Hydrocarbon shortage

Discussion in 'Chemistry' started by BenTheMan, Apr 22, 2007.

  1. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Is it true that most of the hydrocarbons we use (i.e. plastics) are derived from petroleum, or do they come from other places? What are the manufacturing processes used to make plastics? I can't remember ever having learned this as a chemistry major, and I'm too lazy to go diggin around on google.
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  3. Read-Only Valued Senior Member

    Yes, Ben, that's where over 99% of them come from. They can also be synthesized (polymerized) from vegetable oils (soy, corn, safflower, etc.) but it's slightly more expensive.
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Fourty years ago, my soap box was: "It is a crime against your grandchildern to burn oil for its heat." - Now almost all know I was correct, and again I was way ahead of my times.

    This concern with criminal burning of oil is the main reason I set out to solve the fundamental problem* of solar thermal power generation, (and patented my solution about 35 years ago.)
    *see post: http://www.sciforums.com/showpost.php?p=1360439&postcount=20

    PS by edit:
    I did not, 40 years ago, realize just how great a crime it may have been to burn oil. That recognition only occurred about 3 years ago, and few understand it still. My grandchildren's great grandchildren may not be able to live on Earth:

    There is a chance that there will be no life on Earth in about one to two hundred years. If the methane hydrates on the continental shelves are decomposed significantly, so much methane will be dumped into the atmosphere that a run-away-thermal instability may occur, converting Earth into a cooler version of Venus. I.e. the ground level atmosphere will be mainly water in the form of very hot steam. (There is more methane down there than all the CO2 that fossil fuels will ever release and methane is a much stronger “green house” gas.)
    Last edited by a moderator: Apr 22, 2007
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  7. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    This seems apocalyptic. Is there any reason for the dehydration to occur?
  8. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    In some areas it already is! - I saw on TV about 6 months ago an under-water shot of only a few seconds duration (typical TV sequence) of a field of methane bubbles rising from sea floor. - Told my wife at the time that that was the most frightening thing I had ever seen on TV. (Even after I tried to explain, she did not quite see such an innocent looking scene as scary.)

    The hydrates are only marginally stable. Reduce the pressure on them or warm them from their approximate 4degree C temperature and they decompose. - That is well know fact. In addition to the continental shelf hydrates, there is increasing methane release from the thawing permafrost near the artic shorelines.

    I do not expect the run-away thermal instability to happen as the heat capacity of the oceans is enormous and the sea level is likely to rise, adding pressure, but the question is very complex. For example, if the artic ice cover melts before the sea rises, the albedo greatly decrease there, the artic ocean warms irreversibly, the current 4degree flow out of the artic basin along the ocean floor ceases and the continental shelf floor temperature rises, masses of hydrate decompose,... - etc in a strong positive feed back system with more methane released every summer etc.

    What makes this a possible sequence in my mind is if the artic ice cover melts before the ice of Greenland can significantly raise the oceans. It seems from the latest data that is exactly what will happen. I.e. the hydrates on the bottom will heat faster than the pressure rise will keep them stable at a warmer temperature.

    It is not inconceivable to me that mankind may need to use nuclear bombs on Greenland, flood NYC etc. to keep the Earth from becoming a sterile place of hot steam. I also worry that without the cold 4 degree artic flow south along the bottom, the radiogentic heat from the interior of the Earth may be able to release the methane that is often, if not usually, deep within the settlements on the bottom.

    Read up on it a little and tell what you think after better informed.

    I should also mention that H2O is a very strong green house gas. More in the atmosphere without more clouds to reflect sunlight back into space is also a self accelerating instability. These two processes may interact. I.e. the methane alone may only be able to make less than unity positive feed back loop gain but warm the atmosphere enough to prevent the formation of as many clouds as needed to compenaste for the increased H2O in the air. - A very complex problem with many unknowns but a possible disaster of the very worse kind one can imagine.

    I am nearly sure, a stable state of the Earth is one with very-hot, high-pressure, (many dozens of atmospheres as the oceans slowly leave Earth for space over millions of years) steam atmosphere at ground level (Standard adibatic drop in temperature with altitude above that.) Venus is stable. Earth could be a cooler version with hot steam atmosphere at least until the H2O of the oceans has gone into space.
    Last edited by a moderator: Apr 23, 2007
  9. Vega Banned Banned

    The plastic manufacturing process begins by heating the hydrocarbons in a "cracking process."
    Try google for more info!
  10. Ophiolite Valued Senior Member

    Since I have only been saying it for thirty eight years I guess I have to yield you priority.

