Care to comment Jtabeb

[cmalbatros]

Re: Care to comment Jtabeb

My dad put 350K miles on an '81 MBz 300SD turbodiesel; this after my having destroyed his Olds 88 'diesel' (poorly converted gasoline engine) by simply trying to see how fast it would go....

Quite, and there are some London cabs that have done 1,000,000 miles plus, still on their original engine. Made by, I think, Britains only remaining British owned car company, longest running too.

[flintlock]

Re: Care to comment Jtabeb

This sounds good but I'll believe it when I see it.

Same here.

Correct me if I'm wrong JT, but don't jets runs on what is basically kerosene? Not refined to the level of gasoline. What would GAS or diesel cost if made with algae? Remember, the question is not about viability, but rather cost. We already have many alt energy sources but none work at the cost or the scale of oil. I'm not saying this stuff does not have promise, I think it does, but when they reach the point they can make the stuff work and work cheaply, we'll know about it because it is sitting in our gas tank, not because it was announced by some super secret government entity.

I'm always skeptical of "press releases" announcing something is almost there. Especially coming from a government source. There has to be a lot of top down pressure to announce good news in this economic environment. I've just seen too many "we've turned the corner" announcements lately I guess.

Steve Tractor trailers use diesel engines. Hardly weak or short lived engines. It's when they try to make them too cheaply they have the problems you mention. Like anything, you get what you pay for. The Yugo didn't suck because it was a gas engine. It sucked because it was a POS.

[GRG55]

Re: Care to comment Jtabeb

Just a few of the minor problems with diesel engines: crank-shaft damage due to failure of the connecting-bearings due to high compression in the engine, filth and dirt in the fuel and in the engine means a shorter engine life, starting problems in cold weather, fuel injector failure, warping of the head due to high compression, fuel gell in cold weather, battery weight to lug around, lack of availability of auto-diesel fuel, engine weight due to thicker materials required in diesel motors, among other problems.

The love affair in North America with diesels in cars never even got off the ground. Unlike Europeans, we don't enjoy pissing-away money servicing and repairing our cars to death. (We expect more from our cars in North America than Europeans do.)

Although some of what you say is true, your overall conclusion about diesel engines is not correct Steve.

Just one example, you say that "filth and dirt in the fuel...means a shorter engine life". In fact exactly the opposite is the case.

Gasoline is a solvent, and constantly attacks the lubricating oil on the engine internals, thereby limiting the life span of the engine because of the wear rates of the piston rings, cylinder walls and valve guides. Diesel oil doesn't do this, which is why diesel engines can accumulate hundreds of thousands of miles more than gasoline engines before the bottom end and heads have to be overhauled.

The starting problems in cold weather are partly because of the higher compression ratios [which is also why diesels are so much more efficient] and the significant engine mass that has to warm up before the heat-ignition combustion process is working optimally. A decent battery, glow plugs and a proper cold weather warm-up sequence on the part of the driver address this issue more than adequately. I run a Ford pick-up truck with a 6-litre Powerstroke turbo-diesel in a part of Canada that's a hell of a lot colder in the winter than where you live, and I don't have any of the cold weather problems you describe.

On your point regarding expensive maintenance, apparently you haven't taken a modern fuel-injected, computer-controlled, gadget-laden gasoline engined car to a dealer repair center recently. They aren't any different from having a diesel serviced...in both cases when you get the repair bill it usually means you are "buying your car back" from the dealership...:rolleyes:

At least diesels don't ever need spark plugs replaced, or suffer from electronic ignition failures. On the negative side, however, the emissions control systems in diesels tend to be more complicated than gasoline engines, in order to meet the current standards...and those systems do tend to be sources of frequent maintenance requirements and occasional failure.

Finally, diesels make really lousy run-about-town cars for doing shopping and errands. They are in their element when they are run long distances, under load, and at fairly constant speeds [e.g. commuting into the city from a distant suburb]...they are not good in frequent stop-start, short trip scenarios [e.g. running errands in the suburbs].

Never get a car nut going...

[raja]

Re: Care to comment Jtabeb

Okay, but YOUR NEXT CAR, should be a diesel, ok?

(Or EVEN BETTER, why don't YOU WAIT, for a plug-in hybrid Diesel!?!?) That's the Cat's meow, my friend. Trust me, WAIT FOR THIS, I promise you won't regret it!

Why by an original IPHONE when the 4GS will comeout 24 months after initial launch. So MUCH MORE capability, cheaper price, surely you can stomach a mere 24 month wait now, can't you?;)

jtabeb,

I don't get your logic . . . .

Why should I buy any fuel for my car, when I just paid my electric bill for 25 years, and I can buy a plug-in car and power it with my own electricity?

However, I like your idea of a diesel plug-in . . . for long trips where recharging might be problematic.

