More Sustainable Way Of Barbecuing

Being in the middle of summer, backyard parties are going to be on the rise. And I bet that if you go to a backyard party this summer you WILL see a barbecue. Why wouldn’t you? They make for a fun and delicious way of enjoying meats and grilled vegetables.

But did you know that a single charcoal barbecue produces around 5kg of CO2 per hour? If someone uses their barbecue twice a week for half the year that would still just emit 260 tons. And when we consider that 75% of American adults (331.4 million) own a barbecue or smoker. That amounts to 50.1 thousand tons of CO2 emitted per year in America from charcoal barbecues.

These 50.1 tons of CO2 then contribute to the annual 70,000 wildfires, 3.56 cm increase in sea levels per decade, and 0.8 degree Celsius increase per decade.

Contents:

1. Alternatives to charcoal
2. Preparation
3. Usage
4. Conclusion

Alternatives to charcoal

Now that we know that charcoal barbecues are not the most environemtnley friendly. We must explore alternatives. Gas/propane-powered barbecues do not emit as much pollution into the air. They do still burn fossil fuels. And they tend to have a much higher upfront cost than charcoal barbecues.

Coconut briquettes are made from otherwise unused coconut shells. And sometimes other biomass materials such as rice chaff, sawdust and crops. They are then pressurized and rolled like traditional briquettes. When they are burned they have a much lower environmental impact than charcoal briquettes. However, they don’t result in as much of a smoky flavour desired by most. So the food may end up in a smoker defeating the positive environmental impact of using coconut briquettes.

I personally love using my charcoal-fired barbecue! But I don’t like the negative environmental impact as much. And I am not fully fond of the current alternatives. So to take action, during this project I retrofitted my charcoal barbecue to allow me to use the fuel source I want (lump charcoal) and not emit toxic emissions into the environment.

Preparation

Just like with my other carbon capture projects, this one started by first deciding on which method to use for capturing the CO2. At first I was inspired by my first carbon capture project to bubble the CO2 in water and use the barbecue’s heat to remove the CO2. But then I thought of making an actiavated carbon filter to capture the CO2. I ended up choosing the activated carbon filter as I hadn’t used that method yet. And a small filter is easier to use which would make it more easily adoptable by the 331.4 million American adults who own a barbecue.

To first move the CO2 outside of the barbecue I used a dryer hose. And to accelerate the airflow I add a 12v 90mm fan on top of the barbecue’s air vent. Then the CO2 went through an activated carbon filter. And then into a chamber to measure the CO2 levels.

I then made this plan in Blender to help visualize the project

After I modelled out the needed parts in Fusion360 (parmaetric computer aided design program). To measure the amount of CO2 I used the same chamber as in my last project. So I only needed to make the fan mount and adapter…

I then 3D-printed the parts. To make them as heat resistant as I could without using exotic materials like PEEK (polyetheretherketone), I made them out of black ABS (acrylonitrile butadiene styrene). And I printed them with 7 walls and 50% gyroid infill to keep them from warping from the heat for a little longer.

Then to finish the prep, I attached the hose and fan to the top of the barbecue. and attached the other end of the hose into the filter connected tot he chamber.

Usage

Procedure:

1. Test ambient CO2 levels
2. Fire barbecue
3. Test barbecue CO2 levels
4. Test CO2 levels after captured

Like in any scientific experiment, we must have a control to compare our results with. As a control I measured the ambient CO2 levels and the CO2 levels with the barbecue. To start I first put a CO2 monitor in the chamber for 3 minutes. I got a result of 521ppm.

Then I fired up the barbecue with regular charcoal briquettes. And after 3 more minutes I measure the CO2 levels in the chamber again and it increased to 3988ppm.

After I finished the control tests I could get to the exciting part. As previously stated, I used activated carbon to capture the CO2. Activated carbon is a material that can efficiently absorb pollutants like CO2. It’s made of coconut husk, bamboo, wool and other similar materials to give it a larger surface-area-to-volume ratio than regular carbon black.

By replacing the hose in to the carbon filter I could barbecue safely! After a 3 minutes I measured the CO2 levels inside of the chamber again, and they dropped to 546ppm.

Conclusion

Goals

1. Capture at least 80% of the CO2

• I far exceeded this goal by capturing around 93.3% of the CO2!

2. Make it practical to use

• Eventough this project was more of a prototype. The duct tape needing to be replaced every 10 minutes to keep it from melting. And the big chamber and dryer hose beside the barbecue make it hard to use and set up. So in the future, this could be solved by removing the box as I just used it to measure CO2 levels. And the carbon filter could be mounted on top with a mount made of some sort of metal. Also to make it even more practical a thermoeletric generator could be used to power the fan from the barbecue’s otherwise unused heat.

Overall, this project with some hurdles went pretty well. I learned about a new method of capturing CO2 helping me with my future projects. And I have found a way to reduce my environmental guilt while barebcuing.

If you’ve enjoyed this article, I would love a follow and some claps. And if you’d like to learn more, here is a video of this project and the website. Thank you!