Gasification for Renewable Fuel Supply

    With this entry, I wanted to put together in one place some information on gasification technology for the reference of all those interested in renewable fuels and as an introduction to those who are new to this technology.
    Gasification is the process of converting carbon containing materials in the presence of steam, air or oxygen to a gaseous fuel called syngas (short for synthetic gas), which is a mixture of hydrogen and carbon monoxide (and methane in some cases). Syngas can be burned as a fuel as is, used to produce hydrogen or converted into liquid fuels such as synthetic gasoline and diesel using the Fischer-Tropsch process. Gasification is an old and established technology that could offer our societies an unlimited supply of clean fuel, from such materials as coal, petroleum, oil sands, biomass , industrial, household and farm waste. Almost any type of organic material can be turned into clean fuel with this process. Electricity can be produced  using fuel cells running on syngas or hydrogen or by burning syngas in a gas turbine/IC engine-generator system.

    But syngas contains CO, so why is it clean? This CO will eventually be turned to carbon dioxide through combustion. However, the CO comes from carbonaceous matter that would be wasted as landfill, matter which already has had a high price paid out during the production, processing, transportation and storage of the original material. Thus, by recycling this carbon to produce energy, fresh fossil fuels are not required to be burned to produce that energy. Moreover, the residue from the gasification process, known as biochar, is an excellent plant food. The syngas can be turned into other useful organic compounds, plastics, polymers, etc.

    There are two methods of gasification.

  1. High temperature pyrolysis of carbonaceous material: In this method, the material, such as wood, charcoal, coal, etc. are heated to a high temperature (700 to 1000 degree C) to pyrolyze (thermal decomposition) the material into solid, liquid and gaseous products which undergo further processing. The Wikipedia article explains the processes involved in this method. This is the low cost option and is widely in use today. In fact, this method was used during the WW2 era, in parts of Europe and the US, to produce fuel for automobiles to overcome fuel shortages. Presently, biomass gasification and waste gasification processes are being carried out with this technique. There is a growing community of DIY biomass  gasification enthusiasts and plenty of resources are being made avaiable, websites and books for educational purposes and hardware for making fuel from cellulosic or wood waste. Biomass gasifier-generator kits can produce a few 10s of kiloWatts of electric power, enough to power an average sized household or two. The burnt wastes produced by this method are usable as fertilizer, making it an extremely clean, green energy producing technology.
  2. Plasma gasification: In this method, a high temperature (>10,000 degree C) arc or microwave induced plasma is created which cracks the compounds into the constituent elements. The process produces gaseous fuels, molten metal run off and a glassy-slag that can be used as aggregate material in construction and building industries. The syngas is used to run a turbine-generator system that can provide energy for the plasma arc as well as surplus energy that can be fed into the power grid. Read the Plasma Arc Waste Disposal on Wikipedia for more information on this process.
  3. Plasma gasification requires larger investment (several million dollars) and about 1 to 2 years of construction time, but the standard plasma gasifier plant can provide 100s of MegaWatts of electric power as well as gaseous and liquid fuels for transportation and industry, while at the same time reducing land fill. This is a very useful technology that should be more widely adopted. Plasma gasification offers a real and imminent potential for an endless source of renewable fuel supply.

    Here are a list of websites that are useful.

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About propulsiontech

Propulsion technologist, aerospace engineer
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2 Responses to Gasification for Renewable Fuel Supply

  1. Dustcarts says:

    The simple view of heating fuels is that most homeowners are relatively limited in their options for heating fuels. In the Northeast, the choices are largely fuel oil or electricity, although natural gas is becoming available to more homes. For people in rural areas, heating fuels may be limited to propane and wood. People in most of the rest of the country have natural gas and electricity as their main choices.

  2. Gasification is good for people who want to live off the grid. It can also be useful for communities that have shortage of funds or limited access to oil or gas, but have natural, biological waste materials, such as food, wood, etc.
    In the early 1900s, before natural gas and oil became widely available, syngas produced from coal was piped to towns to light street lamps. Using waste biomass to light street lights now is not a far fetched idea.
    I am also a big fan of using natural gas or propane to fuel automobiles. The gaseous fuels are easier to mix with air and combust, have less waste products and can be more efficient than gasoline. The US and Canada have large reserves of natural gas. The widespread drilling of the Barnett shale in Texas is creating lots of jobs there.

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