Evaluating Greenhouse Gas Emissions and Carbon Footprint of Water Reuse and Desalination Facilities

Transcription

1 Evaluating Greenhouse Gas Emissions and Carbon Footprint of Water Reuse and Desalination Facilities December 12, 2013 WateReuse Research Foundation Webcast Series 2013 by the WateReuse Research Foundation

2 About the WateReuse Research Foundation The WateReuse Research Foundation has the world s largest portfolio of research studies and data on the use, acceptance, and practice of water reuse and desalination. More Information Research Reports

3 A Few Notes Before We Get Started Today s webcast will be 60 minutes. You will be able download a PDF of today s presentation when you complete the survey at the conclusion of this webcast. There is 1 (one) Professional Development Hour available for this webcast. If you have questions for the presenters, please send a message by typing it into the chat box located on the panel on the left side of your screen. If you would like to enlarge your view of the slides, please click the Full Screen button in the upper right corner of the window. To use the chat box, you must exit full screen.

4 Speakers and Moderator Moderator: Deana Bollaci, Project Manager, WateReuse Research Foundation Speakers David R. Hokanson, Ph.D. P.E., BCEE Trussell Technologies, Inc. Qiong (Jane) Zhang, Ph.D. Civil & Environmental Engineering, University of South Florida Pablo K. Cornejo Civil & Environmental Engineering, University of South Florida

5 Greenhouse Gas Emissions and Carbon Footprint of Water Reuse and Desalination Facilities Qiong Zhang 1, David R. Hokanson 2, Pablo K. Cornejo 1, Mark V.E. Santana 1, James R. Mihelcic 1 1 Department of Civil and Environmental Engineering University of South Florida (Tampa) 2 Trussell Technologies, Inc. (Pasadena) 1

6 Learning Objectives By the end of this webinar you should: Understand current trends in GHG emissions for water reuse and desalination facilities Be aware of availability and applicability of existing tools to estimate GHG emissions Know how to use two GHG estimation tools: Sophisticated tool - WESTWeb (Water energy sustainability web-based tool) Simple tool - Tampa Bay Water tool 2

7 Contributors Project Title: Feasibility Study on Model Development to Estimate and Minimize Greenhouse Gas Concentrations and Carbon Footprint of Water Reuse and Desalination Facilities, WateReuse Principal Investigators and Affiliations James R. Mihelcic 1, Ph.D., BCEEM Qiong Zhang 1, Ph.D. David R. Hokanson 2, Ph.D. P.E., BCEE Pablo K. Cornejo 1 Mark V. Santana 1 Andrea M. Rocha 1, Ph.D. Sarah J. Ness 1 1 Civil & Environmental Engineering, University of South Florida 2 Trussell Technologies, Inc. 3

8 Motivation Goal of Study GHG Emissions and Carbon Footprint Available Models Demos Practical Implications For Utilities 4

9 What Drives Water Reuse and Desalination? Source:

10 What Drives Water Reuse and Desalination? Source: Source: NRDC

11 What Drives Water Reuse and Desalination? 6

12 Level of treatment Preliminary treatment (Bar screen, grit chamber) Reuse application No uses recommended at this level Disinfection (Chlorination, ultraviolet radiation, ozone)

13 Level of treatment Preliminary treatment (Bar screen, grit chamber) Primary treatment (Clarification, fine screen) Reuse application No uses recommended at this level No uses recommended at this level Disinfection (Chlorination, ultraviolet radiation, ozone)

14 Level of treatment Preliminary treatment (Bar screen, grit chamber) Primary treatment (Clarification, fine screen) Secondary treatment (Activated sludge, membrane bioreactor, trickling filters, rotating biological contactors) Disinfection (Chlorination, ultraviolet radiation, ozone) Reuse application No uses recommended at this level No uses recommended at this level Non-food crop irrigation, restricted landscape impoundments, surface irrigation of orchards and vineyards, groundwater recharge of non-potable aquifer, stream augmentation, industrial cooling

15 Level of treatment Preliminary treatment (Bar screen, grit chamber) Primary treatment (Clarification, fine screen) Secondary treatment (Activated sludge, membrane bioreactor, trickling filters, rotating biological contactors) Tertiary treatment (Nitrogen removal, phosphorus removal, residue solids removal) Disinfection (Chlorination, ultraviolet radiation, ozone) Reuse application No uses recommended at this level No uses recommended at this level Non-food crop irrigation, restricted landscape impoundments, surface irrigation of orchards and vineyards, groundwater recharge of non-potable aquifer, stream augmentation, industrial cooling Landscape irrigation, urban reuse, food crop irrigation, indirect potable reuse

