Nojima, Alison

Alison (Noji) is Brown and Caldwell's national energy leader and specializes in energy financial analyses for various biogas utilization technologies. She supports clients by working together to identify the best combination of alternatives that provide economic value and achieve their energy and sustainability goals. She has served as an engineer on wastewater treatment design projects and feasibility studies, including biogas upgrading to RNG, cogeneration, co-digestion, and digestion. She is passionate about renewable energy and finding grants and opportunities to help the right decarbonization projects move forward. Noji earned her M.S. in Civil and Environmental Engineering from Stanford University and her B.S. in Civil Engineering from Santa Clara University. She is a registered P.E. in California.

Titles from this speaker

A Techno-Economic Analysis on Biogas Carbon Capture for Implementation at Water Resource Recovery Facilities

Abstract

OBJECTIVE: Especially with arising policies and markets for biogenic or green carbon dioxide (CO2), there are greater incentives for water resource recovery facilities (WRRFs) to implement carbon capture utilization (CCU) and carbon capture sequestration (CCS) strategies. In efforts to mitigate climate change, an increasing number of WRRFs are beneficially utilizing biogas for cogeneration or upgrading to renewable natural gas (RNG). Biogas upgrading to RNG produces a waste gas, or tail gas, that is primary CO2 and is typically vented to atmosphere or disposed of in a thermal oxidizer. While WRRFs have historically treated tail gas as a waste product, this paper will explore the emerging opportunities for CCU and CCS project implementation. The manuscript and presentation will include a market assessment for biogenic CO2 end-uses, funding mechanisms and economic incentives, regulations and policies, technological solutions, and a techno-economic analysis of a case study for carbon capture at a WRRF. BACKGROUND: Biogenic CO2 is associated with the natural carbon cycle and comes from the degradation, combustion, or mineralization of organic matter. Biogenic CO2 is sequestered through new terrestrial growth in a 1:1 ratio, making it effectively carbon neutral and a highly valuable commodity for different industries. Biogenic CO2 is a natural byproduct of both anaerobic digestion and from the combustion of biogas in cogeneration. This paper will focus on the capturing biogas from upgrading programs where CO2 must be removed to produce RNG. WRRFs can utilize two pathways for biogenic CO2: CCS or CCU. CCS is the process in which captured CO2 is compressed and injected in underground geologic formations for permanent storage or sequestration. Geologic formations suitable for sequestration include depleted oil and gas fields, deep coal seams, and saline formations. CCS can be used to offset emissions, meet climate goals, or sold as carbon credits. CCU would sell biogenic CO2 as a commodity to manufacturers to produce electrofuels (e-fuels), bioplastics, cement, dry ice, etc. TECHNOLOGICAL SOLUTIONS: Biogas upgrading includes cleaning and separation to remove CO2, H2S, siloxanes, VOCs, and moisture, resulting in RNG and a CO2 rich tail gas containing 0.1 to 7 percent methane. Industrial plants are utilizing the same technologies for CO2 capture as WRRFs are employing for biogas upgrading such as amine solvents, membranes, and pressure swing adsorption. Historically, the tail gas is a waste product that is vented to atmosphere or combusted in a thermal oxidizer. Participating in CCS and CCU market requires further processing of the CO2 gas, which may include further purification, compression, distillation, and cryogenic storage. Table 3-1 presents a summary of the gas upgrading technologies' compatibility for CO2 capture and processing requirements for end use. FUNDING MECHANISMS The Inflation Reduction Act (IRA) of 2022 includes provisions for CCU and CCS tax credits in the form of a direct payment as part of Section 45Q. Section 45Q provides a production tax credit (PTC) per metric ton of qualified CO2 captured up to $85 (Table 4-1). The captured CO2 can be used in enhanced oil and gas recovery, injected in geological sequestration, or for other qualified uses. Qualified uses include photosynthesis or chemosynthesis, chemical conversion to a material or chemical compound, or commercial markets. The Section 45Q PTC is up to $85 per metric ton of captured CO2 depending on utilization and other requirements in Table 4-1. MARKET ASSESSMENT Several economic incentive programs are available to support the market for biogenic and direct air capture (DAC) CO2. Such programs include the IRA for end-users including sustainable aviation fuel manufacturers, and the Carbon Utilization Procurement Grants Program which offset 50% of the costs to states, local governments, and public utilities or agencies to procure and use products developed through the conversion of CO2. Current market prices for biogenic CO2 range from $100 to 300 per MT while DAC CO2 demands a higher price due to the cost (final submission to include pricing data surveyed from various suppliers and end-users). The other avenue to generate revenues from CCS is to sell the offset as carbon credits through the compliance or voluntary market. Carbon market prices have been highly variable in the voluntary market and for CCS to generate more stable revenues the compliance market would need to be accessed (The techno-economic analysis will include an evaluation of CCS vs CCU in the final submission). TECHNO-ECONOMIC ANALYSIS An initial evaluation of funding opportunities and economic incentives for RNG coupled with CCU is provided based on interpretations of the IRA 2022 and values for RINs, biogenic CO2, and commodity RNG (Figure 6-1). Based on a conservative value for biogenic CO2 ($100/MT) and an IRA tax credit of $65/MT, it is estimated that CCU can provide a 20% increase in revenues from an RNG program that accesses the RFS program. The manuscript and presentation will include a techno-economic analysis for a medium sized WRRF to implement a CCU or CCS project that will support climate change mitigation.

