Altered Biogas Lid/Storage

[zacchen15]

I created a markdown file with new calculations on volumetric biogas production based on equations from the textbook and documentation on the altered idea/concept on the lid.

@zam7 can you take a look at the file? I'm going back and forth between a floating gas holder vs a fixed gas holder like the ones shown here: http://www.susana.org/_resources/documents/default/2-1799-biogasplants.pdf

Alternatively we could also have a separate tank of water that biogas can be directed into.

[zacchen15]

This should also help: http://www.suscon.org/pdfs/news/biomethane_report/Chapter_4.pdf

[zacchen15]

Type of Storage	Pros	Cons
Gas Bag	(1) Flexible and easy connection on top of next to reactor (2) Cheap and cost effective (3) Easy to transport for reactor to kitchen use (4) Can visually check gas volume	(1) Fragility and leakage (2) Replace frequently - can these materials be found locally?
Fixed Lid	(1) Durability (2) No concerns about movement (3) Can use prefab barrel	(1) We could need to catch water displaced from reactor in effluent and have storage so that it may return upon offgassing
Floating Lid	(1) No problem of displaced water (2) Same concept as fixed lid (3) Visually see how full it is	(1) Will it float or will it be too heavy? (2) Harder or easier to fabricate track for floating?

[zacchen15]

Meeting with Zoe: 3/9

EXECUTIVE DECISION: SYSTEM DESIGNED AROUND THE GAS BAG

• Good for multi-person use
• Fixed removable lid that can be connected to bag so we can collect or flare directly
• Pegs to hold the lid down
• Parameters to consider: lid height, size of the "chunks"
• See what design components are impacted by the parameters associated --> will the width of the cap does it constrain other parts
• Check valve to prevent excess buildup
• External storage could be like the pressure sensor that the sensor team developed a few years ago

Other things to consider

• Set place for tube settler

[zacchen15]

https://web.wpi.edu/Pubs/E-project/Available/E-project-101614-131013/unrestricted/Biogas_Capture_System_for_Urban_Farms.pdf

[zacchen15]

• Read through the susana stuff to get a better idea of how gas flows from the reactor will work
• Discuss with Zoe tomorrow, if these is still an impasse, talk to Monroe about if this will work

https://www.ck12.org/book/CK-12-Chemistry-Concepts-Intermediate/section/14.14/

[zacchen15]

• setup lab experiment as proof of concept
• hook up the "model reactor" from spring 2017 to the methane pressure sensor from Fall 2016 to get a better idea of the flow of gas
• test whether it'll work?

[IanCullings]

Notes from 3/23/18 Meeting:

Design notes:

• Finish Biogas code
• Determine volume of the attached system and lid system
• Research/shop for gas bags and look at sizing
• Determine maximum time needed before failure
• Determine critical pressure and compare to the current pressure system
• BASED ON SIZE OF GAS BAG

Fabrication notes:

• Cap-like lid is much harder to fabricate than flat lid
• How to fabricate gas-tight system?
• Using bag as inner lining to gas cap???

[zacchen15]

Added the calculations to "Biogas Storage" file in repo

The function takes (1) daily production rate (2) desired maximum amount of storage (3) maximum time before failure (4) diameter of the lid

and calculates (1) the time until failure if the temporary storage is full (2) the height of the lid given the diameter of the lid

Note: I just used diameter because I wanted to have a general shape for the lid. This can be changed if we have a square lid or something.

[IanCullings]

Code is finished and in design manual