Tuesday, February 19, 2013

Governments Must Work Together to Mitigate a Peak Oil Scenario.

Decline in output from the world's oil fields is averaging 5% per year http://aspousa.org/peak-oil-reference/peak-oil-data/oil-depletion/, with some speculation that we may have reached the global production limit for conventional crude oil http://www.skepticalscience.com/Climate-Policy-Peak-Oil_U-Washington.html. Once the loss in output overtakes what can be provided from unconventional sources, it can be said that we have passed the point of global "peak oil". The exact timing of this will be known only to posterity, but its circumstance is widely perceived as an unquenchable and imminent disaster of planetary proportions, and the "End Times" movement, hard-line Christian fundamentalists, mostly in the US, are rubbing their hands in anticipation of such "proof" that God really did tell us 2000 years ago that the Tribulation would befall us, in preparation for the second coming of Jesus Christ, who would ultimately transform the Earth into paradise. A cynic might say that since these are mostly people who live in a nation that consumes vastly more energy, and has more cars than anywhere else on earth, such acceptance is really an act of inertia, and they would rather die than change their lifestyles to anything less energy consuming.

Being essentially an optimist by nature, I am trying to avoid falling to apathy along the wayside, although it is extremely difficult not to see things in a gloomy perspective, especially living in a country that has pledged itself to additional debts of around $1.2 trillion (£750 billion) in the wake of the 2008 banking crisis, and which will take so long to pay-off that the point when (or if ever) the balance sheet comes back into the black is really anybody's guess. If it takes 30 years, one can only speculate as to the kind of world and society that will prevail then, and since I am a man of a certain age, in all probability I won't be part of it.

There are many scary scenarios to be had, and which are gratuitously foretold, but mostly these involve wars over resources, mainly oil and also water. The two are connected inextricably in the matrix of energy and production that forms the web of globalisation, with oil-powered pumps drawing water to bring desert into fecund crop-land and pasture. Thus if oil fails, so does the land, and much of the food production especially in the mid-western United States, once it is no longer possible to extract water, much of which is of fossil origin, drawn up from underground aquifers. These are not routinely refilled by rainwater, but are an essentially finite resource, laid-down millions of years ago http://ergobalance.blogspot.co.uk/2012/08/terminal-shortage-of-water-for-us.html.

It is not worth elaborating the conceivable plots of mayhem, including one I have heard of, where the governments are forced to bomb the inner cities to destroy the rapacious and desperate millions, before they become lawless and soulless roaming hoards, rather as in the 1956 novel "The Death of Grass http://ergobalance.blogspot.co.uk/2012/01/death-of-grass.html. Rather, to consider that there may be a solution, but only one, and that is for the governments of the world to unite in a voluntary and cooperative programme to reduce oil consumption by 3 million barrels/day (ca 3%) per year, in line with the predicted fall in oil production from the present to 2030 http://ergobalance.blogspot.co.uk/2012/03/can-solar-fuels-avert-imminent.html. Any other strategy - including business as usual - will be tough, unpleasant and disastrous, and must inevitably abrade society into conflict and all-out wars between regions and between nations. In a nutshell, oil-producing nations must agree to reduce their production by 3% per year and oil-importing nations to reduce their imports by an exactly matching amount. Production will fall and must be planned to fall, while consumers take-up the slack in supply, in the form of fuel rationing.

We need a clear strategy to gear-down our dependence on personalised transportation and on the carriage of essential goods such as food and water to the extent that should this mechanism fail, in Britain we have probably three days supply before the supermarket shelves are empty and the country begins to starve. To put it another way, a fall in oil provision by 3% per year means building more localised means that depend less on transport by that same figure, pro rata. Since the problem is a global one, the solution can only be found globally, and individual nations - under the leadership of their governments - must cooperate in creating an overall less fuel-dependent ideology and putting this into practice. Fuel rationing is key and a reconstruction of societies so that the means for shelter, work, food production, money and all else are not separated, but become part of the integrated hive of community.

Wednesday, February 06, 2013

The Petroleum Rollercoaster.

