The long term security of the Yucca Mountain storage facility for nuclear waste will depend on a complex interplay between human engineering and natural geological factors, so concludes a report by scientists at Indiana University Bloomington (IUB) and Los Alamos National laboratory. The site is intended as a repository for 75,000 tonnes of high level radioactive waste, for which the surrounding geology is rich in zeolitic tuffs - rocks containing natural zeolites, such as clinoptilolite and mordenite. Indeed, the presence of these materials is considered a major plus in choosing the location of any such storage facility.
Zeolites are aluminosilicates, containing a honeycomb framework which carries an overall negative electrical charge. Much as nature is said to abhor a vacuum, she has a similar antipathy for loose unbalanced electrical charges, and consequently the negative charge on the framework is balanced by an according number of positively charged cations, rendering an overall electrical neutrality. The cations that are naturally present, e.g. Ca2+, Mg2+, K+, Na+, may be readily exchanged by radioactive cations such as Sr2+, Ba2+ and Cs+, which are products of nuclear fission, thus absorbing them from the immediate environment. Thus, any leakage or adventitious spillage can be intercepted, by the intrinsic property of cation-exchange by these natural zeolites.... a natural fail-safe barrier should the engineering not prove completely true.
Zeolites absorb appreciable quantities of water, in some cases up to half their own volume of it, and this may act to absorb and buffer the heat generated during the radioactive decay of cations such as Sr2+, Ba2+ and Cs+ when they are absorbed within its structure. [Zeolites are also known as microporous solids, since the honeycomb structure contains pores of molecular dimensions and so can act as molecular sponges].
Some fission products are formed as anions, with a negative charge, and are not readily absorbed by zeolites since there is no anion-exchange mechanism possible, in counterpart with the case for cations. Very large ions are also excluded by clinoptilolite and mordenite, and so are not absorbed either, thus the process is not perfect. Nonetheless, zeolites are used for both preemptive protection of the environment from radioactive ions, e.g. to filter the waters from nuclear power plants and reactors, and in direct emergency decontamination strategies, e.g. Chernobyl, where 500,000 tonnes of zeolites were employed to absorb fall-out from the radioactive cloud that emanated from the smouldering unit 4 reactor, on its way across western Europe. Zeolites were fed to cattle and even baked into biscuits for children to remove some of the radioactive ions from their bodies, thus mitigating radiation injury, both directly and via the food chain, e.g. drinking milk from contaminated cattle.
Over 2,000 samples taken from 17 cores drilled across Yucca mountain, at depths ranging from 20 metres to 1,800 metres below the surface. X-ray diffraction measurements showed that there are zeolites present extensively, and moreover at depths reckoned as optimum for the storage of nuclear waste, i.e. 300 metres below the surface of the mountain and 150 metres above the water table. The idea is to construct a containment space above the zeolitic safety-region.
David Bish, the report's principal author and Professor of Applied Clay Mineralogy at IUB stressed the need to understand more about how water flows through the repository horizon and how the incorporation of large amounts of high level radioactive material might modify the geology, mineralogy and hydrology (i.e. the structure and properties, chemical and mechanical), of the zone of rock in which it will be included. The intention is to construct a 3-D image of Yucca Mountain, of sufficient detail that it could be used in licensing considerations.
If all goes well, nuclear waste could be sent to Yucca Mountain by 2010. The site is 100 miles from Las Vegas and near to the DOE's Nevada test site where numerous A-bomb tests have been performed since its inauguration in 1948.
Related Reading.
"Yucca Mountain site must make use of geological safety net, say IU and Los Alamos scientists." http://newsinfo.iu.edu/news/page/print/1174.html
Friday, November 28, 2008
Wednesday, November 26, 2008
Congo - War Over Minerals.
Throughout history, wars are always fought over resources, be they land, slaves, oil or other mineral wealth. The connection between oil and conflict in Iraq appears close, and western companies now have 30 year exploitation rights over the Iraqi oil. Afghanistan is more complex, since it has little oil, although there is rumour that a pipeline is planned to carry oil from central Asia through Afghanistan and Pakistan, to Karachi and the southern Pakistani coast, thus obviating the far longer route through China. Whatever is the truth of this, I don't believe that such military actions as are currently ongoing there are simply in the interests of overthrowing a dictatorial rule and restoring freedom to the people. Resources must underpin the proceedings in some way.
