Got Methane?

Inspiration

The grumbles of our stomachs filled the Klaus Atrium. When brainstorming ideas on Friday night, hunger dominated our minds. All of our thoughts were circling back to food in some way; inefficiencies in processing, harvesting, and growth, food waste, single-use cutlery, and tableware. Finally, we thought about an earlier stage of food, the one that lays in the fields all day eating grass.

The processes around utilizing a cow’s resources are extremely inefficient, and yet the least sustainable part of the process is the most natural one. Cows are responsible for over 40% of the world’s methane emissions, just from their mouths (not their farts, contrary to popular belief). Since methane is around 80 times worse for the environment than CO2, we thought this was a hugely impactful problem to try and tackle. The only existing ‘solution’ we could find is changing the cow’s diet to mostly seaweed, but this isn’t a good solution since very few ranchers are willing to adopt dietary changes to reduce methane emissions at the cost of decreasing the quality and quantity of output from their cows.

What it does

This is where ‘Got Methane?’ comes into play. We’ve designed wearable technology for cows that captures the air from a cow’s burp so that its methane can be extracted, stored, and put towards more sustainable practices. For example, captured methane would be sold by farmers to the energy sector to be used for sustainable energy production. The process of combusting methane to produce energy converts methane to CO2 and water. Thus, instead of methane being released into the air by cows, the methane goes towards energy production, and a smaller amount of an 80x less harmful gas is released(CO2).

Our mechanism captures these methane burps with a tube secured to the halter of a cow, which is a padded rope around a cow’s head used to lead them. One end of the tube goes down their head between the eyes and opens just above their mouth, while the other end of this tube connects to a vacuum pump. This pump then connects to a large form fit Tedlar bag, which is designed specifically for containing VOC (Volatile Organic Compounds) gasses, such as methane. Also, the Tedlar bag has a check valve, which enables gas to only enter the bag through the tube connected to the vacuum pump, and not reverse pressurize the pump. Our system is attached to the cow in a saddle - manner with buckle straps with a hard shell on top to hold electronics and the vacuum pump. The final component is a methane sensor attached to the tube near the mouth of the cow that detects when the cow has burped or is releasing methane. This triggers the vacuum pump to turn on and suck the cow’s breath through the tube, capturing it in the Tedlar bag.

Twice a day, cows are led through automatic milking stations, so the addition of a bag emptying station would only add a single easily automatable process to their routine. The future goal would be to add automatic battery charging when the cow is in the stall as well as emptying the bags. Both of these things only require making one soft connection which is extremely cheap and viable to autonomously implement.

How we built it

After researching existing air pump systems and making an in-depth plan for how to build our fully functioning cow methane container, we started by searching for parts at home depot and McMaster-Carr, and finally made a bill of materials. After conceptually designing our methane intake system, we wanted proof that our conceptual product could truly be made into reality and ensure that we weren’t overlooking any aspects of our design. Thus, we created a 3D version using Solidworks. We individually imported pieces from McMaster-Carr, and organically drew the tube system and custom halter. After designing it in Solidworks, we initially wanted to make a full-scale prototype, but we quickly realized that the special parts we needed weren’t something we could gather from the maker-spaces on campus.

Instead, we decided to create a mock up of the main functional parts. To start, we 3D printed the head of the cow. Next, we machined wood into two semicircles and connected them with dowels to make a rib cage of sorts that represents the body of the cow. In order to make this actually look like a cow, we connected the 3D printed head and the wooden cage with glue and covered the cage in gray cloth. After which, we 3D printed the mock vacuum pump and tube and connected them with hot glue to the entire ‘cow’ as well. Lastly, we tied a halter out of yarn and put it onto the head.

Challenges we ran into

When it comes to taking a cow's breath away, we found that roses, charm, and a nice dinner just didn’t seem to do the trick. The challenges that we ran into while designing our product were validating feasibility and finding the exact right parts to make our mechanism. For example, when trying to find our vacuum pump we had to calculate the airflow speed, volume, and contents of a cow’s belch. The only airflow data we could find online was about putrescine molecules from human farts which have a different speed, density, and composition than a cow’s belch. We had to dig through chemistry and physics textbooks and random research papers on particle trajectory to apply methods and derive equations for our specific situation. It was only after calculating the speed and volume of a cow's burp that we were able to search for a vacuum pump that was cost-effective, small in size and weight, and had the required flow rate to optimize collecting a cow’s burps.

Another challenge that we faced was safety. By having electronics and methane in close proximity, we had to ensure that all of our wires and electronics could be properly insulated and grounded to remove the risk of any static electricity buildup. We originally wanted active carbon methane filtration inside of the Tedlar bag on the cow’s back, but we pivoted from this idea in order to keep the electronic components as far away from the methane as possible, thus minimizing the risk of combustion.

Accomplishments that we're proud of

The level of research we collected about cow methane emissions, its inner workings, and the many technologies and areas of expertise even touching the area was truly something to be proud of. As silly as becoming a subject matter expert in the aerodynamics of cow methane emissions sounds, it truly is a feat we’re pleased to have accomplished.

Aside from learning the intricacies of the diffusion rate of cow belching, we’re most proud of our full-scale 3D design. We created a working, wearable, and organic technology with real-world materials. Performing a multitude of flow, pressure, and power calculations to create a product that is scalable instills in us an unmatchable feeling of success and pride. The only way we could have topped this hackathon is if we had access to cows to truly execute full-scale production of the design and see it in action ourselves.

What we learned

In our ideation process, we learned about the importance of constraints, complex planning, and 3D design. For constraints, we started by thinking too big, which slowed us down in the beginning as we tried to tackle too much at once. By constraining ourselves to smaller problems and more specific instances we were able to target one specific aspect of a problem and fully develop the solution. This is where our complex planning skills greatly developed. We realized after every single part that we added we needed smaller supporting parts, regulatory parts, and cross integrative parts.

It was difficult to resist diving in and immediately building our prototype, but we learned that the way to make the best product was by planning and designing every single aspect before touching any physical part and building a body. By doing this we found that we really deeply understood every single aspect of our design and could make optimizing decisions during the design process; for example, analyzing the pros and cons between a self-priming pump and a peristaltic pump. Finally, we had to learn about how to optimize and scale our 3D models so that we could 3D print them for our model body.

What's next for Got Methane?

As much as we love animals, we don’t think our next step is going to be buying and taking care of a cow to measure our methane capture efficiency. In all seriousness though, our current nozzle for ‘vacuuming’ up cow burps is our most significant means of power consumption and also isn’t able to get 100% of a cow's methane output. We want to improve this by having a more passive input method that also has a greater capture efficiency since the end goal is capturing 100% of a cow's methane output.

Additionally, we would like to explore more feasible ways of incorporating CO2 methane filtration in the cow’s harness rather than relying on outside sources for the filtering process. The only non-industrial methods available today are experimental polymeric matrices with metal-organic framework and nano-pores. This technology is unfeasible, because of its cost and inability to scale.

If we are able to capture 100% of the methane put out by cows (removing around 40% of global methane emissions) and put this directly to use in more sustainable practices, we would dramatically support the recovery and well-being of the environment and our oh-so-important home, planet Earth.

Built With

• grabcad
• imovie
• solidworks