September 28th, 2020, 04:52 PM
How is it likely that in a distant future majority of power on Earth will be generated from biofuels? Such as biofuel motor fuels, biofuel powered power plants and biogas stoves and home heaters? Will it likely win or loose competition with other technologies? Or which technologies will win in the long run, do you think?
Hard to say. Seems a race between coming up with an affordable biodiesel process and batteries with anywhere close to comparable energy density.
Biofuels are taking up land, employ many, can be taxed, and are generally better than fossil fuels, because they don't add CO2 from the soil to the air. However, they take up more land than a solar or wind farm would, generating the same energy.
So it would only work on high subsidies.
They can be the majority of energy used only if in the future humans stop being extravagantly wasteful and use a lot less energy than we do now. Maybe if we turn to simplicity, frugality and self sufficiency in a big way and use oil seed crops and digesters and woodlots to power a lifestyle of reduced energy use... hey, it is a vision that comes complete with ponies!
Of course our distant descendants could turn out wiser, smarter, organised, efficient, ethical. May need to become something other than human to get there - the knowing better but doing it anyway thing needs a bit of evolution or bioengineering or medical intervention or something; we are capable of doing a lot better than we do now.
I do think there will be continuing advances in modern takes on biofuels - gmo crops and algaes, improved yeasts for ethanol, more efficiencies. There will be important uses for combustible liquid fuels, but biofuels can't compete with solar and wind for electricity. EV's have shown they work just fine and batteries don't have to be as energy dense as fossil fuels to do it well enough. Batteries will get better and cheaper and more ubiquitous as the massive expansion of storage R&D flows through the pipeline; tech device makers want better, cordless tool makers, EV makers, energy equipment makers, power companies and government agencies all want better. The patent on the best new battery will be worth US$trillions and they all know it. I think that the state of science has never been better fitted to go after the best possible battery. Or batteries; doing stationary grid scale storage has different requirements to transport and can get away with being more energy dense.
And then there is Hydrogen too, for steel making, for transport and as large scale energy storage. Possibly as a transitional fuel for gas plants. Biofuels aren't in the running.
Not according to a relatively recent study. they are actually worse than fossil fuel gas. https://link.springer.com/article/10...584-016-1764-4Originally Posted by Zwolver
A bit off topic but if renewables are apparently now often cheaper in terms of producing electrical energy than fossil fuels should we just ,as a society junk liquid fuels on large scales until they become viable again?Not according to a relatively recent study. they are actually worse than fossil fuel gas. https://link.springer.com/article/10...584-016-1764-4
As the American Commander in Chief implies **, this is war and we have to follow the exigencies.
**"guess I am a War President" ,beaming idiotically.
So much time and money being spent on technology, from bio fuels to batteries, but is there anyone working on a fossil fuel energy producing source that reduces CO2 output? To me it makes sense to use what's plentiful and work on improving the emissions from burning it. So if somebody tomorrow invented a way of using/burning fossil fuels with next to no CO2 released into atmosphere would it make sense to just carry on?
Is that carbon capture?
Not really although I suppose it could be. I'm thinking more of an engine design that burns fossil fuel yet produces or emits little to no CO2.Is that carbon capture?
Wonder if someone actually thinks it can be done or is working on it.
For something to be efficient as fuels you must use chemistry that produces products in which the sum of the enthalpies of the chemical bonds are stronger than in the sum of the enthalpies in the bonds of fuel and what you are reacting it with. Not many options stronger than C=O bonds so CO2 is probably unavoidable from fossil fuels unless you are willing to accept efficiencies so low you might as well chuck it at a wind turbine!
While I got you here PH perhaps you can answer couple questions.
1. When you burn a hydrocarbon, water is also a byproduct. Never hear about what more water is doing to the environment so is it good or bad?
2. Is there such a thing as synthetic hydrocarbons and if so, do they pack the same negative effect as natural hydrocarbons?