I wrote the following in a previous posting http://ergobalance.blogspot.co.uk/2012/03/can-solar-fuels-avert-imminent.html but there are a number of points of issue, which I shall now address. In particular, the aspect of the apparent rate of decline of oil production needs clarification, and indeed what exactly is meant by "oil".

"It has been estimated that the world's road transportation fleet will reach 2 billion by 2020, of which at least 50% will be cars. China’s and India’s automobile fleets are expected to grow at an annual rate of around 7 or 8%, while in the United States, it will be under 1% a year, and around 1 to 2% in Western Europe, but this depends tacitly on finding an expanding liquid fuel supply, and it is this which is at issue. Indeed, the International Energy Agency (IEA) has issued a report to the effect that a shortfall in oil production of 64 million barrels a day (mbd) can be expected by 2030, which represents a loss of 62% of the world supply of conventional crude oil, currently 84 mbd, assuming a demand by 2030 of 96 mbd, a figure significantly downgraded from prior estimates by the IEA of 120 - 130 mbd. At a mean decline rate of 2.9 mbd/year (-3.4%/year) this value accords closely with the prediction in a recent U.S. Army report that there will be a deficiency of 10 mbd by 2015, following a loss of any spare capacity for crude oil against demand for it by the end of this year (2012)."

In essence, the above is saying that, while demand mainly for cars, and hence liquid fuels to run them, is expected to double during the present decade, an enlarging hole in the production of conventional crude oil is expected to occur, against demand for it. However, in my expression of the situation, I have been rather louche with the term "oil". I am in good, or at least numerous, company in this respect, since the whole business of oil production has been obfuscated by reference, over the past decade or so, to "liquids". Back in 2005, production of total liquids did indeed amount to around 84 mbd, but since then, and up to the present, the proportion of that which is actual conventional crude oil (plus condensate, since the two are customarily reckoned together) has been around 72 mbd, although the production of liquids had "climbed" to 87 mbd in 2011.

Now, much of this increase in volume is due to an increasing amount of natural gas plant liquids (NGPL) being produced and included in the tally, in part as a side-product of shale gas production, through horizontal drilling and fracking. Overall, the procedure of combining NGPL and crude oil, in the same tally, seems a little disingenuous and rather misleading, since the two are not the same thing at all or even “close substitutes” in terms of what they can be used for. Globally, NGPL provides around 9 mbd, biofuels, coal-to-liquids and a very small amount of gas-to-liquids altogether provide another 2 mbd. Another 2 mbd is due to “refinery gain”, which is not real additional oil (or liquids) production, but measures the increase in volume of the total products obtained e.g. from cracking heavy oil. Indeed, it can be considered as a measure of the energy expended to “refine” crude oil http://www.energybulletin.net/stories/2012-07-08/how-changing-definition-oil-has-deceived-both-policymakers-and-public. But of actual crude oil, there has been no increase in production for about 8 years, which has led to the view that we may have hit the ceiling of world conventional crude oil production http://www.skepticalscience.com/Climate-Policy-Peak-Oil_U-Washington.html.

According to the U.S. Energy Information Administration (EIA), “the term ‘liquid fuels’ encompasses petroleum and petroleum products and close substitutes, including crude oil, lease condensate, natural gas plant liquids, biofuels, coal-to-liquids, gas-to-liquids and refinery processing gains.” Since the major gains in production have been in the form of NGPL, it is a matter of some importance to consider the exact properties of these materials in comparison with conventional crude oil, particularly in relation to providing liquid fuels. As the following data show http://www.spe.org/industry/docs/UnitConversion.pdf, a barrel of these liquids contains far less energy than a barrel of crude oil (6.12 GJ), natural gasoline (4.87 GJ), iso-butane (4.19 GJ), n-butane (4.56 GJ), propane (4.05 GJ), ethane (3.25 GJ) – data from original source converted from Btu to GJ. Moreover, they are far from being “close substitutes” for crude oil, in terms of their molecular and physical composition, and are mainly used for other purposes. The major single component of NGPL is ethane (42%), which is converted to ethylene mainly to make plastic from. Roughly 28% of NGPL is propane, which is mostly used to run small heating appliances, e.g. barbecues.

