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Sun Jan 3, 2021, 08:10 AM

Synthesizing Clean Transportation Fuels from CO2 Will at Least Quintuple the Demand for Electricity.

Last edited Thu Jan 28, 2021, 10:56 PM - Edit history (1)

(Graphics in this post may not be visible in Google Chrome, but should show up in Microsoft Edge, Firefox and Android.)

The paper I'll discuss in this post is this one: Synthesizing Clean Transportation Fuels from CO2 Will at Least Quintuple the Demand for Non-carbogenic Electricity in the United States (Johnathan E. Holladay, Jonathan L. Male, Roger Rousseau, and Robert S. Weber, Energy & Fuels 2020 34 (12), 15433-15442)

Electricity, as I often note, is a thermodynamically degraded form of energy. The second law of thermodynamics, which largely dictates, with a few major caveats, the environmental impact of any process, requires that if any form of energy is transformed from a primary source, a portion of that energy will be lost as entropy, usually represented by the generation of heat. Since electricity is not a primary source of energy its generation always requires thermodynamic losses. If electricity is "stored," as in a battery, which converts electrical energy into chemical energy while charging, and then back into electrical energy while discharging, two thermodynamic losses are involved. This is why batteries generate heat, sometimes extreme heat. This is something I discussed in a recent post in this space, when I discussed - on a necessarily superficial level - a review paper about electrolytes in lithium batteries.

Because of their thermodynamic inefficiency (but higher mass efficiency than other batteries) as represented by thermodynamic losses expressed as heat, lithium batteries can cause, and have caused, fires. They are evidence of the overlooked fact that distributed energy involves distributed danger and distributed risk. The widespread belief that distributed energy is environmentally superior to centralized energy sources is nonsensical, and is a large factor in why we are stumbling into an environmental abyss.

The most graphic, and environmentally pernicious (up to now) form of distributed energy is the automobile. Of course, in the first world, the car CULTure is so engrained in our way of life that we don't pay much attention. Although the car CULTure is not sustainable, and thus represents a crime against all future generations, we often engage in fantasies about "green cars." A famous award winning "green car" was the Audi A3 TDI/Volkswagen Jetta TDI, it's "green" proving to be fraudulent. I contend that all "green cars" are frauds; there is no such thing as a "green car." The Audi A3 TDI/Volkswagen Jetta TDI were diesel engine powered that utilized software "defeat devices" to lower emissions only when undergoing emissions testing, and not during normal use. Electric cars, also purported by advocates as being "green," simply move their pollution in a three card monte scheme to the power plant producing its thermodynamically degraded form of energy, electricity, while hyping the lie that most or all electricity is or will be produced by so called "renewable energy." This lie is Trumpian in its scale. The proportion of electricity that is produced by the combustion of dangerous fossil fuels is rising, not falling. The so called “renewable energy” is a toxic failure when it comes to addressing climate change.

It is important to note that in making these remarking - I know, I know - I am purely a hypocrite. I am a participant in the car CULTure. I own a car and I use it. I also have embraced, at various times, the view that the diesel engine has the potential to be cleaner than any other internal combustion engine in the case where it is fueled by the wonder fuel dimethyl ether (DME). However, it is not true that distributed DME will make the car CULTure sustainable. It is not sustainable, pure and simple. The time will come when it will be abandoned, either by catastrophe or in a controlled fashion. How this comes about will be a function of public morality.

With respect to the contents of the paper under discussion, this is really another battery paper, inasmuch it is a function of the idea of degrading the already degraded form of energy, electricity, by storing it as chemical energy. However, as this chemical stored energy will be converted directly, in a heat engine, to mechanical energy, it is questionable whether it will more thermodynamically inefficient than a lithium battery which needs to go through two energy transformations, chemical to electrical, electrical to mechanical. Graphics and discussion in this paper address this point.

An important point: Thermodynamic efficiency depends on path, and is best described using line integrals. Almost all of the world's electricity is produced using heat engines, and of these, the overwhelming majority are Rankine heat engines utilizing steam cycles. Rankine cycles typically offer thermodynamic efficiencies, depending on the temperature of the steam, in the neighborhood of 33% plus or minus a few percentage points. This is largely independent of the source of heat, and applies to the overwhelming majority of the existent nuclear plants, the majority of which are pressurized water reactors (PWR) or boiling water reactors (BWR) as well as other baseload power devices such as dangerous coal plants, and to the extent that they are increasingly utilized as baseload power dangerous natural gas powered plants.

The most thermodynamically efficient heat engines now in wide use for the generation of electricity right now are powered by dangerous natural gas: Combined cycle plants. These devices use a Brayton cycle device in which compressed air is mixed with dangerous natural gas and ignited with the exhaust expanding against a turbine. These types of devices are now possible because of developments in materials science. Specifically, they depend on the development of "superalloys," generally nickel based, coated with a thermal barrier coating, a ceramic material with low thermal conductivity and a high melting point, often zirconium oxide. I'm sure I've linked this paper about thermal barrier coatings before now in this space, a paper from Dr. Emily Carter, who I've briefly met in a social setting after one of her lectures, published on the occasion of her admission to the National Academy of Sciences: Atomic-scale insight and design principles for turbine engine thermal barrier coatings from theory. (Kristen A. Marino, Berit Hinnemann, Emily A. Carter, Proceedings of the National Academy of Sciences Apr 2011, 108 (14) 5480-5487) (I think it unlikely that all three authors of this paper are women is an accident.)

