Climate Change: The Solution
At last, rational thinking is appearing on the horizon of the debate on Climate Change (earlier called Global Warming). The issue has been discussed in my book “The Year 9000” (available on Amazon.com) and elsewhere in my writings, including an earlier blog here (The Politics and Science of Global Warming). My delight is based on reports that a long-neglected viewpoint is germinating in Climate Change activist circles: the need to control the carbon dioxide content in our ambient atmosphere to return the climate we have lived with for the past century or so, and not just to limit its production by our use of fossil fuels. After all, the unannounced agenda is to control the global climate, isn’t it?
Climate will periodically change with or without our inputs. We must understand that, and that increased use of energy, which can influence the local weather and the global climate, is unavoidable if we want to keep up the progress of our civilization. Everything we have achieved technologically entails the use of energy. Fortunately, the technology needed to keep our global climate stable is already available.
Governments and influential activists have been diligently warning us that doom is on the horizon unless something is done about the threat of a looming warming trend caused by increasing levels of carbon dioxide in our environment due to the use of fossil fuels. Although this position may be overwrought, the fact is that we have become used to a specific average global climate, namely that of the past century, a time when we developed a high level of technology that requires the use of a lot of energy. This energy was mainly derived from the burning of fossil fuels., which release carbon dioxide into the atmosphere. The carbon dioxide thus produced is the bone of contention.
Carbon dioxide is a natural and essential component of our atmosphere. It comes from many natural sources, and without it there would be no vegetation on earth. Carbon dioxide is also a “greenhouse gas.” Increasing its content in the atmosphere will lead to some increase in the global average temperature and thus disturb the global climate. Leaving aside whether the last century has had the best climate for human comfort and prosperity, it does present us with a range of temperatures which can be averaged to provide a setpoint for which governments can aim with their shambolic policies. The problem is how to attain this setpoint.
Unfortunately, there is no such thing as a free lunch. We will need more, not less, energy to achieve climate control: lots more energy. We also need reliable and easily controllable energy in the form of heat and/or electricity, depending on how we decide to deal with the problem. The most important issue is that this energy must come from sources which do not produce carbon dioxide.
We all know of recent developments in the production of energy from solar radiation, wind power, tidal power, etc. These sources are not able to satisfy current, not to mention future, energy needs. We cannot power our future using such means alone; they are too unreliable, intrusive, and expensive for many applications. We might for example try to use more wind power, but to satisfy the needs of the USA we would need easily twenty times as many windmills as presently exist, with their associated dependence on the inconstant wind as well as replacement, maintenance and esthetic costs. Battery storage to level out the power production variability of this inconstant “clean” source is very expensive.
The one safe clean source we keep ignoring, due to scare campaigns in which governments are complicit, is nuclear power. This essentially limitless source is entirely within our control, independent of cloud cover, wind velocity or tidal periodicity. Nuclear energy is the solution to our concerns about the climate and its role in our future. Major advances have been made in the design, economy and safety of nuclear reactors, but these have yet to be widely adopted in commercial installations. Why new reactors are not being deployed is a problem I will leave for another time (I have already written one blog here entitled “The Future of Nuclear Power.”) Nuclear power must be employed to run any future industrial-scale remediation of natural or man-made climate irregularities. Such intervention is possible and should be able to control both increases and decreases in temperature from any designated setpoint.
It seems reasonable that, since carbon dioxide can influence the temperature of our environment, we should concentrate on controlling its concentration in ambient air. Yes, during a warming trend we can remove some of it as it is vented at the source, but we may also have to add it to the atmosphere during a cooling trend to fend off a new ice age. In other words, we need to be able to “titrate” the atmosphere with carbon dioxide to maintain a stable climate. What we need are “titrators” which can add or subtract carbon dioxide from the atmosphere. These installations will have to be massive, and must be located at appropriate sites since they will alter downstream air composition for some distance. If we remove carbon dioxide from the ambient air, the air downstream will be poor in carbon dioxide, inhibiting the growth of plants and therefore will have a negative influence on agriculture and forest growth. Moreover, it will be enriched in oxygen, with whatever results may follow from its increased oxidative power.
Such global climate control operations will need to be managed and funded by central globally-oriented agencies and resources, necessitating oversight and funding by a well-functioning future international body. Clearly, the titrators would not eliminate regional and local storms, extremes of heat or cold, or of drought or rain, that we currently experience. Only the global climate would be controlled. I will leave the problem of selecting a “setpoint” for global climate that will optimize local preferences to those skilled in the arts of diplomacy and concentrate on the possible technology of global climate control.
