Henry the Hydrogen Tractor
Henry is a 1948 Ford 8-N Tractor who was converted to run on hydrogen by Middlebury students in 2008, guided by two Middlebury alumni. In 2012 and again in 2013, a month-long course was offered by the two alumni in which students tested and tuned the tractor to run smoothly on multiple gaseous fuels including methane, and to explore potential fuel sources in the region. I participated in this course both Januaries.
When:
January 2012 and January 2013
Where:
Middlebury, Vermont
For:
A month-long course in January, called J-term*
* A note: I was not actually enrolled in this course either January due to additional major requirements. But through the generosity of classmates, professors, and the Physics Department, I was able to participate in most activities.
Process
In 2012, Henry was in a workable but unfinished state. The goal of my classmates and I by the end of the month was to help Henry run efficiently on 3 fuels: hydrogen, propane, compressed natural gas. To accomplish this, we studied how a 4-cylinder internal combustion engine operates and looked at the characteristics of each fuel to determine how much of each fuel would be required to acquire optimal power. A programmable engine control unit (ECU) had been installed in Henry so that we could easily manipulate engine function variables such as air-to-fuel ratio and timing of ignition from a software interface.
Fig. 1. The January 2012 class in Champlain Valley Equipment's garage with Henry.
This was my first introduction to trial and error engineering and troubleshooting. When the engine was making an inconsistent hum, we isolated each cylinders' function through the ECU to determine which spark plug was malfunctioning. One day, would barely run at all and we discovered that an additive in the propane fuel had gummed up the fuel injectors, prohibiting injection.
Once Henry was humming smoothly we determined the power output achieved from each fuel by attaching a Dynamometer to the Power Take-Off, the mount at the back of the tractor connected to the engine shaft through which implements dragged behind the trailer can access the engine's power. The Dynamometer told us the maximum horsepower of the tractor on each fuel. Hydrogen, though originally the focus for the tractor, proved difficult to gain high horsepower at feasible compression and in reasonably sized tanks.
In 2013, the course took a broader and more practical perspective - looking beyond creating an efficient tractor and exploring the utility of such a tractor and how alternative fuels might be sourced. We focused on methane and took field trips to nearby farms and energy operations using it. One dairy farm was collecting manure from their jerseys and producing methane to power their operation. If a similar methane collection system could be compressed into tanks, then a farmer could foreseeably have a carbon neutral operation.
Why is this important?
For me:
This hands-on project working with problem-solving, trial and error, and mechanical theory first got me fired up about mechanical engineering. I then became involved with the Green Engineers school club.
For others:
Converting a tractor to run on more environmentally friendly fuels, and finding locally sourced, renewable fuel - even if carbon based - is a great step forward for the agricultural industry in the region and elsewhere.