on the importance of emission limitation and control

7/29/2019 On the Importance of Emission Limitation and Control

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On the Importance of Emission Limitation and

Control with Methods

Isaac D. Cobb

12.01.2009


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All human activity puts some un-natural chemicals into the air. Most pollution

results indirectly from human activity, the world is so intertwined that arguing the

preceding statement is a fool's errand. Human civilization is awash in a sea of air, which

polluted on a daily basis. Limiting the affect of this pollution is a less desirable option to

treating the problem from the roots. There exist a limited number of options available for

changing emission patterns in the air all must share. Primarily there are three, control

and/or limitation, new technology, and new engineering. The following will attempt to

rationalize the ability of each to alter emission patterns as well as assert foreseeable flaws

in the knowledge presented.

First, examine the chemistry of the air that surrounds all living things. The primary

source of many emissions is transportation. Internal combustion engines are responsible

for a large percentage of nitrogen oxide emissions, in conjunction with the power industry

(3). Major power outages have shown the dramatic contributions of nitrogen oxides to

atmospheric pollution by the dramatic decrease in the oxides, ground level ozone, sulfurous

oxides, and particulate matter. Major power outages result in a loss of industrial

production and vehicular traffic in conjunction with a loss of general modernity. The

complex chemistry of atmospheric pollutants causes them to be cyclic throughout the day.

The addition or subtraction of a relatively small amount of one pollutant can cause a

dramatic shift in the presence of other reactants. This is exacerbated by the fact the

endemic complexity of weather patterns can transport air pollution from one part of a

region to another, perhaps, hundreds of miles away. Below lists a series of reactions, the

direct and indirect responsibility of human activities, causing increased nitrogen oxides in

the atmosphere:


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1. NO2 + UVA NO* + O*2. O* + O2 O33. NO* + O3 NO2 + O24. Olefins + (O2,NO,nitric radicals) aldehydes5. VOCs HOO- or ROO- + NO OH* + NO26. OH* + NO2 HNO3Early in the day, the concentrations of nitrogen oxides are at their lowest because

over the course of the night they largely dissipate. By mid to late morning though

vehicular traffic and general human activity has increase the concentration of NO and over

the course of the late morning the NO in the atmosphere is oxidize to NO2. As seen in the

series of reactions above, NO2 transforms into ground level ozone by a 2-step mechanism

initiated by UV-A radiation. Other reactions that can be important in the broad scheme of

vehicular traffic include this non-comprehensive series:

1. C(s) + NO2 CO + NO2. S(s) + combustion SO2 (g)

Sulfurous emissions are awkward to deal with because, in excess, they can generate acid

rain and sulfur inherently poisons the catalytic converters and scrubbers used to reduce

other emissions. Carbon monoxide is especially toxic to the respiration cycle of mammals

because it effectively binds to the hemoglobin of blood preventing gas exchange in tissues.

The image on the next page, taken from newworldencyclopedia.com, has been

included to show the complexity of the earths atmosphere and the chemistry proceeding

daily. The previous list, remember, was not all-inclusive nor is the diagram. Notice that


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some gases active in the complex chemistry of the atmosphere are natural while others are

anthropogenic. In rural areas, gases involved in atmospheric chemistry can be contributed

by natural sources the majority of the time. However, in urban areas, the contributions of

such natural sources are so low they are negligible. Air currents also play a role in

pollution because some pollutants absent in rural areas help provide a means for

elimination of synthetic gases and emissions. Large natural sources of atmospheric

pollution are volcanoes and other massive geologic events. Many natural processes are in

balance with the surrounding environment but the anthropogenic sources complicate and

throw processes out of equilibrium leading to the formation of products in populated areas,

which would not otherwise occur.


