Energy Recycling and Waste
Today Fuels from residual substances and biologically regenerating
raw materials represent the future of energy development without the centralized control that exerted by large oil
companies exploiting the world's existing fossil fuel resources. With technologies now becoming available, these
“synthetic fuels” will increasingly replace declining oil reserves in the future. Synthetic fuel production is
possible because sufficient quantities of raw materials exist to develop deliverable quantities to replace fossil
fuel production. These materials include wood and plants, the bio-waste products of our civilization like plastics,
animal and plant wastes, waste oils and other organic residual substances - all of which are usable because of
their intrinsic energy content.
In addition to the intrinsic energy content of synthetic waste
materials, there is an additional objective in using these materials: capturing the hydrocarbons contained in them
for conversion to fuel. Present day recycling procedures, like high temperature gasification that follows the
Fischer Tropsch synthesis model and with overall efficiency ratios of approximately 10%, cannot recover
hydrocarbons. Other well-known procedures, like pyrolysis, are not able to capture hydrocarbon pollutants, such as
halogens and metal steams, which often remain in the final product of existing recycling plants.
Unsatisfactory results from present-day recycling efforts result
from the essential structure of existing processing methods. Transforming residual substances
with each of the well-known recycling procedures requires temperatures of 450°C and above, a temperature at which
coke crystals begin to form from residual substances. Such high temperature procedures decompose the hydrocarbons
in the plant nearly completely into coke crystals and methane. Thus, relocated hydrogen atoms convert the existing
hydrocarbons, CH2, into methane, CH4 and coke crystals, C. In other words, solid coke and methane gas, CH4, are
produced from liquefiable hydrocarbons.
But while coke and methane can be used further as an energy output,
the by-products of such high temperature procedures, like CO2, Dioxin and Furan, are unacceptable environmental
Other technologies, which are based on alternative sources of energy
that are complex and limited, such as platinum, are still in the early stages of development.
Taken the waste disposal and environmental protection situation of today this process would
already be worthwhile for these countries, if they would give away the produced Diesel fuel for
The quality of the produced Diesel fuel turns out to be even higher than expected. Even the
problem loaded bitumen, one of the distillation residuals of oil refineries, can be used by this process and
produces a Diesel fuel with a Cetane value of above 50, i.e. a high quality fuel. This is why this process is
especially attractive to countries where the produced Diesel fuel represents a value. In these environments
the process can gain high importance as a future fuel supply source.
The high efficient level of this catalytic low temperature process of residual transformation
results in CO2 savings of 80 - 90% and thus has a highly positive influence on the overall CO2 balance. Many
countries are now planning to set in force strong restrictions or even prohibit the dumping of untreated
waste materials. For the future this CO2 balance will be significantly depending on the methods we choose to
handle the variety of waste and residual materials. This will soon generate additional sources for
A Quote from a Government Report about Green power Inc in
" Recent rapid rises in the market cost of a barrel of oil during
the past two years have encouraged and enabled many companies worldwide to expend resources in research and
development for alternative energy sources. Even though the price of a barrel of crude has
fallen significantly recently due to the economic slowdown, it is not likely that the price of oil will stay
low over the long run due to strong market factors, such as a very likely increase in demand from countries
such as China and India. Much of the technology and many of these alternative energy
sources have been investigated in the past, and some development has previously been done, particularly
during the 1970's energy crisis when the rise in the cost of oil also made it economically viable to do
so. There are some technologies that are currently being developed, or are being
re-visited, that appear to be currently economically viable, and also with the state of today's technology,
possible to implement.
One alternative energy technology
that shows promise in helping to address the energy needs of the country has been developed by Green Power
Corporation of Issaquah, WA. The technology makes use of a chemical catalytic process called
Catalytic Depolymerization to "crack" the hydrocarbons contained in organic materials, with the highest quality
diesel-like product produced from materials made from reprocessed wood.