First of all, we need to capture the carbon dioxide from the ambient air. Since the concentration of carbon dioxide in air is small (0.04%) we will have to treat vast volumes of air to scrub out enough carbon dioxide to make a difference. This explains the huge size of the necessary titrator installations and the need for considerable energy to pump the air through equipment, to carry out the requisite purification processes, and to provide energy for the processes involved. I expect that a number of huge installations will be required and that they will be scattered around the globe in remote locations.
If you have seen extensive wind farms of today, you can imagine the much-denser collections of powered fans over significantly larger areas of landscape which the titrators will require, and you will begin to appreciate the enormity and intrusiveness of the installations we would need to build. I expect that these installations will have to be located in deserts or on sparsely inhabited plains such as those in parts of Africa, China, eastern Russia, Argentina, Australia and several other places with vast sparsely-inhabited regions; but probably not in Europe, North America or Malaysia. Such remote locations would be ideal for siting not only the titrators but also their associated nuclear power plants.
The carbon dioxide in the air would be scrubbed out by a suitable sorbent (probably a liquid amine) which, on being heated, will release the absorbed carbon dioxide in the form of concentrated gas. This kind of operation is already standard in many chemical industries and nothing stands in the way of its success in the proposed titrators, but it will be applied on an unprecedented scale. We will need a lot of electrical energy to pump the air through the absorbers, circulate the absorbing liquid, and to provide energy for the heat-dependent recovery operation of liberating the carbon dioxide from the scrubbing liquid. The scale of the overall titrator plant will be unprecedented but, in this well-established way, carbon dioxide can be removed from ambient air. Below is a small experimental set of fans of the kind I envision. A full scale titrator would require an installation perhaps a hundred or more times that shown at each titrator site.
In the on-site nuclear power plant supplying the electricity for driving the fans and powering the overall process, the condensation of the working fluid driving the turbines which drive the generators does not have to depend on a source of cold water from a river or the sea. The cooling could be done using the massive air flow generated by the absorber fans.
Many suggestions have been put forward for the disposal of captured carbon dioxide, such as sequestering in soils, vegetation, oceans, and caverns. I do not like any of these; they are temporary band-aid solutions that would leave a festering problem for the future. Soils, vegetation and oceans are, at best, limited-capacity reservoirs; furthermore, adding significant amounts of carbon dioxide to such ecological reservoirs will surely cause distortion of ecologies. Caverns in turn, are not available everywhere and can leak, or suffer catastrophic failures. I am in favor of taking apart the carbon dioxide and releasing the oxygen to the atmosphere, while making use of or storing the dense, stable and relatively non-intrusive solid carbon. The permanent disposal of the carbon dioxide can therefore be accomplished, but will require associated plants involving a series of processes.
Let me suggest one cycle and several variations on the theme. A minimum of three essential processes is involved, as shown by equations 1, 2 and 4 below. We begin the overall process in the first step expressed by equation 1 when we turn the carbon dioxide into a hydrocarbon, mostly methane. This is a well-understood process called the Sabatier reaction and consists of reacting carbon dioxide with hydrogen at a reasonably accessible temperature and pressure in the presence of a catalyst.
1) 4H2 + CO2 + catalyst → 2H2O + CH4
Several catalysts that will do this are available now and no doubt better catalysts will be developed. The problem is where to get the hydrogen.
The hydrogen production process will require a large share of the energy needed for the titrators. Nuclear reactors are the only reasonable source for generating the electrical energy required: clean, economical, and available on demand. The electricity produced would be used to electrolyze water (equation 2), yielding hydrogen to be used in the Sabatier reaction shown above and releasing oxygen into the atmosphere.
2) 2H2O + electrolysis → 2H2 + O2
Notice that, according to equation 1, the Sabatier reaction will automatically supply the water needed for the electrolysis in reaction 2, which would produce half the hydrogen for its needs. This means that we will not need as much water from the environment as we would to supply all the hydrogen for the Sabatier process by electrolysis, and therefore we will not need as much water at the site of the titrator. The titrator can therefore be situated where agriculture is unlikely but enough water is available to supply relatively low make-up needs for the electrolysis plant. It also would also mean that less power would be required for electrolysis if we could make the missing hydrogen in some other way than electrolysis of make-up water from the environment. We will soon see that things are very promising in this regard.
In equation 1 we produce methane (CH4) but we do not want to burn it as fuel for power generation the since this would defeat our effort to remove carbon dioxide from the air.
3) CH4 + 2O2 + combustion → CO2 + 2H2O
We have to dispose of the methane in some non-polluting, preferably useful and perhaps profitable way. We could try to sequester it underground. Storing large volumes of methane will present even more problems than that of storing carbon dioxide. We should instead try to obtain pure carbon from the methane and recycle its hydrogen for use in the Sabatier reaction, thus reducing the amount of both energy and water which would otherwise be needed for electrolysis. As it happens, this is not a difficult problem and can be as simple as pyrolysis of the methane at an elevated temperature.
