Biogas Opportunities: From Fuel to Flame

Transcription

1 Biogas Opportunities: From Fuel to Flame Matt Krumenauer Senior Policy Analyst Oregon Department of Energy Paul Suto, P.E. Supervising Engineer Bureau of Environmental Services July 23, 2014 Environmental Services 1

2 CNG Vehicle Fuel Opportunities-Presentation Outline What is Biogas? CNG Treatment Technologies and Fueling Systems CNG Related Policies Funding Opportunities /Criteria The Business Case City of Portland s Biogas History, including vehicle fueling CNG Opportunities and Challenges Environmental Services 2

3 What is Biogas? Municipal Wastewater Sludge as Feed Stock Anaerobic Digester Gas Composition Methane: 50-65% CO 2 : 35-50% H 2 S: 350 ppm Siloxane: 25 ppm Water Vapor Energy Content Btu/Cubic Ft Environmental Services 3

4 Biogas Utilization Heating Boiler fuel, steam or hot water Electricity internal combustion engines, CHP, fuel cells Transportation fuel CNG Upgraded and injected into the natural gas system Fuel Cells? Biorefineries? Small scale applications? Environmental Services 4

5 CNG for Vehicle Fuel Digester Biogas Conditioning CNG Fueling Nat Gas Blending Environmental Services 5

6 Biogas Conditioning Moisture Removal Dryer Purification Activated carbon, silica gel, iron sponge, bio-filtration Upgrading Water scrubbing, pressure swing absorption, amine scrubbing, membranes Environmental Services 6

7 Biogas to CNG Fueling Station Compression 3,000-5,000 psi Storage/injection Fuel Pump Environmental Services 7

8 CNG Vehicle Requirements Engine Requirements Retrofits New Vehicles Environmental Services 8

9 CNG Policies Federal Renewable Fuel Standard New EPA rules consider biogas to be qualified for cellulosic RINs Oregon Clean Fuels Program Related Efforts Biogas Study, Waste characterization, Funding criteria Environmental Services 9

10 CNG Project Funding Opportunities and Resources Alternative Fuel Vehicle Infrastructure Incentives 35% of project costs Program can support vehicle conversions in 2015 State Energy Loan Program Financing available for projects, fleets, infrastructure Biomass Collection Tax Credits Incentive offered for each unit of biomass delivered for energy production Environmental Services 10

11 CNG Vehicle Fuel Business Case Considerations Revenue potential Value of product and attributes RECs/RINs Amount of gas produced to make CNG/electricity Capital Costs Cleaning Technology, Redundancy, Storage, O&M Costs Media, Power Alternatives and non-revenue values Environmental Services 11

12 City of Portland CBWTP Biogas History and CNG Opportunities and Risks Environmental Services 12

13 1952- Biogas Used to Heat Digesters and Admin Bldg

14 CBWTP Biogas Utilization Timeline 1974 Sludge processing boilers Heat the facility buildings and tunnels Four digesters and Digester Control boilers Heat all eight digesters Malarkey gas line Supply methane to Malarkey Roofing Company to heat boilers. Environmental Services 14

15 Biogas Utilization Timeline (Cont d) 1999 Fuel Cell. Converts methane to electricity Four microturbines. Produce electricity Two Combined Heat and Power Generators Produce electricity and heat. Environmental Services 15

16 Fuel Cell (200 kw) Environmental Services 16

17 Heat Recovery Heat Exchanger Carbon Vessels Refrigerated Dryer Desiccant Micro-Turbine Booster Compressor Compressor Microturbines- Four at 30kW Environmental Services 17

18 Engines Electric: 850 kw Each Thermal: 3.6 MBTU /hr / Unit Efficiency Electrical: 37% Thermal: 47% Total CHP: 84%

19 Gas Treatment System for Cogen Environmental Services 19

20 BES Biogas Generation and Utilization Environmental Services 20

21 CBWTP Biogas Utilization July 2008 to April 2013 Environmental Services 21

22 CBWTP Existing Gas Utilization Environmental Services 22

23 But we still have BTUs being FLARED!

24 The Next Flared Biogas Utilization Project Project Scope developed as Cogen Expansion in No grants available to help financial payback Participated in ODOE Feasibility Study Identified rcng as a viable option compared to cogen. Also looked at pipeline NG. Environmental Services 24

25 Biogas Utilization Alternatives Analyzed ALTERNATIVE ALTERNATIVE ALTERNATIVE ALTERNATIVE ALTERNATIVE Cogeneration Expansion without Biogas Storage Cogeneration Expansion with Biogas Storage Biogas Treatment for Vehicle Use Biogas Treatment for Sale to Industry/ Pipeline Injection Biogas Used in Biosolids Drying Environmental Services 25