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In addition to the gaseous emissions, there are also particulate emissions under two

classifications. Those particles which are inhalable, greater than 2.5 micrometers but less

than 25 micrometers, and those which are respirable, less than 2.5 micrometers. The

respirable particles pose a greater health risk because they can readily infiltrate the lungs

and alveoli. However, it is not simply their size posing a danger to humans. While very

small particulate matter within the lungs is expelled very slowly, the greater danger is in

the fact that these airborne particles give a surface for a good deal of very complex, and

possibly, harmful chemistry to take place. While this is worth mentioning, it is not within

the discourse of the current work to cover the complexity of site reactions on airborne

particles. It is sufficient to say that the smaller the particle the more potentially harmful it

is as an exposure risk. Large particles will fall out of suspension at a rate directly related

to their diameter. Thus, once something very tiny is airborne it will have a longer

suspension episode, posing a greater inhalation risk.

Because of the large-scale use of fossil fuels as a mode of transportation and energy

production, it is important to discuss them as something that is not going to go away soon

(9). It is desirable to continue to improve and engineer vehicles, industries and plants with

more fuel efficiency, while maintaining or improving their power output and/or

consumption. The petrochemical industry is large, established, and infiltrates nearly all

facets of modern life. Materials, fuels, and even food owe something to the petrochemical

industry.


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This flow chart of one facet of the petrochemical industry, taken from

Britannica.com, shows how many products come from the distillation of crude oil. Most

first distillation products go through further processing to yield a variety of commercial

goods. Crude oil, coal, and natural gas can all be converted to carbon dioxide and

hydrogen gas through a steam reformation process under heat and pressure. This process

opens up a variety of options for synthesis. The preceding information shows that fossil

fuels have a diversity not seen in many other products or raw materials. Using fossil fuels

responsibly and efficiently simply makes use of an abundant and versatile, if not

renewable, natural resource.

One of the earliest and simplest implementations used to reduce emissions from

vehicles and industry involved the catalytic conversion of harmful byproducts from

combustion of petroleum-based fuels. Simply, a catalytic converter (today) is a three-stage

process (4). The first stage is a reduction stage. Platinum and rhodium reduce potentially

harmful nitrogen oxide emissions to diatomic oxygen and diatomic nitrogen. The transition


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metal chemistry is complex, but simply put the metal complexes with nitrogen to stabilize

the formation of atomic nitrogen, which can then form diatomic nitrogen as a stable

product. The second stage is an oxidation step where the catalyst drives the combustion

cycle to completion. This step drives carbon monoxide formed during combustion to

carbon dioxide. While carbon dioxide is less directly harmful to humans debate rages over

its contributions to the green house effect. Green House Effect is a topic the author wishes

to discuss only as a theory as it potentially relates to emissions. Platinum and palladium

accomplish the oxidation step via another complex transition metal chemistry. The final

stage monitors the exhaust gas and gives the information to the injection and intake system

to help maintain proper stoichiometric ratios for proper combustion. While the three steps

are mentioned sequentially, it does not mean that the steps are not ongoing concurrently

during combustion and emission discharge.

This representation taken from lordgrey.org shows the basic layout of a modern

catalytic converter. The probe monitors the gases entering converter to assure that the


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proper mixture of fuel and air within the combustion chamber. The converter's stainless

steel housing is filled with a porous ceramic substrate layered with metal catalyst. The

porous nature of the ceramic substrate enhances the available surface area utilized as

catalytic sites.

One of the greatest shortcomings to this system is that it is only truly effective at

higher temperatures. Simply moving the converter closer to the combustion block is not

feasible because the hot gases would be a detriment to the converter. The batteries on cars

are not amply robust to heat catalytic converters to light off via a resistance heater. The

inclusion of a battery large enough to do so would likely cause more environmental

consequence than it would eventually solve. The value of the metal catalysts, also present a

target for theft, theft of catalytic converters is becoming epidemic as thieves steal the

converters in hopes of exploiting the precious metals mounted within the ceramic substrate

for profit.

One interesting manner of heating catalytic converters to light off temperatures

more rapidly is called the Spark Ignition Internal Combustion Engine (SIICE). This

engine design uses a rich air/fuel mixture, which causes a higher temperature of

combustion (12). The heat of oxidation for the products of rich fuel combustion may also

help to heat the catalyst to light off temperature more quickly. The excess of oxygen in the

early fuel mixtures can convert hydrogen gas and carbon monoxide to the more innocuous

water and carbon dioxide during the phase of thermal oxidation, and exothermic step

resulting in the release of heat as more stable covalent bonds form. This process supposes

that the increased temperatures may help the catalytic converter reach light off after only a


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few seconds because of the increased temperature of exhaust gases. The increased initial

heat, however, may damage seals inside the engine.

