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Advantages
of NaturTech System
To
illustrate the advantages of this patented technology, it is
useful to reexamine some of problems commonly associated
with conventional composting methods.
Common Organic Waste Disposal Methods:
Traditional outdoor static pile or windrow composting can
transform organic residuals into useable products at low
cost. However, these simple composting methods require more
time and land area. More significantly is the other
drawbacks which will adversely affect the value of
traditional composting methods.
Loss of Ammonia (Nitrogen Value)
For
decades, composting has been used largely as a method of
waste disposal, converting undesirable heterogeneous organic
materials into a homogenous soil amendment, compost. The
nitrogen or plant nutrient content of compost has been a
secondary issue to its soil amending and soil conditioning
properties. Composting has also been criticized as a
processing technology that reduces nitrogen values through
the release of 50% of the feedstock’s nitrogen to the
atmosphere in the form of ammonia.
Beside
taking up vast space of land area,
stockpiling and windrow composting allows leaching
and oxidation activities reduce nitrogen content of the
biomass.
Air and Water Pollution
Ammonia
released to the air is the main source of odors at
traditional composting facilities and nitrates from
unprocessed organics, especially manure are a ground and
surface water pollutant. Air emissions such as fugitive
methane and volatile organic compounds are also identified
as by-products of non-aerated windrow composting, leading to
regulations such as California law AB1133 enabling air
quality management districts to require composting
facilities to reduce air emissions to protect local air
quality.
Finance Opportunity from Carbon Credit
Windrow
composting systems are unlikely to receive carbon credits as
the greenhouse gas air emission deductions exceed the carbon
sequestration credits while forced aeration technologies
with temperature control and bio-filtration prevent these
emissions. The NaturTech Composting system, representing
BMP, is eligible for significant carbon credits.
Lack of Maturity of Final Product:
Traditional composting produces low quality compost if
composting is carried out without Quality Control
instrumentations and computerized control.
Compost
maturity is an important aspect of compost quality. Immature
compost may have an adverse effect on crops for several
reasons, including the heat it generates as decomposition
proceeds, the nitrogen taken up by microorganisms during the
process of decomposition, and the presence of phytotoxic
compounds.
Several parameters have been developed to
determine the maturity of compost, hence it is crucial to
include these quantitative instrumentations to optimize
maturity and consistency of end product.
Many high
nitrogen manures must go through conditioning before they
can be applied onto the soil or applied only in relatively
light application rates in order for soil organisms to
convert the raw organic matter and nitrogen into biological
forms usable by plants. In fact, even chemical fertilizers
much undergo some sort of microbial conversion process in
the soil before the nutrients can be utilized by plants. A
goal of chemical fertilizer manufacturers and applicators is
to either dilute the fertilizer or put it into a slow
release chemical bond to avoid the same sort of “burning” or
phytotoxicity characteristic of unprocessed manures.
NATURTECH COMPOSTING SYSTEM
The establishment of BMPs coupled with the demand for low
impact, space efficient, high efficiency, simplicity and
sound economics has been the driving factor for a new
generation of waste management technologies which led to the
development of the NaturTech Composting System.
The NaturTech Containerized In-Vessel System is a
development of the BMPs of the US Composting Council. The
initial 7 to 21 day composting process in closed containers
is monitored and controlled by computer system and process
controller. This enables the operator to adjust aeration,
moisture and temperature to stimulate composting bacteria
and optimize the decomposition process. Using an in-vessel
system, composting materials are enclosed so that odor and
leachate can be collected and treated while ensuring that
regulated air emissions are prevented. With recent capital
cost reductions, this cutting edge technology is recognized
as a worldwide leader in the composting industry, currently
being installed at the USDA research facility in Beltsville,
Maryland for processing cafeteria organics from Capital Hill
in Washington DC into compost.
Advantages of NaturTech Technology
The
following is a summary of the advantages of NaturTech
Composting System compared with other composting systems.
