Did you notice that they specifically refer to engines produced before 2010. Maybe you don't know when DPFs were introduced, but it sure seems like the "improvements to emissions" are referring to diesels without DPFs or other complex emissions.
I'm not sure what non ethanol isn't available in many areas means.
https://www.pure-gas.org/ It's available in all of the areas that I searched on.
I read the OP's cited report - did you?
It was dated March 2006 so all of the experimental results were based on technology of that era (e.g. pre 2010) , and I think the OP seriously misunderstood their conclusions just as you are misunderstanding the more current data I provided.
Here are a few quotes from the OP's 2006 report. The bullets are direct quotes from the conclusions section followed by my editorial comments. If you want the full story go read the report - its chock full of very solid experimental results.
- Results show that on average, the BPT is 45°C lower than 2007 certification diesel for B20 blends and more than 112°C lower for neat biodiesel .
This is critical - biodiesel at all concentrations is most effective at eliminating PM emissions when exhaust gas temperatures are lowered not raised. That was contrary to the prevailing DPF design practice in 2006.
- Transient emissions tests show a 25% PM reduction for B20 without the DPF installed
This is what happens on pre-2010 engines that do not have DPF - a big drop in particulate matter and why pre 2010 engines benefit the most from bio-diesel.
- Installation of the DPF caused PM emissions to drop by more than a factor of 10 for petrodiesel.
This what happens when you add a DPF to a pre 2010 engine, A factor of 10 reduction is massive and why DPFs were being added to engines.
- Use of B20 with the DPF produced an additional PM reduction of 67% below the petrodiesel+DPF level
This one you have to watch out for. That 67% reduction is the
marginal improvement over petrodiesel + DPF so it is not as huge as the number suggests but still an improvement over pure petrodiesel.
- Filter regeneration rate measurements indicate that biodiesel causes a significant increase in regeneration rate, even at the 5% blending level.
Whoa Nellie!!! Everything was looking good so how can this be true as well. This is where the OP stopped reading. If he had continued he would have found there is much much more to the story.
- Overall the results suggest significant benefits to the use of biodiesel blends in engines equipped with DPFs.
Watch you mean Willis!!! You just told us the regeneration rate goes up with bio-diesel not down. What Willis means is the research is only beginning to clarify the effects of bio-diesel and DPF and more testing of alternative designs is needed. Read on.
- The significant lowering of BPT and increase in regeneration rate might allow passive DPFs to be used in lower temperature engine duty cycles, avoiding the need for actively regenerated filters and their associated fuel economy penalty. The work reported here shows measurable improvements in DPF regeneration performance at steady-state conditions with biodiesel blends and suggests the potential for biodiesel blends to extend the useful range of a given DPF design to lower operating temperatures. Actively regenerated systems might require less frequent regeneration, also resulting in a lower fuel economy penalty
Passive regeneration is what happens behind the scenes. Its when the DPF is burning off the PM as it is produced and preventing it from clogging up the filter. They want to know more about how that works and whether a redesigned DPF might leverage that behavior to improve passive regeneration and reduce the frequency of active regeneration. Remember - this is 2006 and DPFs are just beginning to appear on the scene. Designs were very much in flux.
- The next phase of this research will investigate transient operation with baseline diesel and biodiesel blends over a range of controlled differences in mean exhaust temperature. Mean exhaust temperature would be controlled by installation of a heat exchanger on the exhaust line upstream of the DPF. The data acquired will show if the improvements in DPF regeneration performance with biodiesel blends are significant enough to allow biodiesel blends to be an enabler for successful application of catalyzed DPFs in lower exhaust temperature applications that would not be suitable for passive DPF technology. The data will also allow an assessment of the potential for DPFs to be smaller and/or contain less precious metal for design applications, which use biodiesel blends. In addition, this work could determine if active regeneration of DPF systems leads to fuel savings by operation with biodiesel blends by minimizing the time and amount of fuel required during active regeneration periods.
This is where they went next and what they found is described in my post #5. In a nutshell what we have learned in the ensuing 17 years is current DPF's designed to operate at a lower BPT combined with biodiesel blends can and does reduce the level of PM produced and that translates into better passive regeneration and a reduction in those pesky active regens.
Dan
