Introduction: Fusion Jr. Home Energy Reactor

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The “Fusion Jr.” Home Energy Reactor is in essence a mini-generator that derives its power off of combustible waste material (like paper, wood, yard clippings, and even some plastics) inspired by “Mr. Fusion” as seen in the movie “Back to the Future II”. The potential for energy generation is great, and, in fact, this technology was used to power many cars during World War II and is a suggested energy source for developing countries (to provide gas to power stoves mainly). This is a truly unique project (never been done before), and, if completed, you can say that you have successfully converted garbage into electricity!

This is a green technology that derives power from an alternative fuel source that can be built by mostly salvaged components (well, not everything).

The Gasifier unit cleanly converts garbage into a burnable gas often called “syngas” or “woodgas,” then burns it creating heat which can be used to cook food (I have personally used this to cook a pot of soup) or Peltier Cells can convert the heat directly into electricity. The current produced by the Peltier Cells is sent to a Charging Module. The Charging Module charges a rechargeable Storage Battery. The Storage Battery supplies energy to run a Power Inverter. The Power Inverter can be used to run electrical appliances. Later we will see that after setting up the battery, inverter, and charger, turning this into a solar project is as easy as substituting the Fusion Jr. with any solar panel.

The minimum energy expected from one unit is dependent on how many peltier cells are used. Each cell contributes about 3 continuous watts. Potential energy from a Fusion Jr. system is well over 2000 watts, but harnessing all of that energy is difficult, especially since peltier cells are at less than 3% efficient.
Appliances with high watt ratings can be run even with low input because energy is stored in the Storage Battery.

Step 1: Get a Coffee Can

(See Diagrams)
 The Gasifier Unit is one of the most crucial components of the Fusion Jr. system. The Gasifier Unit comes in 3 parts, labeled as A (chimney), B (housing), and C (reactor). Each part comes apart.
Trash is put through the chimney and is ignited using an igniter (a lighter). The trash begins to combust with oxygen supplied through holes at the base of the housing. The oxygen travels from the outside into the housing, then into the reactor through the lower holes. As temperature rises and more trash is supplied, the oxygen supply is cut off as the lower holes are blocked off by embers and ash and the trash can no longer combust. The high temperatures cause the creation of “syngas” which primarily consists of the combustible gases carbon monoxide and hydrogen. The “syngas” does not combust, even though there is a high enough temperature, until it reaches the combustion zone labeled by the diagram. The “syngas” combusts with oxygen supplied by a series of holes. The result of this combustion is the release of carbon dioxide, water vapor, and heat. The Gasifier Unit effectively burns garbage without excessive pollution and smoke. Unfortunately, when starting up the gasifier, when the gasifier runs out of fuel, and during windy conditions, smoke is produced. The Gasifier will provide heat for up to a half hour after the flame dies down.

I used a coffee can, a bean can, a small cookie tin can, and a camping pan to make this setup, but you can experiment with different setups. Puncture holes as dictated by the diagram. More holes provides more oxygen and thus a better burn, while less holes allows for more partial combustion which is needed for the formation of gas. The key is to experiment with oxygen intake. Gasification relies on what is sometimes referred to as "partial combustion," which means that, to produce intermediate flammable gases, you must adjust oxygen available in the combustion zone (the number and size of holes).

Step 2: Get Some Peltier Cells Online

Peltier cells utilize semiconductor technology much like standard solar cells. Two polarized semiconductors convert heat flow into electrical current. Naturally, the greater the heat gradient, the more current is produced. A set of 10 peltier cells can be purchased for $70. Surprisingly, this price is cheaper (since I last checked in 2007) per watt produced than solar cells. Peltier cells are often used in heating and cooling applications because when current is passed through a peltier cell, one side becomes hot, and the other side becomes cold.

It is highly recommended that a cooling element (heat sink) is placed in the opposite side of the peltier cell (the side not touching the Fusion Jr.). This allows for a greater cooling gradient. In some cases, fans or even ice can be used as a coolant to allow for a gradient. Don't let the peltier cells get too hot or they will melt though! 

Placing the cells just right for them to get a maximum heat gradient is optimal. Use aluminum tape to attach the cells.

If you do not wish to use peltier cells, other technology can be used as well such as small steam engines or stirling engines. Both can produce enough power to charge batteries or small appliances.

Step 3: Get Some Fuel and Do Some Tests

Initially, tests must be done to ensure that your unit is gasifying properly. To do this, insert solid fuel, hot coals, and/or a bit of tiki torch fuel into the unit. The unit should produce a clean, smokeless flame. This indicated the presence of "biogas." An obsolete book or woodchips should burn nicely.

In my photos, I use no tiki torch fuel or coals, only solid fuel! Notice the clean burn.

This is why this technology is suggested as a fuel source for developing countries and was used to run cars during World War II.