1. Highly efficient and simple
Simplified Production Process: It’s easy as 1-2-3
The NaturTech composting process minimizes material handling
by making composting a simple and predictable step-by-step
process.
1)
mix
2)
aerate
3)
unload
4)
cure
5)
screen
6)
blend
The process begins with mixing feedstock materials
together to obtain the right blend of materials, moisture
level and amount of porosity for the composting process and
placing the mixture in the containerized in-vessel
digesters. Next, these digesters are connected to a
computer controlled aeration system to optimize the
composting process. After 21 days of composting, the
digesters are unloaded for curing, where the
materials are allowed to cool and dry to 40% moisture. The
resultant compost product is screened and used as a
concentrate to enhance topsoil or blended with other
materials to manufacture potting soil or planter mixes for
landscaping and horticulture.
PLC and
Computer Controlled Aeration System
The NaturTech system’s temperature feedback and computerized
process controlled aeration system delivers the proper
amount of air into each individual composting digester so
that materials do not need to be turned to receive the
oxygen needed during the composting process. This efficient
way of air delivery optimizes the composting process and
reduces the amount of labor and heavy equipment otherwise
needed to turn materials. Variable speed blowers reduce
energy use and the cost of operating the composting
facility. Forced aeration reduces the need for bulking
materials from typical 3-1 in windrow operations down to 3-2
or even 1-1 in composting. In cases where the biomass
feedstock provides the necessary porosity and available
carbon, the process may not require additional bulking
materials.
Not
Affected By Weather
The NaturTech system uses isolated digesters to maintain
moisture and temperature. This minimizes the effect of
weather conditions. Either summer or winter, dry or rainy,
the composting process proceeds year round without
interruption. The technology has been used in severe cold
winters of Minnesota, rainy conditions in the state of
Washington, and in the desert of New Mexico, representing
extremes of wet, cold and hot climates.
2. Cost-effective
Less
Land Required
Compared to other composting systems or technologies, the
NaturTech containerized composting system uses less land
first because piles are in rectangles rather than triangular
windrows and secondly BMPs optimize the rate of degradation
such that stable compost can be made in weeks rather than
months typically associated with outdoor windrow or static
pile systems. This allows an operator to process more
materials per year per hectare than most other systems,
maximizing the use of land resources and lowering initial
capital costs. The double stacking option can reduce land
required by an additional 50%.
Low
Operating Costs
The NaturTech process minimizes material handling which
reduces energy use, front-end loader or tractor time, wear
and tear and labor needs. Air is less expensive and more
effective than steel flails characteristic of windrow
turners. In the static system proposed herein, the
containers will be filled with a 200HP farm tractor in
conjunction with a15 ton container filler. This approach is
a compromise factoring relatively high fuel costs and
relatively low labor, representing a particular application
of the NaturTech system using the digesters as stationary
bunkers with lower initial capital cost and higher labor
requirements. The digesters provided, however, are
reinforced for handling 40 or more tons with container
moving equipment if the facility is subsequently converted
to a mobile operation. Should the mobile container option
be implemented at a later date, container moving equipment
carrying 40 tons per container with 78 horsepower could save
fuel over front-end loaders at 225 HP moving only four tons
per bucket.
Low
Maintenance
The NaturTech system requires less maintenance than other
composting technologies, mostly due to comparatively few
moving parts. Aside from the chipper, end-loaders, mixers,
screeners and conveyors, the only moving parts are the
system’s blowers and dampers. These can be easily replaced
or repaired within hours minimizing down-time. With fewer
moving parts or components, there is less that can go
wrong. The first NaturTech system installed in July, 1994
is still functional today, recently replacing old steel
perforated floors with new PP perforated floors and lining
the digester walls with replaceable FRP plastic insulation
liners used in new NaturTech digesters. The original
digesters did not have superior CorTen steel or epoxy
coating featured in the newest digesters, but still remained
functional with over 14 years in service. With proper
maintenance and replacing gaskets and flexible hoses, the
new replaceable wall liner feature suggests a virtually
unlimited operational life, even in the harshest working
conditions.
