Wood gasifier how does it work

One example is the Philips stove, which had previously been built in small numbers in India and is now produced in South Africa. The company used to produce the Phillips stove and has now developed its own model. The ACE1 stove is made of a ceramic combustion chamber placed in a stainless steel body. It uses a solar panel to charge the battery, which can also be used to charge a mobile phone or run a LED unit.

When fully charged, the battery will power the fan for over 20 hours of cooking. According to the company, 40, stoves have been sold up to A TChar stove starts with almost any type of dry biomass as fuel for gas-style cooking while making hot charcoal that is subsequently burned to continue the cooking on a charcoal stove that is the base of the TChar unit.

There are various types of natural-draft stoves with a conical fuel hopper for rice husk. The advantage of these designs is that they do not require electricity and allow for continuous feeding — also referred to as quasi or semi-gasifiers.

The disadvantage is that they need constant attention and a good bit of experience to operate: the flow ability of rice husk is poor, so it is necessary to tap the stove frequently every 5 to 10 minutes to keep the fuel feeding the burner and to prevent the fire from going out. Tapping it too hard, however, can cause the rice hulls to spill out of the bottom and disrupt the cone of coals. The stoves are much shorter than the rather tall and top-heavy TLUD rice husk gasifiers and a promising option for areas where stove height might be a barrier for cultural acceptance.

It is also ideal for areas where electricity access is a challenge and purchasing power demands low-cost options. Countless tin-smiths in many Asian countries manufacture these stoves.

Alexis Belonio from the Philippines proved otherwise. He designed a burner head that permits for preheated secondary air supply in a single-walled unit.

Up to now over 3, stoves have been sold since Several commercial rice-husk gas burners are now based on his concept. All of these processes are naturally present in the flame you see burning off a match, though they mix in a manner that renders them invisible to eyes not yet initiated into the mysteries of gasification. Three of these processes tend to confuse all newcomers to gasification.

Once you understand these three processes, all the others pieces fall in place quickly. These three non-obvious processes are Pyrolysis, Cracking, and Reduction. Pyrolysis is the application of heat to raw biomass, in an absence of air, so as to break it down into charcoal and various tar gasses and liquids. It is essentially the process of charring. The biomass breaks down into a combination of solids, liquids and gasses. The solids that remain we commonly call charcoal.

The gasses and liquids that are released we collectively call tars. The gasses and liquids produced during lower temp pyrolysis are simply fragments of the original biomass that break off with heat. These fragments are the more complicated H, C and O molecules in the biomass that we collectively refer to as volatiles.

As the name suggests, volatiles are reactive. Or more accurately, they are less strongly bonded in the biomass than the fixed carbon, which is the direct C to C bonds. The input to gasification is some form of solid carbonaceous material— typically biomass or coal. All organic carbonaceous material is made up of carbon C , hydrogen H , an oxygen O atoms— though in a dizzying variety of molecular forms.

The goal in gasification is to break down this wide variety of forms into the simple fuel gasses of H 2 and CO— hydrogen and carbon monoxide. Both hydrogen and carbon monoxide are burnable fuel gasses.

We do not usually think of carbon monoxide as a fuel gas, but it actually has very good combustion characteristics despite its poor characteristics when interacting with human hemoglobin. The gasification process occurs as the char reacts with carbon and steam to produce carbon monoxide and hydrogen. In addition, the reversible gas phase water gas shift reaction reaches equilibrium very fast at the temperatures in a gasifier. This balances the concentrations of carbon monoxide, steam, carbon dioxide and hydrogen.

In essence, a limited amount of oxygen or air is introduced into the reactor to allow some of the organic material to be "burned" to produce carbon monoxide and energy, which drives a second reaction that converts further organic material to hydrogen and additional carbon dioxide. Wood is the ideal fuel for rural heating in Maine, especially if you own a woodlot. Firewood harvests are an opportunity to improve the forest by removing dead, dying, diseased and poorly formed trees, enabling residual trees to grow faster, produce more oxygen and use more CO2 greenhouse gases.

If you are a gardener, wood ash adds calcium, potassium, other nutrients and bio-char to the soil but apply only after and according to recommendations of a soil test, as wood ashes can raise the soil pH quickly and excessively. From the energy standpoint, buying wood from a local supplier is far better than buying pellets from afar and minimizes consumption of motor fuels.

It also provides local employment and keeps money in the local economy. Skip to content. Winter A wood gasification boiler. Wood is burned in the firebox top , and gases travel downward and are burned at 1, to 2, F in the ceramic chamber below.

The hot gases then pass through a fire-tube heat exchanger to transfer heat to water stored in a large tank.

Flue temperatures are usually under F, and there is no creosote.