The dangerous natural gas exhaust containing the dangerous fossil fuel waste carbon dioxide emerging from the turbine remains hot enough to boil water and thus drive a Rankine cycle heat engine. This the origin of "combined cycle," a Brayton cycle and a Rankine cycle are combined: This is an example of a heat exchange network, or heat integration, and it has been the subject of a vast amount of research in recent years. The thermal efficiency of a combined cycle dangerous natural gas plant can significantly exceed 50% as opposed to 33%, even approach 60%. This of course, does not make dangerous natural gas "clean," or "green" - it still dumps the dangerous fossil fuel waste carbon dioxide into the air 0 but it does make it slightly less noxious. The mess left behind by mining dangerous natural gas, specifically the garbage leaked into future ground and surface water supplies from hydraulic fracturing, "fracking" will remain for all time, an artifact of our contempt for future generations.

The absolute dependence of the so called "renewable energy" on access to dangerous natural gas - without access to gas the so called "renewable energy" industry would collapse immediately - is in my view a reason that this affectation, the lie that world energy supplies can be addressed by it, will be condemned in history. It is important to note that when a dangerous natural gas combined cycle plant shuts down because the wind is blowing and/or the sun is shining, the thermal performance of the dangerous natural gas plant is degraded. The restart of these plants requires reheating for a period in which the plant will not be producing electricity and in which all the expenditure of energy is wasted. Stopping and restarting frequently also places greater strain on the turbines and devices, causes all of the external costs associated with manufacture, construction and maintenance to rise, reduces the economics and financial viability of the plants by converting all internal and external costs into stranded assets for brief periods, and effects land use via the need for redundant systems.

It is always the case that continuous processes are less environmentally and economically onerous than batch or interrupted processes. This is why so called "renewable energy" is proving to be environmentally unacceptable and why so called "renewable energy" will never be as clean or sustainable as nuclear energy, since worldwide, nuclear plants have the highest capacity utilization of all forms of energy, albeit, in almost every case, for the production of a thermodynamically degraded form of energy, electricity.

It is not widely known, but early nuclear plants, including the first commercial nuclear plant in the Western World, the British Calder Hall nuclear plant, might have operated as Brayton cycle plants and not Rankine plants as they were gas cooled. Although Calder Hall, built using 1940's and early 1950's technology, operated for nearly 50 years, from 1956 to 2003, it did not obtain the high thermal efficiency that its designers envisioned because of materials science issues that the primitive technology of the time did not address. The successor reactors, built on 1970's technology, the British AGCR, operate, as their name (Advanced Gas Cooled Reactors) implies, with gas cooling, but are not combined cycle plants, although their thermal efficiency, greater than 40% is higher than that of boiling water or pressurized nuclear reactors. Were they combined cycle plants, they might have well achieved higher thermal efficiencies, but the materials science, along with the neutron spectrum of the design, again on what is now 50 year old technology, did not allow for this.

Carnot efficiency, which may be translated on some level to situations that do not involve heat engines, is a function of the energy difference between the heat source and the heat sink, which is often, but need not be, water. A combined cycle dangerous natural gas powerplant derives some of its efficiency from precisely this factor, and coal plants have also been designed that utilize very high temperatures as well, driven not by steam, but by supercritical water. (Supercritical water nuclear reactors have been designed, but none have been built to my knowledge.)

An early pilot/test commercial nuclear high temperature reactor operated in the United States, the Peach Bottom reactor, and was followed by a full scale commercial version, the Ft. St. Vrain reactor. The latter reactor was about 40% efficient, but operated only for ten years as a nuclear plant, from 1979 to 1989. It's design was entirely based on 1960's technology. It was beset by a large number of technical problems, and - to the joy of stupid anti-nukes who are killing the planet with ignorance, short term thinking and selective attention - was shut, for economic reasons, as a nuclear plant, and subsequently converted to a dangerous natural gas plant, thereafter discharging its waste products directly into the planetary atmosphere where such products are accumulating at an alarming rate.

Anti-nukes are completely unconcerned with dangerous fossil fuel waste, which is literally choking the planet to death, but incredibly concerned with what, in their blissful but entrenched ignorance, they call "nuclear waste," although in general, they know zero about used nuclear fuels. Used nuclear fuels have not killed people, dangerous fossil fuel waste and biomass combustion waste kill between 18,000 and 19,000 people per day. Although anti-nukes pay significant attention to the famous energy moronic "maven" Amory Lovins, who argued in the 1970's and early 1980s that energy efficiency and so called "renewable energy" would save the world - they didn't - because he was not well read enough to have heard of Jevon's Paradox, they are spectacularly unconcerned with energy efficiency, since they believe that everything comes down to electricity from intermittent sources. Again, electricity is a thermodynamically degraded form of energy, and storing it degrades it further.

These are facts. Facts matter.

