Yes CO2 recycling with hydrogen will be a good source of liquid fuel when nuclear hydrogen becomes available as is happening soon in France. This recycling has even been shown to be done by organisms that produce ethanol. In any case, large scale chemical processes work sufficiently well. The prodution of CO2 is lowered now if any hydrogen from non petroleum sources is added to crude oil during the refining process. Even the use of hydrogen from natural gas (methane) saves the production of CO2.

It must be said that hydrogen produced from spare nuclear power capacity is very cheap, and France will and should install facilities to make hydrogen when this power is not wanted by its neighbors. This hydrogen energy is cheaper than crude oil. Phénix type high temperature reactors might make very cheap hydrogen with a thermochemical process; Nuclear heat is very very cheap. Hydrogen made directly from water and coal is also cheap; sometimes cheaper than natural gas; Sequestation of CO2 is also possible where such facilities are built.

The direct oxidation of methane to methanol with oxygen from air would lower the world production CO2 by eliminating natural gas flaring. The inventers of a simple processes to do this should get a Nobel prize for chemistry and somebody, not likely the inventors, will get very rich off the process. ..HG..

Nuclear hydrogen will never cut it as solution to the energy problem. There isn't enough world supply of uranium to last more than about 80 years. Solar thermal plants which generate electicity via a steam turbine is more viable. The electricity can be used to produce the hydrogen with an electrolyser.

The planet is blessed with a fusion reactor located 93 million miles away. The solar energy incident on the planet is on the order of 166 PW, 30% of it is reflected back into space and 19% is absorbed by clouds. This leaves 85 PW which can be exploited. The present world energy consumption is about 15 TW. The 85 PW then is 5000 times more than the present world consumption.

Only 8% of the land area of all the hot desert regions of the world is sufficient to generate all the energy we need using low tech trough collectors hooked up to steam turbo generators.

The sun's energy is free, it will sustain us for at least 500 million years before the sun turns into a red giant. Let's use its energy while we can.

Do we really want to build half a million square miles of Solar collectors on Earth's surface, plus a million miles of transmission lines to connect them all to their customers?

There is thousands of times more thorium in the world than uranium. Primary nuclear fuel problem, solved.

Mannstein,

It is quite apparent that you have little scientific training. While true that we have a Fusion reactor some 8 light minutes away, the energy available while prodigious, is not very concentrated, or usable. Please study the Laws of Thermodynamics and the difference between energy and enthalpy.

You are off by at least one order of magnitude if not three on the low side in estimating conventional uranium fuels. That is without even considering mining the Oceans, or reprocessing and 'actinide burning' spent fuel as all the world except the USA does. This provides as much as 90% more fuel. And it also eliminates more than half of the less than 1% of waste that remains radioactive for millenia. Meanwhile it reduces the volume of other high-level waste by some 90-95%. The Caterite idiocy, at last, is close to being reversed, by the Obama Administration and Dr. Chu.

But even if correct, you have twice as much fuel as we will need, as Fusion is less than half that time away from full commercialization. ITER, now building in Cadarache France, is both the last physics Fusion experiment, and the first pre-prototype of a commercial Fusion power plant. When operational in half a decade, it will routinely generate half a Gigawatt of Fusion energy, which is more than equal to the all the windmills operating in the USA.

Stan Peterson,

According to the World Nuclear Association (www.world-nuclear.org) at the current rate of consumption with conventional reactors there are only 80 years of world uranium resources available at reasonable recovery cost levels. Nuclear power presently only supplies 5.7% of the world's total energy, thus if we hypothetically supplied the whole world with nuclear power there would be only 5 years supply.

Today there are a total of 9 Solar Energy Systems (SEGS) farms in California. 2 are located at Dagett, 5 at Kramer Junction, and 2 at Harper Lake all in the Mojave Desert. The total area occupied is 2.4 sq km generating 354 MW of power. These figures scale up to an area of 320km by 320 km if one was to supply 15 TW of energy the world uses with this technique. The 9 plants have been gradually installed from 1984 to 1990 demonstrating over 20 years of performance without malfunction. Source: Power Corp.

This installation in California serves as an existence theorem for low tech. Solar, if you will.

It demonstrates that there is sufficient area available in central Australia, for example, to generate all the power the world currently uses without the nuclear waste and safety concerns. Clearly SEGS farms would not be built in just one desert location but be spread out to suitable parts of the globe near the energy users.

Germany for example is planning to build an SEGS farm located in Algeria with power to be transmitted by high voltage DC lines to Aachen Germany.

Here is what Sir Chris Llewellyn-Smith chair of ITER council has said about low tech solar.

"The potential of solar energy is so great that developing means to tap it more efficiently and store it must be a priority."

The consolidated utility time (CUT) of various energy sources has been estimated by a number of researchers. CUT is the time it would take for each resource to run down reasonably recoverable reserves if it individually had to supply the whole world's energy needs, in isolation.

The CUT for Solar Hydrogen is 1 billion years.
Nuclear Fusion: 100 years.
Coal:35 years.
Gas: 14 years.
Oil: 14 years.
Nuclear Fission: 5 years.

For long term sustainability we should put our money on the Solar Hydrogen economy. It may be low tech but has none of the pollution, green house gas, waste storage, or safety issues.

The only issue for hydrogen is that the hydrogen leakage be less than 5% otherwise we would be out of water in a billion years. You see if hydrogen is lost it eventually makes its way into the stratosphere where a fraction of it will end up in outer space. But since planet earth will be un inhabitable by that time frame anyway it's really not a problem.

Finally, hydroelectricity currently provides 20% of the world's energy. In case you didn't know, Stan, the ultimate source of hydroelectric power is solar energy (via rain). This is a salient reminder that large power levels can be obtained compared to nuclear power if one taps the sun directly even though as some critics charge, yourself included, that solar energy is much too diffuse to be practical.

