Carbon dioxide emissions per barrel of crude
Thanks to a disastrous decision to rely upon data published by BP, I royally cocked up a calculation involving their Miller Field carbon capture project (see previous post). However, that calculation was preceeded by — in my view — a more important one; an estimate of the amount of atmospheric CO2 emitted by a single barrel of crude oil. Thanks to the kerfuffle surrounding the error in scaling (an error, let me again stress, based upon some bad data from BP), the original calculation is being rather obscured.
CO2 emissions
Petrol:
1 litre: 2.331kg of CO2
1 US gallon: 8.824kg of CO2
Diesel:
1 litre: 2.772kg of CO2
1 US gallon: 10.493kg of CO2
Crude oil:
1 barrel: 317kg of CO2 (min.)
1 tonne of CO2 is:
429 litres / 113.33 gal of petrol*
360.75 litres / 95.3 gal of diesel
3.15 barrels of crude oil
* less than 8 fills of an average-sized car with a 55 litre tank
In the (probably vain) hope of rescuing it from that obscurity, and due in no small part to a comment on the previous entry which suggests to me that it’s still a useful piece of information, I’ve decided to reproduce it here in isolation. I invite comment and correction, as always.
How much carbon per barrel?
First up, it’s important to realise that crude oil is (almost) never used directly. Instead it’s refined into a wide range of products, most of which we burn in various engines, but some of which never get converted into CO2 (lubricant oils, plastics, asphalt, etc.). Different grades of crude oil will produce significantly different amounts of each. So a barrel of light / sweet crude might produce lots of petrol and kerosene but only a small amount of asphalt (as a very simple example). But a barrel of heavy / sour crude would produce more asphalt (still less than the amount of petrol produced, but more in comparison with the sweeter oil). This means that, ironically, less of the heavier and more sulphuric stuff, although it’s called sour (and sometimes “dirty”) oil tends to end up as atmospheric CO2 (we coat our roads with it instead).
So while we could, no doubt, work out a figure for the CO2 emitted by burning a given barrel of crude oil, it would be very much a red-herring. To get any meaningful figure for CO2 per barrel we’re going to need to do our calculations on the products of crude oil.
It makes sense to perform this calculation on oil that is of average quality (i.e. not some kind of heavy sulphuric sludge or tar-sand) to make it more generally useful. So taking Riegel’s Handbook of Industrial Chemistry as our guide, we know that the average barrel (~159 litres) of crude oil to pass through U.S. refineries in 1995* yielded the following products:
1. Gasoline: 44.1% (70.12 litres)
2. Distillate fuel oil: 20.8% (33.07 litres)
3. Kerosene-type jet fuel: 9.3% (14.79 litres)
4. Residual fuel oil: 5.2% (8.27 litres)**Percentage values from Riegel’s Handbook of Industrial Chemistry, 2003 edition (Page 515, Fig. 15.6). Litre values based upon conversion rate of 159 litres per barrel.
All of the other products*** of refined crude have sufficient alternative uses to make it possible (even if not entirely probable) that they will not end up as atmospheric CO2. Of the four grades of fuel listed above, however, it’s fair to say all of it is destined to be burnt. It’s worth noting, therefore, that our final result will represent a minimum CO2 per barrel.
Now, the litre values are no good to us by themselves. Each of the fuels has a different specific gravity (a different weight per litre), and it’s the weight of carbon we’re looking for, not the volume. Once we’ve multiplied the volume of each fuel by the relevant specific gravity we’ll have a rough “kilogram per barrel” number for each fuel. So:
1. Gasoline: 70.12 litres x 0.74 = 51.89kg
2. Distillate fuel oil: 33.07 litres x 0.88 = 29.10kg
3. Kerosene-type jet fuel: 14.79 litres x 0.82 = 12.13kg
4. Residual fuel oil: 8.27 litres x 0.92 = 7.61kg****
Overall, this suggests that the average barrel of crude refined in the United States in 1995 yielded a shade over 100kg of liquid fuels (that’s an uncannily round number… 100.73kg to be exact). Now, we know that a carbon-based fuel will emit 3.15 times its own weight in CO2 when burnt.