The future of crude oil (and liquids) production has been given a more detailed consideration by Antonio Turiel http://www.resilience.org/stories/2013-02-05/the-twilight-of-petroleum and is most alarming in its conclusions. Using the graph for the forecast of "World oil supply by type in the New Policies Scenario" in the latest annual report of the International Energy Agency http://www.peakoil.net/headline-news/an-analysis-of-world-energy-outlook-2012-as-preparation-for-an-interview-with-science, Turiel has arrived at the following production levels in mbd for the year shown. I am using a slightly different presentation, which lists a running total under each heading, up to the final sum.

Year. Current crude. "New" projects. NGPL. Unconventional. Tight oil. Refinery gains.
2000        65.9                0                   73.8               74.9                0             76.9
2005        70.0                0                   79.7               82.0                0              83.9
2011        68.2                0                    80.2              83.2                84.4         86.2
2015        64.1              68.2                 82.6              86.8                89.3         91.7
2020        56.3              66.5                 82.1              88.0                91.1         94.0
2025        48.0              65.9                 82.1              89.2                93.3         95.8
2030        36.7              65.3                 82.1              90.9                94.6         97.6
2035        25.9              65.3                 83.2              93.3                97.0         100.0

Turiel makes many pertinent points, including the mismatch in properties and energy density between other liquids and crude oil. Most significantly, he stresses that it is misleading to use liquid volumes, rather that the energy content of the "liquids" (energy equivalents) would be a more meaningful measure of what is being produced, in terms of "oil equivalents". This takes the 2035 total down from 100.0 to 87.5 mbd.When the EROEI is applied, the figure for 2035 falls further to 79.7 mbd, indicating that we are "very close to the zenith of petroleum energy". When other considerations are made, as to the actual likelihood of production especially of the "new" projects, the 2035 energy equivalent is just short of 40 mbd.

However, it is actual crude oil that is at issue, and what rate of decline in its supply might be expected, since this represents the "hole" that must be filled from unconventional sources just to maintain our status quo. Obviously there will be fields with weaker or stronger production, but -5%/year appears to be the global average http://aspousa.org/peak-oil-reference/peak-oil-data/oil-depletion/. According to the data in the table, over the period 2005--2035, a fall in output from 70.0 mbd to 25.9 mbd implies a decline rate of only -2.1%/year. This is significantly lower than either the -5% global average, or the -3.4% that I had deduced crudely for total liquids, assumed as "oil", though the latter figure is in accord with analyses by both the German and U.S. military; the latter concluding that we can expect a shortfall of 10 mbd by 2015. It is of note that while the data are in the region of a -2%/year decline up to 2025, the rate does increase to around -5%/year over the subsequent decade, to 2035. I have used a simple division by year, rather than a compounded percentage decline, because the data seem to behave this way, and the discussion is illustrative. I note that a compounded -3.4%/annum decline from 2005 does agree quite well (24.8 mbd) with the observed 2035 value (25.9 mbd), though in all other cases it provides an appreciable underestimate of the amount of oil remaining.

Thus, the raw data in the table imply that in a little over 20 years time, we will only have about 38% of our current supply of conventional crude oil, or a shortfall of more than four Saudi Arabias to fill from other sources. This rises to nearer five Saudis, when the EROEI factor is included, to measure the difficulty of extracting oil post-peak, which is the top of the easy-oil rollercoaster ride that humanity is presently on. If the actual decline does maintain at nearer -5%/year, then, frightening though Turiel's conclusions are, they may underestimate the urgency and rake of the inevitable crash downwards. But before then, civilization will have either fallen, or re-adapted through localisation and by establishing resilient local communities. Yet, it is almost a matter of denial to ignore how little time we may have left to make the Transition.

Friday, February 01, 2013

The Achilles' Heel of Algal Biofuels - Peak Phosphate. - An Update.