[ThePythonicCow]

Re: Care to comment Jtabeb

Finally, diesels make really lousy run-about-town cars for doing shopping and errands. They are in their element when they are run long distances, under load, and at fairly constant speeds [e.g. commuting into the city from a distant suburb]...they are not good in frequent stop-start, short trip scenarios [e.g. running errands in the suburbs]

Why's that?

[gnk]

Re: Care to comment Jtabeb

Care of Yves at Naked Capitalism

http://www.guardian.co.uk/environmen...n-fuel-problem

"The brains trust of the Pentagon says it is just months away from producing a jet fuel from algae for the same cost as its fossil-fuel equivalent."

Yves also posted this "game changer" recently:

http://www.physorg.com/news184310039.html

This is great for the Pentagon - it's an energy source independent of imports. Thus it is a national security win for us.

However, I just don't see this being scalable. I don't see it ever putting a dent in current total petroleum use.

Here's the relevant quote:

She said the projects, run by private firms SAIC and General Atomics, expected to yield 1,000 gallons of oil per acre from the algal farm.

1,000 gallons per acre? The US consumes 380 million gallons of gasoline a day. Say we replace 20% of current gasoline consumption with algae (we need 76 million gallons of green stuff - and I'll ignore refining for the moment, which would increase the #). We would need to commit 76,000 acres. But will 76,000 acres produce 76 million gallons a day? Obviously not. I would like to know how long it takes an acre to produce 1,000 gallons. What is the life cycle of this stuff? How much water is needed? How much land do we have near that amount of water?

http://tonto.eia.doe.gov/energyexpla...e=gasoline_use

To be scalable and to ward off peak oil, I would guess that competing uses of land - agriculture for food - would be severly impacted. Like a $30.00 a can of beans impact. And that's not even factoring in inflation from the ongoing financial crisis.

Can someone please correct me? I was really positive of this development when I saw the headline.

[Serge_Tomiko]

Re: Care to comment Jtabeb

Can someone please correct me? I was really positive of this development when I saw the headline.

I don't think I can correct you - but I'll say this: Algae refers to a kind of plant that exists in water. It is the oldest form of life capable of photosynthesis. If this stuff can be grown in salt water, then there is no problem. If it requires fresh water, then it is useless.

[Serge_Tomiko]

Re: Care to comment Jtabeb

I don't think I can correct you - but I'll say this: Algae refers to a kind of plant that exists in water. It is the oldest form of life capable of photosynthesis. If this stuff can be grown in salt water, then there is no problem. If it requires fresh water, then it is useless.

from the article text:

Unlike corn-based ethanol, algal farms do not threaten food supplies. Some strains are being grown on household waste and in brackish water. Algae draw carbon dioxide from the atmosphere when growing; when the derived fuel is burned, the same CO2 is released, making the fuel theoretically zero-carbon, although processing and transporting the fuel requires some energy.

Brackwish water is the key. This means they haven't yet figured out a way to do this in pure salt water.

[gnk]

Re: Care to comment Jtabeb

from the article text:

Unlike corn-based ethanol, algal farms do not threaten food supplies. Some strains are being grown on household waste and in brackish water. Algae draw carbon dioxide from the atmosphere when growing; when the derived fuel is burned, the same CO2 is released, making the fuel theoretically zero-carbon, although processing and transporting the fuel requires some energy.

Brackwish water is the key. This means they haven't yet figured out a way to do this in pure salt water.

I understand that it needs in water - I fish in bays and frequently come up against the stuff all the time on my fish hooks.

Anyway, it is still land and water intensive. Where are all those ponds going to go? And if one acre of water produces 1,000 gallons - then I just don't see it being scalable. We use 380 million gallons a day of gasoline.

Water and land affects food supplies. I agree that brackish is the way to go - but careful with introducing a new algae species in estuarine/brackish environments - it's not a good thing and could destroy local fish populations and native algae.

[thriftyandboringinohio]

Re: Care to comment Jtabeb

I understand that it needs in water - I fish in bays and frequently come up against the stuff all the time on my fish hooks.

Anyway, it is still land and water intensive. Where are all those ponds going to go? And if one acre of water produces 1,000 gallons - then I just don't see it being scalable. We use 380 million gallons a day of gasoline.

Water and land affects food supplies. I agree that brackish is the way to go - but careful with introducing a new algae species in estuarine/brackish environments - it's not a good thing and could destroy local fish populations and native algae.

Go to National Renewable Energy Laboratory (NREL.gov), search for algae.

Here's a recent report http://www.nrel.gov/biomass/pdfs/benemann.pdf

[gnk]

Re: Care to comment Jtabeb

Go to National Renewable Energy Laboratory (NREL.gov), search for algae.

Here's a recent report http://www.nrel.gov/biomass/pdfs/benemann.pdf

here's the most important and realistic quote in that presentation:

"The advantage of biofuels and other renewable energy sources is that they will be so scarce and expensive that we will need to use them very frugally instead of wasting them wantonly as we do now with fossil fuels, and would with nuclear energy." - John Benemann

Has anyone seen David Fridley's presentation on "The Myths of Biofuels?" He's a staff scientist at Berkeley Labs and used to work with the current Sec of Energy, Steven Chu.

http://www.sfbayoil.org/sfoa/myths/index.html

[GRG55]

Re: Care to comment Jtabeb

Why's that?