When fuel oil is burned, it is converted to carbon dioxide and water vapour. Combustion of one kilogram of fuel oil yields 3.15 kilograms of carbon dioxide gas. Carbon dioxide emissions are therefore 3.15 times the mass of fuel burned.
Calculating the Environmental Impact of Aviation Emissions, Oxford University Study (PDF file)
This may seem anti-intuitive at first glance, but it’s a result of each atom of carbon reacting with two atoms of oxygen to produce CO2. The “extra” weight is being drawn from the air (hence why a fuel fire will die out if deprived of oxygen).
Using the 3.15 multiplier, we see that the combined liquid fuels from an average barrel of crude oil will produce a minimum of 317kg of CO2 when consumed.
* I don’t have more recent numbers, but there’s no reason to assume 1995 wasn’t a representative year.
** 1: automobile grade fuel. 2: includes home heating oil and transportation diesel. 4: industrial grade fuel oils; used in ships and oil-burning power plants.
*** Still gas, coke, asphalt, road oil, petrochemical feed stocks, lubricants, etc.
**** Specific gravities taken from this list. The value of 0.92 is an educated guess for what is a mixture of heavy oils with a range of specific gravities. I will gladly accept correction if someone can point me towards a more accurate number.
41 responses to "Carbon dioxide emissions per barrel of crude"
March 20th, 2008 | 5:16pm by The Quiet Road » Blog Archive » Oil companies and Climate Change
[...] Oil companies and Climate Change January 17th, 2008 | 2:19am by Jim Bliss UPDATE 20-03-2008: A significant error has been revealed in a section of the following post (relating to the amount of CO2 that would have been captured by BP’s Miller Field CCS project). For details of this error, please read the correction / apology: Oil companies and Climate Change Redux. For the calculation estimating the quantity of CO2 emitted by a single barrel of oil, please see: Carbon dioxide emissions per barrel of crude. [...]
August 15th, 2008 | 7:46pm by martin b
Source: GAM – Globe & Mail
A couple of questions based on this article (below) is global co2 emission simple one cmo (or 28 billion barrels )x 3.15 for oil? Not sure if this article listed actual consumption.
M
Aug 13 03:29
Page: B2
Section: Report on Business Column
Edition: Metro
Byline: NEIL REYNOLDS
OTTAWA
As global energy resources and Zimbabwe’s dollar showed, numbers get harder to comprehend as they grow larger. Everybody routinely expresses oil resources in the billions of barrels – though it’s hard to imagine a single billion barrels, let alone the 412 billion barrels (of oil-equivalent energy) that the U.S. Geological Survey says await discovery north of the Arctic Circle.
Complicating things further, we have national differences in the way we express the same resource. Canadians and Americans cite natural gas resources in the trillions, either as cubic metres or as cubic feet – a significant difference when you multiply these units a few trillion times. More significantly, Canadians express the energy value of these resources (as opposed to the volumes) in gigajoules, which are billions of joules, and Americans do it in quadrillions of British thermal units (BTUs), which are units equal to 1,000 joules.
We need a simpler way to measure global energy resources, preferably one that uses a scale befitting the limitations of human imagination. We should be able to form easily a mental picture of what we’re measuring, something as simple to grasp as a yard or a metre, a pint or a litre. And – presto! – we may now have it in U.S. energy analyst Ripudaman Malhotra’s provocative new unit of energy measurement: the cubic mile of oil (otherwise known as the CMO). One CMO is the quantity of crude oil that fits into a cube one mile long, one mile wide and one mile deep. From this basic measure of volume, the CMO can be used to express the oil-equivalent energy content of all other resources.
