Biomass Energy Frequently Asked Questions

Why move to Biomass?

Bio mass has been termed the current “hot button” in strategies for combating rising energy costs and lowering pollution impacts in the United States. The U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy Office puts this in perspective; “The use of The Biomass combustion, such as burning wood, has been one of man's primary ways of deriving energy from biomass from prehistoric times to the present. It is not, however, very efficient. Converting the solid biomass to a gaseous or liquid fuel by heating it with limited oxygen prior to combustion can greatly increase the overall efficiency, and also make it possible to instead convert the biomass to valuable chemicals or materials”. The EERE is continuously dedicating resources to this subject in a “national effort to develop thermochemical technologies to more efficiently tap the enormous energy potential of (biomass)”.

What is Biomass?

Per the EERE; “Biomass is any organic material made from plants or animals. Domestic biomass resources include agricultural and forestry residues, municipal solid wastes, industrial wastes, and terrestrial and aquatic crops grown solely for energy purposes.

Biomass can be converted to other usable forms of energy and is an attractive petroleum alternative for a number of reasons. First, it is a renewable resource that is more evenly distributed over the Earth's surface than are finite energy sources, and may be exploited using more environmentally friendly technologies.

Agriculture and forestry residues, and in particular residues from paper mills, are the most common biomass resources used for generating electricity and power, including industrial process heat and steam, as well as for a variety of bio based products.”

What makes Biomass Gasification Environmentally Friendly?

Biomass is organic matter- and Biomass energy development likes to take what is usually thrown away and turn it into energy. Our technology, Vertically Integrated Gasification & Combustion, allows business and industry to operate "off the grid" using their own waste stream (pallets, boxes, paper), or materials from agriculture such as farming, milling and ranching. We use clean technology to take the stored energy from these materials and create heating, electricity, even cooling. By using a renewable waste stream, our clients reduce or remove their need to buy fossil fuel derived energy.

I'm used to hearing about wind, solar, biodiesel, and ethanol - How is Biomass different?

Biomass is everywhere, anytime. Unlike wind and solar it can be stored and used on demand. Ethanol and biodiesel are liquid fuels made from solid biomass requiring steps to take organic matter and turn it into energy. We use the biomass in a solid form vs. liquid. But as often is the answer there are synergies between these approaches. For example, the byproducts of making ethanol and bio diesel are excellent fuel for our units. This means we can recover energy costs that had been sunk costs by using the refining spoils to energize the refining operations. Another important note is that by using waste materials to create energy, we are not encroaching on our food supply.

Are you burning the solid fuel to create energy?

Absolutely not, and that's one of the major misunderstandings of our technology. We use a process called "direct gasification" to extract the energy from solid fuels. It is different than "burning" because burning consumes all of the matter at once, which is problematic. Gasification actually separates or elutes combustible gas from a solid in a controlled temperature, oxygen starved chamber. This synthetic gas is then mixed with air and combusted, producing heat or steam. It is a subtle but critical difference.

Is this a new technology?

No it is not. European countries who have been dealing with high costs and limited supply of fossil fuel have burned solid fuels for decades. Think of our steam locomotives. Wanting the energy but not emissions, our Italian partners at Uniconfort have perfected this conversion process of Vertically Integrated Gasification & Combustion. Our technology has been used for energy production for over 50 years in Europe. As a practical example of biomass energy, Sweden currently converts 3.1 million tons of waste to generate 9 billion kilowatt hours of energy.

Can I use Biomass energy today?

Absolutely. Solid fuel-to-energy has been and is happening anywhere there is a coal or wood fired plant. We have simply taken it another step. While we won't use coal, our process uses varying types of biomass- anywhere from a few hundred pounds to multiple tons per hour and does so cleanly and efficiently. Having been in the business of combustion and power for 54 years, we have a deep appreciation for the existing infrastructures and processes that rely on opening a valve and creating power. This is why our stated objective is to deliver Biomass consuming equipment that is as automated and easy to use as those fueled by fossil fuels.

What is “Vertically Integrated Gasification & Combustion” (VIGC)?

Biomass fuels can be converted to energy through several approaches. Examples are fixed base digesters which are referred to as “Gasifiers” where bio mass is converted to gaseous state via organic reduction and methane if pulled off for combustion in a separate process. Then there is thermal Biomass gasification where synthetic gases are thermally released, captured and processed through a gas treatment and cleaning train. In this article we are reviewing what our findings show as the optimum answer, Gasification and vertically integrated combustion.