16 Level of treatment Preliminary treatment (Bar screen, grit chamber) Primary treatment (Clarification, fine screen) Secondary treatment (Activated sludge, membrane bioreactor, trickling filters, rotating biological contactors) Tertiary treatment (Nitrogen removal, phosphorus removal, residue solids removal) Specific trace constituent removal (Ion exchange, advanced oxidation) Disinfection (Chlorination, ultraviolet radiation, ozone) Source: Mo and Zhang, 2013 Reuse application No uses recommended at this level No uses recommended at this level Non-food crop irrigation, restricted landscape impoundments, surface irrigation of orchards and vineyards, groundwater recharge of non-potable aquifer, stream augmentation, industrial cooling Landscape irrigation, urban reuse, food crop irrigation, indirect potable reuse Indirect and direct potable reuse 7

17 Energy Consumption of Water Reuse and Desalination Source: Lazarova, Choo, and Cornel 2012

18 Energy Consumption of Water Reuse and Desalination Source: Lazarova, Choo, and Cornel

19 Greenhouse Gas Emissions and Carbon Footprint GHG Protocol Corporate Accounting and Reporting Standard 9

20 Greenhouse Gas Emissions and Carbon Footprint Greenhouse Gases (GHG) GHG Emissions (kg) Global Warming Potential* CO CH N2O *IPCC Second Assessment Report 100 year time horizon Carbon Footprint (kg CO2 equivalent) Total Carbon Footprint = = 520 kg CO2 equivalent 10

21 Goal of Study Assist utilities employing water reuse and desalination in estimating GHG emissions and carbon footprint Recommend accessible models to utilities to provide estimations of GHG emissions and carbon footprint 11

22 CO 2 Emission and Carbon Footprint of Desalination 12

23 Desalination Trends Electricity is the largest contributor to CO 2 emissions

24 Desalination Trends Electricity is the largest contributor to CO 2 emissions Reverse osmosis (RO) has lower emissions than thermo-based desalination RO emissions vary based on TDS and pretreatment option

25 Desalination Trends Electricity is the largest contributor to CO 2 emissions Reverse osmosis (RO) has lower emissions than thermo-based desalination RO emissions vary based on TDS and pretreatment option Energy recovery devices and use of renewable energy sources can substantially lower the carbon footprint 13

26 Change with Technology Technologies/ Processes CO 2 Emissions (kg CO 2 /m 3 ) Total Electrical Energy (kwh/m 3 ) Multi effect distillation Multi stage flash Reverse osmosis

27 Change with Technology Technologies/ Processes CO 2 Emissions (kg CO 2 /m 3 ) Total Electrical Energy (kwh/m 3 ) Multi effect distillation Multi stage flash Reverse osmosis

28 Change with TDS and Pretreatment Treatment Type Seawater Reverse Osmosis (SWRO) Brackish water Reverse Osmosis (BWRO) Influent TDS (mg/l) 30,000 40,000 Pretreatment Carbon Footprint (kg CO 2 eq/m 3 ) Not specified Conventional Media Filtration Membrane ,000 15,000 Either

29 Change with Energy Mix and Energy Sources Energy Mix European Mix Spanish Mix California Mix U.S. Mix Photovoltaic Solar Thermal Wind 0.4 Carbon Footprint (kg CO 2 eq/m 3 )

30 Change with Energy Mix and Energy Sources HIGH Energy Mix European Mix Spanish Mix California Mix U.S. Mix Photovoltaic Solar Thermal Wind 0.4 Carbon Footprint (kg CO 2 eq/m 3 ) 16

31 CO 2 Emission and Carbon Footprint of Water Reuse 17

32 Key Water Reuse Trends Electricity and direct emissions are dominant contributors to carbon footprint Secondary treatment usually has higher GHG emissions than tertiary treatment

33 Key Water Reuse Trends Electricity and direct emissions are dominant contributors to carbon footprint Secondary treatment usually has higher GHG emissions than tertiary treatment Resource recovery can offset the carbon footprint of water production

34 Key Water Reuse Trends Electricity and direct emissions are dominant contributors to carbon footprint Secondary treatment usually has higher GHG emissions than tertiary treatment Resource recovery can offset the carbon footprint of water production Energy mix can substantially affect carbon footprint 18

35 Water Reuse Emissions Sources Electricity and direct emissions are dominant contributors to carbon footprint Electricity associated with operation of treatment process equipment Direct emissions from wastewater treatment processes 19

36 Change with Treatment Level End Use No use recommended Non food crop irrigation Indirect potable reuse Indirect potable reuse Direct potable reuse Recommended Treatment Level Carbon Footprint (kg CO 2 eq/m 3 ) CO 2 emissions (kg CO 2 /m 3 ) Primary Secondary Tertiary only Secondary and tertiary Specific trace constituent removal

