Saturday, April 30, 2011
The authors of the present study (http://www.pnas.org/content/108/17/6843.full.pdf+html) do not claim to have proved a case for abiotic oil, but they note that hydrocarbons could be formed by purely mineral means in particular geological environments such as rifts and subduction zones where the temperatures and pressures are "right", i.e. 1,500 K and 50,000 times the pressure at the surface of the Earth. The calculations indicate that the formation of longer chain hydrocarbons can happen in pure methane but the process is accelerated when the methane molecules are in contact with metal or carbon surfaces, e.g. diamond which act as catalysts for the methane-polymerisation to occur.
Fascinating of course, and undoubtedly these results will be taken in some quarters to mean that we will never run out of oil, Peak Oil being bunkum. But even if there were proven to be vast underground lakes of hydrocarbons, if we cannot recover them fast enough to begin matching the current 30 billion barrels/year of contemporary use and rising, it makes no difference. We should not be thrown any red-herrings that we need not press-on toward a future that is far less dependent on oil, and indeed a better planned use of energy in all its forms.
Wednesday, April 27, 2011
The power generated by a wind turbine is directly proportional to the sweep area of the blades and the cube of wind-speed. As the generating power of wind-turbine units increases, so does the dimension of the apparatus to provide it, hence a blade span of 124 metres is required for some 5 MW units, with a unit height of 114 metres.
The use of permanent magnet generators eliminates the need for gear boxes, and can be accomplished with the application of Neodymium-Iron-Boron REE magnets, known as "Neo-magnets". These designs increase mechanical efficiency and reliability, and reduce the internal energy losses in the machines. However, some of the larger units, say 5 MW rated capacity, might require a tonne or more of neodymium. I am aware that ferrite magnets can be used instead of REEs, but my understanding is that weight for weight they are less powerful by a factor of about ten than REE magnets requiring heavier engineering of the wind-power unit to support them. The matter may not be so straightforward however, according to the following written by an experienced engineer in the magnet/wind-power field (http://www.usmagneticmaterials.com/documents/HarvestingWind.pdf):"One might think that on a pound-for-pound basis, permanent magnet generator using sintered NdFeB will provide the highest energy-conversion efficiency, but this is not necessarily true. In
order to optimize the generator efficiency over a wide speed range, it is best to have some control over the amount of magnetic flux in the circuit, so that the flux can be weakened at higher wind speeds. Sintered NdFeB, with its extremely high flux density and high coercivity, is quite “permanent.” At high speeds, this “permanence” can saturate the generator with flux, leading to greatly increased iron losses. Also, sintered NdFeB is electrically conductive, causing eddy current losses and inductive heating in the magnets.
At higher wind speeds, these parasitic losses increasingly eat into the efficiency and heat up the generator, causing a rapid degradation in performance. Non-conductive sintered ferrite magnets are better in this regard, providing a bit more efficiency headroom at higher speeds. Though the energy product of sintered NdFeB is roughly 10 times that of sintered ferrite, the cost per kilogram of sintered NdFeB is 30 times that of ferrite. The higher cost of NdFeB provides, at best, an incremental gain in overall system efficiency, and I believe that sintered ferrite can provide the best return on investment for a permanent magnet wind turbine generator. There are many interesting magnetic circuit topologies and control schemes that provide flux weakening at higher speeds, thereby increasing the overall system efficiency.
With continuing advances in power electronics and control algorithms, these designs emphasize the “electro” part of the generator with copper and steel, at the expense of the “magnet” part. Several clever generator designs employ lower-energy permanent magnets, such as injection-molded ferrite, to boost the output of what would typically be a non-permanent- magnet machine. These “hybrid magnetic circuit” designs can produce the highest efficiency over the widest speed range, providing the best long-term bang for the buck in a wind turbine system. The cost of such generators is driven by the cost of power electronics and controls, more so than the permanent magnets, wire and steel."
It seems to me that there are definite advantages to using REEs, and there is a move to having 25% of wind-power generation from units containing Neo-magnets by 2015. But since it seems clear that providing sufficient REEs to fill the hole dug by demand for this technology is unlikely, finding an alternative path to such renewable energy is critical. Most of the ongoing efforts to do so are at the "research level" and so having actual wind-devices generating significant green-electricity as fossil-fuel power declines is years away. Even were there no problem over resources or choice of technology, there is a distinct lack of manufacturing capacity for wind energy, certainly on the scale of demand to meet UK "green energy" targets set by the European Commission. It is the perennial rate of flow, conversion or recovery that limits the inauguration of all new technology.