WRRFs with AD can implement CO2 capture alongside RNG programs to enhance resource recovery and generate additional revenues. WRRFs are one of the few sources of biogenic CO2 and the high concentration of CO2 in biogas upgrading can generate a green CO2 product for decarbonization. A TEA found that CO2 capture systems larger than 1,200 of biogas with IRA funding can result in a NPV that is positive. However, there are still many significant challenges that need to be addressed.

SpeakerNojima, Alison

Presentation time

16:30:00

16:50:00

Session time

15:30:00

17:00:00

SessionWhat Will You Make of Your Biogas?

Session number430

Session locationRoom 346

TopicBiosolids and Residuals, Energy Production, Conservation, and Management, Intermediate Level, Sustainability and Climate Change, Utility Management and Leadership

Author(s)

Nojima, Alison, Le, Trung, Guo, Peibo, Valenti, Alexis, Ross, Adam

Author(s)A.C. Nojima1, T. Le2, P. Guo2, A. Valenti1, A. Ross1

Author affiliation(s)1Brown and Caldwell, CA, 2Brown and Caldwell, VA

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2024

DOI10.2175/193864718825159687

Volume / Issue

Content sourceWEFTEC

Word count15

Designing Cogeneration for the Real-world: A Comprehensive Approach

Abstract

Digester gas is an asset utilities’ can use to maximize beneficial reuse of their resources and reduce their climate impact. In Fairfield, CA, the Fairfield-Suisun Sewer District (District) plant is already an industry leader by employing cogeneration, solar photovoltaics, and wind turbine sources to generate renewable energy and produce the majority of its electricity demands onsite. When looking to replace systems and further advance their energy program, the District engaged Brown and Caldwell to complete a digester gas utilization study. Due to increasing complexity of electric utility rate schedules, the existing varied energy resources at the facility, net metering/export limitations, and potential gas/energy storage, the typical annual average evaluation approach was no longer sufficient to reach realistic conclusions. New tools and methods were required that incorporated time-domain analysis and plant-level energy balance. Simulating minute-resolution digester gas production, real time energy production, and gas storage, allowed for a more accurate evaluation for the District, while using annual averages caused an over estimation of the benefits of the various scenarios evaluated. The selected design was one 1,100 kW engine with natural gas blending to accommodate variability in gas production, take advantage of spark spread, and reduce flaring.

Biogas utilization maximizes resource recovery and reduces climate impact. Fairfield-Suisun Sewer District employs renewable energy generation sources and produces most of its electricity onsite. To evaluate and size a biogas engine, a new method was developed that incorporated a time-domain analysis balancing generation sources, plant demands, and simulated real time biogas and resulting engine output.

SpeakerChouinard, Tracy

Presentation time

15:30:00

15:50:00

Session time

15:30:00

17:00:00

SessionOptimizing Energy Investments Part II: Energy Use is in the Details

Session locationRoom S402b - Level 4

TopicEnergy Production, Conservation, and Management, Facility Operations and Maintenance, Intermediate Level, Utility Management and Leadership

Author(s)

Chouinard, Tracy

Author(s)T. Chouinard 1; K. Klittich 2 ; A. Nojima 3; T. Chouinard 1;

Author affiliation(s)Brown and Caldwell 1; Brown and Caldwell 2 ; Brown and Caldwell 3; Brown and Caldwell 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159040

