Solar distillation of ethanol alcohol for fuel

Using sunshine to make fuel! It's not moonshine, it's sunshine.

Read below about how we use a parabolic dish and a reflux still to produce fuel alcohol.

ALCOHOL FUEL PRODUCER PERMIT #AFP-CO-15040

Here's how it works:

The reservoir tank (A) is filled with wine, beer, or other fermented liquid. It is pumped by the circulation pump (B) through the solar collector coil (C) which is heated by solar energy focused on it by the concentrator dish (D).

Hot liquid and steam is injected back into the bottom of the reservoir tank which brings it to a boil (A). Steam rises into the reflux column (E). The temperature gradient in the reflux column fractions the rising steam into water and ethanol. Water vapor condenses and falls down the column while ethanol vapor rises to the top and passes into the water jacket condenser, (F) where it condenses back into liquid and is collected in the fuel canister (H).

The water jacket condenser requires a constant flow of cool water pumped from the cooling water reservoir (G) to condense the ethanol vapors back into liquid. Cooling water also is circulated at a regulated rate through the cooling coils on the reflux column to keep the still head temperature from rising too high and allowing water into the condenser.

Hot water exiting the condenser and cooling coils can be used to heat the next batch for distilling. This way, we use maximize solar energy.

Here is a photo of the the parabolic concentrator dish and the reflux still. The entire setup can be run from a 12 volt battery that is charged by a 5-10 watt solar panel.

Here is a photo of the beer reservoir and reflux column. As it turns out this dish generates a bit more steam than the 1" reflux column can handle. The stripping cooling coil at the bottom of the reflux column needs a fair amount of cool water flowing through it to keep excess water from ascending into the column and watering down our fuel. We believe a 2" diameter reflux column may work better with this dish.

There is controversy surrounding ethanol and whether it contributes a net gain or loss in the sustainable energy equation. One of the main drawbacks with ethanol fuel is that it takes energy to manufacture - first in the cultivation and harvesting of sugar crops, and again in the distillation process. Another drawback is that the cultivation of crops to make fuel could compete for resources needed to grow food.

But consider this: - regardless of where it fits into the sustainability equation, ethanol is one of the only liquid fuels that can be easily made by the average person. If the gas stations run dry, not to worry! If you can procure sugar and yeast; with a well crafted still you can make fuel to power your car, motorcycle or lawnmower. It might not be very feasible on a large scale, but on a small scale, this process empowers the individual tremendously.

With the exception of Italy and New Zealand, personal manufacture of ethanol is illegal. Fortunately, in the United States a person can apply for an alcohol fuel producer permit, which provides a legal avenue for citizens to make their own ethanol for fuel. The catch: you must surrender the property where your still is located to spontaneous government inspection. This is a big deterrent for many people.

The people we talked with at the TTB were professional, friendly, and to the point. They issued our permit in less than a month. It seemed to move things along that we had a facility dedicated to this type of research and had everything setup and ready to go.

Reference Information:

Heat properties of Ethanol vs. Water

Energy content of various fuels
This information was copied from...

http://peswiki.com/index.php/Directory:Butanol

Energy Content in Btu/gallon
64,000 Methanol
84,000 Ethanol
105,000 Butanol
114,000 Gasoline
120,000 Bio diesel
130,000 Petrodiesel

The following table and descriptions were taken directly from the following link where full explanations of this table and references also can be found. Most of the information is more specific to butanol, a bio fuel produced by fermenting bio mass with bacteria rather than yeast.

http://en.wikipedia.org/wiki/Butanol_fuel

Energy content and effects on fuel economy
Butanol is reported to yield 36 MJ/kg (15,500 BTU/lb) when burned. This can be expressed volumetrically as 29.2 MJ/l (104,800 BTU/US gal).
Switching a petrol engine over to butanol would in theory result in a fuel consumption penalty of about 10% but butanol's effect on mileage is yet to be determined by a scientific study. While the energy density for any mixture of gasoline and butanol can be calculated, tests with other alcohol fuels have demonstrated that the effect on mileage is not proportional to the change in energy density.

Air-fuel ratio
Alcohol fuels, including butanol and ethanol, are partially oxidized and therefore need to run at richer mixtures than gasoline. Standard gasoline engines in cars can adjust the air-fuel ratio to accommodate variations in the fuel, but only within certain limits depending on model. If the limit is exceeded by running the engine on pure butanol or a gasoline blend with a high percentage of butanol, the engine will run lean, something which can damage it. Compared to ethanol, butanol can be mixed in higher ratios with gasoline for use in existing cars without the need for retrofit as the air-fuel ratio and energy content is closer to that of gasoline.

Specific energy
Alcohol fuels have less energy per unit weight and unit volume than gasoline but at the same time require richer mixtures. To make it possible to compare the net energy released per cycle a measure called the fuels specific energy is sometimes used. It is defined as the energy released per air fuel ratio. The net energy released per cycle is higher for butanol than ethanol or methanol and about 10% higher than for gasoline.

Heat of vaporization
The fuel in an engine has to be vaporized before it will burn. Insufficient vaporization is a known problem with alcohol fuels during cold starts in cold weather. As the latent heat of vaporization of butanol is less than half of that of ethanol, an engine running on butanol should be easier to start in cold weather than one running on ethanol or methanol.