Green Power has constructed a 100 ton/day waste-to-fuel
(W2F) conversion plant (Figure 1) in the industrial district along the Columbia River in the southeast
corner of Pasco, WA. This plant stands over 3 stories tall and contains a 6,000 gallon reaction
bath (used in heat transfer for the reaction), with approximately 4,000 additional gallons of reactant liquid being
pumped around or sitting in a separate evaporator tank. Green Power also has two demonstration
units: a mobile trailer capable of producing 600 gallons per day, and also a small 6 gallon
demonstration unit. Both demonstration units utilize the same technology as the larger unit in
Green Power's depolymerization reaction is carried out in a cylindrical reactor
containing a reservoir of oil for heat transfer. Organic material mixed with catalyst is added
to the oil in the reactor. The reactor is heated to and maintained at 360 degrees C near
atmospheric pressure. As the mixture is heated, the catalytic reaction occurs and through the
process of distillation, liquid hydrocarbons are released, along with water. Some waste material is left behind,
and various means to utilize and dispose of the waste have been identified.
Depolymerization is a process for the reduction of complex organic materials
(feedstock of various sorts, often known as biomass) into light crude oil. It mimics the natural
geological processes thought to be involved in the production of fossils fuels. Under pressure
and heat, long chain polymers of hydrogen, oxygen, and carbon decompose into short-chain petroleum hydrocarbons
with a maximum length of around 18 carbons. The depolymerization process for fuel production
from organic materials takes two forms, thermal and catalytic.
The thermal depolymerization approach uses high temperature to crack the diesel from
the hydrocarbon molecules. Although the thermal depolymerization (Fischer- Tropsch) process has
been understood for some time, human-designed processes were not efficient enough to serve as a practical source of
fuel because more energy was required than was produced. Research breakthroughs in the 1980's
led to efficient processes that were eventually commercialized. Some thermal depolymerization
demonstration plants were constructed in the late 1990's, including a commercial plant in
Carthage, Missouri, about 100 yards from ConAgra Foods' Butterball turkey plant, where it is expected to process
about 200 tons of turkey waste into 500 barrels (21,000 gallons) of oil per day.
Thermal depolymerization process has a variety of limitations.
The process only breaks long molecules into shorter ones. Longer molecules are not created, so
short molecules such as carbon dioxide or methane cannot be converted to oil through this
process. Therefore, additional refining steps are likely necessary. In
addition, since the thermal depolymerization approach generally requires temperatures much greater than 400 °C,
there is the risk of producing toxic byproducts such as dioxin and furan in addition to carbon dioxide and
The catalytic depolymerization process occurs at relatively low temperatures and low
pressure. Due to the low temperatures, a catalyst is required to crack the hydrocarbon
molecule. The process requires a temperature above 270 °C and the use of an ion exchange
catalyst. The process can be operated below 400 °C to avoid the production of carbon dioxide,
dioxin's and furan's.
The catalytic approach is preferable to the thermal approach, both from efficiency
and safety/environmental aspects. The latter requires substantial energy input to reach required
temperature, a reactor that can withstand high pressures, and further processing to deal with toxic
byproducts. Assuming a suitable catalyst is available, the catalytic approach only requires a
temperature greater than 270 °C and proper mixing to insure complete reaction of the feedstock with the
The product created by Green Power's Catalytic Depolymerization process is a mineral
oil, versus a vegetable oil that is created through biodiesel production. The biodiesel is a
diesel with limited durability, and may cause engine problems from viscous organic substances. The mineral diesel
is much cleaner with zero organic substances. It is a diesel with higher durability and less engine problem than
A comparison of the GC of the Final Diesel Product and GC of commercial petroleum
diesel is shown in Figure 10. It is apparent The Final Diesel Product is very
similar to commercial petroleum diesel. The Final Diesel Product has less heavy components and more lighter
components than commercial diesel, and therefore should be a cleaner burning diesel with a higher heating value
than commercial diesel.
The Final Diesel Product was tested for several properties for comparison with
commercial diesel specifications. Results are shown in Table 2. It appeared the Final Diesel has either met or
surpassed all specifications for a commercial diesel. Figure 11 shows a sample of
the Final Diesel Product.