Volume / Issue

Content sourceWEFTEC

Word count9

Pursuing Bioenergy Projects in a Dynamic Funding Environment

Abstract

Low carbon, energy recovery projects at wastewater treatment plants are typically discretionary and require a return on investment to execute. As carbon and energy markets evolve, long-term project payback is subject to variability in incentive pricing and can reduce confidence in decision making. Two case studies of recent biogas utilization projects in California are presented to demonstrate a strategy for driving forward the 'right' projects in a dynamic funding and regulatory environment. The first case study describes the City of Roseville's Pleasant Grove Wastewater Treatment Plant, which completed construction of a grant-funded biogas upgrading to renewable natural gas for onsite vehicle fueling, microturbines, and codigestion. The second case study covers the Fairfield-Suisun Sewer District Wastewater Treatment Plant Bioenergy Generation Project, which is installing a new IC engine. Both case studies provide perspective on how to align bioenergy projects with grants and incentives to maximize return on decarbonization investments and increase confidence in decision making.

Understanding legislation and economic markets around WWTP energy recovery investments are critical to bioenergy project development. The manuscript and presentation will focus on capitalizing on current incentives and markets such as Renewable Identification Numbers (RINs), Renewable Energy Certificates (RECs), the Clean Water State Revolving Fund Green Project Reserve (GPR), and the California Low Carbon Fuel Standard (LCFS), and the 2022 Inflation Reduction Act (IRA).

SpeakerValenti, Alexis

Presentation time

16:00:00

16:10:00

Session time

15:30:00

17:00:00

SessionCreating Renewable Revenue Streams with RNG

Session locationRoom S402b - Level 4

TopicAdvanced Level, Energy Production, Conservation, and Management, Utility Management and Leadership

Author(s)

Valenti, Alexis

Author(s)A. Valenti 1; A. Nojima 1 ; A. Valenti 1;

Author affiliation(s)Brown and Caldwell 1; Brown and Caldwell 1 ; Brown and Caldwell 1;

