Biodiesel Combustion and its Influences in NOx Emissions
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Transcript of Biodiesel Combustion and its Influences in NOx Emissions
BYDAVID GUTIERREZ
CHEMISTRY TEACHER AT
MISSION HIGH SCHOOLMISSION CISD
BASED IN THE RESEARCH PROJECT OF DR. TIMOTHY JACOBS
ADVANCED ENGINE RESEARCH LABORATORYMECHANICAL ENGINEERING
Biodiesel Combustion and its Influences in NOx Emissions
Biodiesel Combustion
Biodiesel fuel has gained public appeal for its promise to contribute toward a sustainable energy system and reduce the emission of carbon into the atmosphere. A potential challenge for biodiesel fuel, particularly in the transportation sector, is called “biodiesel NOx penalty”. NOx or nitric oxides, are harmful, toxic, combustion generated pollution that lead to troposphere ozone, smog, and acid rain. Several researchers have observed increases in NOx with the use of biodiesel fuel, compared to petroleum diesel.
Biodiesel Combustion
Dr. Timothy Jacobs Research ProjectThe objective of this research project is to evaluate
the physical mechanisms that cause differences in NOx emissions with biodiesel (relative to petroleum diesel fuel) in diesel engines including two specific objectives
1. Identify the root causes of differences in NOx and other emissions from biodiesel fueled engines and petroleum diesel fueled engines.
2. Determine how energy resources in Texas can be used to produce qualifying fuels.
The research is conducted both experimentally and analytically using a 4.5L medium-duty diesel engine as the test apparatus.
Biodiesel combustion
OBJECTIVES: The Learners Will Apply in classroom what Mechanical and Chemical
Engineers do Distinguish between renewable and nonrenewable fuels How substitution of biodiesel fuel for petroleum
biodiesel benefits the environmentThe major differences between gasoline and diesel
enginesHow an engine makes powerThe three way catalyst exhaust carbon monoxide,
unburned hydrocarbons , and nitric oxidesHow determine density, evaporation point and other
physical properties of biodiesel
Biodiesel Combustion
The definition of a renewable fuelHow biodiesel fuel is made from new and
used vegetable oilThe chemical analyses necessary to
determine the biodiesel efficiency and qualityHow to assess the finished products from the
biodiesel reaction How to evaluate the efficiency of biodieselHow to evaluate the impact in local and US
economy
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 piston’s up anddown motion within thecylinder.A “four-stroke” engine indicatesthe piston’s motion for onecomplete mechanical cycle.
Biodiesel Combustion
GASOLINE ENGINE and PHYSICAL PROPERTIES OF GASES
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 mixture is compressed, the spark plug releases a spark the gasoline mixture explodes and forces the piston down first position and repeats turning the drive shaft and the car moves.
The size of the cylinder is called displacement. If each cylinder is 0.5L and you have 8 cylinders you have a 4.0L engine that may have about 200HP
Biodiesel Combustion
Gasoline versus DieselAside from the type of fuels used, the major
differences 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, as opposed to the amount of air (throttle).
Biodiesel Combustion
Biodiesel background informationDr. Rudolf Diesel first demonstrated his diesel engine, which
ran on peanut oil, to the world in the early 1900’s. The high compression of diesel engines creates heat in the combustion cylinder, and thus does not require a highly flammable fuel such as that used in gasoline engines. The diesel engine was originally promoted to farmers as one for which they could “grow their own fuel”. Diesels, with their high torque, excellent fuel efficiency, and long engine life are now the engine of choice for large trucks, tractors, machinery, and some passenger vehicles. Diesel passenger vehicles are not presently common in the United States due to engine noise, smoky exhaust, and cold weather starting challenges. However, their use is quite normal in Europe and Latin America, and more diesel are starting appear to appear in the US market
Biodiesel Combustion
Stock Photo - Diesel engine: internal combustion engine invented by Rudolph Diesel in 1897 (c1910)
Biodiesel Combustion
Over time, the practice of running the engines on vegetable oil became less common as petroleum diesel fuel became cheap and readily available. Today, people are rediscovering the environmental and economic benefits of making fuel from raw and used vegetable oils.
Biodiesel is a renewable fuel now accepted by the federal government as an environmentally friendly alternative to petroleum diesel, biodiesel is in use throughout the world
Biodiesel Combustion
All Sources of Bio-Diesel on the West Coast
Biodiesel Combustion
Public PumpsB100
Yes! You can drive from Mexico to Canada on Biodiesel
Biodiesel Combustion
Biodiesel benefits compared to petroleum diesel
Using a waste product as an energy sourceClean burning: lower in carbon monoxide, and
carcinogensLower in sulfur compoundsSignificant carbon dioxide reductions: less
impact on global climate changeDomestically available: 30 million gallons of
waste restaurant grease are produced annually in US
Biodiesel Combustion
Biodiesel Combustion
Biodiesel benefits compared to petroleum diesel
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 engineBiodiesel is less flammable than diesel. It will
get at a higher temperature (typically around 20F) and thus should be mixed with petroleum fuel in cold weather
Biodiesel Combustion
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 combustion process.
C8H18 + 12.5(O2 + 3.76N2) 8CO2 + 9H2O + 47N2A stoichiometric mixture is one where there is a
chemically correct amount of air to combust the fuel.
A lean mixture has an excess of air. A rich mixture has an excess of fuel
Biodiesel Combustion
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
Biodiesel Combustion
How does an Engine Make Power ?Gasoline SI= Spark IgnitionDiesel 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.Ignition5.Combustion:C8H18 + 12.5(O2 + 3.76N2) 8CO2 + 9H2O +
47N2
Biodiesel Combustion
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 monoxide2.HC Unburned fuels CH4 methane3.NOx Nitric oxide
Biodiesel Combustion
IS THIS CHEMISTRY?Yes! Automotive engineers have to take
Chemistry in college automobile/car/truck/tractor/tires all contain air pressure or
THEY ARE FLATSince pressure and volume are indirectly
proportional (opposite).Boyles Law V1P1=V2P2 if the pressure of an
ideal gas increases the volume decreases
Biodiesel Combustion
Bibliography file:///H:/Biodiesel%20Formula.htmwww.biodieselamerica.comwww.biodiesel.orghttp://www3.science.tamu.edu/CMSE/activities/index.asphttp://teachersummit.tamu.edu/resourcesA and B Scott Organic Chemistryhttp://members.ophnet.com.au/scottsoftb/
BIodiesel Combustion
BibliographyHOLT, RINEHART and WINSTON MODERN CHEMESTRY Texas Edition
Labs and Demonstrationshttp://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/
Biodiesel Combustion
Thank youE3 Teacher Summer Research Program Dr. Timothy Jacobs The Dwight Look College of Engineering
Texas A&M University The Texas Engineering Experiment
Station The National
Science Foundation