Anaerobic Digester Presentation - CSU, Chico · 2020-06-16 · Dr. Gregory Watkins with CSU Chico’s Mechanical, ... Rick Harris with CSU Chico’s Manufacturing Department fabrication

ANAEROBIC DIGESTER California State University, Chico

Capstone Design Experience

MECH 440 B

Anaerobic Digester

Team Members

� Evan DaBreo (Mechanical)

� Jacob Matthewson (Mechanical)

� Kyle Martin (Mechanical)

� Bo Perkins (Mechanical)

Anaerobic Digester

Team Members

� Faculty Advisor:

� Dr. Greg Watkins

� Sponsor:

� Ryne Johnson� Center for Entrepreneurship

� Customer:

� Standard Household

Anaerobic Digester

Background Information

� 250 Million tons of waste produced each year in the U.S.

� 31% recycled, 14% incinerated, 55% landfills

Anaerobic Digester


� According to an EPA study, the average American produces approximately 470 pounds of food waste per year.

� Less than 3% of food waste is recovered and recycled.

� Diverting food waste from landfills prevents harmful uncontrolled emissions (methane) from polluting into our atmosphere.

Anaerobic Digester


� Anaerobic digestion is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen, to manage waste and to release energy.

Anaerobic Digester

Need and Goal

� Need Statement:

� A solution is needed to reduce the amount of organic municipal solid waste that is destined for landfill or incineration.

� Goal Statement:

� Design, Build, and Test a reliable system that can process diverted organic municipal solid waste to a more useful form.

Anaerobic Digester

Project Requirements

Requirement

Must

Do/Should

Do/Would

be nice

Engineering

Specification Metric Condition Target

Method/

Device

Value Must Do Cost USD Total Material Cost <$3000 Reciept

Organic Load Rate Must Do Mass per day lb VS/ daySelf Separated and loaded into a known volume

0.93 Scale

Biogas Yield Must Do Volume per Mass ft3/ daySTP Volume produced at steady state

≥3.27Temp Sensor,

Pressure Gauge

Footprint Should Do Dimensions FeetDimensions based on standard truck bed

Length<4.2

Width< 6.5Tape Measure

Continuous Operation

Should Do QualitativeAs opposed to batch operation

Automated Control System

Would Be Nice

QualitativeMonitoring pH, temperature, pressure conditions

Testing

Compliance to Specifications

Requirement Metric Target Actual Values Pass / Fail

Value USD <$ 3000 $ 2997.12 Pass

Organic Load Rate lb VS/day 0.93 1.29 Pass

Biogas Yield ft3/ day ≥3.27 N/A Fail

Footprint FeetLength<4.2

Width< 6.5

Length<4.2

Width< 6.5Pass

Continuous Operation - - Yes Pass

Automated System - - No Fail

Anaerobic Digester

Design Solution

Induction

Tanks

Frame

Data

Collection

Pumps

Anaerobic Digester

Overview

Design Solution

Block Diagram

� Mesophillic Temperature Range

� (77 and 104 °F)

�Fully Submergible Heaters

� Adjustable Temperature

� Dedicated Tank Functions

� Weekly Feeding

� Hydrolysis, Acidogenesis,

Acetogenesis

� Methanogenesis

�Foil-Faced Bubble Wrap Insulation

Anaerobic Digester

Tanks, Heaters and Insulation

�Macerator Pumps

�Handle suspended solids

�Large Inlet

�Self-Priming

�Serviceable

�Run-dry Protection

�Braided Vinyl Hose

�Clear, non-toxic FDA/NSF Listed

�Corrosion and Abrasion resistant

�High operating temperature capacity

Anaerobic Digester

Pumps and Piping

� Records system parameters

�Gas Pressure

�Liquid Temperature

�Gas Temperature

�Methane Content

�Multiple Output Modes

�LCD

�USB Serial

�SD Card w/ Excel Format

�Automated Pump Cycling

Date/Time Water Temp 1 Gas Temp 1 pressure1 Water Temp 2 Gas Temp 1 pressure2

May 2nd, 2011 11: 15 am 93.05 °F Gas Temp 2 1.43 PSI 93.32 °F 93.19 °F 1.43 PSI









Anaerobic Digester

Automated Data Collection Unit

Fabrication

Fabricated Parts

� Steel

� 1-1/4”x1-1/4”x .065” Square Tubing

� 3/16”x8”x24” Plate

� 1/8“x1“x6’ Strip

Fabrication

Off the Shelf Parts

�Macerator pumps

� Plastic fittings

� Arduino 2560

� Plastic tanks

� Plastic tubing

� Insulation

� Heaters

� Car battery

� Trickle Charger

Testing

Feedstock

� Bananas

� 32.5 lbs per week

� Add water for a total volume of 10 gallons

� 10% Total solid content of mixture

Testing

Snapshots

Testing

Biogas Yield Data

Weekly Reading Pressure (psi) Temperature (°F) Volume (gallons)

