Engines | Biodiesel | Methane | Ethanol | Wood (Producer) Gas | Wood Heat
Electricity from wood waste (links)
Gasification* is the cleanest, most efficient combustion method known. It has been used for decades where clean heat is
required. Examples include the thousands of vehicles which were directly fuelled by Gasifiers during the Second World War, or the coal gas "works" which were common in cities all over the World before natural gas. These produced gas which combusted so clean it was used in chimney-less household appliances such as cookers and heaters, without adverse effects. http://www.waterwide.com/gasi.htm
WOODGAS POWERED VW'S AND OTHER VEHICLES - Fuel shortages during WWII prompted searches for alternative fuels in England, Germany, Scandinavia and many other countries. One of the most unusual solutions involved the modification of vehicles for use with wood, charcoal, or coal. Typical modifications included A) a gas generator; B) a gas reservoir; and C) carburetor modifications and additional plumbing to convey, filter, and meter the gas into the engine.
The gas generator was an airtight vessel into which was introduced a charge of wood, charcoal, or anthracite coal. Heat was applied to the fuel either internally or externally to initiate a self-sustaining gasification of the fuel in an oxygen deprived environment. The resulting "woodgas" was piped to the reservoir, or in the case of small engines, directly to the engine carburetor. Wood-gas modified vehicles were therefore technically a "dual fuel" vehicle in that a self-sustaining gasification of the wood charcoal, or coal required another fuel to start the process.
Gas reservoir sizes depended upon vehicle, engine, and gasifier size. Small vehicles and engines could be supplied directly from the gasifier, thus eliminating large reservoirs. Larger, more powerful vehicles required separate gas reservoirs to compensate for gasifier outputs which were less than the fuel consumption rate of the engine. These larger reservoirs usually took the form of gas bags that were attached to the roof or rear end of the vehicle. The largest mobile reservoirs were gas bags fitted to busses which were often several feet in diameter and as long as the vehicle. http://www2.whidbey.net/lighthook/woodgas.htm
Dedicated to Promoting Biomass Energy -
particularly pyrolysis, gasification and alternate fuels ...http://www.woodgas.com/
New technology is opening up the prospect of utilizing wood waste from forest harvesting and sawmills for efficient, small-scale electricity production. Potential benefits include worthwhile cost savings as well as the "greenhouse-friendly" replacement of fossil fuels with a renewable energy source.
Wood gas burner.
The gas will be used
to power a micro-gas turbine
alternator for electricity generationA research team led by Paul Fung at the Forest Products Laboratory, Clayton, expects to demonstrate the feasibility of the proposed approach by the end of this year. Fung is confident that easy-to-operate generating units, with a capacity in the range 30-200 kW, will be on the market within about 5 years. Where a wood supply is available, they should prove a practical alternative to petrol or diesel generators.
The units will couple a wood gasifier to a new type of gas "micro-turbine" developed in the United States. Expected to be launched commercially later this year, the micro-turbines more than match the efficiency (30-35%) of conventional coal-fired power stations in converting fuel to electricity.
Their American developers envisage them generally being powered by natural gas, LPG or diesel. However, on a visit to the United States last year Fung found considerable interest in the prospect of running them with wood gas, with a manufacturer agreeing to provide CSIRO with equipment for the research project. "They are very keen on what we are doing," he says.
The micro-turbine will be coupled to a prototype wood gasifier. Fung and his colleagues developed a wood gasifier system in the 1970s in a project prompted by the jump in fuel prices that followed the 1973 Middle East "oil shock". The idea was to develop equipment that could be retrofitted to fuel oil burners, with the cheaper wood gas either replacing or supplementing the oil.
The research proved successful, with the prototype equipment able to produce a supply of gas not only from woodchips but also from peanut shells and pelletized rice hulls. However, the project was aborted in the late 1970s when the oil crisis passed.
The gas is produced by partial combustion of the wood. The process will be tuned to ensure that the wood gas meets the thermodynamic requirements of the micro-turbines; Fung has no doubt that this can be achieved. Another research priority will be to ensure that the gas is clean - free of ash - when it enters the turbine. "We can't afford to have gritty material getting in," he says.