It is a fact that the lower combustion temperatures of diesel engines cause less

nitrogen oxide emissions (3). Naturally, diesel has its own set of problems. Diesel fuel

combustion forms more particulate emissions and diesel fuel generally contains more

sulfurous compounds because sulfur tends to migrate to heavier hydrocarbon fractions.

Sulfurous emissions are harmful to the environment, but are also a detriment to the

catalytic converter. Other problems with diesel include the particle trap. While this

reduces the emission of particulate matter, it forms a site for the active oxidation of

elemental carbon, soot, by nitrogen dioxide to form carbon monoxide and nitric oxide.

Diesel is also somewhat problematic in colder climates because of the long chain paraffin

residues within the fuel raise the cloud point and pour point of the fuel (6). For this reason,

diesel formulations must be regional and the blends often sacrifice combustibility (cetane

rating) to allow for cold weather performance. Cetane rating relates to the ability of the

fuel to attain auto ignition under pressure and has a widely accepted fuel rating of greater

than 40 with a performance plateau of about 55. Strategies for blending diesel fuels to

achieve a proper cetane rating and have cold weather performance should be investigated.

Despite the en vogue thing, fuel cells, automakers continue to research new forms of

internal combustion engines that run on petrol distillates (9). One attractive approach to

solving the emission dichotomy between diesel and gasoline fuels is the Homogenous

Charge Compression Ignition (HCCI) engine. The design incorporates diesel like efficiency

with the clean burn of traditional American unleaded gasoline (Popular Mechanics). The

technology has been in existence since the late 1970s. At the time of its conception, the


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engine designers lacked the computing equipment to control the precision timing required

of the HCCI engine. HCCI is only one of many technologies under exploration behind the

closed doors of industry and academia alike since primary personal propulsion systems will

likely fall under the domain of petrochemical fuels for decades to come. Thus,

investigations into practical solutions for petrol based fuel engines are imperative.

Research involves the digital control of fuel systems, thermal regulation of exhausts,

exhaust recycling, and improving cylinder design.

HCCI is one of the oldest technologies under development for modern use. The idea

is simple, but does require a good deal of new engineering to include all the control sensors

and other systems vital to timing. The HCCI engine uses exhaust gases to help maintain

engine temperature at levels sufficient for the ignition of gasoline. HCCI engines are able

to maximize the efficiency of gasoline at lower temperature burns. Using high pressures,

HCCI engines achieve ignition but keep their temperature below 2000 degrees Kelvin,

above which the formation of nitrogen oxides is favored via a thermal oxidation

mechanism. While computing and engineering of these engines has come a long way,

timing the cycles properly at high RPM remains a difficulty. At modest speeds, the cycle is

somewhat easy to maintain but as the vehicle requires power for acceleration, the timing

issue becomes problematic. There remain, however, other engineering ideas that may

improve the overall efficiency of internal combustion engines, thus lowering overall

emissions.


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See the differences between the cylinders in the three types of engines in an image

taken from wired.com. Diesel is ignited by increasing pressure to the air/fuel mixture,

gasoline is ignited causing a higher temperature burn by the spark plug, and HCCI engines

have a better air/fuel mixture that is ignited by the high-pressure compression. These

engines actually achieve a lower burn than diesel engines. The low fuel burn temperature

and homogenous nature of the fuel/air mixture achieve a reduction in nitrogenous

emissions as well as particle emissions.

Inventor Eddie Struman believes that to way to improve overall efficiency is to

micro-manage airflow coming into the engine. In his cam less engine, he replaces the

overhead cam with digitally controlled valves, which optimize airflow for a variety of

driving situations and fuels. This system also allows for the deactivation of piston cylinders

during times of idle driving where not acceleratory power is required. This will help


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maximize fuel economy in much the same way that a 4-cylinder engine gets better fuel

economy than an 8-cylinder engine. The cam less engine also utilizes exhaust gases to help

initiate the fuel burn helping keep engine temperature below that of the temperatures seen

in traditional internal combustion engines.

