biosolids - up in smoke? mark cullington nbma annual conference lake chelan 21 september 2010
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Biosolids - Up in Smoke?
Mark CullingtonNBMA Annual Conference
Lake Chelan
21 September 2010
(EJN, 2010)
Outline
• Thermal Conversion (Incineration)
• Biogasification• Drivers• Case Study Waste-to-energy
Drivers
Feedstock - Annually 7,180,000 dry tons of biosolids are generated from ~16,000 WWTP’s
Feedstock - Annually 250,000,000 tons of MSW
Energy demand - 99,900,000,000,000,000 BTU
Public and political pressures
(Brown, 2009; WEF, 2010; NEBRA, 2008)
Biosolids Ordinances
• Have developed or are considering ordinances: WA, AZ, CT, ME, NH, MA, RI, VT OH, NC, GA, FL, VA, NY, IL, WI
Restricted Use – Class A
None
Ban
Practical Ban
Reasonable
(CA EPA, 2009)
Drivers
Feedstock - Annually 7,180,000 dry tons of biosolids are generated from ~16,000 WWTP’s
Feedstock - Annually 250,000,000 tons of MSW
Energy demand - 99,900,000,000,000,000 BTU
Public and political pressures Thermal conversion as ‘green’ energy
(Brown, 2009; WEF, 2010; EPA, 2008)
Drivers
Feedstock - Annually 7,180,000 dry tons of biosolids are generated from ~16,000 WWTP’s
Feedstock - Annually 250,000,000 tons of MSW
Energy demand - 99,900,000,000,000,000 BTU
Public and political pressures Thermal conversion as ‘green’ energy Economies of scale
(Brown, 2009; WEF, 2010; EPA, 2008)
(Stillwell at al., 2010)
Drivers
Feedstock - Annually 7,180,000 dry tons of biosolids are generated from ~16,000 WWTP’s
Feedstock - Annually 250,000,000 tons of MSW
Energy demand - 99,900,000,000,000,000 BTU
Public and political perception Thermal conversion as ‘green’ energy Economies of scale Energy recovery dollars Design-Build-Own-Operate
(Brown, 2009; WEF, 2010; EPA, 2008)
Country Annual Production (Dry Tons)
Agriculture Landfill Incineration Other
Austria 320,000 13 56 31 0
Belgium 75,000 31 56 9 4
Denmark 130,000 37 33 28 2
France 700,000 50 50 0 0
Germany 2,500,000 25 63 12 0
Greece 15,000 3 97 0 0
Ireland 24,000 28 18 0 54
Italy 800,000 34 55 11 0
Holland 282,000 44 53 3 0
Japan 1,800,000 0 15 80 5
Spain 280,000 10 50 10 30
Switzerland 50,000 30 20 0 50
UK 1,075,000 51 16 5 28
US 5,357,000 54 18 19 9
Total/Avg. 11,988,000 38 43 10 9
(Adapted from United Nations, WEF, MN Metro, 1996-2010)
• What are the best ways to capture Volatile Solids energy potential – 10,000 Btu/lb VS (23 000 kJ/kg VS)?
Two “Pathways” For Energy Recovery From Biosolids
(Adapted from Scanlon, 2009)
Anaerobic
Digestion
Lots of energy!
Digestion
Biosolids
Electricity
Class B Soil Amendment
Methane
Engine
Wastewater
Food Waste
FOG
Class A Products
• What are the best ways to capture Volatile Solids energy potential – 10,000 Btu/lb VS (23 000 kJ/kg VS)?
