 20.0 g/h. A commercial-size new OWB must be equipped with a permanent stack extending a minimum of 18 feet above ground level. Notwithstanding the foregoing, the Department may require that the permanent stack extend up to two feet above the peak of any


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roof structure within 150 feet of the OWB when necessary to adequately disperse smoke emitted from an outdoor wood boiler. Finally, a commercial-size new OWB must be located 200 feet or more from the nearest property boundary line, 300 feet or more from the nearest residential property boundary line, and 1000 feet or more from a school. Notwithstanding the above, a commercial-size new outdoor wood boiler installed on contiguous agricultural lands larger than five acres must be sited 300 feet or more from the nearest residence not served by the outdoor wood boiler and 1000 feet or more from a school.

A memo from Ronald E. Piester, R.A., Director, Division of Code Enforcement and Administration, New York Department of State, clarifies the applicability of new regulations:

“The outdoor wood boiler is an appliance and is accessory to the building being heated on the same piece of property. As an outdoor appliance both the Residential Code of New York State (RCNYS) section M1401.4 and the Mechanical Code of New York State (MCNYS) section 303.6 require the boiler to be listed and labeled for outdoor installation, and installed in accordance with the manufacturer’s installation instructions. The penetration of the building wall by the pipes suppling the heated water to the building needs to be inspected. The requirements for a building permit for the pipe penetrations in the building wall are the jurisdiction of the individual local government. The outdoor boiler is an appliance and is not an accessory structure. The codes regulate the location of an accessory structure relative to the adjacent building and relative to the property line. The codes are silent relative to the location of an outdoor appliance. Therefore, the location of an outdoor wood boiler is a zoning issue.” [Piester 2003]

Two units—a boiler and a firebox/storage unit—are required, with the boiler ranging from 9 to 20 ft^2 and the firebox from 2 to 4 ft^2. Depending on the size of the boiler, an outdoor boiler would require a stack at least 18 feet off the ground—perhaps more, depending on the applicability of regulations on smoke dispersal.

Specific Technology Charts

Econoburn Wood Boiler comparison chart (2011)[10]

Boiler Model EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O

Design Application Indoor Indoor Indoor Indoor Indoor Outdoor Outdoor

Btu Output 100,000 150,000 200,000 300,000 500,000 150,000 200,000

Boiler Dimensions EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O

Depth 47" / 119.4cm 47" / 119.4cm 47" / 119.4cm 50" / 127cm 63" / 160cm 54.25" / 137.8cm

54.25" / 137.8cm

Width 25" / 63.5cm 26" / 66cm 30" / 76.2cm 36" / 91.4cm 41" / 104.1cm 48.4" / 48.4" /


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122.9cm 122.9cm

Height 60.25" / 153cm

63.75”/ 161.9cm

64.25" / 163.2cm 70" / 177.8cm 76" / 193cm 80" / 203.2cm 80.5" /

204.5cm

Weight Empty 1,560 Lbs / 708 kg

1,670 Lbs / 757 kg

1,980 Lbs / 898 kg

2,515 Lbs / 1,141 kg

3,405 Lbs / 1,544 kg

~1,800 Lbs/ 816 kg

~2,100 Lbs / 953 kg

Firebox Dimensions EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O

Depth 23" / 58.4cm 23" / 58.4cm 23" / 58.4cm 26" / 66cm 32" / 81.3cm 23" / 58.4cm 23" / 58.4cm

Width 15" / 38.1cm 16" / 40.6cm 21" / 53.3cm 24" / 61cm 27" / 68.6cm 16" / 40.6cm 21" / 53.3cm

Height 25" / 63.5cm 28" / 71.1cm 29" / 73.7cm 33" / 83.8cm 39" / 99.1cm 28" / 71.1cm 29" / 73.7cm

Maximum Log length 21" / 53.3cm 21" / 53.3cm 21" / 53.3cm 33" / 83.8cm 33" / 83.8cm 21" / 53.3cm 21" / 53.3cm

Firebox Door Height 12" / 30.5cm 12" / 30.5cm 12" / 30.5cm 12" / 30.5cm 12" / 30.5cm 12" / 30.5cm 12" / 30.5cm

Firebox Door Length 15" / 38.1cm 15.75" / 40cm 20.5" / 52.1cm 23.5" / 59.7cm 27.5" / 69.9cm 15.75" / 40cm 20.5" / 52.1cm

Piping Data EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O

Water Volume 30 Gal / 114 L 37 Gal / 140 L 42 Gal / 159 L 79 Gal / 299 L 95 Gal / 360 L 37 Gal / 140 L 42 Gal / 159 L