You're wrong on one other point, I do have an advanced engineering degree. I'm familiar with the laws of thermodynamics, entropy and all the rest, hold 14 patents in electronics etc., but then I digress.

Stan Petersen

Fusion has been promised to be ready in the early 1970s for commercial power generation in 20 years this is still the case today.

Fusion reactors use tritium for their operation. Tritium is produced on earth by reactin neutrons with lithium. tritium is sufficiently dangerous that nuclear authorities limit its absorption by the walls of the reactor. Therein lies the problem with fusion.

Estimates of commercial fusion reactors by 2050 are simply over optimistic. The ITER has the largest ever approved tritium retention limit of 350 g. to put this into context, with carbon walls ITER would reach this limit in about 1 week of operation. The reactor would then have to be powered down to allow access to clean the walls for the removal of tritium before fusion operation can be resumed. Exactly how to clean the walls, how to manage the resulting toxic dust, and the magnitude of the resulting down time are all uncertainties without any current solutions. The problems of neutron embrittlement still are not solved.

Furthermore, the super conducting magnets to convine the plasma use niobium alloys. To attain 15TW would exhaust world niobium reserves, assuming 500 tonnes of niobium per 1 GW fusion reactor. Niobium is also used for superalloys in engines. Thus a full analysis of the materials inventory for fusion reactors is still required.

Engineer-Poet:

The numbers I'm quoting are sourced at www.world-nuclear.org. Check out the following link: http://www.world-nuclear.org/info/default.aspx?id=438&terms=recoverable+thorium

There are only 80 years supply of "recoverable" uranium to supply the present reactors which provide 5.7% of the world's total electricity, that is 15 TW. If present reactors were to generate the full amount to reduce GHG to near zero the supply would last only 5 years.

The uranium in seawater is not "recoverable" with present day technology. It's in the water alright but to extract it is not economic hence not "recoverable".

The FBRs fans claim to extend the useful lifetime of uranium by a factor of 60. However, since the first US breeder in 1951, they have not met with commercial success. Thus FBRs turn out not to be cost competitive as well as having a number of safety issues.

I refer you to the report by M. V. Ramana and J. Y. Suchitra, "Slow and stunted:Plutonium accounting and the growth of fast breeder reactors in India" Energy Policy, vol. 37, no. 12, pp.5028-5036, 2009.

The reactors use liquid sodium as a coolant and there have ben safety problems with leakage. The US Clinch River Breeder Reactor construction was abandoned in 1982. After a serious leak and fire during 1995, the reopening of Japan's Monju reactor has been stalled. France's Superphenix reactor closed down in 1997 due to it's rate of mafunction and sodium leaks. During its 11 year lifetime there were 2 years of accumulated downtime due to technical faults at a total cost of 12 billion dollars US. Ther are many uncertainties with FBRs: their life cycle efficiencies are unknown and how does one therefore compare their energy return on investment (EROI) with other energy generation methods?

Thorium is claime to be the answer when uranium stocks run outas it is a more "abundant" element. However, its occurence is only 3 times that of uranium, which is not significant. Moreover the economically "recoverable" world reserves of thorium are only half the reserves of uranium.

Mannstein, you did it again.  SEVERAL times:

There are only 80 years supply of "recoverable" uranium[1] to supply the present reactors[2] which provide 5.7% of the world's total electricity[3], that is 15 TW[4]. If present reactors[5] were to generate the full amount to reduce GHG to near zero the supply would last only 5 years.

1. "Recoverable" depends on price.  The supply available at $200/lb is a large fraction of the amount in the oceans, and that is with current technology.
2. "Present reactors" (LWRs, not FBRs) are only used because uranium is cheap.  The supply of LEU is 1/6 or less of the supply of NU, and perhaps 5% of LEU is fissioned in an LWR; this is a total utilization of less than 1%.  FBRs can use close to 100% of NU.
3. US reactors ALONE supply about 5% of the world's electricity; the world total is about 15%.
4. You're talking electricity but comparing it to raw (thermal) world energy consumption from all supplies (about 13 TW).  In other words, you are counting it as if humanity would take nuclear electricity and throw it into resistance heaters to make steam to run today's coal-fired powerplants.
5. See #2.

Now stop using misleading and incommensurable figures to lie.

The French are using their surplus nuclear generated electricity to generate hydrogen by plain electrolysis. This is mentioned on the website of the French power company. Small electrolysis units could be situated anywhere hydrogen is being used for chemical production or could be used if available. Hydrogen can be used to support some kinds of fermentation including perhaps ethanol production. An "ANTI-FUEL-CELL" that produces methanol from electricity and CO2 and water is what could be used now. Hydrogen produced from cheap industrial off peak French nuclear electricity is far cheaper fuel than crude oil at $150. Most of the cost of the hydrogen is the capital cost of the electrical equipment and not the cost of the uranium. The use of accelerator driven reactors, proposed by Nobel prise winner Prof. Carlo Rubia, make it possible to use all thorium, all uranium and depleted uranium and used fuel rods and any elements heavier than uranium now produced in reactors including all isotopes of plutonium. All of these materials can be used as fuel in Rubbia reactors. The accelearators need for these reactors are already working in prototype form and used for neutron studies. Just look up the new neutron producton facility at ORNL.

A combination of fusion reactors with fission reactors can also increase the fuel supply in the same way. Fusion reactors, if ever built, can increase the ability to produce plutonium for bombs by a large factor because they are an infinite source of neutrons.

It is even thermodynamically possible to build an energy releasing reactor that fissions lead, gold, mercury and a few dozen other elements. Such reactors may be easier to build and operate than fusion reactors. ..HG..