A key requirement in developing a practical unit - "one that will run with minimal attention, like a petrol generator" - will be devising an automated handling system that provides a constant supply of chipped wood to the gasifier.
Fung's calculations suggest that a gasifier/micro-turbine unit should consume wood at a rate of slightly less than 1 kg per kilowatt-hour of electricity generated. That translates to around 13 kg of wood a day to meet a typical household's average electricity demand - less than 5 tonnes a year.
Fung says the units' 30-200 kW generating capacity should suit groups of houses, farm homesteads, small towns and small factories. A survey he conducted in 1996 of the cost of different fuels per unit of energy produced confirmed the economic attraction of wood as a fuel in areas with a reliable supply. Wood residues were cheapest at 0.25 cents per megajoule - just ahead of coal at 0.27-0.29 cents but much cheaper than LPG, fuel oil and diesel (1.17-2.16 cents).
Options for use of a unit will include connection to the power grid; the operator could draw on the grid at times of excessive demand and sell surplus electricity to it at other times.
Dr Paul Fung
Tel: (03) 9545 2487
E-mail: Paul.Fung@ffp.csiro.au
Wood-gas stoves
Wood-gas cooking stoves are perhaps the best answer so far. These are gasifiers that produce gas from wood and then burn the gas, leaving ash and charcoal. They're clean, fast and efficient. They burn small pieces of wood, sticks, wood chips, corncobs or nutshells, producing a clean, blue flame and no smoke. A lot of cunning engineering has gone into the development of these stoves, and yet they're easily made from locally available materials -- even tin cans.
Swosthee wood-gas stoves in Malaysia
Technically, they're called "inverted downdraft gasifier" stoves, operating on natural convection. How wood-gas stoves work: "A Wood-gas Stove For Developing Countries", by Tom B. Reed and Ronal Larson, Biomass Energy Foundation. 300g of sticks or chips burn for 30-45 minutes at high efficiency with low emissions.
Richard Boyt's low-tech wood-gas stove, made from 10 tin cans
http://journeytoforever.org/at_woodfire.html
Construction of a Simplified Wood Gas Generator for Fueling Internal Combustion Engines in a Petroleum emergency
This report is one in a series of emergency technology assessments sponsored by the Federal Emergency Management Agency (FEMA). The purpose of this report is to develop detailed, illustrated instructions for the fabrication, installation, and operation of a biomass gasifier unit (i.e. a "producer gas" generator, also called a "wood gas" generator) which is capable of providing emergency fuel for vehicles, such as tractors and trucks, should normal petroleum sources be severely disrupted for an extended period of time. These instructions have been prepared as a manual for use by any mechanic who is reasonably proficient in metal fabrication or engine repair. http://www.gengas.nu/byggbes/index.shtml
Wood fired gasifier. This couple with their trailer mounted gasifier, uses various solid fuels to power the gasifier.The truck can start and run on the wood gas that is produced.
"The gas producer should operate on any solid fuel. We have even tried using old tyre treads and dry sugar cane. We are told that cattle dung will work. We have used charcoal but not used coal. No doubt it would provide more KM's per tonne than wood."
"To get optimum amount of hydrogen means to introduce the optimum amount of steam at a given temperature. This inevitably means at times a little more steam than necessary which condenses in the resulting gas as moisture and makes it almost impossible to operate a dry filtering system. My personal finding is that a wet filtering system is the answer. It is of paramount importance that a 100% clean gas be delivered to the engine.
