Water Use By Biofuel Facilities: Source, Process and Fate. Presented by Mark S. Mason, PG Natural Resource Group

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1 Water Use By Biofuel Facilities: Source, Process and Fate Presented by Mark S. Mason, PG Natural Resource Group

2 NRG Biofuel Experience To date, NRG has worked on more than 220 potential Ethanol and Biodiesel sites in over 35 US states and Canada

3 Why Ethanol Works with existing infrastructure Price Supply Oxygenate Clean octane Home grown renewable fuel Cellulosic technologies Local economic development

4 Renewable Fuels Standard (RFS) Schedule, billions of gallons Year Corn Ethanol Advanced Biofuels Total RFS

5 Ethanol and Water Use Factoid A person driving 12,000 miles per year at 20 miles per gallon using E10 (10% ethanol) will have indirectly used 1,590 gallons of water associated with the production of the ethanol for the gasoline. That same person will use 8,760 gallons of water per year for washing and other daily use (24 gallons per day).

6 Water Use Factoids 3-4 Gallons of water per gallon of ethanol 9.3 gallons of water per one can of vegetables 16.6 gallons of water per one pound of beet sugar 24 gallons of water per one pound of plastic 44 gallons of water per one gallon refined crude oil 1,500 gallons of water per one barrel of beer Source: USGS, USEPA 2007

7 Water Use Factoids A recent water study by the Met Council indicated the sevencounty Metro area used 1.16 billion gallons of water a day. The latest estimates indicate the ethanol industry in the entire state will use around 2 billion gallons per year.

8 How is Ethanol Made? Established Production Processes Fermentation of Sugar Organic Syntheses from Petroleum Emerging Production Processes Lignocellulosic Biomass Sugar platform Gasification platform

9 Established Production Processes Fermentation route Conversion of starch in grains to sugar; yeast ferment the sugar to ethanol Dry milling Wet milling Direct conversion (fermentation) of sugar to ethanol Catalytic conversion route Hydroxylation of ethylene to ethanol Industrial alcohol Does not qualify for the federal excise tax exemption

10 Ethanol Dry Mill Process

11 Water Design Considerations Top 3 Considerations For Water Design: 3) Plant Requirements (i.e. loads, process water limits) 2) Incoming Water (i.e. source, quality) 1) Discharge Limits Most Influential

12 Example Discharge Limit Comparison Location A: TDS < 700 ppm Location B: TDS < 2500 ppm Location GPM In GPM Out Gal H 2 O/Gal EtOH A B

13 Water Quality: Primary Parameters Fouling Concerns: Iron Manganese TSS Biological

14 Water Quality: Primary Parameters Scaling Concerns: Silica Calcium Magnesium Alkalinity Strontium

15 Water Quality: Primary Parameters Corrosion Concerns: Sulfate Chloride

16 Water Supply Options Surface Water Groundwater Sand/Gravel, Bedrock Wastewater Treatment Plant Discharge Industrial Discharge Concentrated Animal Feed Operation (CAFO)

17 Underlying Aquifer Options Alluvial sand and gravel aquifer Galena Aquifer Most wells finished in this aquifer, below site St. Peter Aquifer, below site Prairie du Chien aquifer, below site Jordan aquifer, below site?

18 Aquifer Water Quality Aquifer Iron, mg/l Sulfate, mg/l Chloride, mg/l Dissolved Solids, mg/l Hardness Mg/L Jordan < < Ironton Galesville Not Listed Mt. Simon Not Listed 340 Target Conc. < 0.3 mg/l < 200 mg/l < 100 mg/l < 500 mg/l < 150 mg/l

19 Hydrogeology of the Cambrian- Ordovician aquifer system. St. Peter, Prairie du Chien, Jordan aquifer.

20 Water Treatment Processes Reverse Osmosis - Reverse osmosis (RO) is used to reduce dissolved solids from feed waters The semipermeable membrane allows the passage of water, but not ions (e.g., Na+, Ca2+, Cl-) Water Softening Water softening exchanges the sodium ion for the calcium and magnesium ions which contribute to the hardness.

21 Water Treatment Processes Multi-Media Filters Utilizes several layers of filters to remove small particles. Backwash regenerates filter. Greensand Filters Used to remove iron and manganese through the use of oxidation to precipitate the iron and manganese. Regenerated by injection of potassium permanganate.

22 Water Treatment Processes Cold Lime Softening A watersoftening process in which water is treated with hydrated lime (sometimes in combination with soda ash), which reacts with dissolved calcium and magnesium compounds to form precipitates that can be removed as sludge.

23 Water Treatment Chemicals Otter Tail Ag Enterprises, LLC Product Use

24 Water Flow Through An Ethanol Plant

25 Water Flow Through An Ethanol Plant With Process Discharge

26 Ethanol Plant Synergies Concentrated Animal Feed Lots (methane and water recycle) Power Plant (share steam and water supply) Industrial Facilities (Share water supply and water treatment) Landfill (methane and biomass source)

27 Water Appropriation Minimum 7-day pumping test Well interference evaluation Monitor private/city wells before, during and after test

28 Test/Production and Observation Well Installation

29 Pump Flow Rate Control

30 Discharge line to local drainage

31 Automated Groundwater Elevation And Barometric Pressure Monitoring With Transducers/Dataloggers

32 Well Survey Monitoring Locations

33 Underlying Aquifer Cross Section

34 Galena aquifer response to the aquifer test

35 St. Peter aquifer response to aquifer test

36 Prairie du Chien Aquifer Response to the Aquifer Test

37 Jordan aquifer response to the aquifer test

38 Test Well Aquifer Response

39 Predicted Long-term Drawdown

40 Biodiesel Water Use (1.5 Gallons of Water per Gallon of Biodiesel Produced)

41 Cellulosic Ethanol Water Use Fresh Water Demands Cooling Tower Makeup (percent) Boiler and Process Makeup (percent) Overall Water Demand, Gal H2O/Gal ETOH Corn Ethanol Cellulosic Ethanol Biochemical Cellulosic Ethanol Thermochemical Source: Water Usage for Current and Future Ethanol Production, National Renewable Energy Laboratory, September/October 2007, Southwest Hydrology page 22-23

42 Cellulosic Ethanol Production Fresh Water Demands Yield Per Acre (bu.) Gallons ethanol per acre #2 Corn Switchgrass Miscanthus ton dry 12 ton dry (canes only) ,200 Source: Biomass: The next field of dreams, September 2007, Farm Futures, pages 18 24

43 Other Water Conservation Options Use of chillers Currently cost prohibitive. Use of underground cooling coils requires large land area and is cost prohibitive. Use of closed loop cooling tower Currently cost prohibitive. Establish an ethanol sector NPDES discharge permit. Modify surface water classifications. Streamline variance process. Recycle all water back to obtain a Zero Liquid Discharge (ZLD)

44 Zero Liquid Discharge Pros No surface discharge, eliminates need for expensive pipeline. Water Conservation Cons Expensive equipment required, potential solid waste disposal, high energy costs

45 The Hydrologic Cycle Ground water Supply 691 gpm Cooling tower evaporation 288 gpm Ethanol process 195 gpm Utility discharge 208 gpm

46 Questions? Mark S. Mason, PG Natural Resource Group, Inc. 80 South Eighth Street 1000 IDS Center Minneapolis, MN Phone: Fax: MINNEAPOLIS HOUSTON DENVER PROVIDENCE ANCHORAGE CHARLOTTE, BATON ROUGE, LAS VEGAS, PORTLAND