Fossil Fuels

[marko]

Maybe I'm out in the weeds here but I thought everyone knew what I was taught in grade school 60 years ago: Petroleum comes from decayed plants and animals that lived millions of years ago and formed deposits.

Methane (gas) still oozes from the bottom of swamps and underground. Very little pressure on the deposits and you get gas. A little more pressure you get an oily, sticky petroleum, even more pressure and you get coal (which sometimes has impressions of ferns or other plants).

The Permian Basin et.al. were once seas where for millions of years, plants, plankton, animals, slowly deposited and built up.

Our oil/gas/petroleum and "oil feedstock" (to make plastics) today was once living matter and where the 'carbon' (CO2 byproduct) comes from. Fossil? Ok, fossil not in the sense of rock impressions but in the sense of a once living thing more or less still laying there in a different form.

Doesn't anyone wonder why the old Sinclair oil company used a dinosaur for their logo?

Last year, I made the above claims and about 20 of us started a discussion. I was amazed that nobody in the group knew, or even believed this. So much so that I began to doubt my grade school teacher!

[Winemaker]

Your grade school teacher was right, marko. For every foot of coal seam, there was approximately 8 feet of plant material, and coal seams are pretty vast, once being a lake or sea bed. These coal seams were formed horizontally and flat due to gravity pulling the dead plant material to the bottom. For the most part, the seams are still flat, but the overlying surface has changed. For example, the Pittsburgh coal seam extends from Pittsburgh, where it outcrops along the Monongahela river and extends down to Clarksburg WV and is about 90 miles wide. The hilly SW PA and northern WV surface has been carved and washed away over the past 300+million years. The surface we walk on today, has not been the same surface formed over those 300 million years. I live on a hill, and the Pgh seam is about 600' below my house, the folks in the valley behind me, the Pgh seam is about 475' below them. All told there is about 80 different coal seams beneath my feet, some are not mineable. The surface that I walk on in my property is ~60 million years old, meaning that the rock, earth, dirt that was here above me 59+ million years ago, has all been washed away or pushed somewhere down stream, perhaps sitting in Alabama or Loiuisiana now.

[Murf2]

This thread is pretty interesting, so I think I’ll ask my stupid question.

How did all this stuff “get buried”? Where did all the material that covers it come from?

Yes, I’m serious. I just don’t get it.

Murf

[folivier]

Back when I was working for a drilling fluids company when drilling an exploratory well there was always someone who was analyzing the drill cuttings. They were looking for diatoms and other small organisms usually. That indicated they were getting close to an oil/gas producing formation.

[Koolau]

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Originally Posted by ls99 So, scientifically, when we talk about plastics being made from “biomass” as a means of becoming “green,” we’re not really talking about anything new. Petroleum is made from aquatic phytoplankton and zooplankton, and because petroleum is created by biomass, plastic is a form of biomass. It makes sense, then, that we can create plastic from corn, sugar cane, switch-grass and other plants. Plastics are plants in another form.

I think one of the major issues with starting to make almost anything from biomass is it is (so far) much less efficient than starting with (forgive the expression) "fossil fuels." Sort of like making liquid fuels from biomass is very doable but costs more energy than it gives (classic example is ethanol which arguably takes more energy than it provides upon burning in an ICE.)

I'm neither for nor against research along these lines, but it would seem there is a steep hill to climb anytime we convert biomass into things we've been producing with FFs for 100 years. First is the learning curve and second is the inherent difference in the inherent energy of the source. FFs are just about as dense an energy source as exists (other than nuclear fuels.) Biomass is very low energy and requires a lot of energy input to convert it into useful products. My SWAG: the most productive use of biomass to avoid the use of FFs is directly as a heating fuel (firewood comes to mind.) Big problem is, there isn't enough biomass produced (especially in the form of firewood) to make a large dent in domestic or industrial heating. That doesn't even address the issues of inconvenience of huge amounts of biomass to replace relatively small amounts of (easily transported) FFs.

Let us hope that biomass (and other technologies) can replace much of our FF usage. However, I'm not optimistic though I have no training or degree that would validate my pessimism. Heh, heh, for years, I did use biomass (fire wood) to heat my house (at least while I was there to safely do so.) YMMV

[Masquernom]

Here's a good book about oil production;

Hubbert's Peak: The Impending World Oil Shortage
by Kenneth S. Deffeyes

The author drew the wrong conclusion at the time. It was before fracking came along. But the book explains in understandable terms the formation of oil and natural gas.

In very simple terms, coal is layers of plants laid down and buried over time. Oil is plankton from the ocean that settled to the bottom and became buried over time. If the plankton goes too deep and gets too hot, you get natural gas. If it stays at the right temperature, you get oil. Over long periods of time, the oil will slowly seep upward. When it gets trapped under things it can't seep through, like a salt dome or impermeable rocks, it collects in a pool underground. These are what oil drillers originally hunted for. Geologists always knew there was oil trapped within rock layers, and widely dispersed. But it came out of those layers so slowly, it wasn't economical to drill for it. Then, horizontal drilling came along with the ability to fracture the rock layers. So you can drill into the rock layer with very dispersed oil, drill horizonally through the layer, then fracture the rock layer to provide paths for the oil to reach your hole. These "fracked" wells have shorter production lives and are less economical then traditional wells that are basically straws sucking oil out of a pool.