Mr. Malhotra is a senior energy analyst at SRI (Stanford Research Institute) International, an independent research company based in Menlo Park, Calif. Along with two colleagues (Ed Kinderman and Hewitt Crane), he has written a book on CMO measurement, titled A Cubic Mile of Oil , scheduled for publication by Oxford University Press.
One CMO holds 28 billion barrels of oil and represents an energy equivalent of 157 quadrillion BTUs. Using this measurement, the world now produces 1.06 CMO of oil a year, 0.81 CMO of coal and 0.62 CMO of natural gas – or, combined, 2.49 CMO of fossil fuel energy. Nuclear power produces 0.15 CMO and hydroelectric power produces 0.17 CMO. Biomass – mostly meaning the conventional burning of wood – produces slightly more energy (0.19 CMO). Among the emerging alternative energy technologies, only geothermal registers on this scale (0.01 CMO); solar and wind don’t yet make the list.
Add up these dominant CMO measurements and you get global energy production of 3.01 CMO a year, with fossil fuels providing more than 80 per cent of it and alternative energies providing less than 1 per cent. Mr. Malhotra and his associates calculate that the world would require the construction of 20,000 mega-sized nuclear power plants to displace one CMO of fossil fuel energy. Alternatively, it would require 32,850 wind power turbines a year for 50 years, 91,250,000 solar rooftop panels a year for 50 years or four Three Gorges Dams a year for 50 years.
The CMO unit of measurement illuminates the world’s energy reserves as nicely as it illuminates energy production. The world has 46 CMO of proven, conventional oil, with another “probable” 52 CMO awaiting discovery. The world has 300 CMO of unconventional oil (oil sands, heavy oil, shale oil). Total reserves: 398 CMO – or 283 years at the current rate of production. Mr. Malhotra’s conclusion: “If oil provided 100 per cent of global energy, and we used twice as much as we do today, [we would have] a 59-year supply of oil based on known reserves.”
Global coal reserves are more abundant, with 1,471 CMO of energy in known reserves. Mr. Malhotra again: “If coal provided 100 per cent of global energy, and we used twice as much as we do today, [we would have] a 218-year supply of coal based on known reserves.”
Global natural gas reserves equal 301 CMO. Mr. Malhotra again: “If gas provided 100 per cent of global energy, and we used twice as much as we do today, [we would have] a 45-year supply of gas based on known reserves.” (This calculation does not include gas hydrates, which have the energy equivalent of 5,000 CMO.) Add up these reserves and multiply by two (to allow for a doubling of consumption), and you have enough known energy reserves to meet all of the energy needs of the entire world for 300 years (once again without counting gas hydrates).
Mr. Malhotra says alternative energies will indeed supply an ever-increasing share of global energy production but he says that people should not underestimate the time it will take to displace one fossil fuel CMO. Put a solar panel on every rooftop on earth, he says, and you’ll run out of rooftops long before you equal a single cubic mile of oil.
August 29th, 2008 | 12:52am by Morris Rubesin
The SRI authors should be commended in expressing the World’s energy problem in units that are consistent and comprehensible. It would be interesting if additional computations were made of the the entire amount of energy deposited on the earth by the sun of the possible overall efficiencies of converting it into a useful form by all the manners of energy conversion. Such computations would complement their own by shedding light on the question of whether there can ever be an equilibrium or steady-state of “renewable” energy if mankind continues to grow in number and in its use of energy per capita. If “steady-state” cannot be reasonably achieved, than “renewables” can only delay the time when mankind has to reduce its use of energy through reduced standards of living or population. The authors indicate that the stored hydrocarbons will be each be depleated in a few hundred years that can be extended somewhat when allowance are made for sequences of use of the materials. Even the introduction of breeder reactors that completely use up the earth’s uranium won’t last indefinitely. Complete depleation of past deposits is likely in a few thousands of years. It seems that if mankind continues to consume the earth’s stored energy in all its forms at current or increased rates, the role of renewables will be to delay the day of reckoning if an achievable sun-earth equilibrium is unlikely to produce the energy desired. It would be interesting if the authors would supplement their work by estimating the years mankind can extend their standards of living by shifting to the use of renewable energy in increasing amounts, knowing full well that the latter is unlikely to be able to do the job alone.