Tuesday, April 26, 2011
Such a reminder of Chernobyl is all the more poignant in view of the troubles at the Fukushima power station in Japan, triggered by the recent earthquake and tsunami there. It is thought it will be 3 months before all leaks of radioactive material are stopped from the plant and 9 months before the whole is securely buried in concrete. When such catastrophes occur, nuclear power becomes a demon in the public gaze, while mostly it is regarded with a quiet respect such as for a sleeping rottweiler.
I commented about Chernobyl that it is not simply a matter of accounting the magnitude of the disaster in terms of the immediate death count, but that the toll placed upon a regional and national psychology and the effect of despair and powerlessness imposed upon the human spirit constitute a broader and more lingering legacy. http://ergobalance.blogspot.com/2006/05/chernobyl-how-many-really-will-die.html
For the Japanese people, as for the Russian people after Chernobyl, there is undoubtedly a profound sense of uncertainty and of dented national pride. But amid such catastrophes always emerges a deeply rooted courage and resilience and an ability to transcend adversity that defines us as members of the human family, whatever our nation, race or creed.
Tuesday, April 12, 2011
Nonetheless, his comment was salient: "In the late 50s, we were told that fusion power was 20 years away and now, 50-odd years later it is maybe 60 years away." Indeed, JET has yet to produce a positive ratio of output power/input energy, and instability of the plasma is still a problem. Dr Warrick explained that while much of the plasma physics is now sorted-out, minor aberrations in the magnetic field allow some of the plasma to leak out, and if it touches the far colder walls of the confinement chamber, it simply "dies". In JET it is fusion of nuclei of the two hydrogen isotopes, deuterium and tritium that is being undertaken, a process that requires a "temperature" of 100 million degrees.
I say "temperature" because the plasma is a rarified (very low pressure) gas, and hence the collisions between particles are not sufficiently rapid that the term means the same distribution of energy as occurs under conditions of thermal equilibrium. It is much the same as the temperatures that may be quoted for molecules in the atmospheric region known as the thermosphere which lies some 80 kilometers above the surface of the Earth. Here too, the atmosphere is highly rarified and thus derived temperatures refer to translational motion of molecules and are more usefully expressed as velocities. However put, at 100 million degrees centigrade, the nuclei of tritium and deuterium are moving fast enough (have enough energy) that they can overcome the mutual repulsion arising from their positive charges and come close enough that they are drawn together by attractive nuclear forces and fuse, releasing vast amounts of energy in the process.
JET is not a small device, at 18 metres high, but bigger machines will be necessary before the technology is likely to give out more energy than it consumes. Despite the considerable volume of the chamber it contains perhaps only one hundredth of a gram of gas, hence its very low pressure. There is another matter and that is how long the plasma and hence energy emission can be sustained. Presently it is fractions of a second but a serious "power station" would need to run for some hours. There is also the problem of getting useful energy from the plasma to convert into electricity even if the aforementioned and considerable problems can be overcome and a sustainable, large-scale plasma maintained.
The plan is to surround the chamber with a "blanket" of lithium with pipes running through it and some heat-exchanger fluid passing through them. The heated fluid would then pass on its heat to water and drive a steam-turbine, in the time-honoured fashion used for fossil fuel and nuclear power plants. Now my understanding is that this would not be lithium metal but some oxide material. The heat would be delivered in the form of very high energy neutrons that would be slowed-down as they encounter lithium nuclei on passing through the blanket. In principle this is a very neat trick, since absorption of a neutron by a lithium nucleus converts it to tritium, which could be fed back into the plasma as a fuel. Unlike deuterium, tritium does not exist is nature being radioactive with a half life of about 12 years. However produced either separately or in the blanket lithium is the ultimate fuel source, not tritium per se. Deuterium does exist in nature but only to the extent of one part in about two thousand of ordinary hydrogen (protium) and hence the energy costs of its separation are not inconsiderable.