From this you will see that we need to aim at the highest temperature possible to make the gas and the lowest temperature possible to deliver it to the engine. Every 30 degrees C the gas is cooled it occupies 10% less volume. The cooler the gas the richer it is with more energy per litre." http://members.tripod.com/~highforest/woodgas/woodfired.html
Repetitive Swing Method for Charcoal and Wood Gas Producing
Kishimoto, Sadakichi, Akizuki, Katsufumi, Hirowaka, Tsuyoshi
There is an worldwide upsurge of revaluation for forest biomass as an sustainable energy resource. Statistics says that we have eight million tons of wood waste annually in Japan. It partly derives from sawmill, but mainly from demolition and construction process. These waste are chipped and utilized as pulping material, reprocessed material (e.g. particle board) and alternative energy resource to half amount produced. The rest of half are burnt uselessly. Energy purpose is the dominant usage, but, the fatal problem appears when wood is burnt in the direct burning boiler system. The problem is plenty of clinker. Ash contains potassium oxide much, which lowers the fusing point of ash, that produces clinker, difficult to deal with. Wood contains many kinds of mineral at certain balance that accelerate the plant's growth, but modern agricultural land lacks it. In direct burning system, burnt at high temperature, minerals become clinker, insolubles, which can not assimilate to plants nor soil microorganism. Minerals are to be the treasure, but currently it's only useless waste.
Under the background above, we have devised the continuous gasification system in Japan. That is a repetitive swinging method, basically a modified moving bed method. Normal moving bed method has a difficulty to blow in the necessary air for gasification at the fixed point, but in this R.S. method, we can blow in needed amount of air from the bottom. And the balance between produced wood gas and charcoal can be controlled by temperature operation.
In Japan, charcoal is getting a new way of utilization, especially to organic farming as a soil amelioration material. When the distillation temperature is set at around 500°C, this system can play a big role against our society's needs for multi-use of charcoal and dry distilled wood gas.
Key words: repetitive swing method, agricultural use of charcoal.
Correspondence: Tsuyoshi Hirowaka, International Charcoal Cooperate Association, 2-9-4 Asano bldg.401, Kitaootsuka, Toshima-ku, Tokyo 170, Japan
Telefax: +81-3-35767298
http://ces.iisc.ernet.in/hpg/envis/doc97html/enbiomassgas613.html Wood gas generators and Harry LaFontaine The Biomass Energy Foundation. Woodgas books and research material.
http://www.ikweb.com/enuff/public_html/Stoves.html Dale has an Ag Bag, normally used for ensilage of forages for livestock feed, hung up in a wooden frame. It is filled with producer gas from an Imbert style downdraft gasifier fed with small wood blocks.
http://www.ise.fhg.de/Projects/Chemenergy/biomass.html A. Heinzel, K. Ledjeff-Hey, U. Maier-Röltgen, A. Schuler, B. Vogel Gasification of biomass, e.g. wood, to create a combustible gas mixture is a well-established technology. The wood is converted to a gas with hydrogen, carbon monoxide and methane as the combustible components, and nitrogen and carbon dioxide as inert gas ballast. In addition, depending on the type of gasifier, dust tar and traces of various impurities can be found in the gas.
http://www.biotech.wisc.edu/jeffries/faq/literature.html Biomass energy and particularly biomass gasification is a field where publications are often difficult to find. The aim of this foundation is to make available information on biomass at reasonable prices. Some of the newer releases and current titles are listed here along with an order form. They will also make available at $0.15/page other papers from our extensive library of technical papers on gasification dating back to the turn of the century. They also act as a clearinghouse to locate technical assistance for biomass projects.
Gasification Mailing List Archive http://solstice.crest.org/renewables/gasification-list-archive/
Producer Gas for Motor Vehicles by John D and Martin G Cash reprinted by Lindsay Publications. Build an experimental gas generator and bolt it to an old car. Other people build race cars that move fast. When the oil shortage comes, your charcoal powered auto might be the only auto moving at all! Nuts and bolts how-to. Details you're not going to find anywhere else. A lot of rare information for the money. Get a book and shelve it, even if you don't build a generator. You'll have it when you want it. I won't have to tell you "I don't offer it anymore" when you finally do decide to build and want a copy. Get one NOW. http://www.lindsaybks.com/bks/producer/index.html
Both these varieties of biomass were found to be quite suitable for gasification, i.e., a process by which the biomass is converted into producer gas through partial combustion in the presence of controlled supply of oxygen. The producer gas thus generated, is primarily a mixture of carbon monoxide, hydrogen, carbon dioxide and nitrogen. The gas which is combustible, can be used in diesel engines to replace upto 80 percent of the fuel. http://www.ecouncil.ac.cr/devalt/nl1297a.htm
