Saturday, December 13, 2008

Diesel Particulate Filters

Newer diesel vehicles being sold often have Diesel Particulate Filters (DPFs) which reduce particulate emissions by trapping them in a filter in the exhaust system. To prevent the filter from plugging, fuel is sent into the exhaust system at intervals to burn off the particulates.

There are a couple problems with this system:
  1. extra fuel is used to burn the particulates, which reduces overal MPG.
  2. extra CO2 emissions are released when burning up the particulates.
  3. Biodiesel, which vaporizes a higher temperature than petroleum diesel, doesn't function the same way in the system, and fuel ends up in the engine crankcase rather than clearing the DPF. [1]
If you have a newer diesel vehicle you may want to investigate these issues before running biodiesel. A good discussion of the issues, with links to more information, can be found here:

[1] It depends on how the system is designed, of course. The problem is caused by using the fuel injectors in the cylinder to place additional fuel into the exhaust gases. Since biodiesel doesn't vaporize per the system design, some of it stays in the cylinder and leaks past the piston rings into the crankcase. If the additional fuel is squirted into the exhaust pipe, and not the cylinder, then you bypass the problem of fuel getting into the crankcase. But that is more complex and maintenance intensive (additional dedicated fuel injectors).

Friday, December 5, 2008

Visit to potential demonstration algae biofuels site

We made a trip today to the site for our proposed algae biofuels demonstration plant. The land, near 19th Ave. and Lower Buckeye Road, just southeast of downtown Phoenix, is really perfect in many respects: great water and power infrastructure, close to downtown but zoned industrial, flat and sunny. The quality of the land coupled with some progress we're making on the grant funding side has me in a state of optimism and excitement with the project at the moment -- which, of course means that the next iteration of frustration and despair is just around the corner, but we'll take what we can get.  :-)

Pictured above (l-to-r) are Grey Fowles, who is helping us with some architectural renderings; Sam West, who is doing superb work as the project lead for DBI on this effort; Mike Bellefeuille of XL Renewables, a potential partner in the effort and a deep expert on algae; and Jeff Collier of Energy Derived, another potential partner and, like Mike, a deep algae expert.      

A couple of other photos of the proposed site below.

Monday, December 1, 2008

EPA releases biodiesel plant manual

This compliance assistance manual serves as a road map of information on federal environmental programs and federal, state, and local agency roles as they apply to parties interested in designing, building, and operating biodiesel manufacturing facilities.