26 Biogas Project Findings Analysis included triple bottom line analysis: Social, Environmental, Financial Key findings that drove selected alternative: Relative low power costs in NW, and clean power generation. Fuel costs are high. No immediate use for additional waste heat. Align with Bureau s Mission and City of Portland Climate Action Plan. Environmental Services 26

27 Renewable CNG Fuel Selected Most Potential from financial revenue standpoint (fuel sale, RINs), and even more beneficial from environmental, social benefit (eliminate diesel pollution, and CACs). Fuel Production: 1,700 DGE/Day from 430,000 CF/Day Biogas Produce more fuel than can be used by internal BES (not City) fleet. Best financial benefit is for internal fleet use. Environmental Services 27

28 CBWTP Vehicle Fuel Schematic Environmental Services 28

29 Renewable CNG Fuel Use Potential Hauling Trucks to use Fuel TCWTP Sludge Trucks: 26 DGE/Day Madison Farms: 432 DGE/Day City Fleet Uses more fuel than the potential CNG produced. Would require conversions, accelerated vehicle replacements, and additional fueling station locations. Still need to identify additional fuel users. City Refuse Haulers, Others Environmental Services 29

30 Translating Benefits of Revenue Stream The projected potential net revenue of the project was converted to show the positive impacts to the Annual BES Budgets (Operating and Capital). Helpful to communicate risk/reward of rcng alternative to obtain organizational support. OPERATING: Approx -0.1% of rate reduction. CAPITAL: Approx $5 million worth of capital projects or offset bond payments. Note: Revenue was based on conservative wholesale market price of CNG, low end estimate for RIN value, and planning level cost estimates. Environmental Services 30

31 Risks and Challenges No immediate CNG users/market. BES does not want to be in retail fuel business. RIN market uncertainty. NG Pipeline backup/interconnection. Gas storage, fuel offtake costs and logistics. Perception that flare gas is free. Land use permitting. Administrative effort to manage user agreements, RINs. Environmental Services 31

32 Opportunities Biogas to rcng is not tied to NG market. Can offer longer term fuel cost certainty for customers. Producing local fuel reduces vulnerability in the event of a fuel supply disruption. As fleet customers grow, can look into expanding gas production (e.g., codigestion of FOG, Food Waste) to produce more fuel and revenue. BES staff has experience in gas conditioning equipment O&M. Environmental Services 32

33 rcng Fueling Station Preliminary Siting Environmental Services 33

34 Biogas Storage Considerations Why is storage needed? Fuel is not produced at the same rate as it is used. Customers need fuel to be available when it is needed. Storage can reduce flaring frequency. Storage locations After gas production. After rcng fuel production. Storage Logistics Environmental Services 34

35 Low Pressure Gas Storage Low Pressure Storage Upstream of conditioning Cost/CF of gas- approx. $5 to $8/cf $1M for 6 hours Provides a wide spot for the whole gas system Sizing is based on digester size Environmental Services 35

36 Biogas to CNG Storage 5500 PSI Cost- $2 to $3/cf $2.3 M for Three days Environmental Services 36

37 Mobile CNG Storage 3200 PSI $1 to $1.5/cf without Truck $2.7M for Three days Storage per truck: 225,000 to 350,000 cf Environmental Services 37

38 NG Pipeline as Storage Requires an interconnection agreement/tariff with NG utility. More stringent NG gas treatment requirements than for direct to vehicle fuel. More costs for treatment. Requires monitoring. Risk if specification is not met. Not being done yet in Oregon. Environmental Services 38

39 Fleet Fueling Considerations Slow Fill 3600 PSI Time: Hours (Overnight) Ideal for captive fleet that can fill overnight. Maximizes volume of fueling in vehicle tank. Requires space to park vehicles to fill. Fast Fill 4200 PSI (Requires additional compression) Time: 15 minutes Ideal where captive fleets are not available. Can not fill tank completely full. Additional compression step required. Environmental Services 39

40 Project Status Evaluating gas treatment technologies: Iron Sponge/Carbon/Membrane, Water Scrubber, Pressure Swing Absorption Working with City Fleet (Portland). Looking for additional partners: Refuse Haulers RFP Solicitation Planned Currently in Predesign Phase. Planning to complete design in Developing approach to allow project to be implemented in phases. Environmental Services 40

41 Questions? Environmental Services 41