Columbus, OH April 4, 2017

Transcription

1 LCA of Aquaculture and Aquaponics Systems in Hawaii Columbus, OH April 4, 2017 Marty Matlock, PhD, PE, BCEE Executive Director, Arkansas Resilience Center Professor, Biological and Agricultural Engineering 233 Engineering Hall University of Arkansas Fayetteville, AR USA

2 This project was made possible by generous funding from the State of Hawaii Department of Agriculture 2

3 US Roundtable for Sustainable Aquaculture Top Priority Issues for Each Dimension of Sustainability Economic Social Environmental Consumer Value Farm Raised Risk of Disease Marketing of US Products Consumer Understanding Sustainability of Feed Sources Cost of Production Product Quality Water Quality Access to Capital Government Regulations Food Safety Affordability Efficiency of Resource Use Environmental Regulations 3

4 Phases of a Life Cycle Assessment Life Cycle Assessment Framework Goal and Scope Definition Functional Unit Reference Flows Inventory Analysis Interpretation Direct Applications: Process Improvement Product Assessment Policy Analysis Strategic Planning Risk Management Impact Assessment

5 Functional Units The Goal and Scope of the LCA will define the purpose and boundaries of the project. The unit of measure that is of concern or causes the impact is the Functional Unit. Beverage packaging liters of packaged drink Flooring material square meters per year Greenhouse gas emissions from dairy kg CO2E / kg milk 5

6 Life Cycle Assessment: Reconciling Functional Units CO 2 CH 4 N 2 O 21 g CO 2 -equiv. / g CH 4 Green House Gas Potentials 6

7 Life Cycle Assessment Allocation By Mass? Kg CO 2 e per kg By Value? + = + + 7

8 Functional Units From Weidema et al, 2004, R9 A common objective of a life cycle assessment is comparison of environmental impacts of one product instead of another (or the choice of a specific product instead of refraining from this product). The functional unit describes and quantifies those properties of the product which must be present for the studied substitution to take place. 8

9 Functional Units From Weidema et al, 2004, R9 A reference flow is a quantified amount of product(s), including product parts, necessary for a specific product system to deliver the performance described by the functional unit. Reference flows translate the abstract functional unit into specific product flows for each of the compared systems, so that product alternatives are compared on an equivalent basis, reflecting the actual consequences of the potential product substitution. Reference flows are the starting points for building the necessary models of the product systems. 9

10 Unit Process 10

11 Reference Flows Raw Material A Product 1 Raw Material B 11

12 Reference Flows Raw Material A Product 1 Raw Material B Boundaries matter 12

13 The Phases of this Comparative Life Cycle Assessment 1. Goal and Scope Definition Tilapia and Lettuce Production Aquaponic System (combined) Recirculating Systems (separate) 2. Inventory Analysis Primary Hawaiian Data Peer-reviewed Literature Industry Data 3. Impact Assessment IPCC GWP Method 4. Interpretation Environmental and economic tradeoffs Comparisons 13

14 Goal and Scope Definition Functional Unit 1 kg production 0.4 kg tilapia 0.6 kg lettuce System Boundaries Begin with lettuce seed and tilapia fingerlings End at the farm gate Impact Categories GWP Water use Energy use Economics Recirculating Systems Two separate systems: Lettuce Hydroponic raft system Tilapia Recirculating aquaculture system (RAS) Aquaponic System One system producing both tilapia and lettuce 14

15 Hydroponic Raft System System overview Annual lettuce production 100 Mt (540,000 heads of lettuce) 6 harvests per year System flush after each harvest 2 acre greenhouse Evaporative cooling system Artificial lighting supplement 2 hours per day 1,900 m 3 system Continuous recirculation 10% of tank volume per hour Continuous aeration 15

16 Recirculating Aquaculture System System overview Tilapia characteristics FCR: 1.5 Mortality: 10% Annual production 64 tons live weight 2 harvests per year Outdoor covered production Continuous recirculation 5% system flush every 14 days Supplemental aeration 12 hours per day 16

17 Aquaponic System System overview Aquaculture and hydroponic systems combined Equivalent annual production 64 tons live weight tilapia 100 Mt (540,000 heads of lettuce) Alterations Reduced plant nutrient inputs Fewer pumps required Systems share pumps 17

18 Operating Costs for Each System Materials and Labor Hydroponics Aquaculture Aquaponics Water $ 1, $ 4, $ 2, Energy $ 15, $ 13, $ 10, Nutrient $ 12, $ - $ 4, Food $ - $ 35, $ 35, Labor $ 120, $ 50, $ 120, Growth Medium $ 14, $ - $ 14, Total $ 164, $ 103, $ 187,

19 Operating Costs Energy and Infrastructure Hydroponics Aquaculture Aquaponics Piping $ 14, $ 6, $ 11, Pumps $ 29, $ 29, $ 16, Infrastructure $ 871, $ 152, $ 1,023, Raft Beds $ 381, $ - $ 381, Tanks $ - $ 63, $ 63, Aerators $ - $ 2, $ 2, Biofilters $ - $ 12, $ 12, Total $ 1,296, $ 264, $ 1,509,

20 LCIA Results from production of 0.6 kg lettuce and 0.4 kg tilapia 100% 90% Impact category Unit Hydroponics and Aquaculture Aquaponics Water liters % 70% 60% 50% GHG kg CO 2 e % 30% Energy MJ % 10% 0% Water GHG Energy Hydroponics and Aquaculture Aquaponics 20