37 Reclaimed Water Use Use of reclaimed water helps offset associated GHG emissions water reuse can offset 36-40% of the total carbon footprint for a wastewater treatment plant in Tampa (Mo and Zhang, 2012) Substitution of high quality water with reclaimed water may result in larger carbon footprint offsets (Tong et al., 2013) 21

38 Desalination versus Water Reuse Desalination generally has a higher carbon footprint than water reuse Water Reuse: kg CO 2 eq/m 3 Desalination: kg CO 2 eq/m 3 Electricity use is a substantial contributor to the carbon footprint of desalination and water reuse Energy mix and resource recovery can greatly affect the carbon footprint of both water treatment scenarios 22

39 Available Carbon Footprint Models for Water Reuse and Desalination 23

40 Method Used in Available Models GHG Emission Estimation Method Description of Methodology Examples of Models that Fit this Methodology Traditional LCA Use process based inventory SimaPro, GaBi Hybrid LCA based models Use both process based and inputoutput based inventory Water Energy Sustainability Tool (WEST), Specific models for estimating GHG emissions Uses input parameters specific to utility WWEST, and WESTWeb Johnston Model, Tampa Bay Water Model Other related models NOT specifically used to estimate emissions from water reuse or desalination facilities, but contain aspects that are applicable UKWIR Model, UK Environmental Agency Model, CHEApet, Systems Dynamics, GPS X Model, mco2, Bridle and BSM2G 24

41 Summary of Model Availability Model Type Emission Models Tool Type Available Website or Contact Information LCA based models Hybrid LCAbased Specific models Other related models SimaPro Software Commercially Gabi Software Commercially software.com SiSOSTAQUA Software Commercially WEST MS Excel Upon request Dr. Jennifer Stokes at WWEST MS Excel Upon request Dr. Jennifer Stokes at WESTWeb Web based Publically west.berkeley.edu Tampa Bay Water MS Excel Upon request Johnston Model MS Excel Upon request Dr. Tanju Karanfil at CHEApet Web based Publically cheapet.werf.org UK Environment MS Excel Upon request Agency Model Bridle and BSM2G Software Publically Author Lluis Corominas at Models System Dynamics Software Commercially GPS X Software Commercially X.html Carbon Accounting MS Excel Commercially Workbook, 5th version mco2 Software Commercially 25

42 Emission Sources Considered in Hybrid LCA and Specific Models Emission Sources Considered Hybrid LCA Models WEST WWEST WESTWeb Johnston Model Specific Models Tampa Bay Water Model Material production X X X Material delivery X X Electricity consumption X X X X X Electricity mix X X X X X Fuel use (on site and fleet vehicles) X X X X Sludge disposal X X X X Chemical production X X X X Direct process emissions X X X Process equipment X X X X Disinfection processes X X X X 26

43 Case Study: Tampa Bay Water Model 27

44 Tampa Bay Water Tool Input data required: Water pumped (MGY or m 3 /yr) Water Produced (MGY or m 3 /yr) Electricity Used (kwh) Electricity Service Provider egrid Emission factors (associated with desired electricity mix) Output: Scope 2 emissions For details on Tampa Bay Water tool application to Tampa, click this 28

45 Potential Application of Models Facility Input Data Used in Tampa Bay Water Model Model Input Desalinated Seawater, Membrane Pre treatment Desalinated Brackish Groundwater Recycled Water Water produced (m 3 /yr) Electricity use (kwh/yr) 36,000,000 36,000,000 36,000, ,600, ,680,000 77,040,000 29

46 EPA s egrid (Emissions and Generation Resource Integrated Database) Step 1: Select data U.S average, sub region,or specific power plants in egrid Tampa Bay Water Model uses specific power plant data 30

47 EPA s egrid (Emissions and Generation Resource Integrated Database) Step 2: Obtain CO2, CH4, and N2O emission rates Export data to excel 31

48 EPA s egrid (Emissions and Generation Resource Integrated Database) Step 3: Convert emission rates to desired units Convert to kg/kwh for consistency 32

49 Calculations Calculate the CO 2 equivalent emission factor: kgco eq kgco kgch kgn O EmissionFactor 2 1* 2 21* kwh kwh kwh * kwh Where, 1, 21, & 310 are global warming potential multipliers 33

50 Calculations Calculate the CO 2 equivalent emission factor: kgco eq kgco kgch kgn O EmissionFactor 2 1* 2 21* kwh kwh kwh * kwh Where, 1, 21, & 310 are global warming potential multipliers Calculate the carbon footprint (CFP): kgco eq CFP 2 m 3 CO kg 2eq * ElectricityConsumption kwh kwh 3 WaterProduced m yr yr 34

