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