Exposure to radiation of many potential materials necessary to make the reactor, blanket, and other components such as the heat-exchanger pipes would render them brittle, and so compromise their structural integrity. Providing a fairly intense magnetic field to confine the plasma (maybe 4 Teslas - similar to that in a hospital MRI scanner) needs power (dc not ac as switching the polarity of the field would cause the plasma to collapse) and large power-supply units containing a lot of metals including rare earths which are mined and processed using fossil fuels. The issue of rare earths is troublesome already, and whether enough of them can be recovered to meet existing planned wind and electric car projects is debatable let alone that additional pressure should be placed upon an already fragile resource to build a first generation of fusion power stations.
World supplies of lithium are also already stressed, and hence getting enough of it not only to make blankets for fusion reactors and tritium production but also for the millions-scale fleet of electric vehicles needed to divert our transportation energy demand away from oil is probably a bridge too far, unless we try getting it from seawater, which takes far more energy than mining lithium minerals.
To quote again the ZETA veteran, "I wonder if maybe man is not intended to have nuclear fusion," and all in all, other than from solar energy I wonder if he is right. At any rate, garnering real electrical power from fusion is so far distant as to have no impact on the more immediately pressing fossil fuels crisis, particularly for oil and natural gas. Fusion Power is a long-range "holy grail" and part of the illusion that humankind can continue in perpetuity to use energy on the scale that it presently does. Efficiency and conservation are the only real means to attenuate the impending crisis in energy and resources.
Monday, April 04, 2011
C.J.Rhodes, Science Progress, 2011, Vol. 94, 1-9.
Political tensions in the Middle East once again remind us of the fragile dependency of the Western nations on imported petroleum, which have driven the price of a barrel of crude oil to above $100, as was the case immediately prior to the world economic crash in 2008. British motorists and owners of haulage companies flinch nervously in the face of rising prices at the pumps for fuel, feared to reach £2.00/litre if events fail to calm down, since supplies of crude oil from Libya, already cut by an estimated one million barrels per day from 1.6 million bpd, may fall to zero, leading to shortages and further hikes in oil and consequently fuel prices. Saudi Arabia has “promised” to make-up the difference by pumping out more oil, but there is doubt as to whether they have in fact sufficient spare capacity to do so, certainly not the light crude which is exported to Europe for refining into petrol.
There is, for that matter, some controversy over how much oil the kingdom does have in its reserves in total, which are thought might be far less than is claimed.1 The latter aspect is critical to the timing of “peak oil”, a phenomenon2 proposed as long ago as 1956 by Dr M. King Hubbert, a petroleum geologist working for the Shell Development Company. Hubbert’s predictions were made for the lower-48 states of America, that U.S. oil production would peak in either 1965 or 1970, depending on the volume of the reserve that he estimated, i.e. the total amount of oil that would ultimately be recovered given prevailing technology and oil-prices. Western civilization has been built literally on sand – underpinned by the desert sands under which most of the petroleum lies. Our position is thus precarious, resting upon an ability to import ever greater quantities of crude oil, to furnish economic and material growth. In the case of the lower-48 U.S. fields, oil production did indeed peak in 1970, as Hubbert predicted, and by application of similar reasoning the peak in world oil production can be expected to occur close to the present time.
The CEO of Shell has stated that the world will be unable to meet its demand for oil by 2015, while other commentators think so as early as 2012. Most of the major oil companies are investing in deep-drilling technologies to recover oil from less accessible regions of the Earth, including the Arctic, and it is likely that there will be further “accidents” such as occurred in the Gulf of Mexico, as new technologies and regions are developed to advance the map of as yet uncharted territory from which to slake our thirst for oil. Not everyone agrees with Hubbert, and yet the United States, once the world’s leading oil-exporting nation now imports 2/3 of the oil that it uses; a substantial proportion coming from the Middle East. It is argued that the Hubbert-peak, beyond which supplies of crude oil can be expected to fall forever, is an oversimplification; that it does not take account of new discoveries of oil, or of the exploitation of “unconventional” oil. In the former regard, world “peak discovery” occurred around 1965 and there have been no giant fields (i.e. those containing proved recoverable reserves of 500 million barrels or more) found since the early 1980s. Indeed, the global consumption of crude oil has exceeded the discovery of new quantities of it since the mid-1980s.
