Just a very simple question : Why does one use bio-fuels?Watch
Why exactly do so many people think using bio-fuels are a good thing?
Consider the following :-
1) Bio-fuels require crops that compete with food crops.
2) Usually (especially in 3rd world countries and USA) uses extensive use of pesticides, herbicides and polluting chemical fertilizers that will eventually get into the waterways.
3) Energy intensive process.
4) Many brews releases more particulate matter than ULSD from Germany or Scandinavia.
5) Using it in pure form will screw up your pump, filters and injectors on most modern diesels due to lack of lubricating properties.
6) Generally to produce 1l of bio-diesel and using the most modern and fuel efficient machinery it would require 1.3l of mineral diesel.
7) Can be a very stupid idea to use it when the climate gets cold as it will congeal up in the fuel tank or even worse in the fuel lines.
8) Usually on most modern diesels the fuel consumption will be higher. Most new petrol engines will require new injectors and head modification for it to use it.
9) Most diesels when run on biofuel will be less powerful than one running on ULSD.
10) Cost more usually unless it had been subsidized. In fact today if it wasn't for the high taxes on diesel, the cost of mineral diesel will be around 70p/l and bio-diesel will be upwards of £1.20 p/l.
Older diesels will run on just about anything given the right properties. I managed to fill my tank up a quarter with petrol, so I topped it up with diesel and had no issues with a 25% petrol blend. They'll also run on kerosene, paraffin, and I know some guys that use WD40 to aid in starting old diesels on cold mornings.
Biofuel will in the end go the same way as petrol and diesel. Once the hydrogen fuel cell is developed to the point its cheap buy/run and uses an efficient amount of energy to produce the hydrogen then that will explode over night (not literally I hope )
- When I was working on a farm, the best prices for grain were for product that met the grade for human consumption. Lower quality was sold off for animal feed and it was generally only surplus that went for biofuel production. I realise that this probably isn't the case universally! One of the managers there did make the comment that it took about a litre of mineral diesel per litre of bio-diesel, though if it's genuinely surplus to other requirements then it's obviously better to use it than let it rot
- There's a massive move towards reducing the use of pesticides/fertilizer etc. in modern agriculture, not only from an environmental point of view but also from a cost point of view. GPS guidance systems have already significantly reduced the overlap (and hence double application) - from memory the number is about a 20% reduction on average. There are also systems in development which monitor the area ahead of the spray boom to identify the required application of chemicals and can tailor the spray package with a resolution of about 30cm. Whilst I won't deny it doesn't still happen, run off into watercourses is something which is actively avoided
- Bio-ethanol can be used as part of a petrol blend to increase octane rating, in place of tetraethyl lead - which undoubtedly has environmental benefits. I think there may be other octane enhancers used in Europe, but ethanol is certainly used in the US
- All diesels will wax at low temperatures, it's simply a question of using an appropriate blend for the climate. Normally this is done by the seller - hence between November and March in the UK you will be buying winter diesel, which has a lower waxing point than summer diesel. My last employer had to get supplies of arctic diesel in one very cold winter, when the diesel was gelling in the tanks of machines in the yard
- Increased fuel consumption is predominantly to do with differing energy densities, and bio-fuels generally have a lower energy density than mineral fuels. Strictly efficiency is a measure of useful energy output compared to energy input, so the volume required for that given energy input is irrelevant. Fuels also expand and contract with change in temperature, so the energy contained within in a litre of fuel varies with the temperature as well. Of course, that's not much consolation if you're still paying a similar price per litre!
- Similarly, the power loss issue will predominantly be down to the fuel metering being set for mineral diesel. (I think) if you injected the energy-equivalent quantity of bio-diesel your power output would be very similar
- With modern engines running exhaust after treatment there should be minimal particulate emission anyway. Whether there are issues with running biofuels with after treatment I don't know
Anyway just a few points that may be of interest - as I said earlier, I don't have any strong feelings on the issue, though obviously I think it's a good idea to make use of surplus crop rather than let it go to waste. Ensuring that it is genuinely surplus is a very valid point.