Senior Design Project

1. Wetland Methane Flux Chamber
Emilie Sidelinger, Madison Dudley, Alec Popichak
Clemson University, Clemson, SC
22 October 2020

2. Outline
● Introduction
○ Background
○ Rationale
○ Objective(s)
○ Approaches
● Literature Review
● Materials and Methods
● Results
● Recommendations
● Acknowledgements

3. Introduction

4. Background
● According to the U.S.
EPA, as of 2018, 10%
of greenhouse gas
emissions were
attributed to methane
● 25% of the worlds
methane is directly
sourced from natural
wetlands

5. Background
● Wetlands contain microbes in
the soil that operate under
anaerobic conditions, leading
to methane production
● These wetlands are the
leading natural source of
methane in our atmosphere
● The amount of methane
released by these wetland
environments are desired by
many researchers and
scientists

6. Background
● Due to tall stature of
vegetation, methane
measurements are
poorly quantified
● There are consistent
improvements to trace
gas analyzing for field
measurements
● Instrumentation and
technology is needed
to expand field based
measurements on
wetlands specifically

7. Background
Tidal Freshwater
Wetland Gradient Study
Study Site:
East branch of the Cooper River

8. Rationale
● With greenhouse gases being an outstanding issue, it is critical to understand
the extent in which the gases are emitted into our atmosphere
● There is a growing need for quantitative data of methane emissions in
freshwater marshes
● Therefore, advanced equipment must be created to accurately measure
methane emissions in freshwater environments.

9. Objective(s)
● The main objective of this project is to design, create, and test a chamber that
can be used for measuring methane emissions from forest soils and marshes.
● The specific objectives are to
○ To design a static portable methane chamber with the following characteristics:
■ Compatible with LiCor 7810 Trace Gas Analyzer
■ Cover 2m tall wetland vegetation
■ Internal fan, quick release tubing, a collar to seal the chamber to the soil
○ To build a prototype of the design
○ To test the prototype by analyzing greenhouse gas emissions from the different types of tidal
freshwater wetlands

10. Approaches/Tasks
Task 01. To perform a literature review of field methane emissions to get an
understanding of the chambers used
Task 02. To review functionality of the LiCor 7810 for pump rate, interactions between flow
rate and measurement accuracy, and sensitivity of measurements to temperature
variation
Task 03. To design a chamber specific for marshes taking into consideration circulation and
cooling
Task 04. To build a physical prototype
Task 05. To test the prototype of the chamber in forest soils and marshes
Task 06. To analyze the performance of the prototype chamber with LiCor 7810

12. Deliverables
● Literature Review: review of published literature on topic
● Chamber Design Plans: materials, parts
● Chamber Prototype: physical prototype of marsh chamber
● Test Performance: utilize LiCor 7810 to test performance of prototype in the
field

13. Gantt Chart

14. Literature Review

15. Literature Review
● Review provided helpful information
specific to design and testing for a
static chamber
● PVC is effective for reflecting sunlight
and limit heating during sampling
● Chamber tops simulate dark
conditions allowing little to no light
during sampling
● Effective collection of samples is best
at 30 and 60 minute intervals and
during daylight hours
Krauss, K. W., et. al (2016)

17. Materials and Methods

18. Methods
Lorem 3
We will first test the
prototype on
campus to make
any additional
adjustments, then
take the chamber to
the designated
marshland to obtain
data.
Lorem 1
With our project focusing
on the physical
construction of a methane
flux chamber, we first
conducted a literature
review for fundamental
chamber design ideas. We
then used these concepts
to construct our design for
wetland marshes.
Lorem 2
We will purchase
materials and then
construct a
prototype with the
help of technicians
on campus.
TestDesign Build

19. Hanging fan + eye hookDigital thermometer
+ rubber stopper
Tygon tubing + Tygon quick release port
Materials
Cylindrical PVC tubing
of various sizes
PVC cement

20. Materials
Licor 7810 Trace Gas Analyzer
● Portable
● Highly accurate
● Tests for:
○ Methane
○ Carbon Dioxide
○ Water Vapor

21. Licor 7810 Trace Gas Analyzer- How it Works
● Lasers scan an array of wavelengths in 0.25 seconds
● These will be partly absorbed by methane and other trace gases
● A photodiode quantifies the remaining light, which it compares to a
reference
● An algorithm is then used to graph concentrations of methane
Source

22. Results

23. Results
Lorem 1 TestDesign Build
● Established the “stacking telescope”
model with multiple components
● Decided on a cylindrical chamber made
from PVC tubing
● Fan, input/output ports, and thermometer
attached to top of the chamber

24. Results
TestBuildDesign
● Models will be utilized as blueprints
for construction
● Prototype is to be built at Clemson
University

25. Results
TestBuildDesign
● Once the prototype is created, it will be tested in the lab
● A trial run will then take place in the field with final modifications being made
as necessary

27. Recommendations
The constructed design we have made meets the requirements set by the
USDA forest service, but improvements can be made in the following
ways:
● Bio-based products, like “Bio-attributed PVC” by Vynova as a
substitute for our standard PVC.
● An automatic temperature sensor
● A low-profile fan
● A backpack or carrying straps to make the chamber even more
portable

28. Acknowledgments
The team would like to give special thank you to Dr. Carl C. Trettin for his
knowledgeable insight and resources that tremendously helped move the team
forward with the construction and design of a methane flux chamber. The team
would also like to thank Rodney Morgan and Rodney Merck with Clemson
University for his expertise and hard work involving the “design and build
portions” of the project. Lastly, we are appreciative and grateful for the advice and
helpfulness from Dr. Christophe Darnault and Dr. Rui Xiao during the entire
duration of the project.

29. Thank You