One hears from time to time arguments, including tortured arguments, usually proffered by nonscientists, that appeal to "peer reviewed scientific articles" (often described in blog posts as "studies" ) as evocations of pure truth. It is not, however, true that scientists are oracular beings. Quite the opposite is true, scientists are human beings, with all the weight of strength and frailty that implies. If one has worked with the scientific literature however, one understands that "peer reviewed scientific papers" often involve all the flaws that characterize humanity. Scientific papers are sometimes retracted, withdrawn, either by the editors or the authors themselves, when the authors recognize honestly that a mistake has been made, or in other cases, as a result of dishonesty or, in some cases, incompetence. The anti-vax movement, which in my view is very similar to the anti-nuke movement since both oppose advanced technologies out of the massive ignorance of the "antis," got its start from a "peer reviewed scientific article" that was retracted - by the editors - on the ground that it was unsupportable nonsense, taken up by stupid people to apply their ignorance to kill and injure other people, most of whom qualified in any case for the Darwin Award. (I was recently accosted here by a person who pointed me to one of those "living near a nuclear plant causes cancer" "gotcha"lazy assed link to a "peer reviewed" paper. I love DU; it has an "ignore" option.) It is important to note that many peer reviewed papers are not retracted, but contain irreproducible nonsense all the same.

The paper under discussion here, shows no evidence of being a poor paper. It is, from what I can tell, an excellent paper, but even before reading it, I was inclined to question it since it insists that the way to make what are called "clean transportation fuels" goes through the route of electricity. The peer reviewed paper does not come to me as a "revealed truth" that is oracular, although it is clearly packed with useful information and insights. It nevertheless ignores another option, which is to dispense with the electricity intermediate altogether, and proceed directly from thermal energy to chemical energy storage.

In the same issue of Energy & Fuels - as of this writing, the current issue, there appears a paper on thermochemical water splitting (and/or carbon dioxide splitting), this one: Improved Performance and Efficiency of Lanthanum–Strontium–Manganese Perovskites Undergoing Isothermal Redox Cycling under Controlled pH2O/pH2 (Kangjae Lee, Dylan C. McCord, Richard J. Carrillo, Bella Guyll, and Jonathan R. Scheffe Energy & Fuels 2020 34 (12), 16918-16926). (Strontium is a clean heat generating fission product, and lanthanum is also a fission product, albeit one that is not radioactive for a long period.) There are many of these thermochemical cycles to split water or carbon dioxide known. The most famous of these is the Sulfur Iodine cycle which was advanced by the same company that designed and built the Ft. St. Vrain nuclear reactor, General Atomics . The people at General Atomics thought of their reactor design as producing hydrogen, with electricity as a side product, in other words, a different kind of combined cycle plant, one utilizing a heat network.

Advances in materials science and some very modern chemical separation technologies suggest to me that this old and much studied cycle may yet prove to be viable in high temperature nuclear reactors, particularly in the case where the iodine is nothing more than a catalyst in the gas phase. The Chinese are exploring the sulfur iodine cycle in a pilot capacity using their HTGR-10 reactor which is built around German "pebble bed" nuclear designs. While all of the high temperature nuclear reactors that have been built as of today utilize the thermal neutron spectrum, it seems fairly obvious, to me at least, that the best concept in nuclear engineering, breed and burn reactors operating on the fast neutron spectrum, may also function very well, particularly utilizing metal vapors or salt vapors as heat transfer fluids.

Citing General Atomics work, recent authors indicate that the thermochemical efficiency of the Sulfur Iodine cycle may be as high as 52%. (cf: Subhasis Mandal and Amiya K. Jana Simulating reactive distillation of HIx (HI–H2O–I2) system in Sulphur-Iodine cycle for hydrogen productionNuclear Engineering and Technology, Volume 52, Issue 2, 2020, Pages 279-286.) The cycle produces a stream of oxygen gas mixed with sulfur dioxide at a temperature of close to 1000 °C which must be rapidly cooled and separated. This obviously allows for process intensification using heat networks in such a way as combined cycle electricity production is certainly possible, as a side product. Even if the side product is only electricity, if from the waste heat (48%) of the thermochemical process achieves 40% efficiency, this adds .48*.40 = .19(2), 19% to 52% for a total of 71% efficiency. These are heady numbers.

Thermochemical hydrogen, thermochemical oxygen, and thermochemical carbon monoxide from reduced carbon dioxide will allow for the production of any transportation fuel, from clean fuels like DME to dirty fuels like FT gasoline and/or FT diesel and or FT Jet fuel. All of these technologies might close the carbon cycle. It is worth noting that both the chemical reactions for the hydrogenation of carbon dioxide to make methanol as a "clean fuel" or to make DME as a clean fuel are exothermic, and thus may be thought of a reductive burning with the possibility to generate electricity or compressed gases, the latter in such a way as to produce an effective heat pump for a heat network. Moreover, the thermochemical oxygen allows for "oxyfuel" combustion of, for example, biomass and/or municipal and/or industrial waste in closed conditions, again at high temperatures, and being closed, in the absence of smokestacks.

The point is it is possible to recover considerable amounts of energy simply by raising the efficiency of the overall system, something that is more and more feasible given advances in the materials science in this century. Since chemical energy produced directly from thermal energy skips the electricity intermediate, it is less thermodynamically degraded than electricity stored as chemical energy, as in a battery, or as in the processes described in the paper cited at the outset.