1. Water is a greenhouse gas but it isn't a big issue, the atmosphere is pretty much saturated with water vapour most of the time and there is a really efficient mechanism that removes excess water from the atmosphere (we fancy scientists call it "rain")
2. A hydrocarbon is a hydrocarbon whether it's natural or man-made (all it means is a molecule containing only carbon and hydroge). The chemistry is no different...
Sounds simple.1. Water is a greenhouse gas but it isn't a big issue, the atmosphere is pretty much saturated with water vapour most of the time and there is a really efficient mechanism that removes excess water from the atmosphere (we fancy scientists call it "rain"
2. A hydrocarbon is a hydrocarbon whether it's natural or man-made (all it means is a molecule containing only carbon and hydroge). The chemistry is no different...
Could there ever be a time when we have to burn hydrocarbons to make fresh water to drink/survive? Might be an interesting dilemma. I wonder if it actually is being done somewhere.
If ever you live in an asteroid colony you might have to heat (but not burn) carbonaceous material to get water. Down here on Earth the possibility that water will cease falling from the sky or be unavailable from rivers, lakes and oceans (which can be desalinated for drinking) looks very unlikely.Sounds simple.1. Water is a greenhouse gas but it isn't a big issue, the atmosphere is pretty much saturated with water vapour most of the time and there is a really efficient mechanism that removes excess water from the atmosphere (we fancy scientists call it "rain"
2. A hydrocarbon is a hydrocarbon whether it's natural or man-made (all it means is a molecule containing only carbon and hydroge). The chemistry is no different...
Could there ever be a time when we have to burn hydrocarbons to make fresh water to drink/survive? Might be an interesting dilemma. I wonder if it actually is being done somewhere.
As for Water being given off during fossil fuel burning - yes it is, however the total amount of existing water is vast and any addition by this means is, by proportion, very small. (Whereas CO2 is added to a relatively small existing amount). It also encounters conditions that cause precipitation, as PHDemon points out, that limits ongoing increase. A warmer atmosphere being able to hold more water vapour is a bigger factor in increasing atmospheric water content than water from exhausts and smokestacks, and it is counted in climate models as a positive feedback. ie it rises because of global warming and adds to global warming (which increases the amount of water vapour, thus the 'feedback').
Have read where 85% ethanol in gasoline/petrol will reduce CO2 emissions 35-45%. However if we used a higher octane gasoline then not only to we get greater fuel efficiency but also less CO2 will be emitted over time. Anyone know what CO2 percentages are for high octane and if there is a great CO2 emissions difference between ethanol use vs high octane?
I‘m thinking the theory is that if we don’t need to fill the tank as often using high octane fuel just means less CO2 is emitted because of that frequency. Or does high octane fuel emit less CO2?
The hydrocarbon that produces the least CO2 when it burns is methane - natural gas. For this reason, replacing oil and coal by natural gas helps to reduce greenhouse emissions. But you still get one molecule of CO2 for every molecule of methane you burn, I'm afraid.While I got you here PH perhaps you can answer couple questions.
1. When you burn a hydrocarbon, water is also a byproduct. Never hear about what more water is doing to the environment so is it good or bad?
2. Is there such a thing as synthetic hydrocarbons and if so, do they pack the same negative effect as natural hydrocarbons?
Carbon capture and storage (CCS) is a technology that a lot of fossil fuel companies are ready to try, but without some kind of carbon tax or other commercial incentive, it won't get off the ground. So far, governments have not yet obliged.
The figures you quote for reduced emissions include the CO2 used to make the ethanol... It is not simply the combustion data that is used when emissions figures/reductions like these are quoted...
As for not filling the tank as often leading to fewer emissions, not necessarily... It is not the volume of the fuel (or miles pef gallon) that determines the relative CO2 emissions... To determine CO2 emissions you need to work out how many moles of CO2 are produced per mole of fuel this can then be converted to a by mass or by volume basis.
