Sciencemadness Discussion Board

Biodiesel improvements

aromaticfanatic - 23-8-2020 at 00:47

So I made biodiesel for the hell of it a while back. I got a yield for sure but did mess up a little initially which resulted in a nasty clean up haha.

I did some reading on biodiesels and found out that they are usually just additives in engines more than primary fuels. This was due to lack of power and I think NOx issues.

So how can one improve these problematic issues? I thought of adding a sort of liquid or chemically bonded oxidizer to increase burn rates and get more power but in the end efficiency and total energy available is the way to go. Plus many oxidizers would either boost the chlorinated emission outcomes and definitely bump up NOx emissions. They wouldn't be of much use from what I see.

I thought about playing around with the structure of the biodiesel to increase the available chemical energy from the fuel's carbons and hydrogens as well as better power. The biodiesels seem to be much cleaner burning in general and have potential.

A large issue is ethanol supply. While you can use plant made ethanol to lower the carbon emissions into negative numbers, you then run into issues of using crops for food or fuel. In struggling countries, the former would be chosen and GHG and pollutants would still be at the bottom of the list of priorities.

Has anyone done any work in this field? I'd like to start a project of increasing the potential of biodiesels in the future because as of now, we are really not making much progress and they seem to be only used as additives. If we can think of ways to make the biodiesels more of an option, then that would be HUGE.

I realize this is likely nothing amateurs could even put a dent in since some seriously smart people have already tried their magic but I figured it'd be nice to learn something and maybe possibly have the chance of coming up with something new that changes the world a tad bit. I like to dream big with this kind of stuff.

Also just like with any proper o-chem research, almost every amateur lacks the resources to do proper tests. You can always call up companies and universities to run sample tests for you but that's expensive.

[Edited on 23-8-2020 by aromaticfanatic]

I prefer to discourage biofuel research

Sulaiman - 23-8-2020 at 02:02

As you stated, growing feedstock for biofuels means less arable land available for food and cooking oil,
and less fertiliser available etc.
and while oil prices are low the economics are unfavourable.

Ithink that it would be better to concentrate on wind/wave/solar power and maybe battery research.

I like the idea of converting used cooking oil to energy,
probably for static heating (boilers for building heating etc)
and food or agricultural waste to compost or animal feed.

unionised - 23-8-2020 at 02:53

Quote: Originally posted by aromaticfanatic  

So how can one improve these problematic issues? I thought of adding a sort of liquid or chemically bonded oxidizer to increase burn rates and get more power

Has anyone done any work in this field?

[Edited on 23-8-2020 by aromaticfanatic]

Yes, someone has done work on it.
They commonly use ethylhexyl nitrate

aromaticfanatic - 23-8-2020 at 03:20

Quote: Originally posted by Sulaiman  
As you stated, growing feedstock for biofuels means less arable land available for food and cooking oil,
and less fertiliser available etc.
and while oil prices are low the economics are unfavourable.

Ithink that it would be better to concentrate on wind/wave/solar power and maybe battery research.

I like the idea of converting used cooking oil to energy,
probably for static heating (boilers for building heating etc)
and food or agricultural waste to compost or animal feed.

Yea but just because there are some issues now it doesn't mean there aren't ways around it. You can still use methanol and it's possible (but probably costly to do this) turn it into ethanol. Methanol is also very useful and while it is made from natural gas sources, it can be made from wood too. So instead of burning the wood directly, You can make "wood gas" and get the methanol from that. I'm sure the spent wood/carbon still has uses and the methanol can be used to make the biodiesels. You don't necessarily take away crops and you plant even more trees for a cleaner fuel source. I think that may be something a bit more drastic of an industrial change but would be well suited for the environment.

As long as gasoline and diesel engines are still around, there is still a demand for cleaner fuels so while I definitely think researching more efficient batteries and solar panels are very important, you can't just jump and ignore a major global warming contributor, right?

I agree with the home heating part! Homes produce more pollution than cars if I recall correctly. So heating homes using such biodiesels is a great way to go greener. I know where I used to live (it was already a very environmentally friendly country) we would still burn tanks worth of oil to heat the house. If you can make a greener fuel for houses, that would be a great place to start.