All these diversions aside, let's now look at the claim in this paper that clean fuels will require the quintupling of electricity production. This paper oozes with useful information.

From the introduction:

Three approaches have been mooted to operate the current and near-future fleet of transportation vehicles with significantly less production of greenhouse gases (GHGs): renewable fuels, electrofuels, and electric vehicles recharged using renewably generated electricity. We use the term “electrofuel” to denote the combining of renewably sourced carbon, hydrogen, and renewably sourced electrical energy to generate liquid fuels that could be used in today’s vehicles or with powertrains specifically optimized for their use (co-optimization of fuels and engines(1,2)). Alternately, renewably sourced electricity could directly recharge all-electric powertrains (or the battery of plug-in hybrid vehicles). We do not explicitly consider the use of hydrogen as a transportation fuel because that topic has been reviewed recently by others.(3−6) We do consider indirect fueling or direct charging, for which the scales of gathering and using energy required for transportation are large enough to affect other aspects of the natural environment. Previous studies have considered land use(7) and water use(8) for making low-carbon fuels from biomass.
Here, we present an estimate of the environmental implications of using of renewably generated electricity for indirect fueling or direct charging. We use the term “renewable” to denote energy derived from biomass, solar power, wind power, and hydropower, and we use the term “non-carbogenic” to cover renewable sources plus nuclear power. To facilitate comparisons among the amounts of energy employed in different applications (e.g., barrels of oil, kWh, and Quad), we have expressed all of the energy flows in exajoule (10^(18) J). For reference, the energy content of 1 barrel of oil equivalent (boe) is about 6.1 GJ, 1 kWh ≡ 3.6 MJ, and 1 Quad = 1.055 EJ. We have chosen to focus on transportation because its use of fossil fuels has become the most significant contributor to the emission of carbon dioxide by the United States(9) (Figure 1).

I like it. In macroscopic energy demand I almost always think in exajoules, and have done so for many years, and often point to the effective lie of using units of power (MW) that is so often used to make the so called "renewable energy" not look like the failure it actually is, where failure is with respect to addressing climate change, and not with respect to spending money and consuming resources uselessly.

Figure 1:

The caption:

Figure 1. GHG emissions in the U.S. by sector.(12)

Further down in the introduction, the means evaluated for addressing the use of clean fuels is described in a brief overview:

Projected mitigations of carbon emissions in the transportation sector include plausible increases in fuel economy for internal combustion engines, co-optimization of fuels and powertrains,(13) switching to electric powertrains in conjunction with the reduction of emissions of the electric grid, and the use of synthetic fuels whose carbon comes either from biomass, organic-laden waste streams, and/or carbon dioxide. For the last case, we provide a lower bound on the required input energy by estimating the energy required to revert CO2 into transportation-relevant quantities of fuels (gasoline or diesel). That energy, which is very large, does not include the input required to capture CO2.

The added bold is mine and is not in the original.

Oxyfuel combustion - combustion in pure oxygen possibly produced in a thermochemical cycle - in theory requires no additional energy to capture carbon dioxide. (In theory. I've thought a lot about schemes built around this idea, in various permutations, but that's for another time.)

The authors then describe the situation as it is in the near term future and the present:

Transportation, like each of the sectors shown in Figure 1, is powered by a mix of types of energy inputs (Figure 2), with the associated GHG emissions ranging from near zero (e.g., nuclear and renewable) to larger, albeit potentially abatable emissions (e.g., from fossil fuels). Despite the growth in electric vehicles, less than 1% of the energy used in transportation now comes from electricity.(15) Because of its dominant role in transportation, petroleum is the largest component of the energy mix in the U.S. (39 EJ/year of primary energy). It is the largest source of GHGs (2.7 Pg/year; 1 Pg = 1012 kg), when summed across the sectors (Table 1). For reference, the combustion of 1 barrel of oil produces around 430 kg of CO2.(16) The GHG emissions attributed to petroleum derive from not only its production and refining (both of which exhibit high energy returns on energy invested) but also primarily (>80%) its combustion as a transportation fuel (Figure 3).(17) Note that the bar representing transportation in Figure 2 contains a subtlety: most of the natural gas used in the transportation sector is employed for the distribution of liquid transport fuels in pipelines (0.97 EJ); the amount employed in natural gas vehicles is about 0.06 EJ.(14)

Figure 2:

The caption:

Figure 2. Sources of primary energy for the major economic sectors of the U.S. economy in 2019.(19)

Table 1:

Figure 3:

The caption:

Figure 3. GHG emissions from the use of transportation fuels, derived from data presented by Han et al.(17)

The authors note that the fuel efficiency of transportation is likely rise, but, consistent with Jevon's paradox and not the 44 year old head up the ass speculations from the poorly educated fool Amory Lovins, this means that more transportation will take place, with the result that more energy, overall will be required.

The projections for increased fuel economy are shown in figure 4:

The caption:

Figure 4. Projected fuel economies for passenger and freight vehicles.(9) 1 BTU mile^(–1) = 0.656 kJ km^(–1); 1 US ton = 0.0907 Mg

Table 2 in the paper gives the projections in the growth of transportation miles:

The authors predict that carbon emissions associated with transportation will go through a minimum, and then begin to rise.