Since Hubbert identified2 a 40 year lag between peak discovery and peak production, this would also suggest that we are close to the point of peak oil, or have even passed it. Oil production is somewhat confounded by the reference to “liquids” rather than “oil”, which includes hydrocarbons that are recovered, sometimes in great quantity, from natural gas wells, which condense from the gas in liquid form once the pressure drops below the dew-point. The latter are also called condensates, and to their volume may be added natural gas liquids, hydrocarbons that exist in fields as constituents of natural gas but which are recovered separately as liquids, including propane, butane, pentane, hexane and heptane, but not methane and ethane, since these hydrocarbons need refrigeration to be liquefied. Thus the production of oil per se may be falling worldwide but total liquids have so far held pace with demand. Unconventional oil is a complex, vexed and multifarious subject, and strictly, the above liquids should be classified under this heading.
More “conventional” oil will certainly be recovered, and we are in no sense running out of it. That noted, it will be necessary to employ and develop new and better methods of extraction both to recover oil from e.g. the deep sea and under miles of salt or in polar conditions, and to get more oil from each well as a proportion of what it actually contains. The world proved oil reserves are close to 1.2 trillion (1,200 billion) barrels, to be compared with 6,300 trillion cubic feet of natural gas.3 Since the commonly used conversion factor is that 1 barrel of oil has an energy equivalent to 6,000 cubic feet of natural gas, the remaining energy reserves of the two kinds of fuel appear nearly equal. There is almost certainly far more oil in the ground to be recovered than this, but I stress it is the rate of recovery that is the more pressing issue, not so much how big the reserve is in total. If the rate of recovery of oil remains too slow to meet (rising) demand, we will experience a demand-supply gap within the next decade, a situation that has been described as “gap oil”.5 At best the maximum in oil production, peak oil, might be delayed, but once it occurs the gap will be enlarged.
There is also the issue of the quality of crude oil. Light sweet (low sulphur) crude is the most desirable as it can be easily refined into petrol, which is burned in spark-ignition engines, world production of which peaked in 2005. Brands of light sweet crude include West Texas Intermediate, Brent oil from the North Sea, and of course that from Ghawar in Saudi Arabia. Heavy sour (high sulphur) crude requires removal of the sulphur and catalytic cracking of the longer carbon chain molecules to shorter species in order to recover petrol from it in quantity. This necessitates more complex and expensive refining methods to process heavy sour oil, for which there is presently insufficient capacity worldwide. Hence new refineries will need to be built as the oil recovered in the future tends more toward the heavy kind, which is better used to make diesel fuel, requiring further a greater production of diesel engines.
Though as noted, natural gas liquids and condensates should be included as unconventional oil, more usually, especially in the media, the term is often used to refer to heavy oil, ultra-heavy oil (e.g. from Venezuela), synthetic oil from bitumen (principally the tar-sands in Athabasca, Canada), oil from shale, and oil made from coal and gas, the latter being termed gas to liquids processing (GTL). When all of these sources are reckoned together, the amount of available “oil” appears huge totalling 4.7 trillion barrels, and this has been taken to refute the notion of peak oil, or at least to mean that there will be no problem with meeting world demand for oil any time soon. However, this ignores the relative energy cost incurred in recovering each resource, usually termed Energy Returned on Energy Invested, with the awkward acronym EROEI, but which is also sometimes expressed as the Energy Profit Ratio, EPR. To place this into perspective, in the 1940s and before, EROEIs of 100 were common, meaning that 100 barrels of oil could be recovered using 1 barrel of oil’s worth of energy, but in the 1970s, e.g. in the North Sea, this had fallen to around 8. In the extraction tar-sand “oil”, the figure is closer to 3. Similar considerations apply to the extraction of “oil” by cracking kerogen present in shale (“oil-shale”), and it has been suggested that rather than using natural gas as the heat source to process both shale and tar-sands, local nuclear reactors could be built to generate the necessary thermal power. To process these materials not only requires a lot of energy but copious quantities of water, in the region of three barrels of water for each barrel of oil. Furthermore, the production of both tar-sand synthetic oil production and shale-oil defiles the environment.2
“Fracking” is a term that has been used frequently and condescendingly in the media recently, in the context of recovering gas from shale. It is claimed that 10% of Britain’s gas-requirements could be provided from shale and there is a pilot project about to be inaugurated onshore near Blackpool, otherwise famous as a holiday resort with its “illuminations”, “kiss-me-quick” hats, “sticks of rock” and “big-dipper” rollercoaster. The process of hydraulic fracturing (called frac’ing in the industry but fracking in the media) has been used since 1947 to fracture rock and assist the recovery of oil and gas. A hydraulic fracture is formed by pumping a fracturing fluid into a borehole drilled into the source-rock so that the downhole pressure exceeds that of the fracture gradient of the formation rock. The pressure causes the formation to crack, so that the fracturing fluid may enter and extend the crack more deeply into the formation. To keep the fracture open once the injection is complete, a solid proppant, commonly a sieved round sand, is added to the fracture fluid. The propped hydraulic fracture then becomes a high permeability conduit through which the formation fluids can flow to the well. Since the fluid contains various toxic materials, including hydrocarbons, benzene etc., there are environmental fears that these may leak out and contaminate e.g. aquifers from which drinking water is drawn. There are cases reported too, where methane can leak-out further afield into wells and tap-water in sufficient quantity that it can be ignited!