Meanwhile unimaginable strife continues to prevail in the Congo. Three million people are reckoned to have died in consequence of the protracted civil war there, mostly from disease and starvation. Congo, formerly the Belgian Congo which gained its independence in 1960, is rich in mineral wealth, most renownedly its gold. Indeed, it is this bestowal of gold, copper, diamonds, tantalite (tantalum), cassiterite (tin) and over one third of the world's known reserve of cobalt that is responsible for much of the country's unstable history, since the rest of the world wants to get its hands on this bounty.
Since the war began in 1998, various different factions have been engaged in the plundering of Congo's mineral resources, which raises ethical issues for the companies, particularly in the electronics industry, who have taken receipt of materials like gold, copper, tantalum and tin which they use in growing amount. There is a need for such organisations and suppliers to investigate at source exactly where these materials come from, before they find their way onto the open market. Of course, profit margins will always be an issue.
Tantalum is an essential component of electronic capacitors, as are used in computers, cell phones, air-bag safety systems, pacemakers and GPS, and most of it is mined in Australia. Nonetheless, there are substantial deposits of tantalite in Africa, in the Congo and Rwanda and also in Ethiopia, Nigeria, Zimbabwe and Mozambique. I find it ironic that both Congo and Rwanda should be in possession of considerable reserves of the same mineral, given their recent tribal antipathies, but I am reminded that many of Africa's troubles are due to divisions created artificially by the former colonial powers who drew chalk lines across a map of Africa, apportioning its lands and its wealth for themselves, unbeknown to the underlying geology of the continent which was laid down long before the rules of men.
Consequently, I doubt there will ever be peace in Africa, and it is always easier to grab resources of all kinds from regions that are unstable, poor and whose populations are rendered devoid of any sense of security, certainty, permanence and hope.
Related Reading.
"Battle for Congo's mineral assets." By Alka Marwaha. BBC World Service. http://news.bbc.co.uk/1/hi/technology/7747692.stm
Meanwhile unimaginable strife continues to prevail in the Congo. Three million people are reckoned to have died in consequence of the protracted civil war there, mostly from disease and starvation. Congo, formerly the Belgian Congo which gained its independence in 1960, is rich in mineral wealth, most renownedly its gold. Indeed, it is this bestowal of gold, copper, diamonds, tantalite (tantalum), cassiterite (tin) and over one third of the world's known reserve of cobalt that is responsible for much of the country's unstable history, since the rest of the world wants to get its hands on this bounty.
Since the war began in 1998, various different factions have been engaged in the plundering of Congo's mineral resources, which raises ethical issues for the companies, particularly in the electronics industry, who have taken receipt of materials like gold, copper, tantalum and tin which they use in growing amount. There is a need for such organisations and suppliers to investigate at source exactly where these materials come from, before they find their way onto the open market. Of course, profit margins will always be an issue.
Tantalum is an essential component of electronic capacitors, as are used in computers, cell phones, air-bag safety systems, pacemakers and GPS, and most of it is mined in Australia. Nonetheless, there are substantial deposits of tantalite in Africa, in the Congo and Rwanda and also in Ethiopia, Nigeria, Zimbabwe and Mozambique. I find it ironic that both Congo and Rwanda should be in possession of considerable reserves of the same mineral, given their recent tribal antipathies, but I am reminded that many of Africa's troubles are due to divisions created artificially by the former colonial powers who drew chalk lines across a map of Africa, apportioning its lands and its wealth for themselves, unbeknown to the underlying geology of the continent which was laid down long before the rules of men.
Consequently, I doubt there will ever be peace in Africa, and it is always easier to grab resources of all kinds from regions that are unstable, poor and whose populations are rendered devoid of any sense of security, certainty, permanence and hope.
Related Reading.
"Battle for Congo's mineral assets." By Alka Marwaha. BBC World Service. http://news.bbc.co.uk/1/hi/technology/7747692.stm
Monday, November 24, 2008
Oil Crunch will Bite on the Tail of the Credit Crunch.
