||Vista International Technology's
five United States patents enable it to engineer solutions to global
waste problems by harnessing the untapped potential of waste for
conversion into low-cost, clean electrical and thermal energy. There
is one U.S. patent pending, as well as an international patent for
European Economic Countries (EEC).
Thermal Gasifier: How it works...
plays a pivotal role in helping Vista International Technologies,
Inc. (VITI) accomplish its core objective to maximum resource recovery
with minimal environmental impact. The proprietary patented technology
is based on a two-stage gasification process. The Thermal Gasifier
efficiently converts the chemical energy contained within waste,
biomass, tires and virtually any solid carbon based processed fuel, into
electricity and thermal energy, while capturing the pollutants and
turning them into useful products.
The Thermal Gasifier
reflects the recognition of the inherent value of many materials that
are typically considered waste. The energy produced has multiple uses in
commercial, industrial and municipal applications and unlimited
potential as a low-cost, stable energy alternative with an economic and
The Thermal Gasifier
efficiently turns processed fuel converted from
feedstock such as waste, biomass, tires and virtually any
solid carbon based material into useful energy without harming the
environment. It does so by extracting
from within solid waste and converts into a clean usable energy.
In the Thermal Gasifier,
gasification and partial oxidation take place in separate gasification
and oxidation areas of a single chamber, and final complete combustion
takes place in the fire tube before entering the boiler.
Within the Thermal Gasifier, these separate areas are established by carefully
controlling air content and temperature along the length of the Thermal
Gasifier. Controlling the areas environment controls the degree of
oxidation, permitting final total combustion to occur within the boiler
instead of within the Thermal Gasifier, delivering maximum heat.
Once the feedstock has
been processed into a fuel, most fuel still contains considerable water
that must be removed before gasification. To accomplish this dewatering,
the fuel first drops onto fire belt 1 into a low temperature region,
about 800 - 1000ºF. As the belt advances, reflected radiant heat from
ongoing downstream reactions increases the temperature to about 1200 -
1500 ºF, extracting as much water as possible from the fuel.
The heat used to
dehydrate the processed fuel is virtually the only energy expended
throughout the entire process that does not produce value - either heat
or reclaimed materials for reuse. To minimize this lost energy, VITI
strives to use processed fuel having a water content of about 10 - 15%,
although the Thermal Gasifier can accept water content up to 50%.
STAGE 1a ¨C GASIFICATION
moving fire belt 1 carries the processed fuel into the gasification
area, the fuel temperature increases and it begins to decompose, or
gasify. (Eventually, the fuel totally decomposes into gas and a solid
residue that gradually cools to about 250ºF as it is conveyed by the
fire belts to an ash pit.) Oxygen in air flowing upward through moving
fire belt 1 reacts with the gases from the gradually decomposing fuel.
The components of the fuel having high volatility begin to break apart,
and some of these volatile components break apart into their
constituents, such as hydrogen and carbon. Fans are placed near the
beginning and at the end of the entire process, keeping the gas moving
through the Thermal Gasifier. As the belt advances, the energy released
by partial oxidation continuously increases the temperature within the
gasification area to about 1200 - 1500ºF, at which point gasification is
complete. The resulting gas and suspended particulates then move into
the combustion area.
STAGE 1b - PARTIAL OXIDATION
The remaining solid fuel then enters the
oxidation area, where it is partially oxidized with controlled air
entering the oxidation area along the length of the moving fire belt 2.
This oxidation releases additional energy in the flowing gas, gradually
increasing the temperature along the length of the combustion area. Some
of that heat energy radiates back into the gasification area to help
support the self-sustaining nature of the gasification process, once
again minimizing the need for external energy to perpetuate the process.
The peak temperature in the oxidation area is around 2000 - 2500ºF, the
temperature at which the gas moves into Stage 2.
At the end of the
combustion area, all of the energy resides in the hot, partially
combusted gas that moves into the fire tube.
- THE FIRE TUBE AND BOILER (COMPLETE COMBUSTION)
To get to the boiler, the producer gas enters
the fire tube, a passageway between the Thermal Gasifier and the boiler.
There, just enough
oxygen is added to the flow of gas in the fire tube to cause complete
combustion before entering the boiler, where the gas releases its
remaining energy and raises the boiler temperature to about 2200 - 2800º
F. As the gas leaves the boiler, all of the energy in the fuel has been
This complete combustion
of the fuel in the fire tube makes the Thermal Gasifier so efficient and
environmentally benign. Complete combustion extracts virtually all of
the chemical energy that was within the fuel. Any small amount of heat
that may be conducted through the equipment only minimally warms the
immediately surrounding air. The unique design of the Thermal Gasifier
causes the gas to retain practically all the energy from the fuel. The
remaining particulates in the gas are stable, chemically non-hazardous
oxides and in the case of used tires, carbon black.
The high temperature
produced within the fire tube has destroyed such dangerous materials as
dioxins and PCB¡¯s, a unique result of the two-stage design of the
To see a list of Thermal Gasifier installations prior to 2004, please click here .
The first of the new Thermal Gasifier models will be the MFG-8, set to debut in our Italian Demonstration project in 2010.
The "MFG" stand for Multi-Fuel Gasifier. We want to make sure our potential customers know that our units are capable of
processing almost any kind of hydrocarbon based waste stream. We fell that this capability of the unit is unmatched in the
The "8" represents that the unit is rated to produce 8 million BTU per hour. This amount of energy corresponds
to roughly 1/2 MW of power if the syngas is converted exclusively to electricity. The company is always concerned with
safeguarding its technology, so we cannot give a detailed view of the unit at this time. Below is a rough drawing of the unit.