High-Quality End Product
The most important feature of the NaturTech system in that
it produces a consistently high-quality compost product.
Once the initial mix is standardized, the compost quality
is excellent week after week, year after year, establishing
confidence with the compost user. This predictability and
uniformity maximizes revenue generated by the facility
enhances the profit that can be made for the composting
plant. The compost product can be blended with other
materials to produce a complete fertilizer for gardeners,
landscapers and farmers. The Mississippi Topsoils facility
in Cold Spring, Minnesota averages $100 per ton for their
compost in a market where many windrow composting systems
struggle to sell their compost for $20 per ton.
3. Well-designed
Proven
Technology
Based upon temperature feedback principles developed in the
mushroom industry in the 1970s and 80s representing the core
of BMPs, the NaturTech containerized in-vessel composting
system represents a new generation of composting technology
that has been widely accepted in the United States and is
setting a new standard of excellence. Because of its
success, the technology is now being introduced throughout the world to handle wastewater treatment plant
solids, food processing residuals, biofuel residuals, animal
manure and organic materials from the municipal waste
stream.
Flexible Sizing
Because the NaturTech system is modular, it can be easily
sized to meet client’s needs. In addition, NaturTech
offers two different sized digesters. One is 20’ in length
and processes 40 m3 of material while the other
is 40’ in length and holds up to 80 m3 of
material. For this initial phase with stationary digesters,
the larger 40’ containers are used.
Longest
Productive Life Span
The interior of the CorTen steel composting digesters and
biofilters are manufactured with a replaceable
anti-corrosion, abrasion-resistant FRP plastic liner so that
with proper maintenance, the containers can be expected to
last for many years beyond their fifteen year design life.
CorTen steel is the most corrosion resistant form of mild
steel, typically more cost effective in corrosive
environments than much more expensive stainless steel.
Mobile
and Easily Expandable
The NaturTech system is modular so it can be easily expanded
as more materials are added to the facility. The
operator can begin with a few digesters and add more at a
later stage. Also, because composting takes place in mobile
containerized digesters that are designed as Intermodal
shipping containers, the system is portable and, if needed,
can be moved from one site to another as the facility is
expanded to process more materials. Some materials may be cured for additional time
as may be necessary to meet specific requirements in
landscaping and horticulture.
4. Clean
Odor
and Leachate Control
The NaturTech Composting system has been designed to meet or
exceed known environmental regulations and standards for air
emissions and ground and surface water protection. The
entire composting process, including curing, takes place
inside sealed containers or under roof, preventing
stormwater contamination. No stormwater retention basins or
water treatment systems are typically required.
Containerization during active digestion enables process air
to be captured and treated in the containerized biofilters
to remove 95% or more of odorous air emissions before
exhaust air is released into the atmosphere. Air emissions
are typically reduced greater than the 80% requirement of
California rule AB1133 which regulates not only fugitive
ammonia, but also fugitive volatile organic compounds. A
drain and tank system captures both leachate and condensate,
enabling these liquids to be recirculated back into the
initial phase of the composting process, eliminating the
need for wastewater treatment.
Computerized Pathogen Reduction Process.
The computerized aeration system controls the temperature of
each composting digester so that materials undergo a
pathogen reduction process, minimizing the risk of spreading
either plant or human diseases. After screening, what is
left is a high-quality compost that can be used for
gardening, landscaping or farming.
5. Quality Control
NaturTech
system provides data management capability and a proven
tracking system which guarantee consistent product results
and traceability from point of entry all the way to delivery
to the end-users. Some of the control features include:
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Start Feedstock Tracking Number |
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Origin of the Feed and Bulking Material |
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Mix Batch Management |
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Digester Batch Tracking System |
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Retention Time and Temperature |
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Curing and Storage Time
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Transportation and Delivery |
6. High quality humus products
The technology fully recovers many organic substances
from industrial waste or process by-products and converts
them into high-quality compost. This can be combined with
minerals and nutrients to produce a complete fertilizer to
help revitalize weak agricultural soils.
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