UKH

Having heard today that the oceans are becoming increasingly acidic from absorbing CO2, I'm having second thoughts in my eyeing up of older diesel estates for when I've hopefully eventually learnt to drive.

At the root of things I'm guessing a comment I heard about it being hard to find a sustainable way of living unsustainably rings true, but would recycled cooking oil from my local eateries emit any less CO2 when burnt as fuel?

In reply to Timmd:


I can't answer that question however the cooking oil will be carbon neutral, the carbon in it has been sequestered from the atmosphere by the plants used to make the oil. Diesel is not as that Carbon has been stored for 1000s of years and is now being released.

In reply to Timmd:


In short , no.

If you bury some diesel oil back in the ground, it's CO2 will be kept out of the atmosphere. If you burn it, the CO2 enters the atmosphere.

If you bury some vegetable oil in the ground, it's CO2 will be kept out of the atmosphere. If you burn it, the CO2 enters the atmosphere.

The vegetable oil should be greener, in principle, because 1) it's CO2 was recently removed from the atmosphere, and is not CO2 removed eons ago. 2) The vegetable oil is manufactured once (with some CO2) cost and used multiple times (frying, driving) whereas diesel oil is manufactured once and used once, so the manufacturing CO2 cost is worse for diesel.

Biofuels are really just another means of solar power. They'll never reduce CO2 levels beyond simply borrowing a bit - short term - to enable their sun + co2 > biofuel > car > co2 cycle. The chances are that mismanagement, greed and incompetence surrounding biofuels will however destroy a lot of important ecosystems, perhaps creating lots more methane (much worse than CO2). Look at what's happening in the USA to feed our Drax plant. My hope is that solar electric will eventually eliminate biofuel and hopefully therefore reduce large scale monoculture, and especially reduce the competition between biofuels and food. That being said, vegetable oil is an exception to this as it's a waste product. I suspect there isn't enough of the stuff to make a big dent for many people.

An alternative fuel, I once calculated that the excess fat carried by all members of the UK is enough to drive a 1.4TDCi Ford Fiesta over 20 million miles.

In reply to wintertree:




Did that calc include the fuel required to render them down?

In reply to woolsack:


No, but I imagine one could build a portable rendering device that uses waste heat from the engine block or exhaust to do the business...

In reply to Timmd:

You really need to account for fertiliser used in Biofuels production as well, some of the processes for producing these are pretty energy, and therefore carbon intensive.

In reply to DaveN:

I was thinking about getting it from catering places and using a Fuel Pod I think they're called (IIRC) to process it into fuel.

I think it could be worth a google to see if there's anything about what emissions are given off when a certain amount of cooking oil is burnt, compared to diesel.

In reply to Timmd:

I don't know about CO2 emissions, but my old Pajero 2.8 TD used to run far better on new cooking oil than it did on diesel. At the time it was 36p per litre compared to 90p for diesel but the difference now is far less. It was a real flaff filling up - had to buy 4 20l drums in Makro, and disposal of those was a pain. I can only imagine how much effort would be needed to filter used cooking oil!!

Trust me, quite apart from the emissions, its just sustainable!! (But it WAS worth it to run quieter, smoother and more powerfully!)

In reply to suilven:

Theses are the fuel pods.

http://greenfuels.co.uk/products/fuelpod-domestic-biodiesel-processor/

There's 2 chip shops and 3 (?) curry houses and quite a few other eatery places round the corner from me.

It's not definite I'm getting a diesel estate, I start thinking about it, and then hear something grim about climate change and wonder if I can justify it to myself...

In reply to Timmd:

I think the CO2 difference would depend on what was going to happen to the Cooking oil if you didn't use it.

If it was going to be sent to landfill there is going to be little difference between the CO2 released from burning cooking oil and the CO2 released from burning diesel (you are releasing it, when it would have been burried).

If the used oil was going to be burned at the waste management plant, then it would release all the CO2 anyway, so you might as well use it in your car.

That makes sense to me, but I don't think I have written it very clearly.

In reply to ablackett:

I've decided to forego buying a diesel estate, the current news on climate change and CO2 emissions is really grim.

In reply to Timmd:

I'd imagine very little difference in overall emissions. Co2 is the product of combustion and a certain amount of energy will be released for each unit burnt.

The key difference is what're change in overall co2 concentration in the atmosphere is, with diesel fuel you will be increasing it. With cooking oil you 'll still be increasing it, but by less. Although the carbon contained within the fuel will be "neutral" the whole process, including carbon intensive fertiliser should be considered.

A certain proportion of fuels from forecourts is already Biofuels that are blended with the fossil fuel in order to assist us in meeting our carbon targets.

After a while you get in to discussions on another finite resource, land. A whether it should be used for food or fuel production.


As for the comments on burning it

In reply to DaveN:




The intention was to use processed cooking oil.