Dr.Bob - 23-8-2020 at 13:11

There is a thread on biodiesel in another are of the forum, might want to look there. Given the properties of biodiesel (can gel at higher temps, etc), it makes good use as an additive in regular diesel, as it makes it work better (lowers viscosity) at 5-20%. That is also simpler than having to have yet another pump at the gas station. And the technology to produce it from methanol is pretty well known, so while it might be improved incrementally, it is pretty well known and proven (and methanol is very cheap from nat gas). Finding a way to make ethanol work better would be nice, as the fuel would be non-toxic, but there are major issues with that route.

The main way to improve biodiesel would be to breed a plant that grows well in poor conditions, thrives without much fertilizer or water, and yields more oil per acre than corn or other crops that grow in the US. In tropical areas, palms can provide 100's of gallons per acre annually, but corn and soybeans only yield a fraction of that in the US. So finding more starting oil to make it from is the biggest challenge to make it more practical. In tropical areas, a variety of crops provide very high amounts of it for good prices.

andy1988 - 23-8-2020 at 14:24

I found this critique to be of excellent breadth and depth.

A couple quotes:
Most fuel crops, such as sugar cane, have problems similar to corn. Because Brazil relied heavily on imported oil for transportation, but can attain high yields from crops in their tropical climate, the government developed the largest fuel ethanol program in the world in the 1990s based on sugar cane and soybeans.

Unfortunately, Brazil is clear-cutting almost a million acres of tropical forest per year to produce biofuel from these crops, and shipping much of the fuel all the way to Europe. The net effect is about 50% more carbon emitted by using these biofuels than using petroleum fuels (Eric Holt-Giménez, The Politics of Food). These unintended effects are why energy policy and development must proceed holistically, considering all effects on global environments and economies.


Thus, efficiently making ethanol out of cellulosics requires a different approach than for corn. They can either be reacted with acid (sulfuric is most common), degraded using enzymes produced from microbes, or heated to a gas and reacted with chemical catalysts (thermo-chemical). Each has its variations, some can be combined, and all are attempting to be commercialized. Still, these processes are stuck at about twice the price per gallon produced compared to corn. Recently, special microorganisms have been genetically engineered to ferment these materials into ethanol with relatively high efficiency.

It’s no wonder we just went with corn!

Biodiesel has criticism over petroleum diesel due to higher emissions of oxides of nitrogen (NOx = NO + NO2, where NO is nitric oxide and NO2 is nitrogen dioxide), of which I consider Ducted Fuel Injection to be a great upcoming technology to help solve that problem. Ducted Fuel Injection should also reduce demand for platinum in $$$ diesel catalytic converters, help VW satisfy the public, and other such impacts. But this is all a distraction anyway, in my opinion any chemistry innovations on this energy topic would just "kick the can down the road" on the problem of unsustainable population growth/consumption, and I think would be a disservice to humanity in that light/context.

[Edited on 23-8-2020 by andy1988]

Dr.Bob - 24-8-2020 at 06:50

Yes, but the nitric oxides problem is one of perspective, not as bad as it looks, as diesels get more miles per gallon, but the ratings are based on the emissions per gallon, not per mile. Compared to gasoline engines, diesels are really no worse, and better in every other category. The governments are using a bad test to compare them to gasoline. And biodiesel is about 3 or 4 to 1 ratio of energy in to out, which is far better than corn ethanol currently, which is closer to 1:1 or maybe 1.5 to 1 at best.

The tropics problem is that they are trying to make enough fuels for Europe to be happy, as they like "clean" fuels. If there was a crop that grew in norther climates that made even a fraction of the oil as some tropic crops, we would be fine. And the thermodynamics should allow it, as there is enough sun energy to do it, just not a crop that has evolved to make oil in the north.

In the US, we already have way more cropland available that is needed, if we could convert even part of the corn crop to something that was good for biofuel and more efficient, we could provide a large portion of our diesel needs that way. So you plant geneticists get to work.