Step 4: Attach Peltier Cell(s)

I have done some work building a larger unit. In this example, I put ice in cooling trays around the unit for a larger heat gradient. Peltier cells are sandwiched between the trays and the actual gasifier. Glue typically does not work because of its tendency to melt or burn off. Aluminum tape works great!

Cooling trays can be filled with snow for a greater heat gradient for those living in cooler climates.

Step 5: Battery, Inverter, and Charger

Now that you have the power source, you need to implement some way to store the incoming power. You will need a 12v rechargable battery, a float charger, and a power inverter. All of these things can be purchased online. You may also wish to buy a $5 voltmeter to monitor the battery's charge.

There are a few subtleties with the components. For example, a squarewave power inverter is not as great as a sinewave power inverter, and a squarewave inverter will not work with many sensative electronics. Some chargers are cheap and actually can damage batteries.  Keep in mind that some lead acid batteries work better than others, and some chargers better than others. Make sure to look at customer reviews before a purchase! Here I just used a standard car battery, but these do not last very long the way that we are using them. Keep an eye out for "deep cycle" batteries. Batteries are measured in "amp hours." In our case, you can estimate how many watts can be powered for an hour using the battery with this formula:
(efficiency %)*(12)*(amp hours)

The power inverter, charger, and voltmeter can be simply clipped to the battery (pay attention to polarity!).

With all of these charging components you can even substitute the Fusion Jr. with a solar panel to provide a usable outlet or power a large variety of solar-related projects!

And That's All!

Step 6: Author's Notes

On Efficiency:
Quite a few have pointed out low efficiency of peltier cells. Perhaps peltier cells are not ideal, yet for a small diy project the simplicity of solid state components makes it attractive and cool. Industrially steam power is more efficient, but on a small scale it would be difficult to make a few mini steam engines/etc by hand and it is no doubt daunting to the amateur DIYer! There has been some talk in the auto industry about replacing a car's alternators with peltier cells at the its exhaust pipe, thus reusing waste heat instead of leeching off of the car's momentum. Peltier cells are not hopelessly inefficient.

On Environmental Effects:
To sequester carbon is to take it out of the carbon cycle. Since all carbon in the carbon cycle enters the gas phase at one point in the cycle, if at any point carbon is added to the carbon cycle at that point it is damaging, and that is the only time it is. Gasification is a technology that is already in use globally, typically gasified using plasma arcs and is an alternative fuel source that is worthy of more attention that it has been given. Every alternative fuel source has drawbacks. In this case a drawback would be the impulse of carbon from one stage of the cycle to another (gas phase) yet the effects are not long term. Introducing sequestered carbon stored underground that is not a part of the carbon cycle (fossil fuels) amplifies the amount of carbon at any stage in the cycle, while introducing carbon already in the cycle amplifies the amount in one stage but takes from another so the net is roughly the same. Not that dinosaurs are not to blame, but burning their gooey remains is! Recycling carbon (gasification) instead of introducing it (fossil fuels) is a more sustainable way to produce energy. 

More on Biomass Gasification:
I have gotten a little mail with other instructables users requesting that I explain the basic process of gasification and how I arrived at my design(s). The flammable gases produced from the gasification process are Carbon Monoxide, Hydrogen Gas, and Methane Gas. Carbon char reacts with water vapor in the presence of heat (surpassing activation energies and enabling reactions to occur) in an environment with a small controlled amount of oxygen. Normally, hydrocarbons or other fuels burn completely, producing Carbon Dioxide and kicking up alot of particles into the air, burning violently (smoke). When oxygen is controlled, a "partial combustion" occurs and instead of the production of Carbon Dioxide, intermediate products of combustion appear (the flammable gases). This produces a clean, efficient, long burn leaving ashes behind in what would have normally been kicked up as smoke particles as well as a stream of flammable gases that can be used. The designs that I came up with were a result of researching "gasifier camp stoves" and designs for car gasifiers. I could not at the time obtain specialized tools to produce required metal bits, so instead I re-purposed some cans and things lying around.

If your Fusion Jr. is not working properly, there are a number of things you can do. Try using thermal grease on the side of the peltier cells facing the "cold" part. Experiment with allowing more/less oxygen into the unit by creating/closing holes. Insulate the core, it might not be getting hot enough. Some woodgas camping stoves use fans to help circulate/suck out oxygen. Try researching designs for woodgas camping stoves of use google images.

Be careful not to burn anything around trees or other flammable material or in an enclosed environment. Use an extended barbecue lighter for igniting the Fusion Jr.! I learned the hard way. I was interviewed by a student at Santa Susana High School to be displayed on the morning announcements but I accidentally cremated his zippo and he posted this video! 

Check back soon for a possible video presentation! Also don't forget to check out my other cool projects (projects such as building a real raygun at home) and youtube channel, and if you like this project, don't forget to vote for it! 
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