Featured Diesel still an Important Part of Toyota's Game Plan in Europe

https://en.wikipedia.org/wiki/Hydrotreated_vegetable_oil

There might be a station chain selling this in California. In the past, HVO may have been referred to as next gen biodiesel. It's made from the same oils as biodiesel, but doesn't have the drawbacks.

 

Interesting development.

Europe's introducing a complete ban on Russian diesel by the end of 2022, so this couldn't have come at a better time.

Going forward I think HVO use will be limited to trucking, as Europe seems to be weaning itself off diesel cars.

A lot of commercial fleets are trialling HVO at the moment, but I don't hear anything about passenger cars (in this part of Europe anyway). It seems that some adjustments to the fuel system are needed, which means that car owners might be reluctant to get on board if, or when, it becomes widely available

 

From the OP article, sounded like the needed modifications are the same as a gas engine needs for ethanol. The lower energy content of the fuel compared to the petroleum stuff means a fuel system that can allow higher flow rates. If you want to achieve the same power outputs. If that isn't a concern, an unmodified engine could run it. The computer might not like what it sees between fuel use and output, and trip the light.

A bigger concern is with this fuel's physical properties and emission systems. Depending on the design of the DPF, biodiesel can end up in the crankcase and dilute the motor oil. That's why many diesel cars have a B5 limit. If HVO behaves closer to biodiesel than diesel, there can be similar issues.

 

Yes this should be similar to the advanced biodiesel in Ca. Basically hydrogenated veggie oils +H2. When veggie oils are completely hydrogenated, they are converted from Triglycerides to paraffins, better known as wax, but lower carbon numbers of wax will be diesel boiling range and fluid at room temp, until winter, that is. California is heavily subsidizing which makes it work financially, but only in Ca. right now. This is part of the story why US refinery output is lower, due to some refineries being revamped to reap the Ca. subsidies for advanced biodiesel.

Of course food for thought, if this is really good:
Europe and UK pour 17,000 tons of cooking oil into vehicles a day | Environment | The Guardian

 

The oils are also being hydrocracked. Basically, the vegetable oil is under going the same processes petroleum does at a refinery to yield products closer to the petro ones in properties. It should have gel at lower temperatures than biodiesel. Also no glycerol to deal with.

 

I think they mean that oil which would normally be used for cooking is being diverted for making biodiesel?

https://www.citroen.ie/about-citroen/environment/alternative-energy.html

Biodiesel is a blend of diesel fuel and vegetable oil produced from plants such as oilseed rape, sunflower, soy or palm oil. This oil is chemically transformed into VOME (Vegetable Oil Methyl Ester), which is then mixed with diesel fuel. European regulations allow 5% VOME in diesel fuel.​

Pretty risky to run a direct injection diesel engine solely on cooking oil. The viscosity's not gonna be good for the injectors, and ISTR it rots any rubber seals in the fuel system

 

I think it's possible the get straight or waste vegetable oil from the pump in Europe. I'm guessing it is mostly blended with diesel. VO cars I'm familiar with have two tanks; you have to let the car warm up on diesel before switching to VO100, and switch back before shutting down.

Never heard of VO being bad for rubber. Biodiesel is, but diesel fuel systems in the US have been using compatible rubbers since the mid-90's. HVO should be as safe as diesel for the car's components.

The cooking oil numbers in the Guardian article likely includes biodiesel and HVO with the VO.

 

I live in Europe + I've driven all over Europe and have never seen a gas station anywhere in Europe selling vegetable oil at the pump. Standards are strictly enforced, and as you can see from my previous post only 5% VOME is allowed. Maybe catering supply stores are missing an opportunity here?

Two-tank vegetable oil setups are for biodiesel nerds only. A diesel car is just an appliance for regular people - they're not interested in replacing injectors, installing a second tank or doing an ECU remap just to save a few bucks when they fill up (or to save the planet).

That Guardian article makes no sense but I note that it seems to rely on research by an ex-Greenpeace climate-change activist. He refers to scarcity due to the war in Ukraine, but refers to consumption in the 2015-2019 time period?? ...seems a bit sensationalist to me

 

The tank systems were for vegetable oil; mainly waste.

Biodiesel can be used in older diesels without issue. Well, assuming the fuel lines and gaskets were compatible.

