Thanks for the reminder. The test results came back last week but I've been a little busy lately.
First, a little background. The tests as performed by the state are NOT full-blown 'forensic style' chemical analysis. Rather they are done to determine if the fuel sample in question meets all the legally-mandated specs required of it. The state petroleum inspection department, established in the 1870's, is an early example of 'consumer protection' legislation. Before, you didn't knew for sure what you were putting in your kerosene lamp. A lot of people died and a lot of property was destroyed in fires caused by all sorts of nasty liquids that were palmed off as lamp oil.
The test on my homebrew bio-d was done by buddy's boss. As you probably noticed he gave a great 'clinical' description of my dubious product in addition to the numbers. The test on the commercial bio-d was an after-hours project done by my buddy himself. Although he ran the same tests, please keep in mind that he isn't as good with words as his boss is.
Like all samples, the commercial biodiesel sample was stored overnight in a freezer. At 18 deg. F, the sample was jelled. It thawed out with no percepitates evident. The thawed product was clear (meaning no particles, clouding or haze) and bright.
API specific gravity: 28.4
Flash point: =>300 deg. F. (Note: not considered a hazardous product!)
Sulfur: 0.0073%
Calculated Cetane: 45.6
Volume Distillation Rate Distillation Temp.
IBP* 575.6 seconds 301.6 deg. F.
5% 24.2 seconds 615.4 deg. F.
10% 3.4 ml/min 624.6 deg. F.
15% 5.7 ml/min 626.0 deg. F.
20% 5.4 ml/min 627.1 deg. F.
30% 4.6 ml/min 628.2 deg. F.
40% 4.6 ml/min 629.1 deg. F.
50% 4.5 ml/min 630.1 deg. F.
60% 4.6 ml/min 631.4 deg. F.
70% 4.2 ml/min 633.0 deg. F.
80% 4.5 ml/min 635.7 deg. F.
85% 4.2 ml/min 638.4 deg. F.
90% 3.8 ml/min 644.5 deg F.
*(IBP = Initial Boiling Point)
The commercial biodiesel did not leave any of the thick goo that was left behind in the labware by my home-made biodiesel. (Washing? Better control over the transesterification process?) As you'll notice the most of the product boiled off in a nice, even rate between 615 and 644 degrees F. This flat curve shows that biodiesel is a very consistant product.
For reference, here are the test results for a typical sample of #2 diesel as it comes from the pipeline.
API specific gravity: 30.2
Flash Point: 172.0
Sulfur: .0208
Calculated Cetane: 41.1
Volume Distillation Rate Distillation Temp.
IBP 436.8 sec. 324.5 deg. F.
5% 69.0 sec. 410.4 deg. F.
10% 4.6 ml/sec. 429.6 deg. F.
15% 4.7 ml/sec. 445.3 deg. F.
20% 4.7 ml/sec. 458.2 deg. F.
30% 4.6 ml/sec. 478.6 deg. F.
40% 4.5 ml/sec. 498.9 deg. F.
50% 4.4 ml/sec. 519.4 deg. F.
60% 4.5 ml/sec. 540.5 deg. F.
70% 4.3 ml/sec. 564.3 deg. F.
80% 4.5 ml/sec. 591.4 deg. F.
85% 4.1 ml/sec. 608.5 deg. F.
90% 4.1 ml/sec. 630.9 deg. F.
You'll notice that petroleum diesel starts boiling 324.5 deg. F., then not much happens until it gets to 410.4 deg. F. After that it boils out over a 200 deg. spread. A far wider range that biodiesel. The engine might not make full energy use of the higher end (boils earlier) components.
For a good description of the petroleum test procedure, check here.
http://oil.cdle.state.co.us/OIL/Tech...nd%20Specs.asp
