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Biodiesel Combustion and its Influences in NOx Emissions. By David Gutierrez Chemistry Teacher at Mission High school Mission CISD Based in the research project of dr. timothy Jacobs Advanced engine research laboratory Mechanical Engineering. Biodiesel Combustion.
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Biodiesel Combustion and its Influences in NOx Emissions By David Gutierrez Chemistry Teacher at Mission High school Mission CISD Based in the research project of dr. timothy Jacobs Advanced engine research laboratory Mechanical Engineering
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 Project The 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 environment • The major differences between gasoline and diesel engines • How an engine makes power • The three way catalyst exhaust carbon monoxide, unburned hydrocarbons , and nitric oxides • How determine density, evaporation point and other physical properties of biodiesel
Biodiesel Combustion The definition of a renewable fuel How biodiesel fuel is made from new and used vegetable oil The chemical analyses necessary to determine the biodiesel efficiency and quality How to assess the finished products from the biodiesel reaction How to evaluate the efficiency of biodiesel How to evaluate the impact in local and US economy
Biodiesel combustion A conventional reciprocating internal combustion engine is composed of cylinders, pistons, crankshafts, camshafts, valves, and other necessary mechanical linkages. The “stroke” of the engine refers to the piston’s up and down motion within the cylinder. A “four-stroke” engine indicates the piston’s motion for one complete 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 Diesel • Aside 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 information Dr. 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 Pumps B100 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 source • Cleanburning: lower in carbon monoxide, and carcinogens • Lower in sulfur compounds • Significant carbon dioxide reductions: less impact on global climate change • Domestically available: 30 million gallons of waste restaurant grease are produced annually in US
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 engine • Biodiesel 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 + 47N2 • A 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 Ignition Diesel CI= Compression Ignition Compression Ignition Atomization: Mixing mechanisms with air obtaining an ignitable air/fuel mixture rate 5/10 means 5 parts of air/10 parts of fuel Vaporization: Pressure and temperature Wait: Chemical bond separation Ignition 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 catalyst • CO carbon monoxide • HC Unburned fuels CH4 methane • 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 FLAT • Since pressure and volume are indirectly proportional (opposite). Boyles Law V1P1=V2P2 if the pressure of an idealgas increases the volume decreases
Biodiesel Combustion Bibliography file:///H:/Biodiesel%20Formula.htm www.biodieselamerica.com www.biodiesel.org http://www3.science.tamu.edu/CMSE/activities/index.asp http://teachersummit.tamu.edu/resources A and B Scott Organic Chemistry http://members.ophnet.com.au/scottsoftb/
BIodiesel Combustion Bibliography HOLT, RINEHART and WINSTON MODERN CHEMESTRY Texas Edition Labs and Demonstrations http://www.google.com/top/science/chemistry/education/Labs_and_Demostrations/
Biodiesel Combustion 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