Another idea, which claims to have a 25 percent increase in efficiency accompanied

by a 50 percent decrease in NOx emissions, is the split-cycle-combustion engine. The split-

cycle-combustion engine (SCCE) separates the 4 cycles of the traditional internal

combustion engine (intake, compression, combustion, exhaust) across two different

cylinders designed to work together. The combustion cycle is optimized by igniting the fuel

mixture after the piston crosses dead top center, the point where the piston begins its

downward stroke. By incorporating this energy usually sapped by continuing the upward

stroke, or sending it in reverse, is eliminated. The cycles are divided over the 2 cylinders in

a manner where the intake/compression and combustion/exhaust are split between 2

cylinders. The compressed air from the first cylinder is transferred to the second cylinder

as the fuel mixes with the air. The increased efficiency is due to the turbulent flow across

the cylinder exchange bridge. The turbidity of the fluid more intimately mixes the air and

fuel leading to a more comprehensive burn.


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The image above, taken from thefraserdomain.com, gives a simple diagram of how a

split cycle engine cylinder pairing might be set up.

M.I.T. has also developed a technology it calls Turbocharged Ethanol Boost (TEB).

This idea claims to be as efficient as a hybrid without the need of a battery. While cars

with large batteries may burn less fuel it is not ridiculous to think that a batter

manufactured by the lowest bidder in a developing nation has a carbon foot print as large

as the car itself. Batteries also pose difficult environmental disposal problems. The TEB

also boast potential savings of about 2000 dollars over price of a hybrid. The engine works

by injecting ethanol into the combustion chamber to vaporize and reduce overall

combustion temperature while at the same time reducing knocking which can be associated

with traditional gasoline. Computer models estimate a 20 percent increase in efficiency

though at the time of the article a full-scale working prototype had not been tested. This is

similar to a technology Ford has been working on for a new generation of engine to move

beyond its new EcoBoost series (1). The technology Ford is using dates back to the 1970s

and is pictured below in an image taken from green.autoblog.com


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The Ford Bobcat engine is a twin turbo/twin fuel engine that works by mixing fuel and air

in the intake manifold and adds the E85 to the combustion chamber to prevent premature

ignition associated with high-pressure turbocharged engines. The direct injection of the

ethanol directly into the combustion chamber raises the octane rating of the fuel mixture to

about 150, from the low 90s. This allows the engine to run on a lean fuel mixture without

increasing thermal oxidation of atmospheric nitrogen. In addition to the decrease in NOx

emissions, Ford promises a 5 to 10 percent increase in fuel economy and power

performance increase similar to that of their current production Turbo Diesel Engines

without the addition of costly diesel particle filters. One foreseeable problem with this

engine design is the increased number of working parts leading to increased incidences of

break down.


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The last engine technology to discuss is not new but is finding new utilization in the

commercial auto industry. Turbo-compounding converts heat from the combustion cycle

into mechanical power (9). By using exhaust heat, turbo-compounding is able to increase

the power generated by smaller engines. Currently, large trucks employ this technology

and they have seen a power increase of about 5 percent with a similar decrease in fuel

consumption. The idea is similar to conventional turbo charging. However, instead of

using a turbine to force more air into the combustion chamber the turbine is located

somewhat further down the exhaust stream and creates a mechanical power used to turn

the crankshaft.

All of these technologies do not necessarily effect the formation of nitrogen oxides or

other vehicular emissions. These new engine designs only hope to decrease overall

emissions by increasing the efficiency over current technologies. The new designs may be

somewhat costly to implement but the idea is that by increasing efficiency the operating

cost is significantly lowered so any additional costs associated with initial cost should be

offset by operating costs.

Properly engineering or formulating fuels may also reduce emissions. New

formulations of gasoline incorporate oxygenated products, which help force the formation

of carbon dioxide over carbon monoxide (3). This helps reduce CO emissions even before

the catalytic converter reaches its light off temperature. Even after the converter has

reached is light off temperature the incorporation of the oxygenated products allows the

converter to have less work to do. This may mean longer catalytic life for the converter.

