How much cleaner is a biodiesel vehicle than a petroleum vehicle?

Question

Im thinking of going biodiesel but i dont know how much cleaner for the environment it is.

Answer 1

The PDF document at the link below gives a good basic summary of biodiesel emissions as compared to petroleum diesel emissions. The numbers are very good; I am hopeful that my next vehicle will be a hybrid electric/biodiesel.

Answer 2

The difference in emissions from the vehicle is not the important thing -- my guess is that they'd be much the same.

The real difference is using less fossil fuel. The carbon dioxide your biodiesel vehicle produces comes from plants, and so is renewable. If you can leave oil, coal or natural gas in the ground instead of burning it, you're ahead and helping to save the planet.

However, not all biodiesel is the same. Modern agriculture uses fossil fuel to grow plants -- some estimates say it may often be more than the fossil fuel saved by the biodiesel (you have to count tractor fuel, fertilisers, irrigation, refining, transport etc). And if the biodiesel farm is on land cleared from forest (for example if it's from palm-oil), then it will take many decades to earn back the vast amounts of carbon wasted when the forest was burnt.

Also worth thinking about what else the land might be used for. If you're using maize (corn) oil or rapeseed (canola) oil, then it's on land which could be used for food. Where is that food going to be grown? It might have to be on less suitable land, grown less efficiently, and so using more fossil fuels, or it might lead to natural habitats being cleared for farming, or it may have social effects on the people who need that food.

So-called "zero-emission" vehicles also have an impact. Not only do they take energy and other resources to make them, but the energy to run them has to come from somewhere. For example an electric vehicle is actually running on power-station fuel, such as oil, coal or nuclear power -- and there are high transmission losses driving the power along miles of wires.

In the long run, you might be better to think about ways of minimising fuel use overall. It doesn't make much sense, for example, running a great fat SUV on biodiesel (or hybrid technology) if the car you really need is a very much smaller one which uses a quarter the fuel. Or do you need a car at all?

Whatever happens, we are all going to have to change our ways very much more than we imagine.

Answer 3

How long is a piece of string. The answer lies in how much and what type of driving you do. Modern diesels are now pretty clean but with any car if you haul around a 3 litre motor when you could get away with a 2 litre or smaller, you are hitting the environment. Just compare the power output of the latest generation 1.3 litre diesel engines with 2 litre motors of 10 years ago. They are way more efficient as well as being more powerful. Choosing biodiesel is just one way of reducing consumption of fossil C and helping to reduce your carbon footprint. But if you insist to drive a huge hummer then your a hypocrit.

What you do need to check out before buying your new motor is to make sure it is compatible with biodiesel (or bioethanol if you decide to stick with gas power).

And for those who assume biodiesel always must come from crops - it doesnt. Second generation biodiesel is on its way and is synthesised from a whole raft of feedstocks including wastes which would otherwise add to our problems. All you have to do is to google "fischer-tropsch" to see all about synthesis which has actually been carried out for decades already. Until recently the political will was not there to push alternative fuels and the economic incentives were not enough.

Answer 4

All I can say it it is much cleaner than conventional diesel in terms of emmission. That's according to numerous studies.

Also biodiesel can clean up your engine's fuel lines and cylinders., removing grime left over by conventional diesel fuel. This can improve efficiency.

Just make sure your engines have metal fuel lines as biodiesel can wear down rubber ruel lines and sealings. You can replace them though.

Answer 5

The main benefit of using biodiesel is that you're emitting carbon that's part of the carbon chain. Since it's just carbon that's been absorbed by plants, you're not adding any new CO2 to the atmosphere, as opposed to burning fossil fuels where you're emitting carbon that's been trapped for a long, long time.

The main downside of biodiesel is that you're increasing demand for the crops that your fuel comes from.

Answer 6

Practically no difference in CO2 emissions. The big difference is that biodiesel if renewable (meaning we have an endless supply, theoretically), and we don't have to import it. But, will make NO difference on global warming.