In his book The Long Emergency, James Kustler describes a situation which is not exactly a crash, but an unravelling sequence of difficulties, in which the stock markets oscillate wildly in perpetuity and a generalised social upheaval occurs as cheap oil runs out. The best possible outcome is an albeit difficult relocalisation of global, urbanised America into smaller communities that are increasingly self-reliant, having been forced to curb their use of transport. The alternative of course, is mayhem and anarchy. Kunstler is an American and so his prognostications are focussed on the collapse of the urbanised system there, but they are innately applicable to all industrialised societies, including those in the U.K. and western Europe in general.
The global nature of modern trade and economics means that no man is an island, and where one stumbles the rest must take-up the strain. In reality, the gaping gaps in our banking system could not be more apparent and it is almost incredulous not to have been aware that a facade "underpinned" by credit - promissory notes in effect - betrays a house of cards. The governments of the world are trying to push more money into the economy, via tax-incentives and so on, but it is unlikely to make much difference as people are too frightened to spend, preferring instead to hang onto their cash when there is so much uncertainty, over jobs, etc. and even the viability of the banks themselves.
Sufficiently desperate is the impending recession that the British government is now threatening to use legal force to make the banks pass on their newly available currency, from the source of a government fund intended to help them out through this crisis of their own making, and to begin lending money again, both to other banks and to small businesses. Too late, the banks are now cautious about lending and if they had been so during the past two decades we would not be in the mess we are now. However, if all goes to plan, it is thought that the U.K. may be coming out of a recession by the end of 2009, so it is reckoned optimistically in Whitehall, although the CBI anticipates a longer run than this into the middle of 2010.
Now this is beginning to time-in with the expected arrival of peak oil, variously reckoned to arrive any time between 2006 (i.e. has happened already) and 2012-2013. The timing of the peak is in fact of lesser importance than the inevitable formation of a gap between rising demand and the supply of oil. The effect will be to force oil prices up again (as we saw last summer), and encourage economic downturn, i.e. the flow of money that the governments are trying to restore, will coagulate once more.
This does sound like a long emergency. That we will never arrive on calm shores after a storm such as we are in the midst of now, but having passed through one, yet another will rip into our sails, ultimately beaching the fleet of the global economy.
The global nature of modern trade and economics means that no man is an island, and where one stumbles the rest must take-up the strain. In reality, the gaping gaps in our banking system could not be more apparent and it is almost incredulous not to have been aware that a facade "underpinned" by credit - promissory notes in effect - betrays a house of cards. The governments of the world are trying to push more money into the economy, via tax-incentives and so on, but it is unlikely to make much difference as people are too frightened to spend, preferring instead to hang onto their cash when there is so much uncertainty, over jobs, etc. and even the viability of the banks themselves.
Sufficiently desperate is the impending recession that the British government is now threatening to use legal force to make the banks pass on their newly available currency, from the source of a government fund intended to help them out through this crisis of their own making, and to begin lending money again, both to other banks and to small businesses. Too late, the banks are now cautious about lending and if they had been so during the past two decades we would not be in the mess we are now. However, if all goes to plan, it is thought that the U.K. may be coming out of a recession by the end of 2009, so it is reckoned optimistically in Whitehall, although the CBI anticipates a longer run than this into the middle of 2010.
Now this is beginning to time-in with the expected arrival of peak oil, variously reckoned to arrive any time between 2006 (i.e. has happened already) and 2012-2013. The timing of the peak is in fact of lesser importance than the inevitable formation of a gap between rising demand and the supply of oil. The effect will be to force oil prices up again (as we saw last summer), and encourage economic downturn, i.e. the flow of money that the governments are trying to restore, will coagulate once more.
This does sound like a long emergency. That we will never arrive on calm shores after a storm such as we are in the midst of now, but having passed through one, yet another will rip into our sails, ultimately beaching the fleet of the global economy.
Tuesday, November 18, 2008
Oil From Algae - How Big Do the Tanks Need to Be?
The comment reproduced below to my article "Wednesday, April 09, 2008; Oil from Algae: Photosynthetic Efficiencies?" prompted some very salient points regarding the size of the tanks or tubular reactor vessels that would be required to grow algae on a large scale, and the quantity of the materials needed to make them from. I have therefore done a few sums, which I hope are illustrative:
I agree completely with Nic's figures which are very close to those I have deduced here previously, and I shall use them now. First I want to consider tube-reactors, and I am assuming that the tube is about a foot (30 cm) in diameter.