The following is an update to a previous posting http://ergobalance.blogspot.co.uk/2012/02/achilles-heel-of-algal-biofuels-peak.html If anything, the situation might be worse that I had concluded then, but the issue of phosphate rock reserves is more complex than I had deduced. So, this article is as written before, but with a few more numbers worked through, to account for "real" phosphate rock, rather than my initial model of it being pure fluorapatite [Ca5(PO4)3F (calcium fluorophosphate)]. The references are as appended to a full article on this subject that will appear in the next issue of the journal, Science Progress http://www.ingentaconnect.com/content/0036-8504

The depletion of world rock phosphate reserves will restrict the amount of food that can be grown across the world, a situation that can only be compounded by the production of biofuels, including the potential large-scale generation of diesel from algae. The world population has risen to its present number of 7 billion in consequence of cheap fertilizers, pesticides and energy sources, particularly oil. Almost all modern farming has been engineered to depend on phosphate fertilizers, and those made from natural gas, e.g. ammonium nitrate, and on oil to run tractors etc. and to distribute the final produce2. If a peak in worldwide production of rock phosphate will occur within the next few decades, this will restrict the amount of food that the world will be able to produce in the future, against a rising number of mouths to feed. Additionally, there is a consensus of analytical opinion that we are also close to the peak in world oil production. One proposed solution to the latter problem is to substitute oil-based fuels by biofuels, although this matter is not as straightforward as is often presented. In addition to the simple fact that growing fuel-crops must inevitably compete for limited arable land on which to grow food-crops, there are vital differences in the properties of biofuels, e.g. biodiesel and bioethanol, from conventional hydrocarbon fuels such as in petrol and diesel, which will necessitate the adaptation of engine-designs to use them - for example in regard to viscosity at low temperatures, e.g. in planes flying in the frigidity of the troposphere. Raw ethanol needs to be burned in a specially adapted (high compression ratio) engine to recover more of its energy in terms of tank to wheels miles, otherwise it could deliver only about 70% of the energy contained petrol, or diesel, weight for weight. In order to obviate the competition between fuel and food crops, it has been proposed to grow algae from which to make biodiesel27. Some strains of algae28 can produce 50% of their weight of oil, which may be transesterified into biodiesel in the same way that plant oils are. Compared to, e.g. rapeseed, which might yield a tonne of biodiesel per hectare, or 8 tonnes from palm-oil, perhaps 40─90 tonnes per hectare29 is thought possible from algae, grown in ponds of equivalent area. Since the ponds can, in principle, be placed anywhere, there is no compromise over arable land, unlike fuel/food crops. Some algae grow well on salt-water too which avoids diverting increasingly precious freshwater from our normal uses for it, as opposed to the case for land-based crops which require enormous quantities of freshwater.

Diesel engines are more efficient27 by about 40%, in terms of tank to wheels miles, than petrol-fuelled spark-ignition engines, and so, in the spirit of energy efficiency, we shall assume that all vehicles are converted to run on diesel. This means that a total of around 40 million tonnes/year of diesel would need to be substituted for. To produce an equivalent amount of algal biodiesel, and assuming a yield of 40 tonnes/hectare (the lower end of the 40─90 t/ha range29), the algae ponds would require a total area of 10,000 km2. Ideally, the algae plants could be integrated with fossil fuelled power plants, to absorb CO2 from smokestacks by photosynthesis, driven only by the flux of natural sunlight. However, for the algae to grow, vital nutrients are also required, as a simple elemental analysis of dried algae will confirm. Phosphorus, though present in under 1% of that total mass, is one such vital ingredient, without which algal growth is negligible. Two different methods are now used to estimate how much phosphate would be needed to grow this amount of algae: (1) to fuel the UK and (2) to fuel the world:

(1) An analysis of dried Chlorella [http://en.wikipedia.org/wiki/Chlorella} is taken as illustrative, which contains 895 mg of elemental phosphorus per 100 g of algae.

UK Case: To make 40 million tonnes of diesel would require 80 million tonnes of algae (assuming that 50% of it is oil and this can be converted 100% to diesel).
The amount of "phosphate" in the algae is 0.895 x (95/31) = 2.74 %. (The Formula Weight, FW of PO43- is 95, while that of P is 31).