October 15th, 2008 | 7:38pm by Richard Gardner
I’d like to see these totals for a barrel of oil:
1) co2
2) co
3) h20
4) sulphur
5) other trace elements/compounds
December 6th, 2008 | 12:07pm by Malaysian release est. 63.25 tonnes of CO2 per day!!! | [lokman]weblog
[...] -source- [...]
December 24th, 2008 | 3:54pm by Justin Gudgeon
Do you believe absolutely that atmospheric CO2 is increasing?
January 6th, 2009 | 10:41pm by Merrick
No Justin, I don’t.
I believe if you take a load of stuff from sealed underground storage and pump it into the air then it won’t increase the amount of it in the air.
It just sort of magically disappears and turns into fairy dust. All the scientists who say otherwise are in the pay of the global warming lobby. Including the ones who wrote books about atmospheric science decades ago that pre-date the widespread concept of climate change.
January 16th, 2009 | 6:31am by Richard Gardner
How much water vapor is produced when burning a gallon/barrel of oil? Is water vapor a “worse” greenhouse gas than CO2?
February 24th, 2009 | 9:34pm by Plans for new coal at Hunterston « SANC news
[...] scheme would have been used to pump an extra 40 million barrels of oil. If burning this oil produces 12.68 million tonnes of CO2, then the 26 million tonnes of CO2 ’stored’ is actually [...]
April 28th, 2009 | 5:16am by how many barrels of oil does it take to make a solar panel? | DIY Solar Panel Kits
[...] Well, a barrel of oil has at least 317kg of CO2 http://numero57.net/?p=255 [...]
May 7th, 2009 | 11:00am by Permaculture Research Institute USA » How Much Should We Leave in the Ground?
[...] http://numero57.net/?p=255 [...]
May 7th, 2009 | 11:01am by Permaculture Research Institute of Australia » How Much Should We Leave in the Ground?
[...] http://numero57.net/?p=255 [...]
May 26th, 2009 | 1:22am by Michael McCurley
More to the point, why not also consider the amount of oxygen which is depleted when this element is ‘fixed’ in the compound of carbon dioxide? This might at first be considered to be negligible, but consider how much of that extra weight is, in fact, oxygen! The more CO2 that is produced, the less oxygen there will be. This won’t be so immediately noticable in the atmosphere as it is and will be in the world’s oceans, where the mix of dissolved CO2 competes to a certain extent with the quantity of dissolved oxygen. Anoxia in extreme cases produces dead zones where no aquatic life can survive.
May 27th, 2009 | 5:02pm by Jim Bliss
Hi Michael, thanks for stopping by. I’ve not actually looked into the level of oxygen depletion created by burning carbon-based fuels. Nor the effects that depletion might have. So I just don’t know whether or not this is a big issue.
A shade over 20% of the air is oxygen, while CO2 still accounts for less than 0.04% despite the amount we’re pumping out. So at first glance, it would appear that the amount of oxygen being removed from the air directly by the combustion of fossil fuels is relatively small in comparison with the overall amount present. This contrasts with the addition of CO2 which starts from a much smaller baseline, so any alteration has a larger relative effect.
NOTE: At this point let me point back to the italicised “at first glance” in that paragraph. In truth a relatively tiny reduction in the amount of atmospheric oxygen may well have dramatic results for the marine environment. I just don’t know; though I would be interested in hearing more about that.
What I would say is that there may be factors that could result in a far greater depletion of oxygen in the air and oceans. Deforestation, for example, is a direct assault on one of the primary mechanisms for producing atmospheric oxygen. And there’s apparently a concern now that Climate Change could spark a huge collapse in forest eco-systems, accelerating the process we began.