That such measures are being seriously considered appears as an abject demonstration of desperation. It seems clear that oil-supplies are going to fail at some point and sooner not later. Given the limited timescale, it is improbable that unconventional oil can be implemented in sufficient amount to take up the slack from conventional production on that 30 billion barrel annual equivalent scale. Agreed that all of that quantity does not need to be replaced in one go, but the ramping-up of unconventional production as the former declines will be unable to meet the shortfall, leading to a rapid decline in the number of the 700 million vehicles that currently grace the world’s roads. There is a further impact on aviation and rising demand for it, which already consumes almost one quarter of all fuel used in the United Kingdom, and is also unlikely to be met. Globalism will fade while "localism", involving a way of life based around small communities appears an almost certain default outcome.
World without Oil?
To, recapitulate, the current dependence of civilization on crude oil cannot be overestimated. While 84% of recovered crude oil is refined into fuels of various kinds, and three quarters of that amount for transportation alone, it also provides a raw feedstock for a plethora of industries, which produce an almost bewildering number of products ranging from plastics to pharmaceuticals. We are also entirely dependent on oil (and indeed natural gas for fertilizers) to produce practically all the food consumed in the world. The aspect of carbon-emissions, and the consensus that these will lead to unfavourable climate-change, further compels the search for low-carbon alternatives to oil since 38% of all the energy used by humans on Earth is derived from oil and fuels refined from it4; to be compared with 23% from natural gas and 26% from coal. Thus the origin of the majority of carbon-emissions for which humans are responsible is crude oil. In an effort to address the oil-problem, the substitution of oil-based fuels by biofuels has been explored, mainly derived from land-based crops. However, the area of arable land available to a single country and indeed the world overall is limited, and hence growing fuel-crops must inevitably compete with growing food-crops.
For example, if the United Kingdom were to cease growing food entirely, and turn over all of its crop-land to rapeseed (canola), it could only match, in the form of biodiesel around 17% of the fuel used nationally as derived from crude oil. In addition to considerations over their energy-content, there are vital differences in the properties of biofuels, e.g. biodiesel and bioethanol, from conventional hydrocarbon fuels such as petrol and diesel, which will necessitate the adaptation of engine-designs to use them, for example in regard to high 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 can deliver only about 70% of the energy-content, kilogram for kilogram in accord with its lower enthalpy of combustion (29 MJ/kg) than is typical for an oil-based fuel like petrol (gasoline) or diesel (42 MJ/kg).5 Most biofuels produced in Europe are made from plant oils such as rapeseed oil, in the form of biodiesel, with a smaller amount of bioethanol that is produced from sugar-beet. In the U.S. the situation is reversed and huge amounts of corn are turned-over to the production of “corn ethanol”. The ethanol industry in Brazil is mature, as made from sugar-cane which grows well there, with the U.S. as its major customer for exports.
While it is not thought that the Brazilian ethanol industry compromises land on which food crops could be otherwise grown, this is a strong objection made to the diversion of corn grown in the U.S. from the world food markets to making ethanol. Indeed, part of the huge increases in the price of basic staple foods has been blamed on the use of arable land to produce biofuels rather than to grow food. There are consequently shortages of rice and wheat, and a significant reduction in the market stockpile of corn, all of which contributes to a potential food-crisis particularly in developing nations, including China and India.5
Oil from Algae.