Supply Pipe (female connection) 2" 2" 2" 2.5" 4" 2" 2"

Return Pipe (female connection) 2" 2" 2" 2.5" 4" 2" 2"

Min Boiler Loop Size 1-1/4" 1-1/4" 1-1/2" 2" 3" 1-1/4" 1-1/2"

Fill/Drain Valve Size 3/8" 1-1/4" 1-1/2" 1-1/2" 1-1/2" 1-1/4" 1-1/2"

Flue Dimensions EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O


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Flue Outlet Diameter 8" 8" 8" 8" 12" 8" 8"

Height to Center of Flue 47.25" 50.75" 51.25" 57" 61.5" 50.75" 51.25"

Operating Data EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O

Max Operating Temperature 210° F / 99° C

Max Operating Pressure 30 PSI / 207 kPa

Output Temperature (range) 170° F - 200° F / 77° C - 93° C

Specified Fuel Wood (recommended moisture content: 15-22%)

Minimum Draft Required -0.02 to -0.06 inch WC / -0.005 kPa to -0.015 kPa

Flue Gas Temperature 280° F - 400° F / 138° C - 204° C

Electrical Data EBW-100 EBW-150 EBW-200 EBW-300 EBW-500 EBW-150-O EBW-200-O

Boiler Power Requirement 110 volt, 15 amp

Electrical Consumption (watts) 100 175 175 175 200 175 175

Aquastat Overheat Setting 220° F / 104° C

Electrical Consumption 5 amps

Frontier Series Wood Gasification Boiler (indoor) specifications (2011)[Greenwood 2 2011]

Model Frontier CX Frontier LX Frontier MXFurnace dimensions 32”w x 54.5”h x 48”d Avail 2011 Avail 2011Boiler Capacity 6 US gallons - -


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Approximate Shipping Weight

1250 lbs - -

Limited Warranty 1yr / 7 yr upon registration

1yr / 7 yr upon registration

1yr / 7 yr upon registration

Operating Range 30 – 75 MBtuh 85 – 120 MBtuh 150 – 225 MBtuhOutput per Firebox 550 MBtu 1000 MBtu 1600 MBtuMin./Max. Supply Water Temp.

140F / 195F 140F / 195F 140F / 195F

Fuel type Log wood Log wood Log woodMaximum log length 21 inchesMaximum log diameter 14 inches

Denali Series Pellet Boiler (indoor) specifications (2011)[Greenwood 3 2011]

Model Denali 100 Denali 150 Denali 300Maximum Output 110,000 Btu/hr 155,000 Btu/hr 315,000 Btu/hrTurndown Ratio 1:5 1:5 1:5Approx. Heating Capacity Up to 4,500 ft2 Up to 7,500 ft2 Up to 15,000 ft2Boiler Dimensions 22”w x 45”h x 62”d 23”w x 47”h x 65”d 27”w x 49”h x 74”dFirebox Volume 3 cu ft 4 cu ft 6 cu ftHeight 45 in 47 in 49 inApproximate Weight 748 pounds 836 pounds 1144 pountsFlue Size 6 inches 6 inches 8 inches

Residential wood pellet boiler.(Windhager BioWin Wood Pellet Boiler, http://www.woodpelletstovesboilers.com/News/Windhager_BioWIN_Wood_Pellet_Boiler.html)

A useful photo gallery of the boiler at the Cayuga Nature Center is available from ACT Bioenergy at http://www.actbioenergy.com/brochure/Cayuga%20wood%20boiler%20photos.pdf

Anaerobic digestion

Anaerobic digestion technologies could convert food and/or animal waste produced within the facility or elsewhere on campus to biogas that could heat the facility or provide electrical energy. The Oregon Department of Energy explains:

http://www.actbioenergy.com/brochure/Cayuga%20wood%20boiler%20photos.pdf


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“Biomass that is high in moisture content, such as animal manure and food-processing wastes, is suitable for producing biogas using anaerobic digester technology.

Anaerobic digestion is a biochemical process in which particular kinds of bacteria digest biomass in an oxygen-free environment. Several different types of bacteria work together to break down complex organic wastes in stages, resulting in the production of "biogas."

Symbiotic groups of bacteria perform different functions at different stages of the digestion process. There are four basic types of microorganisms involved. Hydrolytic bacteria break down complex organic wastes into sugars and amino acids. Fermentative bacteria then convert those products into organic acids. Acidogenic microorganisms convert the acids into hydrogen, carbon dioxide and acetate. Finally, the methanogenic bacteria produce biogas from acetic acid, hydrogen and carbon dioxide.

