irvine ranch water district biosolids & energy recovery ... · pdf fileabout irvine ranch...

Irvine Ranch Water DistrictBiosolids & Energy Recovery Project

A Practical Solution for a Sustainable Future

2012 NWRI Clarke Prize ConferenceNovember 2, 2012

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1. IRWD Background and Services

2. Project Objectives

3. Project Alternatives and Analyses

4. Project Description

5. Odor Control Systems

6. Biogas Utilization

7. Pellet Marketing

8. Project Schedule

9. Research Opportunities

Presentation Overview:

Biosolids & Energy Recovery Project

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Water, Wastewater, Water Recycling, and Urban Runoff

California Special District governed by a publicly-elected Board

IRWD customer base:• Residential population: 340,000• Daytime population: over 500,000• Service connections: 101,600

IRWD service area:• 181 square miles (20% of Orange County)• All or part of six cities and unincorporated county:

About the Irvine Ranch Water District

IrvineTustin

Orange

Lake ForestNewport Beach

Costa Mesa

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IRWD services and system statistics:

Potable Water: Three treatment plant, 25 wells, 1,500 miles of pipelines

Wastewater: Nearly 1,000 miles of sewage collection pipelines

Recycled Water: Two water recycling facilities (28 MGD + 5.5 MGD) and approximately 500 miles of recycled water pipelines

Urban Runoff Treatment: The San Joaquin Marsh and 31 built and planned man-made wetland treatment sites

About Irvine Ranch Water District

Project Objectives

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Should IRWD get back into the biosolids handling business?

• The Michelson Water Recycling Plant (MWRP) processed biosolids from 1967 until 1988 using aerobic digestion and belt presses for dewatering.

• Since 1988, IRWD piped biosolids to Orange County Sanitation District for processing in Fountain Valley and Huntington Beach.

• In 2005 Orange County Sanitation District announced plans to expand their processing facilities for IRWD biosolids by 2016.

• In 2005 IRWD started investigating options to process biosolids at the MWRP.

Project Objectives

IRWD’s Solids Handling Past

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Project Objectives

• Maximize IRWD’s ability efficiently and sustainably use of its renewable resources.

• To make beneficial use of biosolids and biogases produced during the treatment process.

• Provide for greater control of residual (biosolids) management at reduced costs.

• Minimize environmental impacts associated with residuals management.

• Construct a biosolids handling and energy recovery facility that will address IRWD’s future biosolids handling needs.


Project Alternatives

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Class B Class A

Primary Sludge

Waste Activated Sludge

Thickening Anaerobic Digestion

Digested Sludge

Dewatering

Digester Gas Treatment

Composting Partner

Land Applic. Partner

Drying Partner

Landfill

E‐Fuel Conversion

Incineration Partner

Drying & Pelletizing

OCSD

Local Fertilizer

Fertilizer Partner

E‐Fuel Conversion


Raw Sludge Dewatering

Composting Partner


Internal Combustion Engines

Microturbines

Energy Partner

Dryer Fuel

Fuel Cells

E‐Fuel Conversion

Project Alternatives

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1. Baseline Alternative• Continue sending all residuals to OCSD

2. Digest All Sludge• Send liquid digested sludge to OCSD

3. Digest Only Primary Sludge• Send digested primary sludge & secondary sludge to OCSD

4. Digest & Dewater; Private Hauler• No residuals sent to OCSD

5. Digest & Dewater On-Site; Off-Site Incineration• No residuals sent to OCSD

6. Digest & Dewater; On-Site Drying• Produce Class A pelletized product (90% solids)• No residuals sent to OCSD

7. Digest & Dewater; Off-Site Drying• No residuals sent to OCSD

Summary of Project Alternatives

Alternatives Analyses

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Economic Analysis Methodology

Capital Costs

Operating Costs

Life CycleCumulative Costs

Payback


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OCSD Total Annual Cost to IRWD, $ millions


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Life Cycle Cumulative Costs & Payback

Life Cycle ComponentAlt. 1High

Alt. 1Low

Alt. 2 Alt. 3 Alt. 4 Alt. 5 Alt. 6 Alt. 7

Cumulative Cost, $100 million 702 632 480 529 411 423 414 452

Payback Year ‐ ‐ 2021 2021 2022 2022 2023 2023

1 – Baseline

2 – Digest All Sludge

3 – Digest Primary Sludge

4 – Dewater, Private Hauler

5 – Dewater, Incineration

6 – Dewater, On‐Site Drying

7 – Dewater, Off‐Site Drying


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Non-Economic Evaluation Criteria• IRWD Autonomy:

Independent biosolids management decision making.