(.3 m x pi =) .94 m (circumference of tube) x 3.3 x 10^12 m (length of tube) = 3.1 x 10^12 m^2
as the area of plastic needed to fabricate 3.3 billion km of it! If we assume that the wall thickness is 2 mm (0.002 m), we have a volume of plastic = 3.1 x 10^12 m^2 x 0.002 m = 6.2 x 10^9 m^3.
Taking the density of the material as 0.85 (t/m^3), that amounts to 0.85 x 6.2 x 10^9 = 5.3 x 10^9 tonnes. If there are 7.3 barrels of oil to a tonne, that is the equivalent of 38.7 x 10^9 barrels of oil to make the plastic (this is about 3% of all the oil left in the ground). The world uses 30 x 10^9 barrels in total annually, and so this is more oil than the world gets through in 16 months all told.
I agree with Nic that it probably wouldn't be possible to make more than few million km of pipe per year and so it would take centuries to make it. Well before then we won't be recovering significant crude oil anyway, given the total of 1.2 x 10^10 barrels there is thought to be recoverable. On this basis, I think making biodiesel from algae on a large scale in tube-reactors is unlikely.
So, what about the open (raceway) ponds? If we need 1 million km^2 of them, that's 1 x 10^12 m^2. I am going to assume they are each 1 hectare in area. That's 100 million of them. I shall also assume that they are 1 metre deep. The area of the walls is 100 m x 1 m x 4 walls = 400 m^2. But the floor area is 10,000 m^2 (i.e. 1 ha). hence I shall forget the 4% of the total pond area made up by the walls and concentrate on the larger, floor area of 10,000 m^2 for each one.
The ponds could be lined with either concrete or plastic. Let's consider the concrete option first. If the floor is four inches, 10 cm thick = 0.1 m. So we need 10,000 m^2 x 0.1 m = 1,000 m^3 of concrete for each pond. So 100 million of them needs, 100 x 10^6 x 1,000 m^3 = 1 x 10^11 m^3 and at a density of sat 2.3 t/m^3, that's 2.3 x 10^11 tonnes of concrete, or 230 billion tonnes. In 2007, the world produced 2.6 billion tonnes of concrete, and again the job would take centuries assuming that an equivalent amount of additional concrete could be made to current consumption, or some of it diverted from existing purposes. The global warming effect would be pretty severe since making concrete releases huge amounts of CO2.
What about plastic lining? Well, the area is the same, at 10^12 m^2 and I shall assume that a 2mm thickness is O.K. again, so the volume is 10^12 m^2 x 0.002 = 2 x 10^9 m^3 of plastic.
This equals around 12.4 billion barrels of oil, which is about 1% of the world's total recoverable of 1.2 trillion barrels, or 1/3 that for the tubes, and it might be easier to make plastic sheets than tubes, but even if we could make say, a few thousand square kilometers (a few billion m^2) of plastic sheeting annually, the job would once again take centuries. We are dealing with a classic rate of flow (rate of conversion, rate of recovery) problem, and while not hampered necessarily by the resources per se, the engineering can't be done in time to save us from running out of cheap crude oil.
On Nic's final pint about instead using electric vehicles. The best figure I have is that you need a bare minimum of 0.08 g of lithium/Wh of power. But for real Li systems, it is more like 0.15 - 0.32 gLi/Wh. I shall take the mid-range of 0.23. An average PHEV needs around 9kWh. So we need 9,000 x 0.23 g = 2070 g = 2 kg = 0.002 tonnes per vehicle. Now there are supposed to be around 700 million vehicles on the roads. There are something like 30 thousand tonnes of Li recovered per year and so we would need to double production capacity to get something reasonable, i.e. that amount again to make the electric cars etc. [There is plenty of lithium in the ground, 28 million tonnes, I think, but it's the rate of recovery that is the limiting factor].