Another innovation in fuel design is Shells Nitrogen Enriched Gasoline which incorporates

nitrogen into the fuel which helps reduce and remove engine sludge build up in cylinders,


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injectors, and valves (8). The gasoline works because the incorporation of the nitrogen

helps to induce a thermal stability in the gasoline. The increased thermal stability means

that the fuel will not degrade and deposit inside the engine before combustion. By reducing

and removing engine-sludge users can expect increased efficiency from their internal

combustion engines.

The process of refining the hydrocarbons that go into gasoline formulations can also

be complicated (10). Essentially, all gasoline formulations are the same coming from the

refinery. Different service station franchises include their additives after the production

process. They may be added directly to the transport tanker or to the underground tank at

the service station. Fluid Catalytic Cracking (FCC) of coal, oil, and other chemical

manufacturing processes is a major source of sulfur oxide emissions. Sulfur contained in

many petrochemical feedstocks forms a coke containing sulfurous deposits on catalyst

active sites. After leaving the reactor, product and catalyst are separated and the catalyst

goes for regeneration. The FCC can form mixtures of hydrocarbon products. Often, FCC

processes generate gasoline and diesel fuels.


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During regeneration of the cracking catalyst, the coke is burned off along with any

sulfur forming SOx gases. Flue gas scrubbing is a mature technology that is capable of

removing much of the SO2 emissions in FCC regeneration processes (11). However, the

current methods of flue gas scrubbing teach a one size fits all approach toward removing

SOx emissions via flue gas scrubbing while different FCC units may be more effectively

scrubbed using different sorbents and additives depending on the degree of combustion

and oxygenation of the flue gases. Investigations into new scrubbing additives for

proprietary purposes include one or more sorbents and oxidation catalysts. Using new

scrubbing technologies fitted specifically to individual FCC units, emissions will be more

effectively scrubbed while also maximizing the efficiency of the catalyst in a low oxygen

environment. Investigations into varying sorbents, oxidants, and catalyst structure show

that the ability of the catalyst to substantially reduce SOx emissions in different conditions

at low levels of oxygen.


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One other trouble with gasoline is the incorporation of sulfurous compounds in the

catalytically cracked gasoline itself (10). Upgrading hydrocarbon streams for gasoline

production is one way to limit sulfur content in gasoline. Hydrotreating of heavy gasoline

fractions, including naphtha, is a way of forming H2S gas, easily fractionated and

sequestered. By working to decrease the sulfur content of fuels it can be assumed that

lower CO and NOx emissions can be achieved by maximizing catalyst activity that could

have been lost due to catalytic poisoning. The hydrotreating process can be problematic

because it also attacks olefin double bonds lowering octane numbers. Overcoming this

problem involves first forming heavy and light petrol fractions because the majority of

sulfurous compounds in hydrocarbon streams migrate to the heavy petrol fractions. An

additional step incorporated takes desulfonated heavy fractions to reformation over a

platinum catalyst to induce aromacticity. These new aromatic compounds then undergo an

alkylation step because of the carcinogenic effects of benzene. This reforming introduces

the octane boosting affect of aromatic compounds while the alkylation gives the liver a site

for metabolism. Regardless, whether the heavy fraction is reformed or simply recombined

with the lighter fraction the result is a highly desulfonated gasoline.

ExxonMobil has created a licensable process in which naphtha is fractionated,

hydrotreated, and selectively cracked over a size exclusion zeolite to boost octane.

Blending the new fraction with the lighter fraction and subjecting the mixture to an

extractive process for sulfur removal gives another method of forming greatly sulfur free

gasoline. This process works best with streams heavy with naphtha because the decrease in

yield is substantially lower using those streams.


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One component of combustion exhaust often over looked is the fact that all engines

must use a lubricating oil (5). In all combustion cycles, there is a risk that the fuel mixture

is contaminated with a small amount of lubricating oil. Lubricating oils are not under as

stringent governmental regulation as are fuels. Thus, there is still a component of sulfur

and phosphorous in the lubricating oil that can be burned and poison the catalyst. The

burning of the lubricating oil also forms ash and other engine deposits, which can hurt

engine efficiency and oil performance. The loss of efficiency can lead to increased

emissions because of wasted fuel. The loss of oil performance can lead to engine wear and a

degradation of engine life.

Advances in particulate emission control only make the increase use of diesel

engines more attractive. The incorporation of a closed crankcase in diesel engine design

has greatly reduced particulate emission from diesel engines (7). Most of the blow by gases

from engines using open crank cases, which are prevalent in mass transit, marine, and

industrial applications, have large amounts of particulate emissions of which half can be

less than 1 micrometer (deeply respirable). By incorporating a blow by gas collector for

these engines, these emissions can be reincorporated into the combustion cycle. The

incorporation of the blow by gas collector working in tandem with an oxidation/reduction

catalyst, flow filter, and particle filter can greatly reduce diesel emissions. A turbo charger

can offset any additional air resistance induced by the inclusion of an air filter. The

exhaust emissions or even the blow-by-gases can power the turbo charger.

Diesel performance in cold climates is also an important issue to tackle because of

the inherent efficiency of diesel engines (6). It is also important because the Fischer-

Tropsch Process (FTP) makes the formation of sulfur free diesel fuels a reality. The


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paraffin wax content of FTP diesels increases the cloud point and pour point of Fischer-

Tropsch diesel fuels. The cloud point is essentially the point where paraffin wax residues

begin to come out of solution making the diesel fuel appear cloudy. The pour point is the

point where the diesel fuel begins a gelation process and is no longer acceptable for use as a

fuel. Blending of fuels sufficiently free of sulfur can give sufficient cetane numbers while

also giving the desirable low cloud point and pour point. It is important to find acceptable

blends of FTP products lies because feedstocks for the FTP can come from pretreatments

of biomass from agricultural and municipal wastes. There are still many complications to

overcome with the FTP including the lack of selectivity in the catalysts as well as the water-

gas-shift, which results in the formation of carbon dioxide, especially using iron catalysts.

By tackling catalyst design and optimizing the partial pressures of carbon monoxide and

hydrogen gas used as FTP feed stocks along with optimal temperature it may be possible to

minimize carbon dioxide formation and achieve more narrow hydrocarbon product

distributions of exit streams from Fischer-Tropsch reactors.

One of the most environmentally responsible ways of reducing emissions is to

harness them. One of the most overlooked ways in which humans form potentially harmful

emissions is the accumulation of organic wastes and their impending decay (2). Currently,

some municipal wastes are disposed of using an incineration process. These incinerations

produce dinitrogen oxide, nitrogen oxide carbon monoxide, nitrogen dioxide, as well as

sulfur dioxide and sulfur trioxide. These are all gases under regulatory concern and are in

addition to the potential production of VOCs and other hydrocarbons. One of the most

common gases produced from organic municipal waste decay is methane. Methane is a

gas, which is of a concern for the theory of global warming because it has its largest


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absorbance at lower wavelengths (3. Low wavelengths means higher energy, thus any

energy absorbed by methane can be emitted in the form of heat back to the earth. Methane

gas also poses a potential safety risk because if not properly contained, or eliminated, it

may be an explosion risk.

Proper landfill design should be incorporated into city planning as it allows for the

entrapment and harvesting of methane gas for point source power generation. Landfill

design is also important because it helps create a safe landfill based on environmental risk,

not simply the risk of explosion. By trapping the methane gas under a combinatorial layer

of clay, sand, soil, or polymer the risk of explosion decreases so long as the top membrane

remains intact. The same is true for the membrane at the bottom of the landfill. Any

environmental contaminants leeched through the landfill via water transport can be

collected and processed for safe disposal. Below is a diagram of a landfill design to safely

trap and harvest methane gas for power generation and capture leechate for safe disposal

as it collects at the bottom of the landfill. The diagram of the cutaway landfill is taken

from pollutionissues.com.


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Point energy sources are becoming increasingly popular and pragmatic because it

would lower the loss of electrical potential over long transmittance (2). Not only is the

operation of small-scale power production becoming more popular the processes by which

harvest waste gases have become more effective. By creating solid organic waste enclosures

with conditions favoring bacterial growth, the desired methane can be produced more

efficiently and even in greater quantities. One problem with this form of power generation

is the mixture of gases formed by organic decay. As the methane gas formed by the organic

decay permeates up through the biomass, it picks up contaminants that can form SOx and

NOx as well as some VOCs after combustion. These gases are not only of a regulatory

concern but may also be odorous, if not harmful, for anyone down wind. It is vital to

develop a way of separating the gases in the complex mixture. One method of


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accomplishing this separation may be the use of polymer membranes or some kind of wet

scrubbing process utilizing the differences in polarity between oxides and methane.

Combinatorial separation processes generally work best for complex mixtures.

Should the purification of the gas stream become a reality the use of organic decay

as a source of renewable and responsible energy will become a reality. The gases produced

are useful for generating electricity and also heating or cooking. The electricity generated

can be used or sold back to the grid to raise funds for municipal programs. Utilizing the

power for water purification and sewage treatment is another use for the energy created.

Another source of methane can be wastewater treatment facilities where anaerobic

microbes under water produce methane by processing organic wastes. This means that the

water treatment plants and point power production could work in unison to prevent and

utilize potentially harmful emissions. The largest problem outside of purifying the gas

stream is likely the capital required to start large-scale methane gas collection and power

generation operations. The modification of existing landfills for utilization could also pose

a costly engineering dilemma.

The world must acknowledge that pollution problems exist and mitigating the

pollution produced by everyone is going to be a costly undertaking. The afore mentioned

problems cost not only dollars but also man-hours to devise solutions to problems at hand.

Hopes of imagining and creating technologies that can offset cost incurred as an initial

expense or as a maintenance expense are really more than hopes but are becoming realities.

With all new technologies, there are problems. However, as humanity advances what was

once inconceivable becomes mundane. The body of this work has sought to show that

common human activity creates waste and pollution, but there is much to be done and


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much that is being done to diminish the amount of waste and pollution. By utilizing new

technologies currently under development, it is possible to achieve sustainability on fossil

fuels for much longer than experts estimate. By utilizing waste from human activity, it is

possible to realize a truly renewable resource. Research will turn todays problems into

tomorrows solutions. Much as children of the 1960s wanted to be astronauts children in

the 90s and 2000s grow up wanting to be engineers and scientists to tackle the problems of

the future. The dreams of children often become realities and the hope of humanity hangs

on the dreams of today.


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Works Cited

1. Abuelsamid, S. (2009, June 8). Ford's New Bobcat. Retrieved December 1, 2009, from AutoblogGreen:

http://green.autoblog.com/2009/06/08/update-on-fords-new-bobcat-ethanol-injected-turbocharged-

v8/

2. Augenstein, D. (2008). Patent No. 11/975,234. United States.

3. Baird, C., & Cann, M. (2008). Environmental Chemistry(4th ed.). New York: W.H. Freeman and

Company.

4. Catalytic Converter - how it works. (2005, August 3). Retrieved December 1, 2009, from Ford Scorpio:

http://www.fordscorpio.co.uk/cats.htm

5. Jackson, M., Arters, D., MacDuff, M., & Mackney, D. (2008). Patent No. app 11/869,944. United Sates.

6. O'Rear, D. (2008). Patent No. 7,354,462. United States.

7. Schmeichal, S., Schmidt, F., Imes, J., & Dushek, R. (2007). Patent No. 7,257,942. United States.

8. Shell Launches New Nitrogen Enriched Gasolines. (2009, February 3). Retrieved December 1, 2009,

from Shell.com:

http://www.shell.us/home/content/usa/aboutshell/media_center/news_and_press_releases/2009/nitr

ogen_030209.html

9. Tannert, C. (2008, July). Reinventing the Engine. Polular Mechanics , pp. 70-74.

10. Umansky, B., Stanley, J., Melli, T., Smyth, S., & Roundtree, E. (2007). Patent No. app 11/898,674.

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on the importance of emission limitation and control

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