• Implementability:Able to obtain permits within required time frame.

• Community Impacts:Noise, traffic, odors, aesthetics, public health.

• Environmental Stewardship:Biosolids reuse & reduce carbon footprint.

• Technology:Proven and reliable.

• Long-term Viability:Can remain cost-effective; responsive to regulations.


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Weighted Benefit Scores


+ Easy to implement

- Little autonomy

+ IRWD can implement

+ More autonomy

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Benefit Scores vs. Life Cycle Costs

1 – Baseline

2 – Digest All Sludge

3 – Digest Primary Sludge

4 – Dewater, Private Hauler

5 – Dewater, Incineration

6 – Dewater, On‐Site Drying

7 – Dewater, Off‐Site Drying


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Selected Project:

• Anaerobic digestion of biosolids.

• Electrical energy generation by feeding biogas to microturbines.

• On-site drying to produce a reusable pelletized product.

• Started design of MWRP Biosolids & Energy Recovery Facilities in 2009.

• Project operational by 2016.


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Summary of Project Benefits:

• Reduces greenhouse gas effects by using pellets locally.

• Drying and pelletizing reduces export truck loads by factor of four.

• Beneficially reuse as a local fertilizer or e-fuel.

• Greater environmental stewardship and reduced carbon footprint.

• Lower overall cost to community.

• Project positions IRWD and the City of Irvine as a proponents of sustainability.


Project Description

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Project Description

• IRWD to construct facilities at MWRP for:• Biosolids dewatering;• Biogas management and energy recovery; and• Odor control systems.

• IRWD would no longer export solids to Orange County Sanitation District (OCSD).

• Project would also dry solids trucked in from IRWD’s Los Alisos Water Recycling Plant (LAWRP).

• Project to be constructed on disturbed vacant land within the current boundary of the MWRP.


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Project Location

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IRWD Biosolids Facilities Site Location

MWRP

Biosolids and Energy

Recovery Facilities

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EXISTING PRIMARY CLARIFIER

THICKENINGCENTRIFUGE

EXISTING SECONDARY CLARIFIER

ACID‐METHANE PHASE ANAEROBICDIGESTION

DEWATERINGCENTRIFUGE

THICKENINGCENTRIFUGE

DIGESTED SLUDGE STORAGE

MICROTURBINES

BIOGAS ELECTRICITY

CAKESTORAGE & LOADOUT

CLASS BCAKE HAUL(BACKUP)

ROTARYDRUMDRYER

PELLET STORAGE & LOADOUT

CLASS A PELLET HAUL

FATS, OILS & GREASE

CENTRATETREATMENT

TO LIQUID TREATMENT

RECYCLED WATER

PS

WAS

DIGESTER GAS CLEANING

Simplified Process Schematic

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Conventional vs. Egg-Shaped Digesters

Advantages of Egg-Shaped Digesters:• Best design for treatment process• More efficient mixing• Better foaming control• Easier grit removal• Less frequent cleaning = less chance for odors escaping• IRWD’s design will have piping and equipment hidden in basement

and inside walkway• Clean dome appearance

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Egg-Shaped Digester Characteristics

Portion of Digester

Below Grade

Approx 73 Ft

Mesa, AZ

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IRWD Biosolids Facilities Site Plan

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Biosolids Handling Building Interior

Cake Receiving & StorageHeat Dryer

Centrifuges & Cake HandlingPellet & Cake Truck Loading

Cake Bins

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Digestion Facilities

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Acid Phase Digesters

Egg-Shaped Digesters

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Biosolids Handling BuildingDryer and Odor Control

Wet Scrubber Discharge Stacks

3030

Biosolids Handling Building

3131

Centrifuge Room

3232

Dryer System – Lower Level

3333

Dryer System – Upper Level

Odor Control Systems

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Components of Odor Control Process

• Odor control ducting to be placed directly on relevant equipment

• Regenerative Thermal Oxidizer (RTO) for off-gas from dryer.