Also, the increase of CO2 in the air is contributing to a rise in marine acidity, which may in turn inhibit both plankton and algae growth. This will result in less oxygen all round as well as creating those “dead zones” you mentioned.
So you may well be right. This could be yet another negative consequence of our ecological blindness. It wouldn’t surprise me… do enough screwing around with any fantastically complex system and you’ll eventually overwhelm whatever self-correcting mechanisms are built into it. The results will be unpredictable and almost always damaging for anything that relies upon the relative stability of system.
July 10th, 2009 | 12:04pm by how many barrels of oil does it take to make a solar panel? | One Stop Solar & Wind Resource
[...] Well, a barrel of oil has at least 317kg of CO2 http://numero57.net/?p=255 [...]
July 25th, 2009 | 4:45am by Bob Neher
When you look at this fact: “One kilogram of fuel oil (when burned) equals 3.15 kilograms of carbon dioxide gas” you have to think to yourself, “Holly cow that’s a lot of pollution!”. But, I think this reasoning is absolutely wrong. Lets say that the oil not burned (so not releasing CO2 into the atmosphere) is subtracted from the total amount of oil that we pump here or import. Then multiply that amount by 3.15. That gives you a big number, lots of pollution, right? Wrong. When fuel is burned and the carbon dioxide and water vapor is released into the atmosphere, why isn’t the water vapor weight subtracted from the total weight? Isn’t that water vapor going to eventually become rain AND help the environment? Since plants use carbon dioxide as food, why isn’t that also considered good for the environment and subtracted from the “harmful” pollution numbers? Won’t plants do better with more “food” (and rain)?
For the record, I am in favor of conservation, recycling, etc., but lets be realistic. Lets not use inflated numbers and inaccurate facts to support the real issue here, “global warming”. I ask you just one question more. If there have been 10 to 11 previous ice ages (during the past few million years) followed by interglacial warming periods each time (and, assuming the earth is warming now) what makes you think that man’s activities have caused this warming?
Bob
PS. Doesn’t the warming of ocean waters cause the release of carbon dioxide? Consequently, making the waters better for marine life, increasing that source of food for everybody, helping the environment?
July 25th, 2009 | 10:12am by Jim Bliss
Hi Bob, thanks for stopping by.
I am a little confused by your comment though. While it’s true that I have placed this post in the ‘Climate Change’ category, I don’t actually refer to “pollution” or “global warming” or any other potential consequence of CO2 emissions. I do believe it’s an important issue and serious crisis, but this post was very specifically answering the question of how much CO2 is released by burning a barrel of oil.
So in that context, I’d like you to explain precisely which “inflated numbers and inaccurate facts” this article contains.
With regards to the water produced by fossil fuel production, I don’t really know what relevance it has here. Perhaps it is indeed a positive environmenal effect of fossil fuels. That wasn’t the question I sought to answer in this post and frankly I’m not sure you can offset a negative ecological impact with an entirely unrelated positive one.
If I pump poison into your veins, I can hardly claim I’m mitigating it by giving you a back rub and keeping you well fed while I do it.
A simple subtraction of the weight of water vapour from the weight of CO2 makes absolutely no sense at all, unless you can demonstrate that the effects of the water vapour directly offset the effects of the CO2 in precise proportion to the weight of the two.
As for the larger question of the nature of the current Climate Change (anthropogenic Vs. natural)… fact is, I have been convinced by the arguments in favour of anthropogenic Climate Change. I am not a climate scientist, though I like to feel that my engineering background allows me to evaluate claims about physical systems with a degree of accuracy.
Whether or not that’s true, the fact is that I — like everyone else — am forced to rely upon the expertise of others in certain areas. I do not have the requisite education, for example, to assess the claims made by biologists that they have successfully cloned a sheep (and other animals). Nonetheless to doubt those claims without any reason tends towards the irrational.