21 Interpretation of Results Global Warming Potential Electricity use was the major contributor in both systems (~68%) Primarily pumps and fans Aquaponics system uses fewer pumps decreased impact Transport and materials less with aquaponics Water Driven by direct uses in both systems (+80%) Energy Fewer system flushes in aquaponics Similar to GWP 21

22 Comparison with other studies Aquaculture in general produces animal-based protein with fewer GHG emissions Type of Animal Aquaculture 1 GWP (kg CO 2 e/kg LW) Carp (RAS) 0.8 Tilapia 1.67 Salmon 3.4 Other Protein 2 Added benefit from aquaponics (shared resources) Beef 22.5 Pork 3.98 Chicken Davies, Weidema,

23 Economic Results Hydroponics Aquaculture Aquaponics Hydroponics + Aquaculture Capital Cost $1,044,226 $264,776 $1,509,736 $1,309,002 Operation Cost $299,391 $207,675 $347,060 $507,066 Gross Annual Profit $587,736 $246,400 $834,136 $834, Year-Cost $4,038,138 $2,341,522 $4,980,336 $6,379, Year-Net Profit $1,839,222 $122,478 $3,361,024 $1,961, Year-Cost $8,529,006 $5,456,640 $10,186,236 $13,985, Year-Net Profit $6,164,394 $703,360 $10,667,164 $6,867,753 23

24 LCA of Four US Architype Aquaculture Systems Marty Matlock, Ph.D., P.E., C.S.E. Professor and Executive Director, Office for Sustainability Biological and Agricultural Engineering Department University of Arkansas

25 The Phases of this Comparative Life Cycle Assessment 1. Goal and Scope Definition Functional unit, system boundaries, impact categories 2. Inventory Analysis Peer-reviewed Literature Industry Data 3. Impact Assessment IPCC GWP Method, water, energy 4. Interpretation Environmental and economic tradeoffs 25

26 Goal and Scope Definition Functional Unit 1 kg live weight fish System Boundaries Begin with fingerlings End at the farm gate Impact Categories GWP Water use Systems Compared catfish red swamp crawfish rainbow trout tilapia Energy use 26

27 Catfish Production System overview Catfish characteristics 0.77 kg harvest weight FCR: 2.5 Farm characteristics 12 man-made ponds Farm size: 7 ha Total volume: 1,000,000 m3 Paddle wheels for aeration Ponds emptied and refilled every 7 years Annual production: 750,000 kg Image source: 27

28 Crawfish Production System overview Crawfish characteristics 670 kg crawfish/ha/year Feed on decomposing rice Farm characteristics Similar to rice production Farm size: 49 ha Flood fields (~0.3 m) Drain and refill when DO gets low Harvested with baited traps Collected manually using boats Annual production: 33,000 kg Image source: 28

29 Trout Production System overview Trout characteristics 0.55 kg harvest weight FCR: 1.4 Farm characteristics Flow-through raceway Side stream river, utilizes gravity Use feed concentrate Animal byproducts, corn and soy derivitives Annual production: 706,000 kg Image source: 29

30 Tilapia Production System overview Tilapia characteristics 0.55 kg harvest weight FCR: 1.5 Farm characteristics Recirculating aquaculture system Indoor, climatecontrolled facility 12 individual tanks Use feed concentrate Animal byproducts, corn and soy derivitives Annual production: 32,000 kg Image source: 30

31 Life Cycle Impact Assessment Results GHG Energy Water (kg CO 2 e) (MJ) (m 3 ) Catfish Crawfish Trout Tilapia

32 Largest Sources of Global Warming Potential Catfish Crawfish GHG (kg CO 2 e FUˉ¹) GHG (kg CO 2 e FUˉ¹) Feed Electricity Emissions Transport 0.00 Electricity Fuel Fertilizer Seed Bait Emissions Trout Tilapia GHG (kg CO 2 e FUˉ¹) GHG (kg CO 2 e FUˉ¹) Feed Transport Electricity Emissions Other 0.00 Feed Electricity Emissions Other 32

33 Largest Sources of Energy Use Catfish Crawfish Energy (MJ FUˉ¹) Energy (MJ FUˉ¹) Feed Electricity Emissions Transport 0.00 Electricity Fuel Fertilizer Seed Bait Emissions Trout Tilapia Energy (MJ FUˉ¹) Energy (MJ FUˉ¹) Feed Transport Electricity Emissions Other 0.00 Feed Electricity Emissions Other 33

34 Largest Sources of Water Use Catfish Crawfish Water Use (m³ FUˉ¹) Water Use (m³ FUˉ¹) Feed Drainage Evaporation Seepage 0 Seed Flood Up DO Correction Trout Tilapia Water Use (m³ FUˉ¹) Water Use (m³ FUˉ¹) Fishmeal Bone Meat Soybean Meal Poultry Fat Corn Gluten Meal System Water Soybean Meal Wheat Middlings Corn Gluten Meal Poultry Byproduct

35 Conclusions Efficiency of integrated production of aquaculture and hydroponics is driven by hydroponic value GWP was greatest in crawfish GWP for most aquaculture was less than 5.25 kg CO 2 e per kg live wt, similar to pork and chicken Energy use for aquaculture species varies widely based on production strategies Water use, energy use, and GWP benchmarks for US aquaculture provides a foundation for continuous improvement process. 35