SourceProceedings of the Water Environment Federation

Document typeConference Paper

PublisherWater Environment Federation

Print publication date Oct 2023

DOI10.2175/193864718825159121

Volume / Issue

Content sourceWEFTEC

Word count9

Pursuing Bioenergy Projects in a Dynamic Funding Environment

Abstract

Organizations are working to become carbon neutral, seeking renewable energy sources, and reducing reliance on regional energy grids. Reductions in greenhouse gas (GHG) emissions are being regulated at state and federal levels and are monetized through various green energy programs. Low carbon, energy recovery projects at wastewater treatment plants are typically discretionary and require a return on investment to execute. As carbon and energy markets evolve, long-term project payback is subject to variability in incentive pricing and can reduce confidence in decision making. Understanding legislation and economic markets around WWTP energy recovery investments are critical to bioenergy project development. The manuscript and presentation will focus on capitalizing on incentives and markets such as Renewable Identification Numbers (RINs), Renewable Energy Certificates (RECs), the Inflation Reduction Act (IRA), the Clean Water State Revolving Fund Green Project Reserve (GPR), and the California Low Carbon Fuel Standard (LCFS). The reader will learn how to align biogas utilization projects with funding opportunities supporting renewable energy generation and low carbon alternative fuel production. Two case studies of recent biogas utilization projects in California are presented to demonstrate a strategy for driving forward the 'right' projects in a dynamic funding and regulatory environment. The first case study describes the City of Roseville's Pleasant Grove Wastewater Treatment Plant, which is completing construction of a grant-funded biogas upgrading to renewable natural gas (RNG) for onsite vehicle fueling, microturbines, and codigestion. The second case study covers the Fairfield-Suisun Sewer District (FSSD) Wastewater Treatment Plant Bioenergy Generation Project, which is installing a new internal combustion engine. Both case studies provide perspective on how to align bioenergy projects with state and federal grants and incentives to maximize return on decarbonization investments and increase confidence in decision making. The City of Roseville (Roseville) is constructing an Energy Recovery project to collect and co-digest organics such as fats, oil, and grease (FOG) and food waste at the Pleasant Grove Wastewater Treatment Plant (PGWWTP). The additional gas production from high strength waste (HSW) will help drive a new biogas upgrading project aimed at delivering renewable vehicle fuel to Roseville's solid waste collection fleet. Microturbines are also installed to utilize tail gas from the biogas upgrading process to produce electricity and heat for the digesters. The Energy Recovery Project began with a comprehensive analysis aimed at determining the best use of biogas in terms of net present value (NPV). In addition to offering economic benefit over the status quo alternative of operating biogas fueled boilers and flaring excess gas, a hybrid microturbine and biogas upgrading to RNG vehicle fuel project affords greater potential for funding opportunities since both standalone projects have grant and rebate possibilities. By running its solid waste fleet (approximately 34 trucks) via a new on-site RNG fueling facility and ceasing diesel use, Roseville will earn credits through the California LCFS program as it reduces greenhouse gas emissions by about 3,655 metric tons of CO2 equivalents per year. The use of RNG as vehicle fuel is also eligible for generating RINs under the EPA's Renewable Fuel Standard. Both LCFS credits and RINs involve a supply and demand driven market that offer ongoing revenue through the sale of credits. Furthermore, generating electricity with microturbines makes the project eligible for the Clean Water State Revolving Fund Green Project Reserve, which incentivizes projects that address water or energy efficiency and reduces costs for utility customers. To-date, the energy recovery project has received approximately $7.18 million of grant funding with support from the California Energy Commission, Green Project Reserve, and Placer County Air Pollution Control District. Roseville also intends on applying for a clean electricity investment credit through the IRA for up to an additional $7 million. Roseville's vision and follow-through in transforming its wastewater treatment process into a highly sustainable, energy-efficient operation positioned them for grants and renewable credits that will improve the financial security of the PGWWTP. FSSD is no stranger to utilizing biogas beneficially through the production of electricity via internal combustion engines. FSSD originally installed their cogeneration system in the late 1980s and has continued to operate engines to produce electricity and provide heat to their digesters. In 2019, with their existing cogeneration engine reaching the end of its useful life and wanting to continue prioritizing 'doing the right thing' with their biogas, FSSD conducted a Biogas Utilization Master Plan (BUMP). The purpose of the BUMP was to identify which modern utilization technology would be the most economically beneficial option for FSSD. These technologies included biogas upgrading to RNG for vehicle fueling, RNG for pipeline injection, or upgrading the existing cogeneration facility. The BUMP included an evaluation of each alternative and included the benefits of various methods of revenue and funding including, LCFS credits, RINs, and the Self Generation Incentive Program (SGIP). The BUMP determined that a new cogeneration facility would provide the greatest benefit to FSSD economically and from an operational point of view. The BUMP lead directly into the design and construction of the Bioenergy Generation Project (BGP), which includes a new 1.2 megawatt (MW) cogeneration engine and gas conditioning, with the existing 900 kilowatt (kW) engine remaining as a standby unit. FSSD did not base the project feasibility on receiving any funding but did anticipate possibly receiving SGIP funding to offset some of the project costs. However, the revised 2021 SGIP guidelines required full biogas upgrading to RNG prior to cogeneration to qualify, which would significantly increase capital costs in exceedance of the SGIP grant. With original SGIP grant no longer feasible, FSSD was forced to a step back, but ultimately decided on proceeding with the BGP as it remained the best option for the plant and beneficial use of renewable biogas aligned with California's climate goals. FSSD's dedication to doing the right thing paid off, as the BGP became eligible for credits through the 2022 IRA that was passed after construction started. The 2022 IRA amended and extended the preexisting Investment Tax Credit and created a new Clean Electricity Investment Tax Credit to include biogas utilization projects. FSSD plans on pursuing an elective payment through the IRA and is anticipated to receive up to 30 percent of the project cost in the form of a direct pay tax credit. In FSSD's case, uncertainties around funding did not determine the fate of the project, but in many cases these opportunities are what establish whether a discretionary energy recovery project is feasible or not for public agencies. Funding is typically available in the form of grants, which are competitive and cannot be relied on in determining project payback during the planning phase. The IRA provides funding in the form of a tax credit with greater certainty that can be considered during the business case evaluation phase. For public agencies planning to develop bioenergy projects, the certainty of the IRA can shift the scales financially and allow the right renewable energy projects to become economically feasible.

This paper was presented at the WEF/IWA Residuals and Biosolids Conference, May 16-19, 2023.

SpeakerNojima, Alison

Presentation time

8:30:00

9:00:00

Session time

8:30:00

11:45:00

SessionSession 09: Biogas

Session number09

Session locationCharlotte Convention Center, Charlotte, North Carolina, USA

TopicEconomics and Project Delivery