700 x 10^6 x 0.002 t = 1.4 x 10^6 tonnes to make that equivalent car fleet from PHEV's. Well at 30,000 t/year it's going to take 46 years. So, in principle this is the best bet. However it would mean making 15 million cars a year. We'd need a lot of new mining, processing and engineering
though. In all likelihood the world will have far fewer vehicles in the future, and we can supplant urban transport with trams and light railways so long as we can make enough electricity to run them and so need less anyway.
In conclusion I take your point about cars Nic, but still since aviation consumes more fuel per year than we can tool-up for with algal biofuel within decades (centuries) plane-flight does seem doomed in its present form and scale.
But whatever we do it's got to be done against that backdrop of cheap oil running out - yes, I know its cheap now because the world financial system is melting down - but it wont be for much longer; also the economic turndown means that there is little fiscal incentive and little money to be borrowed from the banks in their nervous condition, to build new PHEV factories and mining and processing plants for Li. PHEV's are expensive to make too and that is also bad is the current state of credit-crunch. There are other resource issues to PHEV's too, since they use various other metals, cobalt etc. depending on the exact battery design
Thanks very much,
Chris.
Hi Chris
I was checking some background info on Algae after reading an article “Algae on the Move: The 2008 Algae Biomass Summit Wrap-up” in Renewable Energy World < id="54033"> when I came across your site.
You’re right 14.7%+ is too high for PSE, its limited by the nature of PS process. I can’t remember the exact figures but the maximum practical yield, under ideal conditions, is between 5 and 10%. High concentrations do not improve the situation as only the algae near the surface will photosynthesise and if the light’s too strong they can’t use it all so high agitation is also required.
I attended the International Society for Applied Phycology (algae) conference this summer in Galway and picked up some interesting data on algae, the best algae brains in the world were there so I am fairly confident that their figure of just over 10% absolute maximum for photosynthetic efficiency is correct. If I recall correctly, figures for open (raceway) pond reactors of a few percent would be about right.
I was mulling over the figures for replacing all our oil with algae biomass rather than just diesel, thought you may find my workings of interest:
World oil consumption is ~= 85Mbboe/day @ 6.1GJ/bboe (bboe = barrels of oil?)
= 5.185e17J/day = 12.345Mtoe/day (@42GJ/t)
Assume:
> Most of world’s oil energy is used for fuel.
> Use total algal biomass is for fuel manufacture e.g. via hydrothermal liquefaction (a form of pyrolysis).
> Crude oil to fuel (well to tank) losses ~10%
> Algal biomass to fuel (well to tank) losses ~25%
Realistic practical PSE for algae is about 5%, possibly slightly higher for enclosed reactors and probably about half for raceway ponds, assuming they run 24/7:
,’, @ 5KWh/day energy yield/capture by algae daily yield is
5,000 * 0.05 * 3600 = 900,000J/sq-m
Production space:
Therefore algal biomass energy content needs to be ~15% more than crude production then
Required algal biomass production per day = 1.15 * 5.185e17 / 900,000
= 662,528 sq-Km of bioreactor area
Add to this access roads, space between reactors and space for processing and storage then the total area required is of the order of 1 million square kilometres, or about 10% of the Sahara desert.
Production mass:
Micro algae energy density (HHV) depends very much on relative oil, protein and carbohydrate content but would typically be around 20MJ/Kg (~half of oil)
,’, total algal mass required = 1.15 * 5.185e17 / 20e9 ~= 30 Million tonnes/day
The burning questions are:
How fast could we build this quantity of algae production and processing facilities?
How much will it cost?, is it economically viable etc.
Can we build this amount of infrastructure? Algae ponds will probably need to be concrete or plastic lined over an area of 1million sq-Km plus, closed reactors would probably require (using AlgaeLink system) about 3.3Billion kilometres!!! of bioreactor tubing (my guestimate is that at best we could produce a few million Km of tubing per year so we a talking of a multi century project).
Is there a better solution?
The answer to last question is yes, change to electric technology for land transport, save biofuels for air transport. Electric vehicles far more efficient (~80% tank to wheel) than other technologies, best hybrid might ultimately achieve about 50% and renewable electricity easier to generate than biofuels, best PV nearly 40% conversion efficiency.