Do politicians who make rulings on CO2 emissions know the science? They’re not all the brightest bulbs in the room and under pressure from other mis/uninformed groups. If there ever was a time for science to be a main attraction in the political arena it is now because these MF politicians are going to make things worse....sorry, just ranting a bitThe figures you quote for reduced emissions include the CO2 used to make the ethanol... It is not simply the combustion data that is used when emissions figures/reductions like these are quoted...
As for not filling the tank as often leading to fewer emissions, not necessarily... It is not the volume of the fuel (or miles pef gallon) that determines the relative CO2 emissions... To determine CO2 emissions you need to work out how many moles of CO2 are produced per mole of fuel this can then be converted to a by mass or by volume basis.
With a few exceptions I'd be surprised... not many if them have any scientific training...Do politicians who make rulings on CO2 emissions know the science?Preaching to the choir here... I've said it before, most politicians are after short term wins, very few think further ahead than the the next election (if that far!) let alone longer term impacts of climate change...They’re not all the brightest bulbs in the room and under pressure from other mis/uninformed groups. If there ever was a time for science to be a main attraction in the political arena it is now because these MF politicians are going to make things worse....sorry, just ranting a bit
That's true of course. Though I think Margret Thatcher understood the science, as it then was, at least in outline.With a few exceptions I'd be surprised... not many if them have any scientific training...Do politicians who make rulings on CO2 emissions know the science?Preaching to the choir here... I've said it before, most politicians are after short term wins, very few think further ahead than the the next election (if that far!) let alone longer term impacts of climate change...They’re not all the brightest bulbs in the room and under pressure from other mis/uninformed groups. If there ever was a time for science to be a main attraction in the political arena it is now because these MF politicians are going to make things worse....sorry, just ranting a bit
But politicians do want the votes of people, so if science can teach enough people, the politicians will come to the party. And that seems to be happening, perhaps rather slowly. Today there is a meeting on nuclear's contribution to the UK's 2050 zero carbon target, which even Bozo's otherwise reactionary government has signed up to. Biden has put climate change among his top three priorities. These are good signs.
I thought if we use solar power that will more efficient. Just reading this review https://websolarguide.com/backyard-revolution-review/
Last edited by kimimiesl; November 13th, 2020 at 07:23 AM.
OK, but solar power can't do everything on its own very easily. It is intermittent and it produces only electricity, which can't power existing IC engined vehicles for instance.
Read where the carbon footprint for a desalination plant is high plus it’s devastating to marine life. I suspect hydrocarbons are burned to supply the energy to run the equipment and this is the main CO2 contributor. Not to mention: where does the salt end up...back in the ocean or on our dinner plates?
Apparently the cost is prohibitive also but if you can afford it like Saudi Arabia then go for it. Is the water produced through burning hydrocarbons added to the desalinated seawater, used for irrigation or just allowed to exhaust into the atmosphere?
For carbon capture, is the byproduct water used to mix with the exhausted carbon waste to allow it to be piped somewhere safe underground and if so, will that water eventually make its way back into the atmosphere over time?
The water from combustion will be produced as water vapour (combustion gets hot!). Likely it is just allowed to escape with the waste gases but if will condense at some point either in the pipes or (more likely) in the atmosphere. The solubility if CO2 is such that the amount that could dissolve in the co-produced water will be negligible. All water on Earth cycles through the oceans and atmosphere on a long enough timeline... Every glass of water you drink will contain molecules that gave passed through the kidneys of (insert any historical figure here) and been a part of every ocean...
The salt will be sold, it is an important industrial chemical, not least in the processed food industry...
Sad to think my food choices are probably aiding pollution, GW and killing of marine life....not to mention possibly supporting the economy of tyrannical regimes. We're all hypocrites whether we choose to be or not it seems.The salt will be sold, it is an important industrial chemical, not least in the processed food industry...
It may be sold in some places, but when I was in Dubai the desalination plant at Jebel Ali (which used waste heat from the neighbouring, oil-fired steam power station) just pumped the brine back into the Gulf.