Two “Pathways” For Energy Recovery From Biosolids
(Adapted from Scanlon, 2009)
Thermal Conversion (Incineration)
• Combustion of organic wastewater solids to form carbon dioxide and water
• Generation of heat, some gas, and ‘ash’• Two most common types of technologies:
fluid bed and multiple hearth• 254 Incinerators in the U.S: 197 Multiple
Hearth, 55 Fluidized Bed, 2 Electric Arc• Every new facility built in the past 15 years
has been a fluidized-bed
Thermal Oxidation (Incineration)
(WEF, 2009)
Thermal Conversion (Incineration)
• Biosolids between 15-30% - for every pound of solids to be incinerated, 3-5.25 pounds of water must be evaporated
(WEF, 2006; Dominak, 2001)
Autogenously: solids ~>40%
Thermal Conversion (Incineration)
• Ash generated from 400 to 800 lbs/DT of biosolids
• Quality of ash dependent on feedstock
(Japan SWA, 2002)
Thermal Oxidation (Incineration)
Advantages• Does not require pre-stabilization• Destroys all volatile solids and pathogens• Large volume and mass reduction lowers truck
traffic as compared with other biosolids handling alternatives
• Low life cycle cost for most large facilities• Operates continuously in all weather conditions
Disadvantages• High initial capital costs• Applicable to large facilities• Poor public perception• Not the most appropriate technology for non-
continuous operations• Requires complex permitting process• Not perceived as “green” process - N2O emissions• Ash reuse programs have not been well developed
Biogasification• ‘Convert a solid or liquid substance into a
gas’• Larger molecule carbonaceous solids are
converted, by oxidization-reduction reactions, to smaller molecule combustible gas products
• In place of natural gas at sawmills, panel board plants, pulp mills, and institutional facilities using wood fuel
• Hallmark of process - ‘Syn Gas’ Nitrogen (55% by volume) Carbon dioxide (16%) Carbon monoxide (12% to 30 %) Hydrogen (2% to 10%)
1. Fuel In-Feed System
2. Gasifier ~(1200oC /
2200oF):
Pyrolysis and Partial
Combustion
3. Char/Ash Removal System
4. Syngas
Biogasification
Source: Nexterra Systems Corp
Ventura County Waterworks District No. 1 Biosolids Management Study
California
California
Thousand OaksCamrosa
Moorpark
Simi valley
Camarillo
Source: Ventura County General Plan
Purpose of Project
“Long-Term” Regional Solution
Reduce biosolids handling costs
• Minimize quantity
• Operational considerations
• Explore multiple end use options (except land application) (cement aggregate, heat, electricity, methane recovery, e-fuel)
Regulatory Constraints
Evaluate Innovative and Embryonic technologies in addition to Established technologies
Biosolids Management Alternatives Analysis
• Alternatives Selection Process• Evaluation Criteria• Technology Description• Analysis
Deep Well Injection *
Biosolids Management - Alternatives Selection Process
(EPA, 2006)
Recommendations
Evaluation Criteria:
State of development
Number of Installations
Discharge solids concentration
Energy efficiency
Space requirements
Containment of foul and corrosive air
Constructability (including site location)
Ease of operation and maintenance
Manufacturer support
Life cycle costs
Regulatory Approval
Useful by-products
Technologies - Minergy’s GlassPack
Mechanism: Vitrification
(melting at 30000C,
quickly followed by cooling)
Output solids used as glass
aggregate
Installation: 1 plant in Wisconsin
Needs 90% solids
Business is no longer in existence
Source: Minergy Corp.
Mechanism: Plasma oxidation
in a Rotary Kiln (700oC)
Plasma: Ionized Gas; 4th state of matter
Input solids: 20% solids, FOG,
food scraps, yard waste
(20% organic material)
Output solids: Ash
(fertilizer, cement aggregate)
No pilot / full scale installations in US
Technologies - Plasma Assisted Sludge Oxidation (PASO)
Source: Fabgroups
Technologies - SlurryCarb® Process
Technologies - Deep Well Injection
Demonstration project (Terminal Island) under Class V UIC permit
Mechanism: Sludge injected >5000 ft below earth’s surface;
Biogenesis (thermal + biodegradation): Sludge Methane, Oil, and CO2
~400 wet tons / day
Source: City of LA, 2010; Terralog Technologies, Inc , 2010
Technologies - Fluidized Bed Incineration
Mechanism: Combustion
Output solids: Ash
Potential for electricity
production
~255 operating in US
Air permitting / public
perception hurdles
(WEF, 2009)
Technologies - Gasification
Mechanism: Pyrolysis and Partial
Combustion Produces gas that is used
generate electricity Output solids: Char/Ash (needs
land filling / potential for cement
aggregate) Needs 90% dried solids as
input
Source: Nexterra Systems Corp
Taking it further
Incineration
$50-60 M
Gasification
$60-66 M
Life-Cycle Costs: Including engineering design, O&M, Drying and Engines
Wrap-upThermal conversion use in the
biosolids industry is evolvingFirst full-scale installation of biosolids
gasifier in USHeavily marketedLots and lots of volume to make
these pencil-out (life-cycle costs)