I accept the consensus of informed opinion on issues upon which I am uninformed until such time as I have a reason to doubt it. This is not to say that I accept such a consensus blindly and without question, and — as anyone who knows me can tell you — I do have a tendency to actively question statements from authority. However, I don’t see any reason to find refuge in Climate Denial, no more than I do in Cloning Denial, merely because they are the consensus of educated opinion.
July 25th, 2009 | 10:29am by Jim Bliss
On your last point:
This is a very strange claim. On the one hand, reducing CO2 in the oceans is “better for marine life”, but just a couple of paragraphs earlier you pointed out that “plants use carbon dioxide as food”. Given that the majority of marine life is plant life, I’m wondering how you square these two statements?
Having said that, the fact is that the effects of warming oceans and increased atmospheric CO2 involve quite complex interactions between air and sea. It’s not simply a case of the oceans releasing CO2. Increased atmospheric CO2 induces the oceans to absorb more of it too. Systems theory almost never involves simple subtraction or addition; it’s all about the feedback loops (both positive and negative).
Given that the oceans appear to be demonstrating a significant acidification, I would suggest that the CO2 lost by the oceans via the warming effect is outweighed by that gained through the absorption of increased atmospheric CO2. And ocean acidification demonstrably does not make the “waters better for marine life”.
August 4th, 2009 | 7:05pm by safaa h
Our firm is thinking of establishing a liquid co2 plant in Iraq. one option is to use the cheap heavy fuel oil available as by-product of oil refinaries.
The crude oil is coming with high sulphuric sludge, so my question is if we can rely on such oil to produce CO2 gas.?
August 11th, 2009 | 9:32am by Robin Rutherford RD5, Hunterville New Zealand
The most important fact is that the weight of carbon dioxide released by the combustion of gasoline is over 3 times the weight of gasoline.
On a practical level-
Carbon dioxide emissions per litre of gasoline amount to 2.1kilograms of carbon dioxide per litre of fuel, or per approx 10km. This is huge- a car travelling 10,000km per year emits about two tons of carbon dioxide. And 2.4kilogramms of oxygen is needed for each liter of gasoline consumed, so in a year,using 1000 litres of gasoline, about 2.4tons of oxygen is burnt up per vehicle. With maybe 2,000 million vehicles in the world, approximately 4,000 million tons of carbon dioxide emmitted annually from cars alone, along with roughly the same amount, 4000 million tons, of oxygen being used up from the atmosphere.
September 4th, 2009 | 8:46am by George Monbiot: Wherever temperatures peak, that is more or less where they will stay. There is no going back | Global Climate Change Information
[...] But the rough calculation here suggests that the use of a barrel of oil releases 317kg of CO2 – http://numero57.net/?p=255. There are roughly 7 barrels to the tonne, giving an approximation of 2219kg CO2, or 605kg of [...]
November 3rd, 2009 | 2:22pm by how many barrels of oil does it take to make a solar panel? | How To Build Your Own Solar Panels
[...] Well, a barrel of oil has at least 317kg of CO2 http://numero57.net/?p=255 [...]
November 6th, 2009 | 1:19pm by Got 0 Plans - Page 2 - Snowboarding Forum - Snowboard Enthusiast Forums
[...] fuels from an average barrel of crude oil will produce a minimum of 317kg of CO2 when consumed. Carbon dioxide emissions per barrel of crude (The Quiet Road) So how much Oil is burned on the planet in a year? [...]
November 8th, 2009 | 8:53am by Celine Trojand
HI Jim,
I’m writing a paper for a class this semester and I would like to use the numbers you’ve calculated here. Did you use any other sources to make your calculations? Any idea where I could find more support? I’m trying to attach an estimated carbon footprint to the proposed Enbridge northern gateway pipeline and want to be sure that it’s accurate!
November 8th, 2009 | 1:47pm by Jim Bliss
Hi Celine, all of my sources are listed in the post. And I believe they’re sufficient for the calculation as described. It’s really a very simple piece of mathematics (as you can no doubt see for yourself) and only needs to be based upon a small amount of readily available data.