Curiously, they actually added a tiny amount of brine to the distilled water, as it made it taste better. Apparently, pure distilled water tastes of absolutely nothing, which is a bit unpalatable.
Here is a link with more about how it is today: https://www.appropedia.org/Jebel_Ali_Desalination
Trending....a step towards clean burning hydrocarbon
https://phys.org/news/2020-11-blue-f...rcomputers.amp
This will (very slightly) increase the amount of CO2 generated, since no uncombusted soot is formed. A better approach might be to burn hydrocarbons as badly as possible and extract the soot.
I do that already.I scrape the bottom of my open hearth chimney with with my broken tongs when I want a fireworks effect or just to watch the soot burn in amongst the logs.This will (very slightly) increase the amount of CO2 generated, since no uncombusted soot is formed. A better approach might be to burn hydrocarbons as badly as possible and extract the soot.
I burn a fair amount of wet or greensh wood so soot supply is no problem.
Sadly the soot doesn't burn that well as it falls too compact.
Its going to put chimney sweeps out of a job.I do that already.I scrape the bottom of my open hearth chimney with with my broken tongs when I want a fireworks effect or just to watch the soot burn in amongst the logs.This will (very slightly) increase the amount of CO2 generated, since no uncombusted soot is formed. A better approach might be to burn hydrocarbons as badly as possible and extract the soot.
I burn a fair amount of wet or greensh wood so soot supply is no problem.
Sadly the soot doesn't burn that well as it falls too compact.
Back when I was starting out I cleaned furnaces. People who didn’t know what they were doing would sometimes monkey around with a burner’s air shutter, screw up the fuel/air mixture and carbon up their furnace....a dangerous practice. Anyways you cleaned it the best you could but you set the air intake to improve the flame knowing that a clean burn will take care of any carbon that was tough to get at it. As long as it was venting ok (no blockages) then it was safe to move on to the next one.
Some people clean out their chimneys by setting it on fire ,but If I was to try that I would set fire to my flat roof as it it is flammable.Its going to put chimney sweeps out of a job.I do that already.I scrape the bottom of my open hearth chimney with with my broken tongs when I want a fireworks effect or just to watch the soot burn in amongst the logs.This will (very slightly) increase the amount of CO2 generated, since no uncombusted soot is formed. A better approach might be to burn hydrocarbons as badly as possible and extract the soot.
I burn a fair amount of wet or greensh wood so soot supply is no problem.
Sadly the soot doesn't burn that well as it falls too compact.
Back when I was starting out I cleaned furnaces. People who didn’t know what they were doing would sometimes monkey around with a burner’s air shutter, screw up the fuel/air mixture and carbon up their furnace....a dangerous practice. Anyways you cleaned it the best you could but you set the air intake to improve the flame knowing that a clean burn will take care of any carbon that was tough to get at it. As long as it was venting ok (no blockages) then it was safe to move on to the next one.
I do mine every other year and then I feel more comfortable (for a while) with a raging fire.
( I have some timber/logs that I dry/heat up over night in the oven and when that goes in it can be quite spectacular)
geo..is it soot or creosote? I think creosote is the more deadlier......do you get blobs of black tarry substance falling down from chimney?
Yes ,sometimes it comes down in small tarry lumps. What causes soot and what causes creosote.?
Would it be down to the kind of wood one burned? (I also burn peat )
Burning wood but with improper combustion and/or poor ventilation. Also poor air flow or leaky chimney. The products of combustion are being cooled before they can exit chimney or in the case of that perfect yellow flame, not hot enough. There may not be enough positive air pressure in the house to help ventilate exhaust from chimney quicker also. Recommend to always have a window open while fireplace on initially. Use match test at chimney to see if air being drawn into chimney and usually once chimney warms up it is ok to close window. Check chimney mortar if brick or cinder block but may be hard to see if inside a wall. Buy gas fireplaceYes ,sometimes it comes down in small tarry lumps. What causes soot and what causes creosote.?