This is reflected in figure 5:

The caption:

Figure 5. Projected emissions of carbon dioxide from transportation.(9)

Among the many so called "renewable energy" schemes about which I've been hearing for almost half a century, another one that was supposed to save the world was biofuels, beginning with the administration of President Jimmy Carter, who was very popular in Iowa for suggesting that corn ethanol could address the oil shocks of the 1970's. Biofuels did not save the world. They did destroy the ecosystem of the Mississippi River delta more or less, and in the case of biodiesel for that renewable nirvana in Germany, much of the Southeast Asian rain forest, but no, they did not save the world.

Despite this failure to save the world, I do have some fondness for pyrolytic biomass as a carbon capture device, perhaps in a setting connected with oxyfuel combustion, but I do not expect biofuels to save the world.

The authors discuss biofuels:

While their GHG footprint is smaller than that of fossil fuels (Table 3), biofuels (biodiesel, renewable diesel, ethanol from either corn or cellulosic feedstocks, biogas, and renewable natural gas) account for only 1.6 EJ or 5% of U.S. transport fuel.(20)Table 3 shows that the GHG emissions from the use of renewable fuels is about 0.05 Pg/year compared to the 1.5 Pg/year for all transportation. Therefore, the use of biofuels has decreased the net annual emissions of carbon dioxide from transportation by only about 3%. In 2018,(21) the estimated total investment (research plus tax benefits) in biofuels in the U.S. from 2010 to 2016 averaged about $14 billion per year (regrettably more recent data have not yet been published). That sum divided by the annual GHG savings from the use of renewable fuels in vehicles (0.042 Pg = 42 Mt) gives a ratio of about $330 per ton of avoided CO2. That price is larger than the estimate by the National Academy of Sciences, $250 per ton, for the effect of production tax credits on reducing GHG emissions from electricity

Table 3:

0.045 Pg is 45 million metric tons. This represents 0.01% of global annual carbon emissions, at a cost of $14.4 billion dollars a year at $330/ton.

The paper turns then to "electrofuels." There has been a large amount of literature written in recent years about the electrochemical reduction of carbon dioxide to various organic compounds, in particular, C1 compounds, formic acid, formaldehyde, methanol and even methane.

They write:

In principle, an idealized electrofuel could be made using renewable energy (sunlight, wind, or other non-carbogenic inputs, such as biomass) to collect and revert carbon dioxide back into a fuel. Plants, the original solar fuel, do so, but as noted above, a reasonable estimate of their productivity is only enough to address a small fraction of the energy content of the fuel employed in transportation. Electrofuel technologies could first be introduced to enhance the carbon intensity of today’s fuels derived from biomass and wastes.

Reverting CO2 back into a transportation fuel would require adding at least the heat of combustion of the fuels, more likely a multiple of that energy to account for the energy required to gather and concentrate CO2 and for energy losses in the reversion (electrochemical processes exhibit efficiencies of < 40% for a simple fuel formic acid. Replacing just the enthalpy of combustion of the fuels will require at least doubling the total amount of electrical energy now generated in the U.S. (27.2 EJ/14.2 EJ; Figure 6) and quintupling the amount of non-carbogenic (renewable + nuclear) electricity now generated [27.2 EJ/(2.5 EJ + 2.9 EJ)]. Again, both factors represent the minimum energy that must be added. We expect that the actual increase will be at least 100–300% times larger to account for process inefficiencies, such as overpotentials.(32)

They give the following graphical representation of exactly how electricity is currently produced in the United States:

The caption:

Figure 6. Comparison of 2019 U.S. production capacity of electrical energy and consumption of fossil fuels,(19) with data for biofuels derived from a U.S. EPA source.(20)

This figure, 2.5 exajoules of so called "renewable" electricity seems quite reasonable. The US DOE at it Energy Information Energy (EIA) website, gives an actual breakdown of renewable energy production in the form of a spreadsheet with which one can do calculations. It is here: EIA Electricity Web Page and can be accessed by clicking on the link "By Type Of Renewable Source" For the “year to date” (October, 2020) figures, calculating with the usual Excel functions, we can see that so called “renewable energy” in the United States this year generated 694,137 GWh of electricity, which converts to 2.498893 EJ. In the magic “percent talk” so favored by advocates of the so called “renewable energy” scheme, by source, this breaks down to 39.1% from wind energy, 10.9% from utility scale solar PV energy, 0.4% from solar thermal energy, 4.5% from wood and wood products, 1.3% from landfill gas, 0.7% from “biogenic municipal solid waste,” 0.3% from “other biomass waste,” 2.0% from geothermal, 35.5% from conventional hydroelectricity, and 5.0% from “estimated small scale solar,” presumably home solar systems. It is important to note that in terms of being available in connection with actual power demand, only hydroelectric, wood and wood products, landfill gas and municipal and other biomass waste can be adjusted to demand loads. Hydroelectricity’s availability is certainly threatened by the massive droughts now covering the United States. As of this writing, according to the US Drought Monitor, 66.41% of the US land area was experiencing drought, 22.21% of it in extreme or exceptional drought D3-D4. Hopefully this will not prevail.

