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NNadir

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Climate change contributes to widespread declines among bumble bees across continents.

The paper I'll discuss in this post, having the same title as the post, is this one: Climate change contributes to widespread declines among bumble bees across continents (Peter Soroye1,*, Tim Newbold2, Jeremy Kerr1, Science Vol. 367, Issue 6478, pp. 685-688 2020)

Reference to the article is included in a news item in the same issue of science, from which I'll quote before referring to the paper itself, since it is so well written, and makes a trenchant ecological political point. The news item:

Discovering the limits of ecological resilience (Jon Bridle, Alexandra van Rensburg, Science Vol. 367, Issue 6478, pp. 626-627, 2020).

To wit:

n 1949, environmentalist Aldo Leopold wrote that “one of the penalties of an ecological education is that one lives alone in a world of wounds” (1). Seventy years later, biologists no longer witness such wounds in solitude. Instead, millions of people on social media share evidence every day of how the behavior of a wealthy minority (2) has created unsustainable rates of biodiversity loss and climate transformation (3). Now, on page 685 of this issue, Soroye et al. demonstrate widespread declines in bumble bee species that are better explained by the frequency of climate extremes than by changes in average temperatures (4).


The, um, behavior of a wealthy minority...

Of course, here we like to argue that the wealthy minority consists of people, venal people who are not us, you know, Donald Trump, Koch, Koch, Koch, Koch, Adelson, Murdoch, Murdoch...

We're not "rich."

Bridle and van Rensberg continue:

Despite increasingly precise predictions of rises in average temperatures and the frequency of extreme weather events, biologists still cannot predict how ecological communities will respond to these changes. This means that scientists cannot predict where, and at what rates of climate change, ecosystems will stop providing the rainfall, decomposition, and biological productivity on which all economies depend. Another key unknown is to what extent ongoing habitat and biodiversity loss reduces the ability of ecological communities to evolve in response to the climate crisis (3).

To determine these critical rates of biodiversity loss and climate change as well as where they are being exceeded (5), scientists test for shifts in the distribution of species over time and across their geographical ranges. Such studies reveal that the warming climate leaves a footprint: The abundances of many plant, animal, and fungal species have contracted at low latitudes and elevations, and have increased at high latitudes and elevations (6). How these responses to environmental change vary according to species' life histories, ecologies, and their biotic interactions provides a test of which ecosystems and localities are least resilient to global change.

Soroye et al. used long-term datasets to assess changes in the abundance and geographical distribution of 66 bumble bee species in Europe and North America between two periods, 1901–1974 and 2000–2014. Two of their findings are especially alarming. Bumble bee populations showed substantial declines at southern (warming) ecological margins but fewer compensating population expansions at northern (cooler) margins, suggesting widespread declines in bee biodiversity across both continents. Moreover, the causes of these declines apparently depend more on the frequency of extremely warm years than on increases in average temperatures. As prevailing temperatures climb closer to species' physiological limits, extreme climate events will become increasingly associated with biodiversity loss. In addition, their effects will become more pronounced as cooler habitats, where organisms can survive unusually warm periods (e.g., deeper water, higher elevations), become increasingly rare...


The behavior of a wealthy minority...

We're not rich. Really, we're not.

I personally rail quite a bit about a little fact that um, troubles me:

Today, 2.2 billion people lack access to safely managed drinking water services and 4.2 billion people lack safely managed sanitation services. Unsafe hygiene practices are widespread, compounding the effects on people’s health. The impact on child mortality rates is devastating with more than 297 000 children under five who die annually from diarrhoeal diseases due to poor sanitation, poor hygiene, or unsafe drinking water.


United Nations Water: Water, Sanitation and Hygiene

If any of this troubles you, don't worry, be happy.

Head over to the E&E forum where you can read about the wonders of Elon Musk's car for spoiled children, which is built using cobalt mined by real children working for zero wages under the point of guns, um, slaves, in "The 'Democratic' 'Republic' of the Congo"



"Energy Sage"

The annual per capita income of "The 'Democratic' 'Republic' of the Congo" is reportedly $562, less than $2.00/day.

The "cheap" Tesla car costs more than 60 times the per capita income of "The 'Democratic' 'Republic' of the Congo." The, um, luxury model, costs "only" 220 times as much.

Don't worry, be happy. If you own a Tesla car, you're not rich; you're "green."

Those kids digging cobalt are not afforded the luxury of being green with envy as they admire your Tesla car. They've probably never seen one. They are probably not even aware of what this is all about; since even that would require a rudimentary education. The guns and the whips are all they need to know to understand what this is all about.

