Powers Energy facilities use proven gasification and syngas conversion
processes along with conventional materials handling and ethanol
distillation techniques to produce fuel-grade ethanol, electricity, and
recyclable metals and glass commodities. We call the
ethanol from our facilities "bioethanol" because it is made mostly from
biogenic materials, which are materials produced by biological processes
of living organisms. Biogenic generally refers only to organic
non-fossil material of biological origin. As a result, biogenic
materials are not a source of new carbon dioxide in the atmosphere.
Municipal solid waste is comprised largely of biogenic materials such as
paper, wood, food, leather, cotton, etc. Our technology has been
successfully demonstrated and proven in operating pilot plants.
We utilize existing, conventional
waste collection, transport, and processing operations to prepare the feedstock material for commercial product development. The bioethanol conversion process includes
six major processing areas: 1) feedstock handling and preparation; 2) thermal gasification which produces
synthetic gas, or syngas; 3) syngas cooling and cleaning; 4) biocatalytic conversion of syngas to ethanol;
5) electricity generation; and, 6) distillation.
(municipal solid waste)
The MSW feedstock
is placed and totally contained within an engineered building
designed with state-of-the-art ventilation and odor controls, and with a
concrete floor to prevent leachate migration. The feedstock processing operation includes MSW classification,
automated conveyor sorting lines, shredding, and waste handling equipment. Recyclable metals and glass
are removed from the MSW feedstock and processed for resale. Carbon-based MSW and other feedstock materials
are mixed, crushed or shredded (minus
6 inches), and fed to the gasification plant for bioethanol production;
these materials could include paper, cardboard, wood, food waste, plastic,
yard waste, tires/rubber, textiles, and other carbonaceous materials as may be available. Inert waste materials and residue from the process
are removed and hauled to a landfill for disposal or used for other purposes as may be appropriate.
TYPICAL FEEDSTOCK FLOOR PLAN
CP Manufacturing Inc. provides waste handling design support
Green Energy Production
Gasification of various feedstocks is a mature industry and numerous processes are in use today. We use commercially available gasifiers which have been used to produce
waste materials and other feedstocks. There are
many gasifiers in operation, several in large metropolitan areas, and all meet EPA and state emission requirements. The carbon-based feedstock materials
are converted to a synthetic gas product (syngas) in the gasifiers
using the heat derived from the feedstock and by limiting the available
oxygen. The syngas is derived from the carbonaceous materials and consists
►carbon monoxide (CO),
►hydrogen (H2), and
►carbon dioxide (CO2); with lesser
►nitrogen (N), and
Hydrogen and carbon monoxide typically comprise the majority
of the syngas and are the components of most value in our process.
Nitrogen is the largest component of the air we breath, comprising about 78%
of the volume, and is a harmless gas. Oxygen comprises about 21% of
the air, which is far more oxygen than we use in the gasification process.
Therefore, the amount of air entering the gasifier must be controlled.
Carbon dioxide is also present in the air and is produced by animals while
breathing, by combustion of fossil fuels in power plants and automobiles,
and by burning things like wood, leaves, natural gas, and charcoal, to name
a few. Too much carbon dioxide in the air will trap more energy from
the sun, thus contributing to global warming. Gases such as carbon
dioxide and methane are often referred to as "greenhouse gases" because they
"trap" heat in the earth's atmosphere. Our process helps reduce the
amount of greenhouse gases in the air.
After the syngas is removed from the gasifier, it is rapidly cooled in conventional heat exchangers. The heat from the hot syngas
is recovered from the heat exchangers and used to produce steam for power generation. The cooled syngas
is then passed through cleaning and scrubbing equipment to remove impurities.
Our facilities use patented bacteria in low temperature, low pressure
fermenters to convert the conditioned syngas into ethanol. The
bacteria are anaerobic and die upon exposure to air. We refer to this
technology as catalytic fermentation. The conversion process occurs
very quickly and is essentially continuous, as opposed to the batch
processes required in the corn-ethanol industry. The bacteria consume
most of the syngas in the fermenter.
Multiple gasifiers, cleaning circuits, and fermenters
are used in a modular configuration to enhance system selectivity and availability.
The ethanol is removed from the fermenter as a dilute solution and passed to a distillation tower where it is concentrated
to about 95% purity. The concentrated ethanol is then passed through a molecular sieve to remove the remaining water. The bioethanol is denatured with unleaded gasoline before being stored in tanks
for sale as fuel-grade ethanol (over 99% ethanol content).
The off-gas from the fermenter is further cleaned then routed to a steam boiler for use in power generation. As mentioned earlier, steam is also generated during the cooling of the syngas. The steam generated at the plant is utilized for heating duties within the process
in addition to generating electricity via a steam turbine.
Environmental protection measures
are implemented for all components of our facility. The measures are integrated through the design, construction and operation of the waste handling facility, the gasification system, the bioethanol synthesis system, stormwater runoff controls, and the plant grounds as a whole. The gasifier and bioethanol synthesis system are operated as closed systems – no syngas or other materials can leave the system without treatment.
Our facilities have minimal impact on air quality and meet all local, state, and federal requirements for emissions.
State-of-the-art environmental controls are provided to prevent air, groundwater, and surface water contamination. Additionally, the facilities
are located away from residential areas to prevent noise, odor, traffic, and other possible nuisances to residents.
Air emissions from waste material off-loading and processing are contained within the waste handling
building. Our facilities store, contain, process, and dispose of solid
waste in a manner which prevents threats to human health and the
environment, including the creation of fire hazards, vector intrusion, air
or water pollution, and other nuisances. The waste process building is
operated with a slight negative pressure to prevent odors and particulates
from leaving. Engineered commercial filtering systems remove odors and
contaminants from the building exhaust.
The operation of the gasifier is inherently part of the environmental
controls. The design includes carefully controlled syngas velocities,
reduced oxygen content, and a slightly negative pressure within the gasifier.
The reduced oxygen atmosphere prevents the formation of oxides and
carcinogens such as dioxins and furans.
The raw syngas stream leaving the gasifiers is cleaned and scrubbed to remove contaminants. Immediately after leaving the gasifier,
the syngas is routed through heat exchangers and quench chambers to lower the temperature, then to
filters and scrubbers for further cooling and removal of solids and other
contaminants. Multiple processes are used to remove contaminants such as tar, particulates, chlorine, alkali compounds, hydrogen halides, nitrogen compounds, heavy volatile metals, and sulfur compounds. The fermenter provides additional syngas scrubbing and consumes most of the syngas produced in the gasifier. Final exhaust gases consist almost totally of carbon dioxide, water vapor, and nitrogen.
Waste water is treated onsite in our own plant and recycled through the
facility to minimize water consumption; fresh water consumption is in the range of 1 to 1.5 gallons per gallon of ethanol