Controlled anaerobic digestion requires an airtight chamber, called a digester. To promote bacterial activity, the digester must maintain a temperature of at least 68° F. Using higher temperatures, up to 150° F, shortens processing time and reduces the required volume of the tank by 25 percent to 40 percent. However, there are more species of anaerobic bacteria that thrive in the temperature range of a standard design (mesophillic bacteria) than there are species that thrive at higher temperatures (thermophillic bacteria). High-temperature digesters also are more prone to upset because of temperature fluctuations and their successful operation requires close monitoring and diligent maintenance.

The biogas produced in a digester (also known as "digester gas") is actually a mixture of gases, with methane and carbon dioxide making up more than 90 percent of the total. Biogas typically contains smaller amounts of hydrogen sulfide, nitrogen, hydrogen, methylmercaptans and oxygen.

Methane is a combustible gas. The energy content of digester gas depends on the amount of methane it contains. Methane content varies from about 55 percent to 80 percent. Typical digester gas, with a methane concentration of 65 percent, contains about 600 Btu of energy per cubic foot.” [Oregon DOE 2009]

Many facilities at Cornell, such as dining halls, the plantations, and the vet school, produce appropriate biomass for this purpose. Several faculty members at Cornell have expressed interest in creating such a facility on campus. The Sustainability Research Facility could be an appropriate test case for a small-scale implementation of anaerobic digestion technology. According to CURBI, “CUAES currently composts approximately 8,000 tons of organic waste per year and could generate up to an additional 15,000 tons of biomass from energy crops as appropriate.” [CUAES 2 2010]

The preferred implementation of anaerobic digestion technology would be using a plug-flow digester. Plug flow digesters are typically large canals dug into farm landscape that contain organic material within a covered sheath. Biomass is put into one end of the canal, and the act of putting more biomass into the canal on a regular basis pushes the material through the canal, which is treated with special organic material to undergo digestion. Biogas is produced and can then be used for energy purposes.

Plug flow digestion has also been used in developing countries to promote sustainable agriculture. Small, localized digesters can be an effective way to easily handle agriculture waste. The technology is


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already available, and ongoing research into plug flow digestion is being done at Cornell’s Agriculture Waste Management Laboratory.

Experimental plug flow setups at Cornell’s Agriculture Waste Management Laboratory.

Imagery depicting small-scale plug flow digestion in Indonesia.

Pyrolysis

CURBI explains the operation and utility of pyrolysis systems:


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“Slow pyrolysis systems produce gas by heating organic matter in the absence of oxygen. The resultant biogas or synthetic gas (syngas) is high in carbon monoxide, hydrogen, and other combustible gases. Pyrolysis also produces a charcoal byproduct (biochar) that is a valuable soil amendment with a multitude of beneficial properties and is a carbon “sink”, making it the only currently known “carbon negative” energy technology. Pyrolysis can use a range of biomass wastes, including most urban, agricultural, or forestry residues, such as wood chips, straw or mulch hay, tree bark, animal manure, and recycled organics. The demand for biochar by the research community is very high, with numerous collaborations being formed to study its effect in soils;” [CUAES 2 2010]

The Center for Public Environmental Oversight explains some of the drawbacks:

“The technology requires drying of soil prior to treatment.

Limited performance data are available for systems treating hazardous wastes containing polychlorinated biphenyls (PCBs), dioxins, and other organics. There is concern that systems that destroy chlorinated organic molecules by heat have the potential to create products of incomplete combustion, including dioxins and furans. These compounds are extremely toxic in the parts per trillion range. The MSO process reportedly does not produce dioxins and furans.

The molten salt is usually recycled in the reactor chamber. However, depending on the waste treated (especially inorganics) and the amount of ash, spent molten salt may be hazardous and require special care in disposal.

Pyrolysis is not effective in either destroying or physically separating inorganics from the contaminated medium. Volatile metals may be removed as a result of the higher temperatures associated with the process, but they are not destroyed. Byproducts containing heavy metals may require stabilization before final disposal.

When the off-gases are cooled, liquids condense, producing an oil/tar residue and contaminated water. These oils and tars may be hazardous wastes, requiring proper treatment, storage, and disposal.” [CPEO]

According to CURBI, “pyrolysis has attracted attention from media and public policy makers, including in the Obama Administration, but there is no existing facility in the U.S. that generates biochar at a scale to evaluate the overall energy efficiency. CURBI would be the first. Various types of high-efficiency direct combustion and anaerobic digestion are also being considered.”[CUAES 3 2010]

Biochar is a highly porous organic charcoal made from organic waste. Biochar has received significant praise for its pollution reducing potential:

“Biochar is considered by many scientists to be the "black gold" for agriculture.