Hence this much algae would contain: 80 million x 0.0274 = 2.19 million tonnes of phosphate. By initially assuming the chemical composition of the rock to be that of fluorapatite, Ca5(PO4)3F, FW 504, we can conclude that this amount of PO43- is contained in 3.87 million tonnes of it. However, actual mined rock phosphate is a more impure material than this, and that normally used for fertilizer production is reckoned to contain 29─34% P2O5 (to be compared with 42.3% as may be deduced from the chemical formula of pure fluorapatite, above). Following the calculations so far for the quantity of PO43- involved, and by using the ratio of FW for 0.5 P2O5/PO43- (71/95), we may conclude that there are (71/95) x 2.19 million = 1.64 million tonnes of P2O5 contained in this amount of PO43-. Taking the range average of 31.5% for the mineral P concentration, reckoned as P2O5, this would accord with 5.20 million tonnes of actual “rock phosphate”, yielding a conversion factor of 1.34 up from the value reckoned for pure fluorapatite. We may use the latter in the remaining calculations.

World Case: The world produces and consumes 30 billion barrels of oil a year, of which 70% is used for transportation (assumed). Since 1 tonne of oil is contained in 7.3 barrels, this equals 30 x 109/7.3 = 4.1 x 109 tonnes and 70% of that = 2.88 x 109 tonnes of oil for transportation.

Assuming that 50% of it is water, we would require twice the deduced mass of algae = 5.76 x 109 tonnes of it, which contains: 5.76 x 109 x 0.0274 = 158 million tonnes of phosphate. As before, by taking the chemical composition of the material as fluorapatite, Ca5(PO4)3F, FW 504, this amount of "phosphate" is contained in 279 million tonnes. Applying the factor of 1.34 as arrived at above, to account for the typical degree of impurity in the mineral, we obtain a requirement of 374 million tonnes of actual mined rock phosphate.

(2) To provide an independent estimate of these figures, we may note that growth of this algae is efficient in a medium containing a concentration of 0.03─0.06% phosphorus. To avoid being alarmist, we may use the lower part of the range, i.e 0.03% P. "Ponds" for growing algae vary in depth from 0.3─1.5 m, but we now assume a depth of 0.3 m.

UK Case: assuming (vide supra) that producing 40 million tonnes of oil (assumed equal to the final amount of diesel, to simplify the illustration) would need a pond/tank area of 10,000 km2. 10,000 km2 = 1,000,000 ha and at a depth of 0.3 m, this amounts to a volume of: 1,000,000 x (1 x 104 m2/ha) x 0.3 m = 3 x 109 m3.

A concentration of 0.03 % P = 0.092% phosphate, and so each m3 (assuming a density of 1t/m3) of volume contains 0.092/100 = 9.2 x 10-4 tonnes (920 grams) of phosphate. Therefore, we need:

3 x 109 x 9.2 x 10-4 = 2.76 million tonnes of phosphate, which is in reasonable accord with the amount of PO43- taken-up by the algae (2.19 million tonnes), as deduced above. This corresponds to 4.87 million tonnes of Ca5(PO4)3F, and if the 1.34 “impurity factor” is applied, to 6.53 million tonnes of rock phosphate.

World Case: To meet the requirements of the entire world would demand the substitution by algae fuel of 2.88 x 109 tonnes of crude oil, and an installation to produce this amount would occupy an area of 2.88 x 109/40 t/ha = 7.20 x 107 ha of land.

7.2 x 107 ha x (104 m2/ha) = 7.2 x 1011 m2 and at a depth of 0.3 m the ponds would occupy a volume = 2.16 x 1011 m3. Assuming a density of 1 tonne = 1 m3, and a concentration of PO43- = 0.092%, we need:

2.16 x 1011 x 0.092/100 = 1.99 x 108 tonnes of PO43-, i.e. 199 million tonnes. This corresponds to 352 million tonnes of Ca5(PO4)3F, or (x1.34) 472 million tonnes of actual mined rock phosphate.

This is also in acceptable accord with the figure deduced from the mass of algae, accepting that not all of the P would be withdrawn from solution during the algal growth.