[marko]

Quote:

Originally Posted by Murf2 This thread is pretty interesting, so I think I’ll ask my stupid question. How did all this stuff “get buried”? Where did all the material that covers it come from? Yes, I’m serious. I just don’t get it. Murf

I think it's just natural sediments falling over the eons. Dust, dirt, volcanic action, live matter, all builds up. In the seas it's probably faster.

Go to Rome and see how the Forum and most of ancient Rome is now 10-20 feet below the current street level and that was less than 2000 years.

[Winemaker]

Quote:

Originally Posted by Murf2 This thread is pretty interesting, so I think I’ll ask my stupid question. How did all this stuff “get buried”? Where did all the material that covers it come from? Yes, I’m serious. I just don’t get it. Murf

For my example of the Pittsburgh seam, it was once a huge "Everglades type" area. There has been so much "geological turmoil" that has occurred over those 300+million years, it makes one head spin. Mind you the planet is estimated to be 4.5 billion years old, and a lot of things have occurred. Volcanic eruptions, meteor strikes, glaciers, floods, freeze/thaw cycles, continental drift, reversal of the magnetic poles, movement of magnetic poles, just to mention a few. The Appalachian mountains were once like the jagged peaks of the Rockies, but over their 480 million year life, they have become the worn rolling ranges they are today. These aren't things that happen in 100 years, or 2022 years for that matter.

[audreyh1]

Another example - coal comes from ancient decayed plants trapped underground, including peat bogs which can be directly burned for fuel even today. The term “fossil fuel” seems appropriate.

[audreyh1]

Quote:

Originally Posted by Murf2 This thread is pretty interesting, so I think I’ll ask my stupid question. How did all this stuff “get buried”? Where did all the material that covers it come from? Yes, I’m serious. I just don’t get it. Murf

Have you ever heard of tectonic plates? If not you have some education ahead to understand this stuff.

Erosion from mountains covers a lot of stuff. And mountains are formed all the time - usually from tectonic plates colliding. Huge chunks of earth can even be turned sideways or upside down from such forces. Volcanoes are created from an ocean tectonic plate submerging beneath another. This can occur along coastlines or out in the ocean. Hot spots can also cause volcanoes and huge lava flows covering surrounding land. Land also subsides due to weight of new land on top of it. Everything is floating around on the earth’s mantle. Continental land is continuously recycled.

[Murf2]

Quote:

Originally Posted by audreyh1 Have you ever heard of tectonic plates? If not you have some education ahead to understand this stuff. Erosion from mountains covers a lot of stuff. And mountains are formed all the time - usually from tectonic plates colliding. Huge chunks of earth can even be turned sideways or upside down from such forces. Volcanoes are created from an ocean tectonic plate submerging beneath another. This can occur along coastlines or out in the ocean. Hot spots can also cause volcanoes and huge lava flows covering surrounding land. Land also subsides due to weight of new land on top of it. Everything is floating around on the earth’s mantle. Continental land is continuously recycled.

Well, I said I was a dummy! [emoji846]

What makes me wonder about it is, if a deer gets hit by a car. It lays on the side of the road until it’s taken care of by other animals & weather. I just don’t see how organic matter lays around long enough to be covered up without rotting. I can / do understand a cataclysmic event making it happen on a local scale but everything world wide being covered?

So what do they think the diameter of the earth was before whatever it was buried the fossil fuel? I assume the prehistoric animals were walking on the earths surface.

Thanks
Murf

[Zathras]

Quote:

Originally Posted by Murf2 Well, I said I was a dummy! [emoji846] What makes me wonder about it is, if a deer gets hit by a car. It lays on the side of the road until it’s taken care of by other animals & weather. I just don’t see how organic matter lays around long enough to be covered up without rotting. I can / do understand a cataclysmic event making it happen on a local scale but everything world wide being covered? So what do they think the diameter of the earth was before whatever it was buried the fossil fuel? I assume the prehistoric animals were walking on the earths surface. Thanks Murf

It wasn’t world wide.
Each region can have their own little cataclysms.
It might be as simple as a landslide carrying vegetation into a pond.

As mentioned above, the formation of fossil fuels requires an oxygen free environment.

If all plant matter turned into fossil fuels we would have a hell of a lot oof fossil fuels, and probably no ecosystem.

