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Ethanol Demonstration

By: Stephen Matthews

On Friday we were shown how to produce ethanol in a small batch process. This process was demonstrated using a homemade still constructed from a 10 gallon milkjug and copper plumbing parts. The still used a propane burner as a heat source. The first step is to prepare a mash, the batch that we used had been created using sucrose sugar as a feedstock. Then the resulting liquid called wort is drained off and heated inside the still. The still is a piece of equipment used to separate liquids of different boiling points, in this case ethanol and water. The still works by first heating the wort to the boiling point of ethanol , about 78.4 C. At this point the ethanol will boil and be pushed upwards within the still through a pipe filled with ceramic beads. These beads provide resistance and are the first step in purifying the ethanol. Then the gas collects in a chamber where a seperate cooling coil flows through and condenses the ethanol back to a liquid. Some of the ethanol flows into the collector. While some flows back through the system to be repurified. In the end the system produces ethanol of about 185 proof which can be put through multiple distillations to achieve even higher purity. High purity ethanol can be used as a fuel in an internal combustion engine. Today many vehicles are being built using flex fuel technology, which allows for the vehicle to use a mix of gasoline and ethanol in any ratio.