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    On the plus side(?), if we worked out a nice way to sequester carbon and to mine the hydrates then peak oil is deferred for quite some time. The quantity of hydrates may be an order of magnitude greater than that of hydrocarbons.

    The end Permian extinction , that came close to ending life on Earth, may have been a hydrate release event.
  11. Positron Agony: Not all pain is gain Registered Senior Member

    Ah yes, the Methane Hydrate. Likely the quickest way to make life on Earth extinct. I metion it to people and they just look at me and go, "huh?" it is a commonly held belief that an eruption of methane from one of these shelves caused the end of the ice age. A large underwater earthquake could easily turn us almost into Venus. While I believe in global warming by humans this just shows that no matter what we do global warming will happen eventually.

    On topic though,
    Most plastics are made from petroleum like things, but when we run out of oil, or it becomes expensive, We will probobally awitch over to some other types of polymers, as they are not much more expensive now from what I hear.
    Last edited: Apr 23, 2007
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    On (1):
    Even if we can not use the energy in methane, it would be good to burn it to CO2 and H2O, I am almost sure, as methane is one of the worst "Greenhouse gases" - I never speak against vegetarians or Jewish dietary laws as pig and cows (unfortunately Jews eat them, but the Indians will not) make a lot of methane.

    Rather than waste taxpayers money on going to Mars or subsidies to corn based alcohol etc. I would like to see an effort larger than NASA peak funding level ever going after the energy stored in the hydrates. - As you noted, it is enormous. Would last for more than 1000 years at current consumption rate and combustion is relatively clean. I am not much of a chemist, but think it might be feasible to get two molecules of hydrogen and one of CO2 from each of methane in a few plants and inject the CO2 in oil fields to increase the recovery of oil, for chemical feedstocks, not heat of course.
    On (2):
    Yes, I tend to think that the release of methane from hydrates is how the snow and ice covered (high albedo) Earth escapes for ice ages relatively quickly. This may seem inconsistent with my acceptance of the possibility of Earth becoming sterile as a "cooler Venus" (very hot steam atmosphere at ground level). I.e. one naturally wonders if the hydrates accumulate and then are dumped, why is not the Earth already in this stable “cooler Venus” state.

    I suspect that the methane alone is a positive feed-back temperature increasing system, but that it is not, buy itself, with greater than unity loop gain - I.e. not a run-away thermal instability - just the "ender of ice ages."

    This time may be different because man is releasing the fossil carbon. I.e. the combined release of CO2 and CH4 may achieve the greater than unity loop gain and a trigger the run-away-thermal instability which converts Earth into a cooler version of Venus.

    I hate GWB for so many different reasons it is hard to list them with the worst at top. If his pro-oil, anti-Kyoto treaty stand does convert Earth into a cooler version of Venus, (hot steam atmosphere and completely lifeless), then clearly that is at the top of the list.
  13. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    So does the production of more than the natural cut of gasoline from the longer hydrocarbon chains.

    100+ years ago, the natural cut of octane (gasoline like molecules in general) was far in excess of the demand, which was mainly for kerosene for the lamps.

    Humans do not change much in only a 100 years. Back then, some sellers of kerosene were diluting with gasoline for greater profit. - Explosions and deaths were caused. Now that gasoline is in greater demand, various untaxed paint thiners, etc. are the dilutant, here in Brazil at least. Kerosene would not doubt be used, except for the demand for it from airplanes has held the price of kerosene up.
  14. Mosheh Thezion Registered Senior Member


    but are you aware of the dangers of liquified methane?

    one liquid methane tanker can do as much damage as a small nuke.

    if it was attacked... or crashed real bad...

  15. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

    Billy---The danger with global warming, as I understand it, is that the surface temperatures of the oceans will rise. Hot water is less dense, so I would expect the ocean floor to remain relatively unchanged by all of this.

    And I didn't mean dehydrate, I should have said something like "demethylate".
  16. Ophiolite Valued Senior Member

    But would you jump out of an aircraft with a parachute you hadn't packed yourself and a reserve chute marked For Demonstration Only?
  17. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Certainly, all else equal, warmer water (above 4degrees C to be technically correct) floats on colder water, BUT the warm equatorial waters, from which much of the rains come, are more saline than the polar waters. When the gulf stream is off the East coast of Canada, it begins to sink, under the weight of this excessive salt. In fact oceanographers speak of the cirulation in the Atlantic ocean as "thermohaline" driven. If the artic ocean warms, the gulf stream may stop or not make it so far north. (Norway's North West coastal fiords may be ice filled year round and England much colder.) Also the cold water (now ice temperature water under the artic ice sheet) will not have warmer water from the south to replace it, allowing it to sink and flow as a bottom stream all the way into the Indian ocean, as it does now.

