Student: |
Howard Hess |
Sponsor: |
Air Products and Chemicals, Inc., Program Manager - Peter J. A. Tijm |
Objective: |
To compare combustion and emissions impacts of incorporating various oxygenates into diesel fuels. |
Approach: |
The primary oxygenated fuel additive of interest in this study is CETANERTM, which is produced by Air Products and Chemicals, Inc. from dimethyl ether through an oxidative coupling process. We are considering this additive and other oxygenates in our Yanmar IDI single-cylinder engine and the VW TDI 1.9L turbodiesel. Total particulate, particulate composition, CO, NOx and total hydrocarbon emissions are monitored for a base diesel fuel and for the fuel containing various oxygenate concentrations (typically at or below 4 wt% oxygen). |
Results: |
In the experimental work completed, several oxygenates have been blended with a premium diesel fuel to yield an oxygen content of 4 wt% in the fuel blend. Results have shown that with these blends, particulate emissions can be reduced by as much as 28% when compared to premium diesel fuel. The following are results from the Yanmar TS-180 IDI single-cylinder engine. |
Table 1. Oxygenate blends selected for evaluation.
Oxygenate Blended |
Structure |
Notation |
Wt% oxygen |
Blend Ratio |
| Diethylene glycol methyl ether | CH3OC2H4OC2H4OH |
DGME |
40.0 |
10/90 |
| Triethylene glycol dimethyl ether | CH3O(C2H4O)3CH3 |
Triglyme |
36.0 |
11/89 |
| Diethylene glycol dimethyl ether | CH3O(C2H4O)2CH3 |
Diglyme |
35.8 |
11/89 |
| 1,2-dimethoxyethane | CH3O(C2H4O)1CH3 |
Glyme |
35.6 |
11/89 |
| CETANERTM * | CETANERTM |
36.5 |
11/89 |
|
| 96% 1,2-dimethoxyethane | CH3OCH2CH2OCH3 |
(35.6) |
||
| 4% dimethoxymethane | CH3OCH2OCH3 |
(59.3) |
||
| Methyl Soyate | Mixed esters |
Me Soyate |
11.0 |
35/65 |
*Simplified mixture chosen to represent a potential CETANERTM formulation.
Table 2. Engine test matrix (11,12)
Mode 1 |
Mode 2 |
Mode 3 |
Mode 4 |
|
| Speed (RPM) | 2200 |
2002 |
1760 |
1386 |
| % Rated Speed | 100 |
91 |
80 |
63 |
| Power (hp) | 12.26 |
8.77 |
5.32 |
2.03 |
| % Rated Power | 81.7 |
58.5 |
35.5 |
13.5 |
| Weighting Factor | 0.2 |
0.5 |
0.15 |
0.15 |
Table 3. Results from Testing of Several Fuel Properties.
Oxygenate Blend Tested |
Saybolt Viscosity(SUS), 100ºF |
Gravity
|
Cloud Point (ºF) |
Flash Point (ºF) |
Heat of Combustion (BTU/lb) |
| ASTM Specification | 32.6-40.1 |
Min 30 |
Max 0 |
Min 125 |
------- |
| Premium Diesel Fuel | 34.8 |
45 |
<0 |
160 |
19,707 |
| DGME | 35.7 |
41 |
<0 |
157 |
19,118 |
| Triglyme | 32.3 |
44 |
<0 |
173 |
18,909 |
| Diglyme | 34.0 |
51 |
<0 |
147 |
18,856 |
| Glyme | 32.0 |
48 |
<0 |
<67 |
18, 613 |
| CETANERTM | 34.3 |
45 |
<0 |
<67 |
18,867 |
| Methyl Soyate | 41.4 |
43 |
8 |
180 |
18,793 |
Table 4. Total Brake-Specific Particulate Emissions, g/kWhr.
% wt Oxygen In Blend |
BS PM, g/kWhr |
% Reduction from Baseline (*) |
|
| Baseline BP Premium Diesel Fuel | ----- |
0.673 |
----- |
| DGME | 4.12 |
0.625 |
7.2 ± 16.4% |
| Triglyme | 3.96 |
0.573 |
14.9 ± 10.5% |
| Diglyme | 3.94 |
0.484 |
28.1 ± 13.6% |
| Glyme | 3.97 |
0.481 |
28.5 ± 14.1% |
| CETANERTM | 4.00 |
0.491 |
27.0 ± 11.6% |
| Methyl Soyate | 3.88 |
0.508 |
24.5 ± 16.2% |
* Error range based upon 95% Confidence Interval.