biodiesel: your experiences

I'm not that far from bidding a not-too-fond farewell to the '91 F250 that my girlfriend and I bought a couple of years ago. We'll be better served by a van anyhow, and we needed neither a 4x4 nor an extended cab. We wound up with those because we held out for a diesel so we could run biodiesel.

It all went a bit pear-shaped, and I'm just curious about how this has worked out for other folks.

What we did:

• Had fuel lines switched to viton (IIRC). Didn't update high pressure fuel pump, opting to wait for that to demand the update.

• Ran B99 in summer, B10 in winter. Whatever Sequential had on the pumps. We usually lagged a bit because the truck doesn't see regular use, so I wasn't too surprised when we had some cold-start issues.

After about a year or so, things went downhill: By the time the truck was running badly enough for me to worry about, the filters had plugged so badly they'd taken out the low-pressure pump (I probably should've caught this sooner; I think I was thinking it was just B99/cool weather issues). The shop (which I trust) said it was the biodiesel, and they'd seen a lot of that. Which is corroborated by friends-of-a-friend at a VW dealership who said the same of a lot of TDIs (IIRC, fuel pumps that looked like they'd been dipped in tallow, though I'm unclear on how biodiesel goes that solid...).

The worst part was getting the truck back, throwing up our hands and switching to petrodiesel, and still having to change the filter every fifteen miles (including using up all three of my towing company's annual free tows inside of two months). I think I've got the crud out of the forward tank, but I'm still scared to use the rear tank for fear of having to deal with it all over, though I do now have a spare filter, some diesel, and the tools to do the job roadside packed in the truck. It still surges a bit and blows even more smoke than it used to (on the one hand, it's blueish, on the other, the oil level is rock solid...)

On the filters I've changed out since the shop drained the biodiesel and filled it with petro, the filter base cap has been full of red mud. So I'm kinda thinking that rust/crud which had built up during the truck's first 18 years of life had been loosened up by the switch to bio. I half-wonder whether we could switch back now that it's been worked through the system, but I'm ready to move back to a vehicle I understand better (plus 4x4s are hard to load motorcycles into, and pickups are sub-optimal for moving musical gear).

So, that turned into more of a ramble than I was hoping for, but I'm really curious about people's practical experiences with biodiesel. Does it work okay as long as you start with a clean, new vehicle? Is it just to prone to gumming up and isn't quite ready for prime-time?

It entirely depends on the feedstock. If you were buying commercial bio, it should be manufactured to ASTM specs and not give you those troubles. If you were making it in your garage, the possibilities are endless. I brewed a few batches and tested some. The variations from one brew to the next were frightening. I stuck with commercial bio (when I could find it) and didn't have any real issues for about 15,000 miles - probably 25% of that was running on bio. Getting quality biodiesel with home brewing is ridiculously labor intensive. Each batch requires pH titrating, calculations, and even when its all done my confidence was low.

I sold that car so I didn't have any long-term ability to test anything.

I think it has some great commercial applications as a non-petro fuel source. Statistically, its not sustainable with current agriculture. Even if every farm in the US shifted production away from feeding us and toward biofuel stock, it wouldn't produce enough oil to supply our fat energy consumption by a long shot. Instead, I think its a great supplementary fuel, or maybe a permanent fuel if we all stop focusing on SUVs and trucks as daily drivers. Imagine a small, light hybrid prius with a little diesel engine. 100 mpg is pretty easy when you think about it like that.

There are some algae farms out west that are making some very promising yields of viable oil stock.... like hundreds of times more yield per acre than corn or soy.

I didn't want to get into homebrewing the stuff, and there was really only one place to get it nearby, which was fortunately reasonably conveniently located. A garage/gas station which sold only SeQuential's fuels, both biodiesel and bioethanol.

I stayed away from biodiesel specifically for the reasons curtis mentioned. I have been running WVO successfully for 10,000 miles now, but that includes a secondary tank, heat exchanger, remote fuel filter, etc

curtis73 wrote: There are some algae farms out west that are making some very promising yields of viable oil stock.... like hundreds of times more yield per acre than corn or soy.

That's pretty exciting!

It does seem like the existing approach is untenable, but I'm kinda hoping it can work some of the kinks out of the technology (like my truck's issues) so if something like the algae can make production effective, we'd be closer to being able to use it.

To be honest, I really like the Volt's series hybrid layout: engine speed mostly disconnected from vehicle speed, but with the option to drop the conversion losses out at cruise speeds. Though my hybrid daydream is a series hybrid Unimog powered by a small turbine with motors at the wheels... Dangit, I've thread-jacked myself.

ransom wrote: To be honest, I really like the Volt's series hybrid layout: engine speed mostly disconnected from vehicle speed, but with the option to drop the conversion losses out at cruise speeds.

I have that - it's called a CVT. I'd love to see an analysis to see if a CVT (Which is fairly inefficient by itself) is any less efficient than converting it to electricity. I mean, if you eliminate the idea that you can have some stored up energy from the battery, which a CVT obviously cannot do, is it any worse? CVTs vs a non battery hybrid would be an interesting comparison.

In reply to tuna55:

I'd like to see that analysis, too. My suspicion is that the CVT would win on power transmission efficiency as compared to converting to electricity and back, but in looking at the full package, I think that storage capacity is a big deal. I assume modern CVTs have some sort of lock-up facility for cruise? Actually, how would that work... I guess you'd need a really tall final drive so 1:1 would be like overdrive on a normal trans...

LiPos are a big jump over NiMH, but I'm really looking forward hopefully to improvements in caps, or flywheel storage. The latter seems more efficient, but caps seem like they have the potential to eliminate much of the hybrid weight penalty. But I'm no expert...

calteg wrote: I stayed away from biodiesel specifically for the reasons curtis mentioned. I have been running WVO successfully for 10,000 miles now, but that includes a secondary tank, heat exchanger, remote fuel filter, etc

Same here. About 60K on WVO and loving every mile. I looked into making bio, but after some first-hand experience I decided it was just not worth the risk. I knew a guy and helped him brew it. He was always getting a batch that's a little "off" and having to get towed back. I'd rather just filter and use it.

I think it was probably misguided for us to worry about what we were burning in a truck used almost exclusively for short hops. I think WVO was probably untenable just because most of our trips probably weren't long enough to warm a WVO tank...