Of the various means that are being considered to provide alternatives to oil-based fuels, one is making biofuel from algae. There are many advantages claimed as are indicated in the bullet-points below, but most noteworthy are the quoted very high yields of oil that might be derived from algae per hectare, compared with that even from high-oil yielding plants such as palm, which translates to around 6 tonnes of diesel per hectare. In contrast, it is reckoned that some species of high oil-yielding algae might furnish annually perhaps 100 tonnes of biodiesel per hectare; an attractive prospect indeed, since on this basis an area say the size of the United Kingdom could fuel the entire world.5
*This can be grown in tanks to yield of over 100 tonnes of algal oil per hectare. Hence just 4,000 km2 would suffice to produce 40 million tonnes of biofuel, which is only 1.5% of the total UK land area.
*No need to use crop-land, hence avoiding competition with food-production.
* Grows well on saline water or wastewater, so no demand on freshwater, unlike biofuel crops.
* Can be “fed” nutrients from agricultural run-off water and sewage water, avoiding the need for mineral inputs of N/P fertilizers and cleaning the water/effluent to prevent “algal-blooms”.
*Can be “fed” CO2 from power-plants, improving algal growth and reducing carbon-emissions.
*Easier to process than other biomass, e.g. into CH4 , biodiesel, ethanol or hydrocarbons. *Biodiesel is more biodegradable than petroleum and fuel derived from it.
*50% of algae can be oil (lipid) c.f. 5 – 10% for land-based crops (e.g. soya, rape-seed).
*Reduces CO2 release by replacing oil-based fuels and absorbs CO2 when it grows, through photosynthesis.
*Can be used as a chemical feedstock; plastics.
*Algae (and other biomass) can be processed into organic chemicals, in a “biorefinery”, as a basis for a new “bio – organic” chemicals/industry.
*ExxonMobil, Shell, Unilever and many private companies are working on algae to make fuels and other products.
*One recent study shows that growing algae is most efficient as integrated with cleaning CO2 from power station smokestacks (or a cement plant) and N/P from sewage wastewaters.
“Artificial Cells” May Provide Souce Of Algal Fuel.
In a recent issue of Chemistry World is a report6 describing “the first synthetic cell.” What has in fact been done is to insert a chemically synthesized genome into a bacterial cell. The M.mycoides genome contains over a million letters of genetic code and current DNA-technology can deliver perhaps a few thousand units in one go. The team led by Dan Gibson and Craig Venter have exploited the ability of yeast to join together small pieces of DNA using enzymes. Grown in a petri dish, the synthetic bacterium looks almost identical to the natural version and can similarly self-replicate. For the development of tailor-made life, it is necessary to understand what each gene codes for. The longer-run might be that genomes could be designed, but achieving that is some way off. It is more probable that a simple artificial genome could be created that has the essential properties of a living organism.This could permit other gene circuits being introduced, for example, to produce biofuels or fine-chemicals. Dr. Venter’s company, Synthetic Genomics, intends to use the cell synthesis technology to produce modified algae cells from which to make biofuel.
The aim is to make a complete algal genome from which “superproductive organisms” could be derived. It is possible that the designer method can overcome some of the drawbacks involved with making fuel from algae, namely robustness and competitiveness of particular strains over other organisms, enhanced growth rate and yields of algal oil. The method might be the key to the widescale production of fuel from algae.
Looking For Algal Oil With Near Infrared Light.
A new method7 has been introduced for telling which strains of algae are likely to be any good for turning into biofuels based on Near Infrared (NIR) spectroscopy. The near infrared spectrum runs the range of wavelengths 800 – 2500 nm, and is therefore just below the region of visible light but above the usual mid-infrared, at 2,500 – 30,000 nm. The discovery of infrared radiation is attributed to the British-German astronomer William Herschel, who also wrote 24 symphonies. However, NIR only came to practical use in the 1950s as an analytical device. NIR is less sensitive than normal (mid) IR but can penetrate samples more easily meaning they need less analytical preparation and in the case of algae can be examined in their raw state. Algae vary considerably in their composition, and while some varieties contain around 50% of their weight of oil, others hold as little as 5%. Not only this, but the “oil” should contain a high level of fatty acids to be converted into biodiesel: triglycerides rather than phospholipids.