Would it be down to the kind of wood one burned? (I also burn peat )
Creosote also used as wood preservative but now banned in many countries, including Canada. Carcinogenic & other nasty health threats. Don’t burn treated wood.
Soot is also carcinogenic...
https://en.wikipedia.org/wiki/Chimne...s%27_carcinoma
As if being a chimney sweep back in the day wasn't an unpleasant enough job!
Christ! Life can be cruel. I used to go on emergency calls when people called in for a CO detector going off. I remember one house that had about 200 candles burning at all times. Furnace filter was black and all air return openings as well as heat registers had soot evidence around the edges. Almost everything you touched had a fine film of soot on it. I couldn’t figure out why she hadn’t called before and it turned out she had just plugged in her first detector. So for a long long time she was exposed to CO & soot and I wonder what ever became of her. I know she didn’t like hearing it was the candles being the problem.
Are you sure? Could you provide some approximate calculations? Biofuels use the same Sun power as solar farm, but probably requires less maintenance. And could be grown in the seas or salt waters, not taking any place on the land. So, how come it will take more place?
There is a comparison here: https://theconversation.com/for-effi...-biofuels-9160. which indicates solar generates considerably more power per unit area than biofuels. To add to that, solar can be installed in desert areas where no plants can be grown, and they do not deplete the soil, requiring the addition of fertiliser, itself a big disturber of the ecosystem.Are you sure? Could you provide some approximate calculations? Biofuels use the same Sun power as solar farm, but probably requires less maintenance. And could be grown in the seas or salt waters, not taking any place on the land. So, how come it will take more place?
I expect there is room for both, but given that we need to feed the world's population, it would seem best to use suitable land for food crops and unsuitable land for solar, it seems to me. As for offshore power generation, winds seems the obvious candidate, for shallow seas at least.
Don't want to start a new thread so Ill ask: What is the difference between Thermal and Metallurgical coal? Does one produce more greenhouse gases than the other?
All coals are basically fairly pure carbon so the CO2 emissions per tonne of coal burned will be pretty similar regardless of the type of coal. However, the small levels of impurities are different in different types of coal and can cause problems when it is burned on a large scale. IIRC metallurgical coal has less sulphur based impurities in it so will produce less SO2 (a precursor of acid rain) when it is burned.
Dumb question: When a volcano blows its top or lava spews out from deep ocean vents or via any other means is there any way of knowing exactly what rock/mineral/element is being recycled or is all lava the same? (Assuming the Earth eventually recycles that which was once on or near the surface).
I think it wouldn't be rational to install solar farm in a real hardcore desert (like Sahara) because it will be blown away by the sand storms and dunes movement. And this calculation is based on an axioma that photosynthesis efficiency limit is quite low (3-4%). But is it really so? What is photosynthetic efficiency which could be ever achieved with help of genetic engineering? Perhaps not worse than the best solar farms?There is a comparison here: https://theconversation.com/for-effi...-biofuels-9160. which indicates solar generates considerably more power per unit area than biofuels. To add to that, solar can be installed in desert areas where no plants can be grown, and they do not deplete the soil, requiring the addition of fertiliser, itself a big disturber of the ecosystem.Are you sure? Could you provide some approximate calculations? Biofuels use the same Sun power as solar farm, but probably requires less maintenance. And could be grown in the seas or salt waters, not taking any place on the land. So, how come it will take more place?
That's a fairly big question, actually. No the minerals are not all the same. Typically magmas at mid-ocean ridges and other spreading centres (e.g. The African Rift Valley) or hot spots like Hawaii, are more basic and fluid than those that are landward of subduction zones, which tend to be more acidic and viscous. This is the reason why the really dangerous and damaging eruptions (pyroclastic flows) are usually from the latter. Acidic magmas are usually high in silica (SiO2), while basic ones are basalt: https://en.wikipedia.org/wiki/Basalt.
Subduction zone volcanoes have, I think, minerals in them resulting from the action of water entrained at the subduction zone (ocean trench) which alters them, tending to reduce melting point and/or density and hence giving rise to the volcano, as the molten material rises towards the surface. Dissolved gas is also an issue. But I'd need to read this up and others may correct me.