Combustion is a function of the mixture of oxygen with the hydrocarbon fuel. Gaseous fuels mix with oxygen more easily than liquid fuels, which in turn mix more easily than solid fuels. Syngas therefore inherently burns more efficiently and cleanly than the solid biomass from which it was made.

What is the difference in Pyrolysis, Gasification and Combustion?

In 2005 the Biomass Energy Foundation described Biomass Gasification as follows:

Biomass Gasification = Pyrolysis (break apart), Gasification (conversion of solid to gas), Combustion (burning of the gas to make CO2 and H2O).

Consider what is represented in a lit match stick, it is flaming combustion. Lots of air passing over a small amount of wood, it burns completely to CO2 and H2O.

CH 1.4 O 0.6 + 1.05 (O 2 + 3.76N 2)èCO 2 + .7H 2 O

If you have insufficient air passing through a mass of burning wood, you have “flaming pyrolysis” producing CO and H2, the basis of biomass gasification.

During gasification, air (or oxygen) is passed through a bed of burning biomass. The large excess of fuel causes the following reaction

CH 1.4 O 0.6 + Air è Charcoal, CO, CO 2, H 2, H 2 O

How is VIGC effectively deployed?

How the breakdown occurs (the relative fractional derivatives) depend on the AIR/FUEL ratio.
It is necessary to have the correct air (or O2)/fuel ratio to achieve complete gasification and the air needs to be introduced in stages as fuel is heated.
In our gasifiers there are three phases of air introduction; primary, secondary and tertiary. The correct air/fuel ratio is variable depending on several factors including:

  • Moisture content
  • Type of biomass
  • Air throughput rate

Optimizing this ratio begins with minimal primary air or an oxygen starved atmosphere, as synthetic gaseous fuel is eluted. It is after this first conversion that the secondary and tertiary air is introduced and is the key to simple, clean gasification.

How has solid fuel usage improved?

Most veteran boiler engineers think of solid fuels and the old style “stoker boilers”. Today’s solid fuel generators are far advanced from these past units. Granted the technology is still fledgling in the United States and there is not much manufactured yet in this country.

However, if we look at European nations, solid fuel utilization has been a staple for some time. Its understandable when comparing the resources and their availability in Europe versus the U.S.. Regardless the reason this puts us in a very positive position of taking advantage of years of development and correction due to lessons learned.

Out of the several dozen models one can encounter world wide, the best few have been built with a focus to be automated, to run effortlessly with minimal attendance. Solid fuel boiler systems are by nature, base load units. Again the good ones are dependably modulating capable but prefer to run continuously. Best case of utility is running them at full load all the time.

What is Biomass Gasfication?

Biomass can be described as “stored solar energy”. AESI has secured proven biomass technology that harnesses the stored power in biomass materials using a process called gasification. Gasification is the cleanest combustion method available, and is at the core of each AESI biomass technology offering.

The term "gasification" has, confusingly, taken on multiple definitions depending on the entity using the term. AESI subscribes to the predominant meaning. Wikipedia defines gasification as follows:

Gasification is a process that converts carbonaceous materials such as coal, petroleum, petroleum coke or biomass, into carbon monoxide, hydrogen and carbon dioxide.
In the gasifier, the carbonaceous material undergo three processes:

  1. The pyrolysis (or devolatilization) process occurs as the carbonaceous particle heats up. Volatiles are released and char is produced, resulting in up to 70% weight loss for coal. The process is dependent on the properties of the carbonaceous material and determines the structure and composition of the char, which will then undergo gasification reactions.
     
  2. The combustion process occurs as the volatile products and some of the char reacts with oxygen to form carbon dioxide and carbon monoxide, which provides heat for the subsequent gasification reactions. Pyrolysis and combustion are very rapid processes.
     
  3. The gasification process occurs as the char reacts with carbon dioxide and steam to produce carbon monoxide and hydrogen. The resulting gas is called producer gas or syngas (or wood gas when fueled by wood) and may be more efficiently converted to energy such as electricity than would be possible by direct combustion of the fuel, as the fuel is first combusted in a gas turbine and the heat is used to produce steam to drive a steam turbine.

Also, corrosive ash elements such as chloride and potassium may be refined out by the gasification process, allowing high temperature combustion of the gas from otherwise problematic fuels.

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