Just let me know if there’s a specific reference that you need, and I’ll do my best to find it. But I think the CO2 per barrel calculation is justified by the provided information.
Good luck with your paper!
November 12th, 2009 | 6:13am by JOHNNY A BROWN
Hi Jim
I am just a numb skull but please enlighten me on the following statement
The most important fact is that the weight of carbon dioxide released by the combustion of gasoline is over 3 times the weight of gasoline.
On a practical level- Carbon dioxide emissions per litre of gasoline amount to 2.1kilograms of carbon dioxide per litre of fuel, or per approx 10k
As was written by one of your mail questions do we rewrite the laws of physics how is it worked out that when the burning of one litre of gas can produce three times its weight in CO2
REGARDS JB
November 12th, 2009 | 11:20am by Jim Bliss
Don’t worry Johnny, you’re not a numb skull. It is indeed anti-intuitive until you realise exactly what’s going on. And don’t worry, we don’t need to rewrite any physical laws. In fact it’s really rather simple once you get your head around it.
When you burn a carbon-based fuel, what you’re actually doing is raising the temperature of the carbon until it oxidizes (reacts with the oxygen in the air) which it does explosively (i.e. with a flame). Each carbon atom then bonds with two oxygen atoms and it is these two extra atoms that provide the “extra” weight. So it’s not really “extra” at all, it’s being drawn from the air you burn it in… hence why a fuel fire can be extinguished by depriving it of air / oxygen.
The chemical reaction looks something like this:
C + O2 -> CO2
I hope that’s clear?
November 14th, 2009 | 12:10am by JR
Jim,
I wanted to point out one small error / assumption in your calculation which – frankly – will not impact things very much.
The Oxford study you quote (Calculating the Environmental Impact of Aviation Emissions, Oxford University Study) is specific for jet fuel – or more precisely, Jet A or equivalent, which is the standard aviation fuel in the world today. Since Jet A (density 0.81) has a slightly different chemical composition to the other fuel cuts you used to approximate a barrel of oil, the ratio of kgs CO2 emitted upon combustion per kg of fuel will be slightly different. For the precise calculation you would need to adjust for the C/H (carbon / hydrogen) ratio of the different fuel cuts you have used.
As a simple illustration, we can look at methane (CH4, the primary component of natural gas) and dodecane (C12H26, in the range of diesel fuel). Methane is 75 wt-% carbon and 25 wt-% hydrogen. Combustion of 1 kg of methane, therefore, would yield 0.75 kgs of combusted carbon. This equates to about 2.75 kgs of CO2 once you add in the two oxygen atoms and adjust for the ratio of atomic weights of C and O. (I am trying to avoid using term “moles” because it will probably give everyone bad chemistry flashbacks…or looking in the yard.)
Doing the same thing for dodecane we get the following: 84.7% C and 15.3% H; 0.847 kg C per kg fuel; and, 3.11 kgs CO2 per kg fuel combusted. Pick a different chemical and you’ll get a slight different answer…
Of course, you could do this for every unique C/H ratio chemical in transportation fuels but its not really worth it – we are in the ballpark. In engineering parlance, however, this becomes known as “polishing the turd” and your number of 3.15 is probably a good average number.
Thanks for the calculation and the crisp, clear description of your methods and – most importantly – citing your sources.
– JR
November 14th, 2009 | 12:18am by JR
Jim,
Using energy density, this website:
http://www.epa.gov/grnpower/pubs/calcmeth.htm
calculates a slightly higher number of 430 kgs per barrel of oil. Since this method uses energy density it does assume the entire barrel is combusted so it sets and upper limit on the amount of CO2. Another verification that your number is probably accurate enough…
– JR
November 14th, 2009 | 12:30am by Jim Bliss
Many thanks for pointing that out. I was an industrial engineer — a jack of all trades — rather than a specialist chemical engineer. So it doesn’t surprise me that I missed a nuance in the calculation.