1 0.048 73.10 15

2 0.710 86.56 15

3 1.432 90.79 15

4 1.554 94.17 15

Max Temperature 94.173 °F

Max Pressure 1.554 psi

Biogas Yield 0.204 ft3/ day

Testing

Footprint

Project Budget

Purchased Parts

ID # Manufacturer Description Quantity Unit Cost Subtotal

Shipping +

Handling

per Unit

TaxTotal Capital

Cost

C100 Purchased Parts

C101 Aquatic GroupEheim Jager Heater 250 Watt

1$

26.29 $

26.29

$ 4.29

$ 2.20

$ 32.77

C102 Aquatic GroupEheim Jager Heater 200 Watt

1$

26.99 $

26.99

$ 4.29

$ 2.20

$ 33.47

C103 Tank Depot Ace 15 Gallon Tank 2$

58.99 $

117.98 $

66.48 $

15.22 $

199.67

C104 Tank Depot Ace 60 Gallon Tank 1$

98.99 $

98.99 $

66.48 $

13.65 $

179.12

C105Corral Reef Supply

1" MPT Threaded Strainer 2$

9.95 $

19.90 $

8.09 $

1.64 $

29.63

C145PBM Supply & MFG

Hose Clamps 10$

1.03 $

10.30 $ -

$ 0.85

$ 11.15

Subtotal$2,634.51

Project Budget

Material Costs

ID # Manufacturer Description Quantity Unit Cost Subtotal

Shipping

+

Handling

per Unit

Tax

Total

Capital

Cost

C200 Material Costs

C201 Bi-Rite Steel 3/16" Plate 8"x24" 4$

10.76 $

43.05 $ -

$ 3.55

$ 46.60

C202 Bi-Rite Steel 1 1/4 x 1 1/4" .065 80$

1.37 $

109.60 $ -

$ 9.04

$ 118.64

C203 Bi-Rite Steel 1/8" x 1" strip 15$

0.50 $

7.50 $ -

$ 0.62

$ 8.12

C204 McMaster-CarrFoil-Faced Bubble Wrap Insulation

1$

62.74 $

62.74 $

6.50 $

5.18 $

74.42

C205PBM Supply & MFG

Teflong Tape, 3/4" 1$

1.12 $

1.12 $ -

$ 0.09

$ 1.21

C219 Radioshack 20' 12 Gauge Black Wire 1$

5.29 $

5.29 $ -

$ 0.44

$ 5.73

Subtotal $362.61

Project Budget

Labor Costs

Profession Rate Benefits Overhead Total Rate Hours Labor Costs

Engineering$

36.54 $

13.52 $

14.62 $

64.68 1137$

73,536.38

Machining$

20.60 $

7.62 $

8.24 $

36.46 0$ -

Total Labor Cost $ 73,536.38

Project Budget

Total Costs

Labor

Engineering 73,536.38

Machining -

Subtotal73,536.38

Material

Purchased Parts 2,634.51

Material Costs362.61

Tooling -

Subtotal2,997.12

Project Total $ 76,533.51

Additional Content

Time

Unique Problems Encountered�Time of Construction�Start-up and Testing Timeframe

�Up to 30 days minimum for proper start-up

Solutions Achieved�Start Early�Teamwork and Delegation

Merits of Solution�Successful completion of testing

Additional Content

Internal Pressures

Unique Problems Encountered� Hydraulic Pressures

� Significant stresses on all equipment� Pressure Seal the tanks

Solutions Achieved� Implemented the use of expandable pressure vessel

� Regulated with one way valves and a ball valve� Gasket Maker, Silicone Sealant, Hot Glue

Merits of Solution� Greatly reduce internal tank pressures caused by pumps� Fully Sealed reaction tanks up to the required pressures

(10 psi with the expandable pressure vessel)

Suggestions for the Future

Recommended Design Changes

Tank Material

Current: Medium density polyethylene (non pressure rated)

Recommended: Stainless Steel (Minimum 100 psi pressure rated)

Effects of Change

� Higher Capital Investment� Pressure rated tanks� Removal of expandable bladder from system

Suggestions for the Future

Recommended Design Changes

Fittings

Current: 1. Schedule 80 material2. Large Use of 90° turns (elbows)

Recommended: 1. Schedule 40 maximum2. Remove all elbows and replace with maximum of 45° turns

Effects of Change

1. Large reduction in cost by using a lesser material, without sacrificing digester performance2. Lower chance of digestate material clogging in the transfer lines by using 45° turns� Loose the convince of local suppliers with a lesser grade material

Anaerobic Digester

Acknowledgements

The design team would like to give special thanks to the following people

Ryan Johnson and the Center for Entrepreneurship for their sponsorship and funding of the

Anaerobic Digester Project

Dr. Gregory Watkins with CSU Chico’s Mechanical, Mechatronic department for his guidance and

support as our group advisor

Dr. Joseph Green with CSU Chico’s Mechanical, Mechatronic department for his expert knowledge

and allowance of a testing location

Scott Brogden with CSU Chico’s Manufacturing Department for allowing space and use of tools

within his facilities

~ and ~

Rick Harris with CSU Chico’s Manufacturing Department fabrication assistance

Anaerobic DigesterQuestions

Pump

Documents

Anaerobic Digester Presentation - CSU, Chico · 2020-06-16 · Dr. Gregory Watkins with CSU Chico’s Mechanical, ... Rick Harris with CSU Chico’s Manufacturing Department fabrication