I agree completely with Nic's figures which are very close to those I have deduced here previously, and I shall use them now. First I want to consider tube-reactors, and I am assuming that the tube is about a foot (30 cm) in diameter.
(.3 m x pi =) .94 m (circumference of tube) x 3.3 x 10^12 m (length of tube) = 3.1 x 10^12 m^2
as the area of plastic needed to fabricate 3.3 billion km of it! If we assume that the wall thickness is 2 mm (0.002 m), we have a volume of plastic = 3.1 x 10^12 m^2 x 0.002 m = 6.2 x 10^9 m^3.
Taking the density of the material as 0.85 (t/m^3), that amounts to 0.85 x 6.2 x 10^9 = 5.3 x 10^9 tonnes. If there are 7.3 barrels of oil to a tonne, that is the equivalent of 38.7 x 10^9 barrels of oil to make the plastic (this is about 3% of all the oil left in the ground). The world uses 30 x 10^9 barrels in total annually, and so this is more oil than the world gets through in 16 months all told.
I agree with Nic that it probably wouldn't be possible to make more than few million km of pipe per year and so it would take centuries to make it. Well before then we won't be recovering significant crude oil anyway, given the total of 1.2 x 10^10 barrels there is thought to be recoverable. On this basis, I think making biodiesel from algae on a large scale in tube-reactors is unlikely.
So, what about the open (raceway) ponds? If we need 1 million km^2 of them, that's 1 x 10^12 m^2. I am going to assume they are each 1 hectare in area. That's 100 million of them. I shall also assume that they are 1 metre deep. The area of the walls is 100 m x 1 m x 4 walls = 400 m^2. But the floor area is 10,000 m^2 (i.e. 1 ha). hence I shall forget the 4% of the total pond area made up by the walls and concentrate on the larger, floor area of 10,000 m^2 for each one.
The ponds could be lined with either concrete or plastic. Let's consider the concrete option first. If the floor is four inches, 10 cm thick = 0.1 m. So we need 10,000 m^2 x 0.1 m = 1,000 m^3 of concrete for each pond. So 100 million of them needs, 100 x 10^6 x 1,000 m^3 = 1 x 10^11 m^3 and at a density of sat 2.3 t/m^3, that's 2.3 x 10^11 tonnes of concrete, or 230 billion tonnes. In 2007, the world produced 2.6 billion tonnes of concrete, and again the job would take centuries assuming that an equivalent amount of additional concrete could be made to current consumption, or some of it diverted from existing purposes. The global warming effect would be pretty severe since making concrete releases huge amounts of CO2.
What about plastic lining? Well, the area is the same, at 10^12 m^2 and I shall assume that a 2mm thickness is O.K. again, so the volume is 10^12 m^2 x 0.002 = 2 x 10^9 m^3 of plastic.
This equals around 12.4 billion barrels of oil, which is about 1% of the world's total recoverable of 1.2 trillion barrels, or 1/3 that for the tubes, and it might be easier to make plastic sheets than tubes, but even if we could make say, a few thousand square kilometers (a few billion m^2) of plastic sheeting annually, the job would once again take centuries. We are dealing with a classic rate of flow (rate of conversion, rate of recovery) problem, and while not hampered necessarily by the resources per se, the engineering can't be done in time to save us from running out of cheap crude oil.
On Nic's final pint about instead using electric vehicles. The best figure I have is that you need a bare minimum of 0.08 g of lithium/Wh of power. But for real Li systems, it is more like 0.15 - 0.32 gLi/Wh. I shall take the mid-range of 0.23. An average PHEV needs around 9kWh. So we need 9,000 x 0.23 g = 2070 g = 2 kg = 0.002 tonnes per vehicle. Now there are supposed to be around 700 million vehicles on the roads. There are something like 30 thousand tonnes of Li recovered per year and so we would need to double production capacity to get something reasonable, i.e. that amount again to make the electric cars etc. [There is plenty of lithium in the ground, 28 million tonnes, I think, but it's the rate of recovery that is the limiting factor].
700 x 10^6 x 0.002 t = 1.4 x 10^6 tonnes to make that equivalent car fleet from PHEV's. Well at 30,000 t/year it's going to take 46 years. So, in principle this is the best bet. However it would mean making 15 million cars a year. We'd need a lot of new mining, processing and engineering
though. In all likelihood the world will have far fewer vehicles in the future, and we can supplant urban transport with trams and light railways so long as we can make enough electricity to run them and so need less anyway.