Asked Google for world’s largest oil field. Took this from Page 1Have no idea when the first drop of oil formed within the Earth or how many oil field’s have formed since then. Have read that oil is still being produced naturally at a few sites globally, including Salt Lake. I suspect that over the ages, occasionally a field got destroyed and burned away thanks to the Earth’s recycling of its crust. How much CO2 would the burning of a subterranean oil field the size of Ghawar produce and would that CO2 make it to the atmosphere?.
1 – Ghawar Field - Saudi Arabia - 83 billion barrels Located in Al-Ahsa Governorate, Saudi Arabia. Measuring 280 by 30 km (174 by 19 mi), it is by far the largest conventional oil field in the world.
Ok I haven't had my coffee yet but a quick back of the envelope calculation... (good practice I'm doing an Oxford chemistry mock interview in a few hours!)
A standard oil barrel is about 160 litres (thanks google!). The density of oil is about 800 g per litre.
Each barrel is therefore 160 x 800 = 128000 g of oil
Times by the number of barrels is approx 1 x10^16 grams.
Most oils are around 85% by mass carbon.
So mass of carbon in the oil = 8.5 x 10^15 grams
Molar weights of carbon and CO2 are 12 and 44.
Divide the mass of C by 12 and multiply the answer by 44 gives
3.1 x 10^16 g of CO2 which is 31000000000 metric tonnes of CO2. A fair bit!
As it is a gas, even if it is made underground, unless it is surrounded by airtight rock it will eventually get into the atmosphere. Also a handy volcano could chuck it all up in one go
I suppose the next question is what impact that would have on ppm CO2 in the atmosphere. I'm a bit hamstrung by being unable to find out whether the ppm figure everyone quotes is by mass or by volume. Do you know which it is?
Atmospheric mixing ratios are usually ppm by volume. This makes sense for gases, the by mass tends to be used more for solids and liquids.
A fair bit but I used to think $1 billion was a lot. Thanks for the calculations.
I suppose that a release of such magnitude could affect the atmospheric CO2 levels. But there’s more.
If we added natural oil seepage to the mix. Some seepage areas have been releasing oil into the ocean continuously for thousands of years. One of the largest is off the coast of California (Santa Monica). I would think seismic activity/continental drift and associated fault lines play a major role here. (California seems scary if you toss massive wildfires into the CO2 mix also).
From wiki:I not denying climate change and our role in it. Just like to understand the entire spectrum of CO2 emissions. Nature contributes its share but over time I figure it balances things somehow. We’re guilty of exceeding natural emissions pace I imagine but we have no control over natural emissions which I only assume could occur at any time, at different degrees of intensity. How would we know if nature isn’t doing its thing right now as in over contributing or exceeding normal pace?.
California seeps
Diatomite outcrop containing oil that seeps out in hot weather, near McKittrick, in Kern County California.
Oil stained outcrop near Kern River oilfield, in Kern County California.
Oil Seep in the Simi Valley area of Ventura County, CA
California has several hundred naturally occurring seeps, found in 28 counties across the state.[34] Much of the petroleum discovered in California during the 19th century was from observations of seeps.[35] The world's largest natural oil seepage is Coal Oil Point in the Santa Barbara Channel, California.[36] Three of the better known tar seep locations in California are McKittrick Tar Pits,[37]Carpinteria Tar Pits and the La Brea Tar Pits.[38]
Last edited by zinjanthropos; November 27th, 2020 at 11:00 AM.
There have been long running efforts at understanding the Carbon Cycle and measuring/estimating the quantities, from way before global warming emerged as a significant issue. There is a good understanding of the major processes involved and there isn't much potential for big surprises. The ability to track Carbon, as CO2, natural and human caused, keeps getting better, including with satellites.How would we know if nature isn’t doing its thing right now as in over contributing or exceeding normal pace?
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