• Biogas conditioning prior to use in microturbines

Ventilation Systems

• People areas – positive air pressure

• Equipment areas – negative air pressure

Odor Control Systems


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Odor Control SchematicODOR ET

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Centrifuges

Screw Conveyors

Wet Wells

Truck Receiving

Baghouses

NaOCl NaOCl

NaOH NaOH H2SO4

H2SRemoval

NH3Removal

H2SRemoval

Odor Sources:

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Odor Control at City of Mesa

Biogas Utilization

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Alt. 1 – Base Case

Biogas Priorities:

1. Use in the dryer; recycle waste heat to digesters.

2. When dryer is off, use in boilers to heat digesters, if needed (cold day).

3. Excess gas diverted to enclosed gas burner.

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Alt. 2 – Fuel Cell

Biogas Priorities:

1. Use in the fuel cell

2. Use any excess biogas in the dryer

3. When dryer and fuel cell are off, use in boilers to heat digesters, if needed

4. Excess biogas diverted to enclosed gas burner

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Alt. 3 – Microturbines

Biogas Priorities:

1. Use in the micro-turbines to get SCE incentives.

2. When dryer and micro-turbines are off, use in boilers to heat digesters, if needed.

3. Excess biogas (very little) diverted to enclosed gas burner.

4. Use natural gas in the dryer.

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Electrical Power Summary

MWRP RecycledWater

Production(MGD)

Recycled Water

Treatment Electrical Demand(MW)

BiosolidsHandling Electrical Demand(MW)

Total MWRP ElectricalDemand(MW)

Micro‐Turbine Power

Generated(MW)

Percent of Power Self‐Generated

23 5.1 1.8 6.9 1.0 15%

28 6.1 2.4 8.5 1.5 18%

Biogas Production (Digestion)

Power Generation

(Microturbines)

Power Use (Aeration Blowers)

• Continuous biogas production and power generation.

• All power used on MWRP site.

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Biogas and Microturbines

Odor Control Wet Scrubber

Pellet Marketing

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IRWD Pellet Marketing PlanGoal:

Maximize local reuse opportunities

Priorities:1. Local reuse as fertilizer2. E-fuel in cement kiln3. Agricultural land application4. Landfill cover (last resort)

Competitive Advantage:IRWD’s relationship with recycled water users on Irvine’s many greenbelts & parks

Strategy:Public/private partnerships


Project Schedule

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Project Schedule

DATE ACTIVITYOctober 2012 Supplemental EIR certified by the IRWD

Board of Directors; Project approvedNovember 2012 City of Irvine action on

Conditional Use PermitEarly 2013 IRWD to award Biosolids Facilities

construction contract2013-2016 Construction

Early 2016 Start-up of digestion facilities (Class B biosolids)

Late 2016 Start -up of facilities (Class A biosolids)

Engineer’s Estimate for Construction: $150.8 million

Research Opportunities

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OpenCEL:• A cell lysis technology that treats waste activated sludge with high

voltage DC current to sludge cells to make sludge more biodegradable.

• May result in digester producing less biosolids.• May allow more production of biogas.• May offset methanol use in denitrification process.

Ostara:• Recovers phosphorus from sludge for use as a fertilizer.

Foodwaste:• May allow more production of biogas without producing more solids.

Future Research Opportunities

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Project Delivered by Dr. McCarty’s Students!

Contact Information:

Paul CookGeneral ManagerIrvine Ranch Water District

[email protected]

irvine ranch water district biosolids & energy recovery ... · pdf fileabout irvine ranch...

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