The NIR method is highly specific for the detection of different kinds of fatty acids and it is intended to develop a database of fingerprints for different fatty acid components in algal biomass, with which to analyse actual algae. The method offers the promise of a rapidly and precisely screening intact algae directly rather than the existing time-consuming, cumbersome and error-prone means for analyzing them. Algae To Fuels Under Pressure. The conventional route to biodiesel consists of extracting oil from plants and converting it to the methyl esters of fatty acids that are present in the lipid-components, known as triglycerides. These esters as a mixture constitute biodiesel, a specific kind of biofuel.
High oil-yielding strains of algae can be grown and dried and the oil extracted from the dry algal mass, before being similarly converted to biodiesel in a process called transesterification. Removing the water from raw algae is a highly energy intensive process, and to minimize the overall energy costs of biofuel production from algae, a process called hydrothermal liquefaction8 may instead be employed in which the algae are not dried but heated under pressure such that the water they contain acts as a chemical reagent and solvent that breaks-down the algal cells and converts not only the oil (lipid) but the sugar and protein component into fuels such as liquid hydrocarbons, gaseous fuels like methane and a complex material called “bio-oil” with a similar energy content to crude oil. Clearly, the design of engines will need to be adapted in order to use these alternative fuels directly, or they must be refined in a “biorefinery” along with those from other kinds of biomass.
In both cases of new engines or biorefineries, there will be huge new engineering required on a scale that can only be guessed at if algae really can be exploited to make a nation the size of the United States independent of cheap imported crude oil. Nonetheless, there is a U.S. consortium, the National Algae Association, that is actively seeking a future in which algae are grown on a large scale and converted to oil-alternative fuels. Certainly, it is likely that algae will become an essential component of the mix of means to keep transportation going by means other than crude oil. The claims of the NAA are undoubtedly true, that ultimately the supply of petroleum must decline, oil prices will continue to be volatile with knife-edge consequences for the world economy, and a wholesale industry based on algae would provide precious and needed jobs and economic development in the U.S. The approach could be introduced on necessary levels for all nations and even a village “pressure cooker” to provide algal fuels for small communities.
Biofuel From Algae: Different Prognoses.
There are differing prognoses9 regarding the imminence and feasibility of growing algae and converting it into biofuel to stave off the paucity of oil in the “post peak oil era,” as that final descent has been dubbed in some quarters. One fanfare heralds that the status quo of plentiful liquid fuels can be sustained even in the absence of crude oil, while the counterview is that the technology is “years away”. Certainly it is a better bet than other alternative schemes, particularly hydrogen, since prevailing distribution infrastructure – pipes, tanks and tankers – can be used since we are still dealing with liquid fuels, in analogy with those presently produced from petroleum. Liquid fuels are remarkable and without them the modern world would not have arisen in the form it has.
For transportation alone we need to find around 20 billion barrels worth of crude oil each and every year, and to ramp up that production year on year if we are to believe that the market forces will continue to dictate further demand – i.e. that capitalism is sustainable both as a practice and a philosophy. I doubt that perpetual growth is possible and the energy and resources curve is connecting its ends into a finite loop, set at an elastic limit bent only now in contraction. The hydrogen economy will not emerge in the immediate term10, since its fruition requires a massive supply of new “green” electricity and phenomenal new manufacture, handling and supply infrastructure. Even in a few decades time it isn’t going to happen, at least not on the scale of the crude oil economy – and there rests the crux of the problem. Algae at least can be grown, allowing sufficient installed new engineering, on a large scale that avoids using prime crop land in competition with growing food crops and there is no demand for freshwater since saline water does even better to promote the growth of certain highly oil-yielding algal strains.
Algae can be fed from waste-streams of CO2 from fossil-fuel power stations as a carbon elimination strategy and can also decontaminate groundwater, so there is a potential mix of environmental solutions in aid of a common goal of fuel “beyond petroleum” as is the new name for B.P. That said, it is going to take years, and the sooner we get going the better. It is likely that the best use of algal technology is to sustain smaller settlements of perhaps a few thousand grown in a “village pond” and processed for local use. There is still no means to maintaining global transportation and globalisation in the absence of cheap oil, and it is likely that the overall time-line for this gargantuan and conceptual transition can be drawn over several decades.