Rock phosphate production10 in 2011 amounted to 191 million tonnes, against which must be compared the 472 million tonnes we have estimated would be needed to grow sufficient algae to fuel the world with algal biodiesel. Since food production is already being thought compromised by rock phosphate resource depletion, finding such a significant additional quantity is probably impossible. Currently, the U.S. produces less than 30 million tonnes of rock phosphate annually, but would require 104 million tonnes of the material to produce 22% of the world's total algal diesel, in accord with its current "share" of world petroleum-based fuel. Hence, for the U.S., security of fuel supply could not be met by algae-to-diesel production using even all its indigenous rock phosphate output, and significant imports would still be needed. This is in addition to the amount of the mineral necessary to maintain agriculture. In principle, phosphate could be recycled from one batch of algae to the next, but how exactly this might be done remains a matter of some deliberation, e.g. the algae could be dried and burned30, and the phosphate extracted from the resulting “ash”, or the algae could be converted to methane in a biodigester31,32, releasing phosphate and other nutrients in the process. Clearly there are engineering and energy costs attendant to any and all such schemes and none has been adopted as yet.

I remain optimistic over algal diesel, but clearly if it is to be implemented on a serious scale its phosphorus has to come from elsewhere than mineral rock phosphate. There are regions of the sea that are relatively high in phosphates and could in principle be concentrated to the desired amount to grow algae, especially as salinity is not necessarily a problem. Recycling phosphorus from manure and other kinds of plant and animal waste appears to be the only means to maintain agriculture at its present level beyond the peak for rock phosphate, and certainly if additionally, algae are to be produced in earnest. In principle too, the phosphorus content of the algal-waste left after the oil-extraction process could be recycled into growing the next batch of algae. These are all likely to be energy-intensive processes, however, requiring "fuel" of some kind, in their own right. A recent study33 concluded that growing algae could become cost-effective if it is combined with environmental clean-up strategies, namely sewage wastewater treatment and reducing CO2 emissions from smokestacks of fossil-fuelled power stations or cement factories. This combination appears very attractive, since the impacts of releasing nitrogen and phosphorus into the environment and also those of greenhouse gases might be mitigated, while conserving precious N-P nutrient and simultaneously producing a material that can replace crude oil as a fuel feedstock.

It is salutary that there remains a competition between growing crops for fuel, and those for food, even if not directly in terms of land, for the fertilizers that both depend upon. There is a dissonance in that apparently clean, renewable sources of biofuels, in reality depend on inputs of a mined and finite reserve, which not only is growing more scarce, but its recovery leaves radioactive waste as a legacy (phosphogypsum)18. In principle, at least, recycling phosphorus from one batch to the next, in algae production, might be done more readily than for land-based crops. Along with the higher relative areal yields that are possible with algae, this might alleviate the rising demand for phosphate rock. The above, however, illustrates the complex and interconnected nature of, indeed Nature, which as any stressed chain, will ultimately converge its forces onto the weakest link in the "it takes energy to extract energy" sequence. It seems quite clear that with food production already stressed, the production of (algal) biofuels will never be accomplished on a scale anywhere close to matching current world petroleum fuel use (> 20 billion barrels/annum)27. Thus, the days of a society based around personalized transport powered by liquid hydrocarbon fuels are numbered. We must reconsider too our methods of farming2, to reduce inputs of fertilisers, pesticides and fuel. Freshwater supplies are also at issue2, in the complex transition to a more localised age that uses its resources much more efficiently.

(2) Rhodes, C.J. (2012), Sci. Prog. 95, 203.
(27) Rhodes, C.J. (2008) Sci. Prog., 91, 317.
(28) Rhodes, C.J. (2009) Sci. Prog., 92, 39.
(29) Rhodes, C.J. (2012) Making Fuel from Algae: Identifying Fact Amid Fiction, in Gordon, R. and Seckbach, J. Eds. The Science of Algal Fuels: Phycology, Geology, Biophotonics, Genomics and Nanotechnology. Dordrecht, Springer, p177.
(30) Knoshaug, E.P. and Darzins, A. (2011) Chem. Engin. Prog., March, 37.
(31) Sialve, B. et al. (2009) Biotech. Adv. 27, 409.
(32) Heaven, S. et. al. (2011) Biotech. Adv., 29, 164.
(33) Clarens, A.F. et al. (2010) Environ. Sci. Technol., 44, 1813.