Let’s say I had 1 L of diesel fuel all uniformly C ₁₆ H ₃₄ and I split it in a catalytic convert into octane C ₈ H ₁₈ (somehow adding in the extra 2 H but that’s not important).

Would I end up with 1 L of octane, or 2 L, or some other number in between?

Would depend on density…

According to the first link in a search the density of diesel is 0.832 kg/L

The density of Octane is stated as 0.703 kg/L.

So 0.832kg of Octane will be ~1.2L

But that doesn’t take into account the extra mass from the extra H’s…

furious said:

According to the first link in a search the density of diesel is 0.832 kg/L

The density of Octane is stated as 0.703 kg/L.

So 0.832kg of Octane will be ~1.2L

But that doesn’t take into account the extra mass from the extra H’s…

Yep.

If adding hydrogen then you get about 1% more octane than that
But if no hydrogen is added but instead pure carbon is removed then you get about 6% less octane than that.

That’s assuming no unwanted byproducts, which would end up reducing the yield more.

I like the idea of coal + gas cracked together to yield diesel (or petrol).

mollwollfumble said:

I like the idea of coal + gas cracked together to yield diesel (or petrol).

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

party_pants said:

mollwollfumble said:

I like the idea of coal + gas cracked together to yield diesel (or petrol).

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

IIRC, the last year Australia mined enough oil to meet all its national needs was 2002.

We have plenty of coal and gas, though.

party_pants said:

mollwollfumble said:

I like the idea of coal + gas cracked together to yield diesel (or petrol).

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

To be fair, a coal to liquids plant is very, very expensive. First step is coal to gas. Second step is gas to final product (petrol, diesel, fertilisers, pharmaceuticals etc).

I investigated the notion a few years back, and found that it would never amortise itself.

Michael V said:

party_pants said:

mollwollfumble said:

I like the idea of coal + gas cracked together to yield diesel (or petrol).

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

To be fair, a coal to liquids plant is very, very expensive. First step is coal to gas. Second step is gas to final product (petrol, diesel, fertilisers, pharmaceuticals etc).

I investigated the notion a few years back, and found that it would never amortise itself.

Uh … it’s also more GHGe intensive than just using petroleum. What exactly would be the advantage?

dv said:

Michael V said:

party_pants said:

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

To be fair, a coal to liquids plant is very, very expensive. First step is coal to gas. Second step is gas to final product (petrol, diesel, fertilisers, pharmaceuticals etc).

I investigated the notion a few years back, and found that it would never amortise itself.

Uh … it’s also more GHGe intensive than just using petroleum. What exactly would be the advantage?

None whatsoever. Unless you have an isolated coal basin in a politically isolated country.

Michael V said:

dv said:

Michael V said:

To be fair, a coal to liquids plant is very, very expensive. First step is coal to gas. Second step is gas to final product (petrol, diesel, fertilisers, pharmaceuticals etc).

I investigated the notion a few years back, and found that it would never amortise itself.

Uh … it’s also more GHGe intensive than just using petroleum. What exactly would be the advantage?

None whatsoever. Unless you have an isolated coal basin in a politically isolated country.

Independence and ability to make your own ?

Michael V said:

party_pants said:

mollwollfumble said:

I like the idea of coal + gas cracked together to yield diesel (or petrol).

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

To be fair, a coal to liquids plant is very, very expensive. First step is coal to gas. Second step is gas to final product (petrol, diesel, fertilisers, pharmaceuticals etc).

I investigated the notion a few years back, and found that it would never amortise itself.

First step is not coal to gas. That’s a different process.

Get the combination of heat and pressure and stoichiometry right and it ought to go straight from coal + hydrogen_source to crude oil. It would have to be a high pressure process, but I don’t know how high. It may also need a catalyst to keep the temperature down to something more reasonable.

mollwollfumble said:

Michael V said:

party_pants said:

we seem to have those two resources in abundance in Australia, yet we import most of our petrol and diesel fuels from refineries in Singapore using middle-eastern crude oil.

To be fair, a coal to liquids plant is very, very expensive. First step is coal to gas. Second step is gas to final product (petrol, diesel, fertilisers, pharmaceuticals etc).

I investigated the notion a few years back, and found that it would never amortise itself.

First step is not coal to gas. That’s a different process.

Get the combination of heat and pressure and stoichiometry right and it ought to go straight from coal + hydrogen_source to crude oil. It would have to be a high pressure process, but I don’t know how high. It may also need a catalyst to keep the temperature down to something more reasonable.

Let’s see if I can outline the process.

Step 1 is to dry the coal. It doesn’t have to be completely dry. Put uncrushed coal into a tank (batch process not continuous) and pump out the air. Any free water on the surface of the coal will flash off, and can be collected and separated into components later. There won’t be much of it.

Step 2 is to replace the vacuum with natural gas under a light positive pressure. All following steps are anoxic, reducing.

Step 3 is to grind the mixture, together into a fine powder, particle size of rough order 100 microns. Perhaps finer.

Step 4 is to add Fischer-Tropisch catalysts as powder.

Step 5 is to use heat and pressure for a time (eg. a fortnight) while the mixture transforms into light crude oil.

Step 6 is to refine the crude oil as normal, removing the catalyst for reuse.

35% of USA Democrat supporters would vote for a candidate that was openly atheist. For Republicans it is 55%.

Non, je ne regrette rien.

Most diesel is just a straight run out of a crude oil fractionator.
However the heavy bottoms from the fractionator are then sent to a vacuum unit where more light ends like gasoline/diesel are recovered, the very heavy bottoms from the vac unit are then sent to a catalyst cracking unit where the hot catalyst flashes it off to a gas and changes it’s molecular structure the gas is separated from the catalyst in a series of centrifuges and then cooled and distilled in another fractionator where diesel/gasoline is pulled off at various levels. What’s left at the bottom this time is basically bunker oil.
In a past life I used to run a cat cracker.

Peak Warming Man said:

Most diesel is just a straight run out of a crude oil fractionator.
However the heavy bottoms from the fractionator are then sent to a vacuum unit where more light ends like gasoline/diesel are recovered, the very heavy bottoms from the vac unit are then sent to a catalyst cracking unit where the hot catalyst flashes it off to a gas and changes it’s molecular structure the gas is separated from the catalyst in a series of centrifuges and then cooled and distilled in another fractionator where diesel/gasoline is pulled off at various levels. What’s left at the bottom this time is basically bunker oil.
In a past life I used to run a cat cracker.

> In a past life I used to run a cat cracker.

Wow, you’re an expert then.

So I won’t even make a joke about it.