If you have had the opportunity to expose yourselves to “renewables will save us” types – our benighted E&E forum on this website is a wonderful place to do this – you may find (and it’s certainly been my experience) that the majority of them are most interested in replacing nuclear energy as opposed to dangerous fossil fuels, although in recent years they will pay some rather absurd interest, in displacing coal which has the second highest capacity utilization after nuclear, but none in displacing dangerous natural gas, because without access to dangerous natural gas, the so called “renewable energy” industry would be requiring people to spend considerable portions of their lives without electricity, something that is familiar to citizens of poor countries. The absurdity of the notion that so called "renewable energy" displaces coal is connected that after nuclear, coal has the highest capacity utilization of any electrical energy source and thus is predictable, whereas so called "renewable energy" has a low capacity utilization and is unpredictable. Despite the routine and widespread attacks on nuclear energy, based on the premise that if anyone, anywhere dies from radiation it is therefore acceptable to let millions of people die from air pollution, the nuclear industry in the United States still provides more electricity than all so called “renewable energy” facilities, including hydroelectric facilities, using reactors that were largely all completed by 1985, 35 years ago, designed using 1960’s and 1970’s technology, primitive computational capacity, and over a period of about 20 years. It was about 1970, half a century ago, that the large scale media and organizational attacks on nuclear energy, coupled with renewable energy hype, and rock and roll superstars. While neither Bonnie Raitt nor Jackson Browne would never dream to let Nobel Laureate Glenn Seaborg tell them how to play slide guitar, she and he certainly felt qualified to tell him that his life’s work, including a stint heading the Atomic Energy Commission (AEC), was not workable.

Go figure.

Oh, and coal is not dead in the US despite all the glib dismissive eulogies posted here and elsewhere for it. Worldwide, outside of the provinces in which Americans live, coal has proved to be the fastest growing source of energy worldwide in the 21st century, although this growth is slowing as we enter its third decade. If one reads a scientific journals on energy, one may see by merely scanning the tables of contents, how many articles are written assuming the its future is secure. As long people embrace the lie that so called "renewable energy" is an alternative to coal - it isn't - the longer coal will be with us.

What follows in the text is a discussion of the problem of obtaining carbon dioxide short of direct air capture - or as I discussed above oceanic capture - and consider the fact that the fermentation process to produce ethanol could provide 44 million metric tons of carbon dioxide. This is, however, a trivial amount of the gas.

They write:

Fuel precursors, such as bio-oils from pyrolysis or hydrothermal liquefaction of biomass, have appreciably higher energy contents than CO2. Their heats of combustion are on the order of 40–70% gasoline (Figure 7). Using similar logic as the above CO2 example, one could conclude that these materials may serve as a better starting point for electrofuels. However, biomass is not energy-dense nor is it easily aggregated (Figure 8). Therefore, economically processing a precursor into a fuel or a higher valued chemical or material requires technology that can be deployed economically at small scale (less than 1000 barrel of oil equiv/day) and then numbered up rather than scaled up to achieve the required throughput. We have shown, in one instance,(53) a design for a waste-to-fuel facility that employed equal capacities of hydrothermal liquefaction and electrochemically activated upgrading, that there is a crossover in economics between numbering up and scaling up that is more traditional in chemical engineering. The crossover occurred at a nameplate capacity of about 13 000 boe/day, which is larger than any of the resources depicted in Figure 8.

Figure 7:

The caption:

Figure 7. Map showing that converting biomass-derived feedstocks into fuels requires the addition of less energy than reverting CO2. Heating values of the feedstocks (CO,(33) pig manure,(46) wood,(47) and wastewater sludge(48)) are approximate and depend upon the source and ash content. Heating values of the products (pyrolysis oil(49) and HTL biocrude(50)) are similarly variable and depend upon the feedstock and processing conditions.

Figure 8:

The caption:

Figure 8. Site availability of waste precursors to fuels.(51,52) The entry for CO2 corresponds to the amounts emitted by ethanol fermentation. The right most entry is for ethanol produced by a dry mill.

Reference 52 in the caption is open sourced and is here: Modularized production of fuels and other value-added products from distributed, wasted, or stranded feedstocks (Weber et al., WIREs Energy Environ. 2018;7:e308. ) It indicates that all of this "waste carbon" described above amounts to only about 6% of US petroleum production.

The authors then turn to other concentrated sources of carbon dioxide, one of which is the carbon dioxide produced from the fermentation of grain to make ethanol fuel for cars. They note that the 15 billion tons of ethanol produced each year in the United States results in the production of 44 million tons of CO2 gas. This amounts to about 0.125% of the carbon dioxide we dump into the planetary atmosphere worldwide.

Having the carbon dioxide however, still requires reversing combustion - in effect recovering all of the energy that went into the formation of the carbon dioxide. The authors provide a table reflecting how much energy (ignoring entropy) is required to make some common fuels:

Now things get interesting since the authors deign to discuss the land use requirements were we to reduce this carbon dioxide using the wind turbines we are continuously trained to believe will save the world even if they haven't saved the world, aren't saving the world and won't save the world. They do so while considering the continuously ignored issue of capacity utilization as opposed to peak power.

