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)

Mark Cullingtonmarkcullington@kennedyjenks.com

(503) 866-4188