As you say however, it’s a fairly minor discrepancy. And I don’t think it invalidates the calculation (in the sense that it was always going to be a ballpark figure with an acceptable but non-zero margin of error).
If it was a major thing I’d probably revisit the calculation as a matter of urgency, but given that it’s not (along with the difficulty of tracking down the precise composition of various fuel types) I’ll wait until the urge takes me on a slow day.
As I say though, thanks for taking the time to stop by and comment.
All the best,
jim.
November 20th, 2009 | 4:52pm by Will Peak Oil Save us from Climate Change? | Serendipity
[...] at well over 1200Gb). Let’s split the difference and say 1,000Gb (1×10^12). Jim Bliss calculates that each barrel of crude oil releases about 100kg of carbon. That gives us 0.1 trillion tonnes of [...]
November 25th, 2009 | 1:44pm by Google number ones (The Quiet Road)
[...] CO2 per barrel of crude oil (this post) [...]
December 12th, 2009 | 4:30pm by kenneth
Hello there
Can someone provide the following information
How much CO2 is Produced when 10000 kilowatts of each of the following fuels are burned.
Butane
Propane
Petrol
Diesel
Natural Gas
Kerosene
This is a fairer way of looking at things as the energy content of each fuel by weight varies considerable
December 12th, 2009 | 5:33pm by Jim Bliss
This is a fairer way of looking at things as the energy content of each fuel by weight varies considerable
Hi Kenneth. The point of the above post was to provide a ballpark figure for the minimum emissions produced by an average barrel of oil. The reason for this was to allow people to contextualize statements like “current gloabl oil consumption is 85 million barrels per day” or “a new oil field has been discovered and is predicted to produce 1.2 billion barrels”. It was never intended to be the last word in fossil fuel emissions.
I’m unlikely to get a chance to produce a detailed fuel-by-fuel emissions breakdown this side of the new year, but I’ll consider revisiting the subject early in 2010 and doing a more comprehensive analysis.
December 12th, 2009 | 7:58pm by kenneth
Thanks for that it would great if you could do it for coal ,firewood and peat products too,so people could compare kilowatts consumed /CO2 produced for each fuel as against using weights of various fuels which can create confusion.
Kenneth
January 9th, 2010 | 1:58am by Greg
Thanks for this calculation and information, Jim.
Have you seen a presentation of the total potential emissions per barrel of crude, including extraction, transport, refining, storage, sale, etc.?
That could be quite an informative figure.
Greg
January 22nd, 2010 | 4:29am by mark malone
Hi Jim
Thanks for the calculation. Im helping write up some position papers for an organisation involved in climate justice movements. I know it a little of topic, but i wonder when we try to calculate the CO2 output of burning 1 barrel of oil, even the ball park figure, is it worth noting that we might need to consider the amount of CO2 ceated to bring the oil to use. I guess that chain could be endless, but say even we considered the energy required, and CO2 produced to get it in “barrel state” as it where
Just a thought and wondered what others concerned about global heating might think about how this impacts on total figures.
Great work and thanks again
January 23rd, 2010 | 3:16pm by kenneth
Hi Jim
Did you come up with any figures yet?
March 6th, 2010 | 1:51pm by Jim Bliss
Sorry kenneth, but it hasn’t been a top priority for me so far this year. My head’s been full of other stuff of late. Can’t make any promises as to when I’ll get round to it. Sorry again.
April 18th, 2010 | 5:42pm by Dr Max
Dear Jim:
I acknowledge with thanks the use of your data on crude oil in my blog “Andas Lugnt” (Swedish, meaning Breathe Calmly).
Yours
/Max
June 1st, 2010 | 11:11pm by We All Deserve The BP Oil Disaster « Prose Encounters of the Nerd Kind
[...] unsustainable society. Each of the 86 million barrels of crude oil we use every day translates into roughly 27 megatons of CO2 emission every day. That’s about 10 million million tons of CO2, or a cube of concrete 1.63 km to a [...]
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