Pay attention and note that the amount of CO2 being reduced is only that from US ethanol plants, 0.125% of all carbon dioxide dumped each year.

To wit:

That energy could, in principle, be sourced from renewable electricity; however, the magnitude of the energy input would require a dedicated facility or at the minimum the equivalent construction. There are roughly 200 ethanol fermentation facilities in the U.S. The nameplate capacity of a modern wind turbine now exceeds 3.1 MW of power.(34,35) Therefore, the average fermentation plant would require input from about 350 wind turbines.

Turbines have a land usage(36) of about 35 ha/MW nameplate. The average capacity factor of a modern turbine in the U.S. is 30–40%; (37) therefore, the 216 GW of power generation needed to revert carbon dioxide from all of the U.S. fermenters would require access to at least 19 million ha

which is nearly 50% more than the amount of land needed to grow the corn(38) (15 billion gallons per year at 462 gallons/acre = 13.1 million ha) and larger than the state of Iowa. The land comprising the wind park could be dual-use(39) (farming and power generation), and there are reports of wind turbines benefiting the growth of crops.(40−42) However, some of the wind park is needed for roads and other ground structures that could interfere with the mechanized farming associated with the high yield of corn. The nameplate capacity of the U.S. fleet of wind turbines(35,43) at the end of 2019 was 106 GW, but as noted above, the average capacity factor(37) (actual/maximum) is only about 33%; therefore, equipping all of the U.S. ethanol fermenters to convert their waste carbon dioxide back into fuel would require about 6 times the current total wind-generated electricity now produced in the U.S.

Therefore, making electrofuels from CO2 is challenging in the near term and includes, minimally, adding significant amounts of clean generating capacity along with energy storage and making the electrofuels energy-efficiently. We discuss the capital cost of this option below.

I have added the bold in the above excerpt.

It is popular to wax romantic about electric vehicles, a belief system that embraces the fantasy - but not the observed reality - that all of the electricity that comes out of the wall is generated by so called "renewable energy." It doesn't. The amount of electricity generated from the combustion of dangerous fossil fuels is rising, not falling.

Because of the fact that electric power still comes mostly from dangerous fossil fuels, converting liquid fuel vehicles to electric vehicles, ignoring the mining of vast amounts of copper, lithium, and cobalt (if it can be found) as shown in the following two graphics from the text, will be no better than raising the fuel efficiency of vehicles. Note that this assumes that we don't run out of fracked gas, although nobody really knows how long these gas fields will continue to produce.

The caption:

Figure 9. Electrifying the fleet using today’s technology would decrease the energy demand of the transportation sector much more than would doubling fuel economy, but given the current mix of technologies employed to generate electricity on the grid, electrifying the fleet will ameliorate only about the same amount of GHG emissions as will that doubling in fuel economy. Vehicle usage comes from the U.S. Department of Transportation.(18)

The caption:

Figure 10. Electrifying the fleet of heavy-duty trucks could also provide significant energy savings but could increase criteria emissions. NOx emission rates for hydrocarbon-fueled vehicles assume 0.1 gNOx/bhph today and 0.05 gNOx/bhph for more efficient vehicles. SOx emission rates for hydrocarbon-fueled vehicles assume the use of ultralow sulfur diesel (15 ppm of S). NOx and SOx emission rates for electricity generation from the U.S. EPA survey of power plant data,(80) namely, 0.097 MtNOx/EJ and 0.11 MtSOx/EJ. Hg emissions are those allowed by 40 CFR Parts 60 and 63, applied to the amount and types of coal employed in electricity generation in the U.S. (1.2 tHg/EJ). Vehicle usage statistics come from the U.S. Department of Transportation.(18)

The caption:

Figure 11. Major regions of the U.S. grid would offer different savings in GHG and criteria emissions because they employ different generating technologies (fossil-fueled steam generators, wind power, hydroelectricity, nuclear, and solar). Data were from EIA.(83)

Savings and losses in terms of greenhouse gases is dependent on where the grid is. Note that the heavy reliance in the West on the destruction of rivers for hydroelectric plants depends on it raining, something that is likely to fluctuate under the climate change conditions we have done nothing, nothing at all to address. Despite all the wind and solar talk over the last half a century, the rate at which carbon dioxide concentrations are accumulating is rising, not falling, and doing so dramatically.

It is also notable that the paroxysms of pernicious fear and ignorance, nuclear plants are being shut, with contempt for all future generations.

Grid dependence:

It is technically straight forward to eliminate all fossil fuels from electricity generation by the use of nuclear power, particularly in the case of advancing their design over the 50 year old technology under which our existing, and still operating, nuclear reactor fleet by the incorporation of heat exchange networks, as described above.

It is instructive to consider the land use requirements of providing all of the electricity. For reference, let's consider the Diablo Canyon nuclear plant, the last plant in California, due to be shut, which has two reactors, each of which routinely provides, uninterrupted, 1140 MW of electricity, which is roughly 1/3 of the thermal output provided by the fission of uranium and plutonium. The plant is situated on 900 acres of land, but most of this land is beautiful undisturbed chaparral. The two reactors, with their parking lots, take up about 12 acres of land.