In conclusion I take your point about cars Nic, but still since aviation consumes more fuel per year than we can tool-up for with algal biofuel within decades (centuries) plane-flight does seem doomed in its present form and scale.
But whatever we do it's got to be done against that backdrop of cheap oil running out - yes, I know its cheap now because the world financial system is melting down - but it wont be for much longer; also the economic turndown means that there is little fiscal incentive and little money to be borrowed from the banks in their nervous condition, to build new PHEV factories and mining and processing plants for Li. PHEV's are expensive to make too and that is also bad is the current state of credit-crunch. There are other resource issues to PHEV's too, since they use various other metals, cobalt etc. depending on the exact battery design
Thanks very much,
Chris.
Hi Chris
I was checking some background info on Algae after reading an article “Algae on the Move: The 2008 Algae Biomass Summit Wrap-up” in Renewable Energy World < id="54033"> when I came across your site.
You’re right 14.7%+ is too high for PSE, its limited by the nature of PS process. I can’t remember the exact figures but the maximum practical yield, under ideal conditions, is between 5 and 10%. High concentrations do not improve the situation as only the algae near the surface will photosynthesise and if the light’s too strong they can’t use it all so high agitation is also required.
I attended the International Society for Applied Phycology (algae) conference this summer in Galway and picked up some interesting data on algae, the best algae brains in the world were there so I am fairly confident that their figure of just over 10% absolute maximum for photosynthetic efficiency is correct. If I recall correctly, figures for open (raceway) pond reactors of a few percent would be about right.
I was mulling over the figures for replacing all our oil with algae biomass rather than just diesel, thought you may find my workings of interest:
World oil consumption is ~= 85Mbboe/day @ 6.1GJ/bboe (bboe = barrels of oil?)
= 5.185e17J/day = 12.345Mtoe/day (@42GJ/t)
Assume:
> Most of world’s oil energy is used for fuel.
> Use total algal biomass is for fuel manufacture e.g. via hydrothermal liquefaction (a form of pyrolysis).
> Crude oil to fuel (well to tank) losses ~10%
> Algal biomass to fuel (well to tank) losses ~25%
Realistic practical PSE for algae is about 5%, possibly slightly higher for enclosed reactors and probably about half for raceway ponds, assuming they run 24/7:
,’, @ 5KWh/day energy yield/capture by algae daily yield is
5,000 * 0.05 * 3600 = 900,000J/sq-m
Production space:
Therefore algal biomass energy content needs to be ~15% more than crude production then
Required algal biomass production per day = 1.15 * 5.185e17 / 900,000
= 662,528 sq-Km of bioreactor area
Add to this access roads, space between reactors and space for processing and storage then the total area required is of the order of 1 million square kilometres, or about 10% of the Sahara desert.
Production mass:
Micro algae energy density (HHV) depends very much on relative oil, protein and carbohydrate content but would typically be around 20MJ/Kg (~half of oil)
,’, total algal mass required = 1.15 * 5.185e17 / 20e9 ~= 30 Million tonnes/day
The burning questions are:
How fast could we build this quantity of algae production and processing facilities?
How much will it cost?, is it economically viable etc.
Can we build this amount of infrastructure? Algae ponds will probably need to be concrete or plastic lined over an area of 1million sq-Km plus, closed reactors would probably require (using AlgaeLink system) about 3.3Billion kilometres!!! of bioreactor tubing (my guestimate is that at best we could produce a few million Km of tubing per year so we a talking of a multi century project).
Is there a better solution?
The answer to last question is yes, change to electric technology for land transport, save biofuels for air transport. Electric vehicles far more efficient (~80% tank to wheel) than other technologies, best hybrid might ultimately achieve about 50% and renewable electricity easier to generate than biofuels, best PV nearly 40% conversion efficiency.
Wednesday, November 12, 2008
Abbot Christopher Jamison... the Spiritual Dimension.