Its high carbon content and porous nature can help soil retain water, nutrients, protect soil microbes and ultimately increase crop yields while acting as natural carbon sink - sequestering CO2 and locking it into the ground.


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Biochar helps clean the air two ways: by preventing rotting biomass from releasing harmful CO2 into the atmosphere, and by allowing plants to safely store CO2 they pull out of the air during photosynthesis.

"Soil acts as an enormous carbon pool, increasing this carbon pool could significantly contribute to the reduction of CO2 in the atmosphere," said Christoph Steiner, one of the leading research scientist studying biochar. "It gives us a chance to produce carbon negative energy."

Worldwide use of biochar could cut CO2 levels by 8 parts per million within 50 years, according to NASA scientist James Hansen.”[CNN 2009]

Given the delays and finance trouble in implementing some of the proposals of CURBI, the SRF could supplant this goal by providing the background equipment and laboratory space to develop Cornell into a leader in biochar production.

Works Cited

Energy Information Administration, “Renewable Energy Trends in Consumption and Electricity 2008 Edition” released August 2010, http://www.eia.doe.gov/cneaf/solar.renewables/page/trends/rentrends.html

Union of Concerned Scientists, “How Biomass Energy Works” last revised 10/29/2010, http://www.ucsusa.org/clean_energy/technology_and_impacts/energy_technologies/how-biomass-energy-works.html#1

National Renewable Energy Laboratory “Biomass Energy Basics” last updated 2/9/2010 http://www.nrel.gov/learning/re_biomass.html

ACT Bioenergy LLC “High-Efficiency Wood Chip Boiler at Cayuga Nature Center, Ithaca, NY” 2009 http://www.actbioenergy.com/brochure/Cayuga%20wood%20boiler%20photos.pdf

New York State Energy Research and Development Authority “Biomass Resources” 2004 http://www.powernaturally.org/programs/BiomassResources/default.asp?i=2

[1] Cornell University Agricultural Experiment Station, “Cornell University Renewable Bioenergy Initiative – CURBI” 2010 http://www.cuaes.cornell.edu/cals/cuaes/ag-operations/curbi/index.cfm

EcoHeat Solutions “Solid Biofuel: Wood Pellet Boilers” 2009 http://www.ecoheatsolutions.com/heatingsolutions/woodpelletboiler.html

[1] Greenwood “All You Need to Know About Wood Gasification” 2011 http://www.greenwoodusa.com/Article_All_You_Need_To_Know_About_Wood_Gasification.php

Ronald E. Piester, “Outdoor wood boilers” memo, January 1, 2003, http://www.dos.state.ny.us/CODE/pdf/outdoorwoodboilertb.pdf

Econoburn, 2011, http://www.alternativefuelboilers.com/products.htm


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[2] Greenwood, “Frontier Series Wood Gasification Boiler” 2011, http://www.greenwoodusa.com/frontier-series-indoor-gasification-boiler.php

[3] Greenwood, “Denali Series Pellet Boiler” 2011, http://www.greenwoodusa.com/denali-series-indoor-pellet-boiler.php

Oregon Department of Energy, “Biogas Technology,” March 27, 2009, http://www.oregon.gov/ENERGY/RENEW/Biomass/biogas.shtml

[2] Cornell University Agricultural Experiment Station, “Cornell University Renewable Bioenergy Initiative” concept proposal, January 20, 2010, http://www.cuaes.cornell.edu/cals/cuaes/ag-operations/upload/CURBI_concept_Jan10.pdf

Center for Public Environmental Oversight, “Pyrolysis,” no date, http://www.cpeo.org/techtree/ttdescript/pyrols.htm

[3] Cornell University Agricultural Experiment Station, “Cornell University Renewable Bioenergy Initiative” FAQ, January 20, 2010, http://www.cuaes.cornell.edu/cals/cuaes/ag-operations/upload/CURBI_concept_Jan10.pdf

CNN, “Can 'biochar' save the planet?,” March 30, 2009, http://articles.cnn.com/2009-03-30/tech/biochar.warming.energy_1_carbon-co2-organic?_s=PM:TECH

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Biomass Energy Decision Making Framework - … · Web viewThe objective of this binder is to define biomass energy, describe the history of the evolution of the technology and provide