Bioethanol is an alcohol fuel produced by fermenting biomass. Distillation is required to produce bioethanol pure enough to burn as a liquid fuel. If this distillation can be feasibly done using clean energy, then bioethanol is a completely carbon-neutral and convenient fuel.
My brother Cameron and I are developing a home-made bioethanol distillery. At the moment it is not completely carbon neutral as it uses an electric heating element that draws from the NSW grid, but if the chemistry stage can be made to succeed then we will work on powering it with 100% clean energy.
Our apparatus consists of a large metal tank with a heating element from an old electric kettle. The top of the tank is connected to a condenser made of copper pipe running inside 1 inch poly pipe. A kitchen thermometer enables us to measure the temperature at the start of the condenser.
Today we attempted a distillation. The goal of this experiment was to determine the effectiveness of the distillation apparatus, and so methylated spirits was used to make sure that ethanol was present in the system. 1 L of methylated spirits was added to 9 L of water in the distillation chamber.
As with the first test run, the system heated the 10 L of liquid adequately. The seal of the neck of the chamber worked, and the wooden blocks to hold the condensor pipes to the condensor worked.
However, thermal stresses on the condenser unit caused leaks to occur at the wooden bungs.
Although the sides of the chamber were insultated, a lot of radiant heat from the top and bottom of the chamber suggested heat loss was still significant. These surfaces need insulating too.