A man who seems impossible not to like is Abbot Christopher Jamison, who warns us that "greed is replacing spirituality". I have read a couple of his books (just look him up on google) which have left me with a sense of peace, and that is what seems to shine from the man. There was a six-part series on television entitled "The Monastery", where six guys lived for 40 days with a group of monks and found a firm spiritual foundation in consequence of this experience. As I perceive society beginning to unravel - financially, the "benefits culture" and my expectation that we will all return to agricultural living, hopefully reaping something useful from what we have learned from science and technology (but give-up the hydrogen economy, please, in the short-term), Abbot Jamison's message that we should be less acquisitive - greedy in the material line - does appear salient.
We are kept in a state of fear and unhappiness, which is what sells. But people are holding-on to their cash now, and that might illumine the dawn of a less materialistic thought-process for living. I have a friend who tells me that the only way she can feed herself and her 5 kids in because a certain fast-food burger outlet offers a 99p "meal deal". So that's around six-quid as we say over here.
It may be nice to go-out for a meal, all of them, but she could feed the lot of them for a third of that... that's if she knew anything about nutrition. We seem to have lost a lot of knowledge... how to grow food, cook it, put up shelves, and some spiritual foundation. The "loss" of the family is a lot to do with that, and the benefits culture simply encourages and supports the mess that is reality when daddy buggers off.
In the ensuing age of "less", it will mean that less has to mean more, in the restitution of all the above that we have lost during the past 30 - 40 years. With freedom comes responsibility, and abandoning your kids is not the greatest achievement of a man. Most of the troubles of modern society are born from freedom and excess, and the lack of ability to handle both.
There never was a family like "The Waltons" probably, but we are going to need to stick together in future simply because we will need one another. This is a practical example of spiritual foundation - love, it is sometimes called. I would recommend the Abbot's wise words, in the licence of "Shoppers are selling their souls", as he is quoted below. I spoke to my mother recently who said that "when you were a baby, we were incredibly short of money. So I told the family... there won't be any Christmas presents this year..." This was in the Cardiff of 1959-1960.
It doesn't sound like it was happy affair, but they did get through it. So can we all, but with less material and more spiritual solidity.
"Shoppers are selling their souls", monk warns. By Martin Beckford: http://www.telegraph.co.uk/news/newstopics/religion/3419208/Shoppers-are-selling-their-souls-monk-warns.html
We are kept in a state of fear and unhappiness, which is what sells. But people are holding-on to their cash now, and that might illumine the dawn of a less materialistic thought-process for living. I have a friend who tells me that the only way she can feed herself and her 5 kids in because a certain fast-food burger outlet offers a 99p "meal deal". So that's around six-quid as we say over here.
It may be nice to go-out for a meal, all of them, but she could feed the lot of them for a third of that... that's if she knew anything about nutrition. We seem to have lost a lot of knowledge... how to grow food, cook it, put up shelves, and some spiritual foundation. The "loss" of the family is a lot to do with that, and the benefits culture simply encourages and supports the mess that is reality when daddy buggers off.
In the ensuing age of "less", it will mean that less has to mean more, in the restitution of all the above that we have lost during the past 30 - 40 years. With freedom comes responsibility, and abandoning your kids is not the greatest achievement of a man. Most of the troubles of modern society are born from freedom and excess, and the lack of ability to handle both.
There never was a family like "The Waltons" probably, but we are going to need to stick together in future simply because we will need one another. This is a practical example of spiritual foundation - love, it is sometimes called. I would recommend the Abbot's wise words, in the licence of "Shoppers are selling their souls", as he is quoted below. I spoke to my mother recently who said that "when you were a baby, we were incredibly short of money. So I told the family... there won't be any Christmas presents this year..." This was in the Cardiff of 1959-1960.
It doesn't sound like it was happy affair, but they did get through it. So can we all, but with less material and more spiritual solidity.
Abbot Christopher Jamison warned that rampant consumer culture is taking over people's moral purpose as their material needs are now all met.
He urged people to enjoy the month of Advent rather than celebrating Christmas early. Not a bad idea. I think I will go out and buy an advent calender.
"Shoppers are selling their souls", monk warns. By Martin Beckford: http://www.telegraph.co.uk/news/newstopics/religion/3419208/Shoppers-are-selling-their-souls-monk-warns.html
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