Above we see, in figure 6, that the electric power consumed in the United States amounts to 14.2 exajoules per year. From this, we can calculate that about 400 reactors would be required to completely eliminate all carbon dioxide output connected with electricity, about 4 times as many as we built between 1965 and 1985, using primitive technology. (If, using the techniques described above, we were to raise the thermodynamic efficiency of these plants to 60%, a little over 200 would be required.)

An acre of land is equal to approximately 0.405 hectares. Thus the Diablo Canyon plant itself takes up about 5 hectares, and the surrounding land belonging to the power plant takes up about 365 hectares. The 3.1 nameplate wind turbines, which, allowing for capacity utilization of 33% as suggested in the authors' text, produces about 1 MWe on 35 hectares of land, means that to provide the same electrical power that the Diablo Canyon reactors produce would require 2280 MW * 35 hectares/MW = 79,800 hectares.

Note that this land, unlike the Diablo Canyon site, whose 365 hectares are mostly pristine, the 79,800 hectares would need to be crisscrossed with asphalt or concrete service roads.

The 19 million hectares, described above for the reduction of ethanol's carbon dioxide side product, would also be reduced. The average continuous power produced by 216 GW of power from any source at 100% capacity utilization is about 6.8 exajoules, a huge portion of the current electricity production. This would require about 200 nuclear reactors to meet, although, as I spent considerable time describing above, it would be stupid for a nuclear plant to produce electricity to reduce carbon dioxide, since thermochemical means would be far superior via high thermodynamic efficiency. But if we used the 40-50 year old technology used to design Diablo Canyon, and only produced electricity, 216 GW/(2.28 GW/nuclear plant = 95 nuclear plants would be required. At 365 hectares, mostly unused per nuclear plant, this amounts to around 35,000 hectares, most of which would be undisturbed land, or about 0.2% as much land.

It's been my experience that no amount of information can change the mind of anti-nuke, notwithstanding the fact that when I was young and stupid, I was an anti-nuke. Most anti-nukes, I've observed, are very much unlike me however; their minds are set in stone. They're rather like Republicans in this way.

However, were one to embrace common sense, the implications here should be obvious. They won't be, but they should be.

History will not forgive us, nor should it.

I trust that your New Year will be happy, healthy, and productive.

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Reply Synthesizing Clean Transportation Fuels from CO2 Will at Least Quintuple the Demand for Electricity. (Original post)
NNadir Jan 2021 OP
mahatmakanejeeves Jan 2021 #1
NNadir Jan 2021 #2
keithbvadu2 Jan 2021 #3
My Pet Orangutan Jan 2021 #4

Response to NNadir (Original post)

Sun Jan 3, 2021, 10:29 AM

1. TL; DR, but: "electricity produced by combustion of dangerous fossil fuels is rising, not falling.."

{I had to truncate the quote to get it to fit}


Oh, and coal is not dead in the US despite all the glib dismissive eulogies posted here and elsewhere for it. Worldwide, outside of the provinces in which Americans live, coal has proved to be the fastest growing source of energy worldwide in the 21st century, although this growth is slowing as we enter its third decade. If one reads a scientific journals on energy, one may see by merely scanning the tables of contents, how many articles are written assuming the its future is secure. As long people embrace the lie that so called "renewable energy" is an alternative to coal - it isn't - the longer coal will be with us.

Do you have a graph showing this nation by nation? And the same thing, but for generation by hydroelectric facilities? It seems to me that you posted such a chart once, or it might have been progree who did that. It might have been a year ago.

Thanks. I'll get to this if I have the time.

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Response to mahatmakanejeeves (Reply #1)

Sun Jan 3, 2021, 10:48 AM

2. The statement is based on the 2019 IEA Worldwide Energy Outlook.

I have not yet downloaded the 2020 version, but will do so when the libraries reopen post Covid-19. Over many years of reviewing this annual report, I have noted a consistent and unbroken rise in both energy consumption, and the use of dangerous fossil fuels, and I would be surprised if the 2020 report varied from this trend. The 2021 report, should I live to read it, might be fun as a result of the lockdowns around the world. The fastest way to look at the effect of the lockdowns is to look at the accumulation of carbon dioxide in the atmosphere. I do this weekly. I don't see much of an effect of the lockdowns. It's pretty much consistent with the period from 2011-2020 being the worst ever.

The full editions of the WEO often breakdown the cases by region, but I have not tended to focus on these over the years.

You may be referring to these tables, which I keep handy in a word file for posting when appropriate:

Here is a table of sources of energy taken from the International Energy Agency’s 2017, 2018, and 2019 Editions of the World Energy Outlook:

In this table I have converted MTOE in the original table to the SI unit exajoules in this text. An original table from page 38 of the 2019 edition is here:

2019 Edition of the World Energy Outlook Table 1.1 Page 38]

Additional tables with my commentary are here:

World Energy Outlook, 2017, 2018, 2019. Data Tables of Primary Energy Sources.

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Response to NNadir (Original post)

Sun Jan 3, 2021, 11:20 AM

3. 1+

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Response to NNadir (Original post)

Fri Jan 29, 2021, 12:38 AM

4. An impressive and intimidating amount of work - thank you.

I'm going to start getting educated.

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