Gasification

The technology at the heart of our process consists of a series of steps which convert the biomass feedstock into a form that makes it's inherent energy available in a more flexible form, especially when compared to traditional forms of biomass utililization. The first, most important, and least understood step is gasification. Recognizing that the nation and the world needs to develop more familiarity with a technology that is destined to take a more central role in a fossil fuel contrained world, the Gasification Technology Council has prepared a short introduction to gasification and it's present and future uses:

For a discussion of the history and tecnological evolution please vist our Gasification page. There you will be able to view a video presentation prepared by the Department of Energy's National Energy Technology Laboratory (NETL).

Internal combustion driven vehicles come in all shapes and sizes from motorscooters to the largest cruise ships. Form follows function. So it is with gasifiers. Most gasifiers in use today are designed to process highly carbon dense materials like coal and pet coke in very large volumes of 10,000 tons per day or more. "Earth Movers" if you will. In a typical air or oxygen gasifier, a portion of the feedstock is burned or combusted to provide the process heat which drives the gasification reaction in the same reaction chamber. This design, while much cleaner than pure combustion, always produces problematic combustion products. They are comparatively easier to handle because of their smaller voilume.

As might be expected, gasifiers designed to process less carbon dense biomass differ markedly in design and morphology from those described above. A typical biomass gasifier is of an anerobic design. Anerobic gasification can be described as " the thermal decomposition of carbonaceous matter in the absence of oxygen". Since oxygen is eliminated from the gasifier as much as is practical, anerobic gasifiers produce much less carbon dioxide (CO2) and typically produce a medium to high BTU syngas. Also, since there is no oxygen introduced, flame never touches the feedstock and there is no deliberate combustion or burning. However, there is always some oxygen of composition entrained with most biomass feedstocks and, consequently, some oxidation takes place, forming combustion products, albeit of a much, much smaller magnitude and consequently easily eliminated. Biomass gasifiers offer throughput capacities in the the range of 30 to 1,000 tons per day. After a gas clean-up step, the syngas produced is suitable for further chemical conversion.

Subsequent Conversion Steps

All gasifiers produce "syngas" which is composed of primarily carbon monoxide (CO) and hydrogen (H2) with varying amounts of methane and other organic compounds. CO and H2 are the foundational building blocks of organic chemistry and can be converted into a variety of products from pipeline quality natural gas to liquid transportation fuels to plastics and more. Most of these steps are driven catalytically and have been in widespread commercial industrial use for hundreds of years.

Combustion vs. Gasification

In summary, the hallmark of the technologies we have selected is flexibility: flexibility of input (feedstock) and flexibility of outputs (products). Since before the dawn of recorded history, the principal method of liberating the chemical energy of biomass, including fossil biomass or fossil fuels, is by combustion. However, it has been noted that it is an "Inconvenient Truth" that creating energy through combustion has a great many very negative consequences for humanity and the ecosphere. However, gasification, in particular "anerobic gasification" is a vastly superior way to unlock the energy content of both biomass and fossil fuels. Combustion of the feedstock produces sensible heat and a variety of problematic byprodcts including, but not limited to:

• CO2
• NOx
• SOx
• Dioxins,
• Furans, etc.

Flexibility of Products

On the other hand, gasification principally produces a medium to high BTU "synthesis gas" composed of approximately 50% Hydrogen and 50% Carbon Monoxide. This synthesis gas can generally be used in much the same manner as "natural gas", including:

• production of sensible heat and steam
• firing in an IC or Turbine genset to produce electricity,
• reforming into a variety of chemical products including:
  • Ethanol,
  • Methanol,
  • Syndiesel,
  • Acetic Acid, and
  • A wide variety of other products.

Flexibility of Feedstock

The gasification technology employed by Pyramid BioEnergy will successfully handle a wide variety of biomass feedstocks, including:

• wood chips,
• hog fuel
• waste treatment sludge,
• tires,
• car interiors,
• construction debris,
• municipal solid waste,
• and other problematic, low value waste materials.

In many cases, the cost of the feedstock material may be negative, which can dramatically effect the bottom line profitability of a particular project. Of course, we can meet any feedstock material shortfall by resorting to established biomass markets.

For updated and additional information, please consult our "News and Additional Information" page.