The crew from BioTour made a stop on ASU’s Tempe campus today to promote sustainable living, biofuels, and solar energy. They welcomed everyone to take a tour of their bus and eagerly answered everyone’s questions. As I walked up to the bus I was immediately welcomed by BioTour co-director Ethan Burke and asked if I’d like a tour.
Their bus is powered by waste veggie oil (wvo) which they collect from restaurants in whatever town they happen to be in that day. Ethan said they usually stick to Chinese restaurants because they have the highest quality oil (i.e. it is changed frequently as opposed to used and reused and used again at a fast food chain).
The first thing Ethan showed me is the side of the bus where they suck the oil from grease traps and filter it into storage tanks. He said they are working on better ways to filter the oil because the filters clog a little too frequently. One solution they are looking into is using a centrifuge to achieve better filtration.
Next he showed me the actual tanks they have mounted under the bus. These tanks are heated to thin out the oil making it closer to the viscosity of diesel fuel which is more more fluid than veggie oil when at room temperature. Before they can even run off of wvo it has to reach at least 160 degrees before it can be injected in the engine. They have to start the bus on biodiesel and then switch over to the wvo once it’s hot enough. The switch over is very seamless and can be done while moving.
I asked if they ever have trouble finding enough restaurants to get oil from and he said every once in a while they do but that it’s usually not a problem. They’ll use biodiesel or even regular diesel to get them to their next wvo pickup.
So after seeing where they suck up the oil and store it Ethan took me up to the front of the bus where the engine cover is open, exposing the modifications they’ve made. Unlike biodiesel, which doesn’t require any engine modifications, to run off of wvo a few things have to be done. Since they have to warm up the engine on biodiesel before switching over to wvo a system must be installed to do the actual switching. Also heated tanks need to be installed and heated fuel filters. In the picture on the right you can see they use the heat from the engine’s coolant system to heat the fuel filters. These filter out anything in the oil larger then 20 microns. I asked how long they can go before these clog up and Ethan said they can usually go just over 2,000 miles before they have to change them. That’s one reason they are looking at better pre-filtering so that they can get more life out of these filters. So basically that’s it, after leaving these filters the clean wvo is injected into the engine and off they go.
Quite a few people were asking if the wvo has caused any engine trouble, and being that this is an old bus (1989) Ethan explained they’ve had a few breakdowns, but these weren’t related to the wvo system. I believe he said the steering went out once, and a few other things, but the engine is still running strong.
That was about it for the nuts and bolts of how things worked, Ethan was surrounded by curious onlookers asking about how it all worked, so I headed inside the bus to take a look around. In the bus I ran into Alan Palm who is the other co-director. He was telling stories of their adventures to a few people that were already inside. I caught part of a story about when they broke down and someone that worked for an oil company towed their bus to his house and let them stay for a week while they fixed it.
So this is where they live all year long, touring the country, visiting schools, colleges, and community gatherings. They are continually giving presentations and tours on sustainability on these visits. They drive around 40,000 miles a year and have so far visited 42 states. The two other crew members who I didn’t get to talk to are Fernando Austin and Jenny Sherman. Check out their website where you can get tons more information about their mission, what they do, and even a blog.
BioTour is a journey that aims to enliven the Sustainability Movement while exploring the depths of America—the people, land, and cultures. BioTour addresses the vital issues of climate change, environmental degradation, and peak oil while presenting pathways toward sustainability in renewable energy, active democracy, and understanding the interconnectedness of all living things. www.biotour.com