Unfortunately I wasn't able to come up with a short, simple explanation...

A properly designed diesel engine [e.g. not something like GM's ill-fated attempt to build diesels based on the Oldsmobile 350 cu. in. gasoline engines during the 1970s oil crisis] is a very high precision bit of kit, built to tight tolerances [one of the reasons they are more expensive than gasoline engines]

Because they're a heat [compression] ignition engine they operate at higher compression ratios than Otto cycle [spark ignition] engines, and the internal pressures and stresses are considerably higher. Consequently most everything on the engine including the block, heads, and the engine internals [pistons, rods, bearings, head gaskets, etc] is stronger and heavier than an equivalent gasoline engine.

Because the engine uses heat to ignite the fuel, when all this engine mass is cold it quenches ignition and the result is incomplete combustion of the fuel [you can tell this is happening any time you see grey, not black, smoke coming from a diesel exhaust]...and that means, among other things, that the engine is not delivering the expected fuel efficiency. So it's quite important that a diesel engine be brought up to the design operating temperature range, and kept there.

Most diesel engines do not generate enough heat at idle to accomplish this...they have to have some load on them. And even then, because of the extra mass of the heavier components, it takes longer to bring a diesel up into the design temperature range than a gasoline engine.

Short trips, with lots of idling at stop lights, amd frequent shutting off and re-starting the engine is not conducive to achieving this. In addition, the frequent thermal cycling of an engine built to tight tolerances will dramatically shorten its life, especially in the hands of impatient drivers who want to "hit the starter and go".

Just as an aside, many diesel engines are equipped with turbo-chargers [an exhaust gas expander mechanically shaft-coupled to an intake air compressor]. This engine accessory is particularly intolerant of frequent thermal cycling, and prone to [expensive] failure on engines used in short haul, stop & go service.

Hope that helps.

Never get a car nut going...

[mesyn191]

Re: Care to comment Jtabeb

Brackwish water is the key. This means they haven't yet figured out a way to do this in pure salt water.

They appear to be using the brakish/waste/grey water in lieu of artificial fertilizers to encourage growth, which is actually pretty impressive (they clean the water and grow faster than normal too since the pollutants in the water are great algae food) but still suggests relatively low volume.

The problem with doing algae farming on saltwater is the sheer distance you'd have to cover to farm enough algae. You'd need thousands and thousands of boats constantly farming the sea, and then they have to transport their haul to be processed somewhere since they can only hold so much, which is also energy intensive. On top of that they'd be stripping algae out of the water faster then it'd be growing normally (unless the genetically engineer something that grows much faster, but you wouldn't want to release something like that in the wild as it'd cause all sorts of ecological disasters), you'd run into supply issues just like we're getting with oil right now.

So what they're doing is trying to grow lots and lots of algae in small (well relatively small, you're still talking about something the size of a small lake) man made water ways so they can continuously grow and process the stuff. Its a great idea, its probably one of the most likely "green" renewable sources of energy we could whip up in a reasonably short period of time, but its still fairly risky all things considered and will take years at best to get working on a large scale. Much less on a scale where it'd be enough to make a significant chunk of day to day energy use.

[mesyn191]

Re: Care to comment Jtabeb

Because the engine uses heat to ignite the fuel, when all this engine mass is cold it quenches ignition and the result is incomplete combustion of the fuel [you can tell this is happening any time you see grey, not black, smoke coming from a diesel exhaust]...and that means, among other things, that the engine is not delivering the expected fuel efficiency. So it's quite important that a diesel engine be brought up to the design operating temperature range, and kept there.

Most diesel engines do not generate enough heat at idle to accomplish this...they have to have some load on them. And even then, because of the extra mass of the heavier components, it takes longer to bring a diesel up into the design temperature range than a gasoline engine.

Short trips, with lots of idling at stop lights, amd frequent shutting off and re-starting the engine is not conducive to achieving this. In addition, the frequent thermal cycling of an engine built to tight tolerances will dramatically shorten its life, especially in the hands of impatient drivers who want to "hit the starter and go".

The Europeans seem to have plenty of diesel engines that do the stop and go thing just fine, how are they doing it? More aggressive electronic controlled heaters for idle time? Big heavy flywheels to act as both a constant idle load and to store excess kinetic energy for use on demand like batteries in a hybrid?

[jtabeb]

Re: Care to comment Jtabeb

jtabeb,

I don't get your logic . . . .

Why should I buy any fuel for my car, when I just paid my electric bill for 25 years, and I can buy a plug-in car and power it with my own electricity?

However, I like your idea of a diesel plug-in . . . for long trips where recharging might be problematic.

You seem to get my logic extremely well (RANGE!).