RogueRose - 24-8-2020 at 11:07

You need to understand a few things. MUCH of what you hear or read about "renewable energies", green energy or biofuels, is paid propaganda and a lot of it could NEVER be maintained w/o the massive government subsidies that prop up the industry.

I've never heard that real biodiesel is just diesel with additives and I read A LOT about it for about 6-8 years, it is what got me into chemistry. I'll bet some companies pass off diesel as biodiesel to make more $$. Both fuels should have the same BTU content, some say biodiesel actually has 1000 BTU more per gallon.

I'm not sure how you are going to add more "power" to the fuel w/o making it much more unstable or even explosive. The nice thing about diesel is it has so much energy content but is remarkably stable with only straight oil (vegetable sourced) being of similar energy and being less volatile.

clearly_not_atara - 24-8-2020 at 13:49

The reason that biodiesels are used as additives rather than fuels isn't quality. It's quantity. Biodiesel is already a superior fuel to petrodiesel. Brazil's experience proves this handily. However, even armed with a huge amount of the best farmland in the world, Brazilian biodiesel nonetheless has supply issues and motivated a lot of deforestation.

Even if we had more land, it's not clear if biofuel for land vehicles would be that much of an improvement, environmentally speaking. The use of nitrogen-containing fertilizers to grow biofuels releases N2O into the atmosphere whose radiative forcing means that while biofuel is "carbon" neutral, it is not "climate" neutral and in fact contributes to global warming.

Plus, electric cars are just too good. The fact that the main supplier of electric cars is run by a wild-eyed madman is proof that the technology is sound, because there's no other way that idiot would have gotten away with it.

However, there is one application where biofuel makes sense: airplanes. Even with the best known battery chemistries at their full potential, electric airplanes are not practical for flights longer than 5000 kilometers. Planes will still need fuel, and biofuel still has the advantage of not requiring mining in war-torn regions for jet fuel. Here ordinary biodiesel -- methyl palmitate -- is too viscous, and more volatile/thinner fuels are required, leading to interesting chemistry problems.

[Edited on 24-8-2020 by clearly_not_atara]

Dr.Bob - 24-8-2020 at 16:38

I agree that there is not enough biodiesel to supply all needs, at least in most countries. But adding biofuel to petro based fuels rather than sell it separately makes sense in many ways. And I am saying that adding even a small amount of biodiesel to petrodiesel makes it less viscous, which allows it to flow better in pipelines, which saves a huge amount of energy and money by flowing better. That is one reason petro companies add it to diesel as that saves them a lot of money.

As for fertilizer needs, soybeans add nitrogen to the soil, so they provide both animal feed and oils with little fertilizer, which is one reason they are grown so much. Canola (rapeseed) is even better at making oil per acre, but does not fix its own nitrogen as well. If we could find or make a crop that had mixed propeties of both, with higher oil output, itr would both reduce the acreage needed, as well as well as the fertilizer needed. While electric vehicles are great, the power to run them has to come from somewhere, as electricity does not grow on trees. Any sustainable energy will have to some from the sun, and growing crops is one easy way to do that which does not require nearly as much up front costs and capital as solar panels or wind mills.

So ANY green power will require the use of much acreage to convert solar light to energy, and biofuels could provide a large amount of that quickly, if we can find and make better ways to harness it. Fuels also store power for use anytime, so biodiesel does make sense in that it can be stored easier than electricity in large amount.

Biodiesel is not practical for planes as mentioned, but many pyrolysis methods provide simpler hydrocarbons that are more like kerosene which makes them ideal as fuels. The input can be as simple as wood chips, trash, biomass (crop waste), or many other carbon sources. But that costs well over $5/gallon, which is a lot right now, so hard to compete. My company does research in that area, and we have a large pilot plant for that, but it costs a fortune to run, so the technology will have to get better, cheaper, and scaled up to be practical.

macckone - 25-8-2020 at 02:13

rapeseed grows well in colder climates.
Canola oil is grown in canada at high rates.
But it is mostly used for food, however thanks to the fact americans are fat asses,
the used oils from burger joints are used to make biodiesel.
So the oils are used for foods then used for biodiesel.
Which greatly increases the value of the product.