51 WESTWeb (water energy sustainability tool web version) 35

52 Potential Application of Models Model Inputs (Stokes and Horvath, 2009) Summary of Input Data Used in WEST Model Desalinated Seawater, membrane pretreatment Membrane, filtration, RO, disinfection Desalinated Brackish Groundwater Filtration, RO, disinfection Recycled Water Description Filtration, disinfection Annual water or wastewater production (L/yr) 36,000,000,000 36,000,000,000 36,000,000,000 Piping/aqueduct length (m) supply treatment distribution Electricity use (MWh/yr) supply treatment distribution Chemical use (kg/yr) acid (hydrochloric or sulfuric) alum aqueous ammonia caustic soda chlorine ferric chloride

53 WESTWeb Inputs Modeling Parameters Select system type (water or wastewater) Units selection (SI or US) No. of Scenarios Functional Unit to normalize results per unit volume of water produced 37

54 WESTWeb Inputs Annual Water or Wastewater Production Enter the annual production volume for each scenario (in liters) 38

55 WESTWeb Inputs Infrastructure Enter length of pipe material and/or Enter detailed data about pipe materials (if available) Enter detailed data on concrete and buildings (if available) Enter detailed data on process equipment (if available) 39

56 Detailed WESTWeb Inputs Detailed Pipe Length and Material Piping: Material type Pipe size Length of pipe Fittings, valves and meters Cost 40

57 Detailed WESTWeb Inputs Detailed Buildings and pre cast structures Purchase price 41

58 Detailed WESTWeb Inputs Process equipment Filtration, pumps, blowers, controls, etc. Cost 42

59 WESTWeb Inputs Electricity Mix Enter location (national, state, or custom) For custom: enter percentage for each fuel/energy source 43

60 WESTWeb Inputs Energy Use Enter quantities of energy consumed: Electricity Natural Gas Gasoline Diesel 44

61 WESTWeb Inputs Chemical Usage Enter quantities of chemicals consumed 45

62 WESTWeb Inputs for Wastewater Process emissions BOD and sludge data Select System type % Methane Capture 46

63 WESTWeb Inputs for Wastewater Waste Management Select sludge disposal process 47

64 WESTWeb Outputs Run Analysis For energy and greenhouse gas emissions 48

65 WESTWeb Outputs Carbon footprint results shown for: Infrastructure (piping, concrete, buildings, equipment)) Operation (energy use and chemicals) Output capabilities: Scope 1, 2, 3 emissions 49

66 Model Comparison Output Comparison of Carbon Footprint Using Tampa Bay Water and WESTWeb Models Carbon Footprint (kg CO 2 eq/m 3 ) Desalinated Seawater, membrane pretreatment Desalinated Brackish Groundwater Recycled Water Tampa Bay Water Tool WESTWeb Tampa Bay Water model: include only electricity consumption WEST model: electricity consumption, chemical usage and material production 50

67 Model Comparison Output Comparison of Carbon Footprint Using Tampa Bay Water and WESTWeb Models Carbon Footprint (kg CO 2 eq/m 3 ) Desalinated Seawater, membrane pretreatment Desalinated Brackish Groundwater Recycled Water Tampa Bay Water Tool WESTWeb Tampa Bay Water model: include only electricity consumption WEST model: electricity consumption, chemical usage and material production Findings fall within expected carbon footprint range for: RO seawater desalination (0.4 to 6.7 kg CO 2 eq/m 3 ) is generally larger than RO brackish water desalination (0.4 to 2.5 kg CO 2 eq/m 3 ) Water reuse (0.1 to 2.4 kg CO 2 eq/m 3 ) 51

68 Practical Implications For Utilities Limiting factor: data currently collected by utilities Recommendation on data collection (at minimum) information on electricity providers the amount of water pumped and produced facility-wide electricity usage

69 Practical Implications For Utilities Limiting factor: data currently collected by utilities Recommendation on data collection (at minimum) information on electricity providers the amount of water pumped and produced facility-wide electricity usage Final Thoughts Tampa Bay Water Model provides accurate baseline estimate, but may underestimate true impact WESTWeb provides a more comprehensive estimate, but may be limited by data availability 52

70 Qiong (Jane) Zhang, Ph.D. Civil & Environmental Engineering, University of South Florida David R. Hokanson, Ph.D. P.E., BCEE Trussell Technologies, Inc. Pablo K. Cornejo Civil & Environmental Engineering, University of South Florida

71 Join Us Next Month! January 9, 2014 Seawater Desalination Intake Design Considerations to Meet Impingement and Entrainment Goals January 9, p.m. 3 p.m. EST 11 a.m. 12 p.m. PST A short survey and a link to download the presentation will appear in this window at the conclusion of the webcast For more information, visit: