Biodiesel Combustion

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B Y

D A V I D G U T I E R R E ZC H E M I S T R Y T E A C H E R A T

M I S S I O N H I G H S C H O O LM I S S I O N C I S D

B A S E D I N T H E R E S E A R C H P R O J E C T O F D R .T I M O T H Y J A C O B S

A D V A N C E D E N G I N E R E S E A R C H L A B O R A T O R Y

M E C H A N I C A L E N G I N E E R I N G

Biodiesel Combustion and its

Influences in NOx Emissions


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Biodiesel Combustion

Biodiesel fuel has gained public appeal for itspromise to contribute toward a sustainable energysystem and reduce the emission of carbon into the

atmosphere. A potential challenge for biodiesel fuel,particularly in the transportation sector, is calledbiodiesel NOx penalty. NOx or nitric oxides, areharmful, toxic, combustion generated pollution that

lead to troposphere ozone, smog, and acid rain.Several researchers have observed increases in NOxwith the use of biodiesel fuel, compared to petroleumdiesel.


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Dr. Timothy Jacobs Research Project

The objective of this research project is to evaluate thephysical mechanisms that cause differences in NOxemissions with biodiesel (relative to petroleum diesel fuel)

in diesel engines including two specific objectives

1. Identify the root causes of differences in NOx and otheremissions from biodiesel fueled engines and petroleumdiesel fueled engines.

2. Determine how energy resources in Texas can be used toproduce qualifying fuels.

The research is conducted both experimentally andanalytically using a 4.5L medium-duty diesel engine as the

test apparatus.


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Biodiesel combustion

OBJECTIVES: The Learners Will

Apply in classroom what Mechanical and ChemicalEngineers do

Distinguish between renewable and nonrenewable fuels

How substitution of biodiesel fuel for petroleum biodieselbenefits the environment

The major differences between gasoline and diesel engines

How an engine makes power

The three way catalyst exhaust carbon monoxide, unburnedhydrocarbons , and nitric oxides

How determine density, evaporation point and other physicalproperties of biodiesel


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The definition of a renewable fuel

How biodiesel fuel is made from new and usedvegetable oil

The chemical analyses necessary to determine thebiodiesel efficiency and quality

How to assess the finished products from thebiodiesel reaction

How to evaluate the efficiency of biodiesel

How to evaluate the impact in local and US economy


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Biodiesel combustion

A conventional reciprocatinginternal combustion engine iscomposed of cylinders, pistons,crankshafts, camshafts, valves,and other necessary mechanicallinkages.The stroke of the enginerefers to the pistons up anddown motion within thecylinder.

A four-stroke engine indicatesthe pistons motion for onecomplete mechanical cycle.


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GASOLINE ENGINE and PHYSICAL PROPERTIES OFGASES

When the piston in cylinder is down the volume of air-gas mixture is large

When the piston in cylinder is raised the air-gas mixtureis compressed, the spark plug releases a spark thegasoline mixture explodes and forces the piston downfirst position and repeats turning the drive shaft and thecar moves.

The size of the cylinder is called displacement. If eachcylinder is 0.5L and you have 8 cylinders you have a 4.0Lengine that may have about 200HP


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Gasoline versus Diesel

Aside from the type of fuels used, the majordifferences between gasoline and diesel engines

include: 1. Diesel engines use compression ignition, as

opposed to spark ignition (sparkplugs).

2. Diesel engines control their load (power

production) by metering the amount of fuel, asopposed to the amount of air (throttle).


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Biodiesel background informationDr. Rudolf Diesel first demonstrated his diesel engine, which ran on

peanut oil, to the world in the early 1900s. The high compression ofdiesel engines creates heat in the combustion cylinder, and thusdoes not require a highly flammable fuel such as that used ingasoline engines. The diesel engine was originally promoted tofarmers as one for which they could grow their own fuel. Diesels,

with their high torque, excellent fuel efficiency, and long engine lifeare now the engine of choice for large trucks, tractors, machinery,and some passenger vehicles. Diesel passenger vehicles are notpresently common in the United States due to engine noise, smokyexhaust, and cold weather starting challenges. However, their use is

quite normal in Europe and Latin America, and more diesel arestarting appear to appear in the US market


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Stock Photo -

Diesel engine:

internalcombustion engine

invented by

Rudolph Diesel in1897 (c1910)


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Over time, the practice of running the engines onvegetable oil became less common as petroleumdiesel fuel became cheap and readily available.Today, people are rediscovering the environmentaland economic benefits of making fuel from raw andused vegetable oils.

Biodiesel is a renewable fuel now accepted by the

federal government as an environmentally friendlyalternative to petroleum diesel, biodiesel is in usethroughout the world


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All Sourcesof Bio-Diesel on

the WestCoast


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Public Pumps

B100

Yes! You candrive fromMexico to

Canada onBiodiesel


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Biodiesel benefits compared to petroleumdiesel

Using a waste product as an energy source

Cleanburning: lower in carbon monoxide, andcarcinogens

Lower in sulfur compounds

Significant carbon dioxide reductions: less impact onglobal climate change

Domestically available: 30 million gallons of wasterestaurant grease are produced annually in US


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Biodiesel benefits compared to petroleumdiesel

Biodiesel can be readily mixed with diesel fuel in any

proportion. For example B100 contains 100%biodiesel, B20 contains 20%

Biodiesel can be run in any unmodified engine

Biodiesel is less flammable than diesel. It will get at a

higher temperature (typically around 20F) and thusshould be mixed with petroleum fuel in cold weather


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How does an engine make power? The power producing capabilities of an internal

combustion engine lie in the combustion process.

Near the top dead center position, the fuel and air

mixture ignite and combust during the combustionprocess.

C8H18 + 12.5(O2 + 3.76N2)8CO2 + 9H2O + 47N2

Astoichiometric mixture is onewhere there is a

chemically correct amount of air to combust the fuel. Alean mixture has an excess ofair.

A rich mixture has an excess of fuel


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Emissions formation A continued technical challenge for internal combustion engines is

exhaust emissions. Before, the ideal combustion reaction for iso-octane was given as:

C8H18 + 12.5(O2 + 3.76N2) 8CO2 + 9H2O + 47N2

In reality, however, the products of combustion look something like:C8H18 + 12.5(O2 + 3.76N2) aCO2 + bH2O + cCO + dH2 + eNO +

fHC + soot CO Regulated, toxic NO Contributes to local ozone formation (SMOG) and acid rain

HC Unburned fuel, works to NO to form local ozone Soot Particulate matter, potentially carcinogenic CO2 Global warming gas


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How does an Engine Make Power ?

Gasoline SI= Spark Ignition

Diesel CI= Compression Ignition

Compression Ignition1. Atomization: Mixing mechanisms with air obtaining an ignitable

air/fuel mixture rate 5/10 means 5 parts of air/10 parts of fuel

2. Vaporization: Pressure and temperature

3. Wait: Chemical bond separation

4. Ignition

5. Combustion:C8H18 + 12.5(O2 + 3.76N2) 8CO2 + 9H2O + 47N2


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In reality the products of combustion look like

C8H18 + 12.5(O2 + 3.76N2) aCO2 + bH2O + cCO+ dH2 + eNO +fHC + soot

The engines exhaust three way catalyst1. CO carbon monoxide

2. HC Unburned fuels CH4 methane

3. NOx Nitric oxide


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IS THIS CHEMISTRY?

Yes! Automotive engineers have to take Chemistry incollege automobile/car/truck/tractor/tires all

contain air pressure orTHEY ARE FLAT

Since pressure and volume are indirectlyproportional (opposite).

Boyles Law V1P1=V2P2 if the pressure of an idealgasincreases the volume decreases


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Bibliography

file:///H:/Biodiesel%20Formula.htm

www.biodieselamerica.com

www.biodiesel.orghttp://www3.science.tamu.edu/CMSE/activities/inde

x.asp

http://teachersummit.tamu.edu/resources

A and B Scott Organic Chemistry

http://members.ophnet.com.au/scottsoftb/
http://localhost/USERS/lori.cardenas/Biodiesel%20Formula.htmhttp://www.biodieselamerica.com/http://www.biodiesel.org/http://www3.science.tamu.edu/CMSE/activities/index.asphttp://www3.science.tamu.edu/CMSE/activities/index.asphttp://teachersummit.tamu.edu/resourceshttp://members.ophnet.com.au/scottsoftb/http://members.ophnet.com.au/scottsoftb/http://teachersummit.tamu.edu/resourceshttp://www3.science.tamu.edu/CMSE/activities/index.asphttp://www3.science.tamu.edu/CMSE/activities/index.asphttp://www.biodiesel.org/http://www.biodieselamerica.com/http://localhost/USERS/lori.cardenas/Biodiesel%20Formula.htm


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BIodiesel Combustion

Bibliography

HOLT, RINEHART and WINSTON

MODERN CHEMESTRY Texas EditionLabs and Demonstrations

http://www.google.com/top/science/che

mistry/education/Labs_and_Demostrations/
http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/


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Thank you

E3 Teacher Summer Research Program

Dr. Timothy Jacobs

The Dwight Look College of EngineeringTexas A&M University

The Texas Engineering ExperimentStation

The NationalScience Foundation

Documents

Biodiesel Combustion