(2) Rhodes, C.J. (2008) The oil question: nature and prognosis. Sci. Prog., 91, 317.
(3) World proved reserves of oil and natural gas. http://www.eia.doe.gov/international/reserves.html
(4) Rhodes, C.J. (2009) Solar energy: principles and possibilities. Sci. Prog., 93, 37.
(5) Rhodes, C.J. (2009) Oil from algae; salvation from peak oil. Sci. Prog. 92, 39.
(6) Birch, H. (2010) The first synthetic cell. Chemistry World, http://www.rsc.org/chemistryworld/News/2010/May/20051002.asp
(7) Lewcock, A. (2010) Striking algal oil. Chemistry World, http://www.rsc.org/chemistryworld/News/2010/March/12031001.asp
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Friday, April 01, 2011
It's a great play, insightfully written and skilfully performed, and raises many themes woven around the veracity of climate change, and the dubious politics of academia. The latter seem to fall increasingly in line with the plot of my novel, University Shambles, intended originally as a black comedy rather than some prescient vision of the future. http://universityshambles.com
In the play, one of her students with utterly green credentials including eating lots of garlic to apparently curb his own bodily greenhouse-gas emissions, refuses to go on a field trip in the university minibus on the grounds that it runs on fossil fuels, preferring instead to cycle forty miles there and forty miles back.
Diane asks him: "In your green future, how would we get fourteen students fifty miles to the North Yorkshire Weather Station?"
He replies: "There should be like an electric car/minibus. Electric cars don't have any emissions."
Diane responds: "Electric cars should be called coal cars. 30% of our energy comes from coal. Electricity is not naturally occurring in nature."
Now this does raise an issue about the "cleanliness" of electricity, which is all the more salient in view of the U.K. government's aim to install thousands of electric charging points around the country for electric cars with the aim to "wean us off imported oil". However, the majority of electricity in the U.K. is generated using power stations fired by coal (28%) and gas (45%), and hence even if a substantial substitution of the present 30 million British oil-fuelled cars by electric vehicles could be made, it would entail the consumption of vast quantities of these other fossil fuels instead to provide the additional electricity for them.
The green energy company, Ecotricity refers to electric cars as "wind-cars", to stress that they could run on electricity made from green sources such as wind. Indeed, the U.K. has made the decision to focus on wind-energy to meet its carbon-emissions targets, and plans to build offshore wind-farms on an impressive scale to do the job. It is advised by the Committee on Climate Change that by 2020, 1.7 million electric cars should be on Britain's roads, or just over 5%, which I don't honestly see would make a serious hole in our demand for imported crude oil.
To decarbonize the national grid would require another 30 - 40 GW of green generating power, or "the equivalent of a hundred large offshore wind-farms," according to the chief economist of the CCC. These would need to be large indeed. Assuming a rated capacity per turbine of 5 MW, and a capacity factor (actual output) of 30%, we have 1.5 MW for each. Thus we need around 20,000 - 27,000 turbines to produce 30 - 40 GW of power. So that means 100 wind-farms with 200 - 270 turbines each. If one turbine per day were manufactured, no mean feat given present manufacturing capacity, the process would take 55 - 74 years to complete, with the installation of them as a separate effort. As noted in previous posts, there is the further question of whether there will be sufficient quantities of rare earth elements (REEs) available on the world markets to make the turbine magnets which need about one tonne of neodymium per 4 MW of rated capacity.
Clearly, we have a serious problem in switching from dirty oil cars to green electric cars, which will need to be built themselves. There are many issues of the materials needed per se, and a hybrid car e.g. a Prius needs 1 kg of neodymium for its motor plus 15 kg of Lanthanum for its battery, while a fully electric vehicle will require much more of each. Personal electric cars are still a far better option than personal hydrogen cars for all kinds of reasons, but if governments are serious about introducing electric transportation in place of oil, the creation of electrified mass passenger transport, e.g. trains and trams would be the better way to go.
"Carbon Confusion," by Sylvia Rowley. http://www.guardian.co.uk/electric-vision/electricity-supply-fossil-fuels