Contaminants
Contaminants like silicon may get into gasoline fuel at fuel distribution outlets due to poor housekeeping or due to waste solvents being used as blending component at the market place. Silicon can cause failure of oxygen sensors even in very small concentrations. Water can be present in dissolved as well as in free form in gasoline. Water may lead to blockage of fuel lines, icing of intake system during severe winters in cold countries and corrosion of fuel system components. Water content limits for gasoline are specified in the fuel specifications.
Summary of Gasoline Properties on Emissions
Effects of gasoline quality on the engine emissions are summarized in Table 8.6. The effects of fuel quality on emissions are also dependent on vehicle technology. In this table the results for catalyst equipped vehicles are presented.
| Table 8.6 |
| Summary of Effects of Gasoline Properties on Emissions from Catalyst Cars |
| Property |
Change |
Lead |
CO |
HC-Exh |
HC-Evap |
NOx |
Benz-ene |
Buta-diene |
Alde-hydes |
| Reduce Lead |
0.013→ 0.005 g/l |
↓ |
↓ |
↓ |
0 |
↓ |
-0 |
-0 |
-0 |
| Add Oxygenate |
0→2.7% O2 |
0 |
↓↓ |
↓ |
0-↑ |
+0 |
0 |
0 |
↑↑ |
| Reduce Aromatics |
50→ 20% v/v |
0 |
↓↓ |
↓ |
0 |
↑ |
↓↓↓ |
+0 |
+0 |
| Reduce Benzene |
3→ 2 % v/v |
0 |
0 |
0 |
0 |
0 |
↓↓ |
0 |
0 |
| Reduce Olefins |
10→ 5% v/v |
0 |
0 |
+0 |
-0 |
-0 |
0 |
↓↓ |
0 |
| Reduce Sulphur |
380→ 20 ppm |
0 |
↓ |
↓ |
0 |
↓ |
↓ |
0 |
0 - ↑* |
| Reduce RVP |
70→ 60 kPa |
0 |
0 |
-0 |
↓↓ |
0 |
0 |
0 |
0 |
| Increase E100 |
35→ 65% |
0 |
↓ |
↓↓↓ |
0 |
↑-↑↑ |
0-↓↓↓ |
-0? |
0 - ↓↓ |
| Increase E150 |
85→ 90% |
0 |
0-↑ |
↓↓ |
0 |
↑? |
0 |
↓? |
↓? |
*Contradictory results obtained in different investigations.
Key: 0 = No effect; ± 0 = -2 to 2% effect; ↓ or ↑ = 2 to 10% effect; ↓↓ or ↑↑ = 10 to 20 % effect; ↓↓↓ or ↑↑↑ = > 20% effect; ? = Insufficient data |
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