    Summary: Global warming will very signficantly change (reduce I am almost sure) the slow mass movement of waters in the North Atlantic ocean. Without the current flow of cold bottom water, the sea floor may warm more as the K40 and other unstable isotopes send heat to it, even without considering the "flow" of liquid core's transport of heat.

    Although I do not have a great understanding of all this - it is very complex - there are two chapers in my book that consider the mechanism of climate. One before the passage of the "Dark Visitor" (I.e. a tutorial telling what controls the current climate.) and the other after there has been a very slight increase in the eccentricity of the Earth's orbit, caused by the gravitational impulse of the Dark Visitor as it passes solar system. As Earth is now "just on the edge," that increase cause Earth to rapidly enter a permanent ice age but only for the Northern Hemisphere. This took some careful adjustment of the DV's trajectory in the three-body finite-time-step analysis. - (I live in Brazil and am not entirely crazy or suicidal.

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    Perhaps, in the long run, humanity and the Earth would be better off if everyone in the Northern Hemisphere, where all the nuclear bombs are, died. It could happen this way. :shrug: )

    You can now probably guess why I have this "crazy" theory about there being many small black holes.

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    Do you know that the late 1920s peturbation of Neptune's orbit, which lead to the discovery of Pluto, has no explanation? - Could it have been first of a pair of passing "dark visitors," still gravitationally bound? (Book's Dark Visitor being the second of the pair.)
    Last edited by a moderator: Apr 24, 2007
  18. Ophiolite Valued Senior Member

    This is off topic, but I am fairly sure this is now attributed to faulty maths.
  19. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Yes, some say this, but it is not creditable (note the word I made bold) - they are desperate for any explanation. The mathematics required was well developed and successfully used more than 90 years earlier:
    "John Herschel started to champion the mathematical approach and persuaded James Challis to search for the planet {Neptune}. After much procrastination, Challis began his reluctant search in July 1846. ... Heinrich d'Arrest suggested that a recently drawn chart of the sky, in the region of Le Verrier's predicted location, could be compared with the current sky to seek the displacement characteristic of a planet, as opposed to a fixed star. Neptune was discovered that very night, September 23, 1846, within 1° of where Le Verrier had {mathematically} predicted {nearly 100 years before Pluto's discovery, based on the same math, but more uncertain data.}it to be, ..."

    A somewhat more creditable explanation also offered is that the observations were wrong, but there were hundreds of amateur astronomers and dozens of professionals measuring Neptune's perturbations in hopes of also becoming famous, but it was always small and the mathematical error resulting from the uncertainties in the measurement was much larger. - Pluto was accidentally found as the search, based on the 1920's data was widened out.

    Rich Percival Lowell built the observatory still in use at Flagstaff AZ and paid for special equipment to facilitate the search for Neptune's perturber, including the new "Flicker comparator" that allowed two sky photos taken only weeks apart to display to human eye any slight displacement of a "star." Pluto was actually discovered on a sunny afternoon, with this instrument.

    Until the small size and mass of Pluto was known, circa 1950, everyone believed Pluto was the cause of Neptune's perturbations - I.e. no one was suggesting the measurements were wrong, until this became the only possible explanation. Rather than concoct this somewhat implausible "measurement error explanations," I would have, and still do, prefer to admit we have no very plausible explanation.

    Because of the vastness of space, I admit my suggestion is extremely improbable, but it is possible, and better than none. If, as I also suggest, based on well accepted physics reasons, the spherically symmetric collapse model of the formation of black holes is seriously wrong and dozens, perhaps even a hundred, small black holes* were produced by each dying first generation star, then my suggestion is only "very improbable", not "extremely improbable."

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    *Why I think the spherical collapse model's "one central black hole” formed by each big star is wrong discussed at:

    *See old thread: "(alpha) Dark Matter - What is it?" especially posts:


    And for more detailed discussion of a star photo (now the “Eskimo nebulae”) that may have been captured in this three - stage, multiple small black-hole, formation process only a few thousand years ago. The photo fit’s the three stage model, with the one initial small black hole farthest away, etc. very well. (black holes can not be seen, of course. - but they appear in the photo as about 100 radially out bound, tail going first, "comets" for reasons explained in post 63. The first is the only one now "tailess" ("comet") for reasons also explained. I predict it will soon (few dozen years at most) be invisible.


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