I've seen mention that it is the higher pressure fuel systems in newer diesels that is the problem with biodiesel, thus the low blends. The only technical explanation I have come across involves emission controls though. Specifically the DPF.

The DPF needs periodic regeneration. This is done by spraying it with fuel to burn off the material it has trapped. To save costs, that fuel is sprayed from the cylinder injectors. Fine with diesel, but biodiesel's physical properties means more gets let behind in the cylinder. With too much biodiesel in the fuel, too much then ends up there, and works it way into the motor oil. While the European diesels here were limited to B5 blends. The Ford and GM trucks had a B20 limit. I think they have a dedicated injector in the exhaust for the DPF.

Biodiesel is actually really easy to make in a shed. So there is also some CYA from the manufacturers in case someone puts so low quality homebrew into their tank.

The HVO fuel should be really close to diesel in properties. The Wiki article I linked says making gasoline from the VO with that method is possible.

 

I miss my diesel car I used to have, as far as the way it would drive, the longevity and the fuel mileage. I'm sure a new diesel would be a whole other animal though.

 

I am rusty and out-of-date (retired), but Europe has long been mandating 5% biodiesel, whereas conventional biodiesel in EU is typically made from rapeseed oil, the yellow flowers on the countryside. There is not much "straight" use of raw veggie oils, they are either converted to regular biodiesel ("FAME") or the newer trend is advanced biodiesel. Whereas FAME is Fatty Acid Methyl Ester created by reacting veggie oils with methanol.

 

Or ethanol. The basic reaction is an alcohol mixed with a strong base, usually NaOH, that is then mixed with the oil. You could use animal fat, which does yield better quality fuel, but introduces other issues with most needed to be melted. Commercial plants can do an acid esterfication to further increase yields.

Some US states may have required biodiesel blended in. Pennsylvania might be B2; there is a law requiring a mix based on how much is made in state. The pumps at the station I stop at in Virginia claim to be B10.

 

do the bio formulas still require pee pee (urea) filters?
.

 

I suspect it does. The ultra-low HC content of diesel exhaust needs some HC to 'refresh' the converter to handle the NOx.

Bob Wilson

 

Diesel exhaust can have a lot of oxygen which makes it tough for the current 3 way cat to reduce NOx. There may be a different catalyst that works but urea is likely the cheapest way to get rid of the pollutant.

 

I do not know much about actually owning/operating a diesel vehicle....but the advanced biodiesel is all paraffins, so that's about the cleanest diesel fuel you can get ...not sure if it still makes as much NOx. California is the only one with 100% advanced biodiesel, the other areas have blends with regular diesel would not be much different that regular diesel.

 

NOx is the result of nitrogen and free oxygen mix under high temperatures. A lean fuel mixture in the engine results in unburned oxygen free to react with nitrogen if there is enough heat. Diesel engines are running lean nearly all the time, and most are higher compression than gasoline ones, so there is more heat. NOx with lean burning is also a problem for gas cars, which is why emission compliant ones no longer use the strategy for better fuel economy. The original Insight was likely the last to do so, and it had a NOx trap like a diesel.

In short, NOx emissions are fuel independent.

That's going to depend on the market's emission regulations. For EPA NOx levels, SCR with the exhaust fluid seems to be the best way while keeping all of diesel's advantages.

 

From what I understand, a diesel is overall cooler than a gasoline engine in the combustion chamber. But the point at which the fuel sprays out creates a rich (cool) to stoichiometirc (hot) to very lean (cool) condition. This makes a place in the combution chamber that's always as hot as it can get, and with the added compression, even hotter.

But gasoline engines actually used to produce far more NOx emissions. Part of the reason is running at near stoichiometric in the whole cylinder. This leaves lean pockets (fuel/air mix is never 100% homogeneous) that produce a ton of NOx. Fuel injection, or more importantly head design has helped (better mixing) but I do think the 3-way catalytic converter (which needs unburned fuel and low oxygen levels) really changed things for the gasoline engine.

According to what I've read, once your emissions devices start failing, an old diesel engine will produce less NOx (and CO and HC) emissions than a comparable gasoline engine.

 

Yeah, the 3-way is a game changer. In order to work, it needs the right mix of CO, NOx, and HC though. A lean running gas engine actually produces less NOx than a stoichiometric one, but the pollutant ratio is off. Which leads to more NOx getting past the cat. That is why simply putting a 3-wat cat on a diesel, once the sulfur was addressed, doesn't work.