4) CH4 + pyrolysis → C + 2H2
This process would supplement the electrolysis-produced hydrogen from reaction 2, supplying the other half of the hydrogen needed for the Sabatier reaction, greatly reducing the size and energy demands of the titrators.
In summary therefore, the titrators operate on a cycle which requires electrolysis to produce half of the hydrogen needed by the Sabatier reaction; the rest is produced by the pyrolysis of the methane produced by the first step. The water and hydrogen in the proposed cycle are not irreversibly consumed, but are recycled in several steps according to the above equations. Of course, there is no free lunch, so various inefficiencies in the chemical processes, as well as other factors, will result in the consumption of some water from the environment. On the other hand, there should be no significant release of pollutants requiring special care.
The power requirements, although still large, can be greatly reduced by the reduced demand for electrolysis, as I have described above and by careful energy conservation between operations. Moreover, cooling of the working fluid of the generators’ turbines by air from the absorber fans rather than by water increases the number of locations where the nuclear plants and hence the titrators can be sited. The fact that the titrators will be located in remote locations is also not a problem in terms of supplies; no feedstocks need to be delivered, only maintenance supplies need to be brought in.
An additional benefit of the proposed titrators is that the pyrolysis of methane can be controlled by carrying out only a partial pyrolysis of the methane to yield, with some further processing, not just carbon but the organic materials presently produced by conventional petroleum refineries. This would significantly increase the size of the titrator plants but the processing of the hydrocarbons produced by the partial pyrolysis could become the source of a significant portion of the petrochemicals currently produced by petroleum refineries and used globally as starting materials for the production of everything from lubricants to building materials to pharmaceuticals.
Partial pyrolysis would increase the demand for hydrogen from electrolysis since not all the hydrogen would be recovered from the methane in a partial pyrolysis operation. This in turn would require more water from the environment. Balancing these various possibilities in the light of economic and site-specific considerations will present a delightful problem in optimization of the configuration of each titrator. I will leave the detailed thermal balances, product spectra, energy requirements etc. of the titrators for others to examine. It is a study some agency should be carrying out.
Some of the carbon can be used as it is produced, for example in industrial materials or in soil conditioning, while the rest of this solid and reasonably-stable material could easily be stockpiled above ground, using suitable precautions to prevent accidental ignition. There should be little danger of water pollution from runoff of rainwater from surface piles of carbon produced by a properly-designed pyrolysis unit. The carbon piles would also serve as stored fuel for the titrators, to release carbon dioxide into the atmosphere by combustion in case of a temperature drop due to a possible (even likely) global cooling episode in the future.
There are alternative processes for the chemistry of the titrators such as the Bosch reaction, which would be difficult to commercialize using existing catalysts, but would simplify carbon extraction from carbon dioxide. However, this process would complicate the synthesis of useful hydrocarbons. Alternatively, the captured carbon dioxide could be used to produce carbon monoxide which would then be used to produce hydrocarbons by a Fischer-Tropsch process. More studies are needed, but there is no doubt that currently-available technology can tackle the Climate Change problem and establish a constant climate that governments world-wide must agree upon; there lies the political problem. We need sensible policies, fair and honest compromises, commitment and effective organizations.
Notice that I say climate not weather. The world temperature average can be kept to an assigned value over time, but the weather will continue to vary. At this time, we are not in a position to control regional or local weather except by enclosing volumes of space inside structures, say by building domes over cities. There will continue to be hurricanes and droughts and severe winters and wet summers; all the ups and downs and vagaries of weather we currently experience. What can be controlled is any trend in the average global temperature: i.e. changes in the global climate. Any foreseeable activity due to man or nature which might dislodge the global temperature from its pre-selected average will be leveled by the titrators.
The real sticking points in this whole enterprise are economic and political, not technical. The technology exists. But who organizes and pays for the construction and operation of the titrators? Where to locate them? How to agree on the level of atmospheric carbon dioxide that needs to be maintained to keep a selected global average temperature constant? What average temperature will be acceptable globally if we can control climate to our specifications? All these are questions that a competent international organization will have to handle. It cannot be done by unilateral action or bilateral agreements. I see no organization with the appropriate funding or authority to do this as things now stand. Internationally, our political bodies do not even encourage nuclear energy as a source of energy capable of reducing carbon dioxide release by replacing fossil fuels, never mind to satisfy the clean energy demand for keeping the global climate constant using titrators.
Governments and activists are fussing, threatening, complaining, and fear-mongering. They are proposing non-nuclear solutions that destroy vistas, kill birds and deplete rare-element resources, not to mention putting a burden on global prosperity, but as yet there are no well-reasoned proposals to deal with the inevitable ups and downs of long-term climate cycles. No definitive answer is “blowing in the wind.” Yet the technology is there, ready and waiting to be implemented.