[Masquernom]

Quote:

Originally Posted by Murf2 Well, I said I was a dummy! [emoji846] What makes me wonder about it is, if a deer gets hit by a car. It lays on the side of the road until it’s taken care of by other animals & weather. I just don’t see how organic matter lays around long enough to be covered up without rotting. I can / do understand a cataclysmic event making it happen on a local scale but everything world wide being covered? So what do they think the diameter of the earth was before whatever it was buried the fossil fuel? I assume the prehistoric animals were walking on the earths surface. Thanks Murf

First you form peat. Then the peat gets buried under tons of rock and turns into coal. Here's where peat gets started;

The habitat requirements for peat initiation and accumulation are similar in every geographical location (waterlogging, low pH, low nutrient availability, low oxygen supply, reduced decomposition rate) but the physical and chemical characteristics differ according to specific site characteristics of landscape area and topography, climate, water depth and flow, nutrient availability and biogeographical availability of plant species.

Peat formation is the result of incomplete decomposition of the remains of plants growing in waterlogged conditions. This may happen in standing water (lakes or margins of slow flowing rivers) or under consistently high rainfall (upland or mountain regions). As a result, partially decomposed plant remains accumulate and become compacted, forming peat that changes the substrate chemical and physical properties leading to a succession of plant communities.

This process is referred to as the hydrosere that begins classically in open water and proceeds through fen stages that are influenced by nutrient-rich ground water (and rainfall) to bog that receives nutrients and water supply only from rainfall.

[audreyh1]

Quote:

Originally Posted by Murf2 Well, I said I was a dummy! [emoji846] What makes me wonder about it is, if a deer gets hit by a car. It lays on the side of the road until it’s taken care of by other animals & weather. I just don’t see how organic matter lays around long enough to be covered up without rotting. I can / do understand a cataclysmic event making it happen on a local scale but everything world wide being covered? So what do they think the diameter of the earth was before whatever it was buried the fossil fuel? I assume the prehistoric animals were walking on the earths surface. Thanks Murf

The earth overall diameter is not getting larger. Material is just recycled. Carbon gets recycled into organic matter then decomposes again into soil and air. It’s a closed system (except for sun energy and the occasional asteroid).

Even if an animal or plant is exposed to the elements and mostly decays exposed, some animals and plants did get buried and preserved by various means. Areas can be inundated. Decaying animals/plants in the ocean and lakes can drop to the bottom and build up there, get compressed and covered by eroding soils and rocks from land. Sea levels rise and fall.

As mentioned above, peat bogs don’t really decay (super slow). They eventually get buried.

Most of the source would be ancient plants and algae/zooplankton.

[NW-Bound]

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Originally Posted by Turbo29 Yes, and your cellphone has slightly less mass when the battery is discharged than when it is charged.

Quote:

Originally Posted by Out-to-Lunch Truth!

It's just impossible to have a scale sensitive enough to measure the change.

A typical cell phone battery can store 18 Wh, which weighs less than 1 millionth of a microgram.

[Turbo29]

Quote:

Originally Posted by Zathras If all plant matter turned into fossil fuels we would have a hell of a lot oof fossil fuels, and probably no ecosystem.

'
And this is why termites are absolutely essential.

[Out-to-Lunch]

Quote:

Originally Posted by NW-Bound It's just impossible to have a scale sensitive enough to measure the change.

Also true.

But, IME, many people do not know the principle of this physical truth, regardless of whether or not one can measure it with household equipment.

[folivier]

And we have to understand that the science is all hypothetical until it is absolutely proven to be true. Then along comes more advanced science and a better and/or different understanding of the evolution of our planet. IOW it's basically all guesses. Until we develop a time machine.

[Zathras]

Quote:

Originally Posted by folivier And we have to understand that the science is all hypothetical until it is absolutely proven to be true. Then along comes more advanced science and a better and/or different understanding of the evolution of our planet. IOW it's basically all guesses. Until we develop a time machine.

That is not how science works.

A hypothesis is formed after observations. The hypothesis must be something that can be tested, and is falsifiable.

Tests are performed to either disprove, or support the hypothesis.

Over time, if no tests disprove the hypothesis, it becomes a Theory.

If a test does disprove the hypothesis (or theory) a new hypothesis is formed taking into account what has been learned so far.

To call it “guesses” is dismissive of all the work and experience of people that have spent years/decades studying certain phenomenon.

[Koolau]

Quote:

Originally Posted by Zathras That is not how science works. A hypothesis is formed after observations. The hypothesis must be something that can be tested, and is falsifiable. Tests are performed to either disprove, or support the hypothesis. Over time, if no tests disprove the hypothesis, it becomes a Theory. If a test does disprove the hypothesis (or theory) a new hypothesis is formed taking into account what has been learned so far. To call it “guesses” is dismissive of all the work and experience of people that have spent years/decades studying certain phenomenon.

Semantics

Sorry but hypothesis is the scientific term for what the layman would call a guess. We do base our "guess" (or hypothesis) on observed 'facts'. We (as scientists) DO set up our hypothesis so as to be testable. So there's that.

Remember when there were 4 elements? Air, earth, fire and water. I recall as a young scientist thinking that was pre-alchemy and dismissing it as superstition. Turns out, it was actually rather predictive of reality and was "accepted" as fact for a long time. YMMV