Presentation on theme: "Module 2: Chemical and Physical Characteristics of Ethanol and Hydrocarbon Fuels."— Presentation transcript:
Module 2: Chemical and Physical Characteristics of Ethanol and Hydrocarbon Fuels
2 Objective Upon the successful completion of this module, participants will be able to describe the chemical and physical differences between pure gasoline and gasoline / ethanol blends.
3 Introduction Characteristics of polar solvents & hydrocarbons, their differences, & how they interact Conditions under which ethanol-blended fuels will retain certain characteristics of types of fuel Help emergency responders mitigate various incidents according to conditions found
4 Activity 2.1 — Definitions Purpose: –To allow participants to identify the definitions related to ethanol.
5 Characteristics of Gasoline (A Hydrocarbon) Similar characteristics whether flammable / combustible liquids Produced from crude oil by fractional distillation Non-water miscible / insoluble Flash point -45°F (depending on octane rating)
6 Characteristics of Gasoline (A Hydrocarbon) Vapor density between 3 & 4: –Gasoline vapors seek low levels / remain close to ground level Specific gravity of 0.72–0.76: –Will float on top of water Auto-ignition temperature between 536°F & 853°F Boiling point between 100°F & 400°F
7 Characteristics of Gasoline (A Hydrocarbon) Not considered poisonous: –Harmful effects after long-term & high-level exposure –Can lead to respiratory failure Smoke from burning gasoline is black & has toxic components Greatest hazard is flammability: –Fairly narrow range of flammability
8 Characteristics of Ethanol (A Polar Solvent) Ethanol used with motor fuels denatured with up to 5% gasoline / similar hydrocarbon for transport Denaturant has minimal effects on characteristics
9 Characteristics of Ethanol (A Polar Solvent) Renewable fuel source produced by fermentation & distillation process Most common source in U.S. in 2008 is corn Polar solvent Water-soluble Flash point 55°F
10 Characteristics of Ethanol (A Polar Solvent) Vapor density of 1.59: –Heavier than air –Vapors do not rise Specific gravity 0.79: –Lighter than water –Thoroughly mix with water Auto-ignition temperature 793°F
Miscibility 11 Figure 1 Figure 2 Figure 3
12 Characteristics of Ethanol (A Polar Solvent) Boiling point 173°F Less toxic than gasoline / methanol Carcinogenic compounds not present in pure ethanol Greatest hazard as motor fuel component is flammability: –Wider flammable range than gasoline
13 Characteristics of Ethanol (A Polar Solvent) In pure form no visible smoke & hard-to-see blue flame In denatured form little to no smoke & slight orange flame may be visible Ethanol & some ethanol blends can conduct electricity Large amounts of water required to dilute ethanol to no longer support combustion
14 Activity 2.2 — Comparison of Gasoline and Ethanol Purpose: –To allow participants to discuss the differences & similarities in the chemical & physical properties of ethanol & gasoline.
15 Characteristics of Ethanol-Blended Fuels Ethanol increases heat output of unleaded gasoline: –Lower emissions from unburned hydrocarbons Minimal amounts of water will draw ethanol out of blend away from gasoline: –Ethanol & gasoline more suspension than solution
16 Characteristics of Ethanol-Blended Fuels Gasoline floating on layer of ethanol / water solution –Resulting ethanol / water solution still flammable
17 Characteristics of Ethanol-Blended Fuels Blending fuels alters physical & chemical characteristics of original fuels: –Visual difference of smoke & flame characteristics: Higher content of ethanol, less visible black smoke content & orange flame production
18 Characteristics of Ethanol-Blended Fuels Blending fuels alters physical & chemical characteristics of original fuels: –When foam / water flowed on burning product, gasoline tends to burn off first: May have no visible flame or smoke
19 Summary Polar solvent water-soluble & flammable When blended with gasoline, produces slightly cleaner burn than gasoline alone Blend of gasoline & ethanol can easily go unnoticed by emergency responders: –Ethanol will be last fuel to burn –Ethanol will burn without visible smoke / flame