Don't worry. Be happy. All that fracking is transitional because soon enough we will drag giant steel posts for wind turbines through every virgin ecosystem on the planet and be "green." We swear. We swear. We'll build those wind farms right on through 500 ppm of CO2, and be so proud of ourselves for being "green."

You're not rich, because you live in a country that is the world's largest debtor, run by a brainless cheap carny hack criminal who is the pet puppy of an ex-KGB agent and who is coddled by a bunch of thugs who used to wrap themselves in American flags and complain about "those commies."

You're not rich. You had nothing to do with those bumble bees and their bumble bee problems.

About the bees, from the introduction to the paper cited at the outset:

Recent climate changes have accelerated range losses among many species (1, 2). Variation in species’ extinction risk or chances of colonizing a new area determine whether species’ ranges expand or decline as new climatic conditions emerge. Understanding how changing climatic conditions alter species’ local extinction (extirpation) or colonization probabilities has proven exceptionally challenging, particularly in the presence of other environmental changes, such as habitat loss. Furthermore, identifying which species will most likely be at risk from climate change and where those risks will be greatest is critical to the development of conservation strategies (3, 4).

Although many mechanisms could alter how species fare as climate changes, discovering processes that strongly affect species persistence remains among the foremost challenges in conservation (5). Climate change could pose risks to species in part by increasing the frequency of environmental conditions that exceed species’ tolerances, causing population decline and potentially extirpation (6, 7). Conversely, climate change may render marginal areas more suitable for a species, making colonization of that locale more likely (1). Understanding and predicting spatially explicit colonization and extinction likelihood could identify which species are vulnerable to climate change and where, identify which species may benefit, and suggest interventions to mitigate conservation risks. Colonization and extinction dynamics, in combination across a regional species assemblage, determine how species richness changes. Among taxa that contribute critically to ecosystem service provision, including pollinators such as bumble bees (Bombus), species richness decline could impair ecosystem services (8).

We evaluated changes in bumble bee species occupancy and regional richness across North America and Europe using a database of ~550,000 georeferenced occurrence records of 66 bumble bee species (figs. S1 and S2 and table S1) (1, 9). We estimated species’ distributions in quadrats that measured 100 km by 100 km, in a baseline (1901–1974) and recent period (2000–2014) (9). Climate across Europe and North America has changed greatly between these time periods (fig. S3). Although the baseline period was substantially longer, there were 49% more records in the recent period. Non–detection bias (difficulty distinguishing among true and false absences due to imperfect detection) in opportunistic occurrence records can reduce measurement accuracy of species distributions and overall richness (10). Consequently, we used detection-corrected occupancy models to estimate probability of occurrence for each species in quadrats in each time period (9). We calculated changes in species’ probabilities of occupancy and generated detection-corrected estimates of species richness change between periods (fig. S4).

We predict greater declines in bumble bee species occupancy and species richness where changing climatic conditions more frequently exceed individual species’ historically observed tolerances. Conversely, we predict greater occupancy and species richness in areas where climate changes more frequently cause local weather to fall within species’ historically observed tolerances.


Figure 1 from the paper:



The caption:

Fig. 1 Change in community-averaged measures from the baseline (1901–1974) to the recent period (2000–2015).

Local changes in (A) thermal and (B) precipitation position indices are shown. Increases indicate warmer or wetter regions and that, on average, species in a given assemblage are closer to their hot or wet limits than they have been historically. Declines indicate cooling or drying regions and that, on average, species in a given assemblage are closer to their cold or wet limits than they have been historically


More text:

...Our measurements of bumble bee species occupancy over time provide evidence of rapid and widespread declines across Europe and North America. The probability of site occupancy declined on average by 46% (±3.3% SE) in North America and 17% (±4.9% SE) in Europe relative to the baseline period (Fig. 2). Declines were robust to detection-correction methods (figs. S6A and S7) and consistent with reductions in detection-corrected species richness (fig. S6B) (9)...


Figure 2:



The caption:

Fig. 2 Percent change in site occupancy since a baseline period (1901–1974) for 35 North American and 36 European bumble bee species.


More text:

...Declines among bumble bee species relate to the frequency and extent to which climatic conditions approach or exceed species’ historically observed climatic limits, particularly for temperature. We modeled change in probability of site occupancy with phylogenetic generalized linear mixed models using thermal position variables (baseline, change since baseline, and the interaction between these), precipitation position variables (baseline, change since baseline, and the interaction between these), the interaction between baseline thermal and precipitation position terms, and the interaction between change in thermal position and change in precipitation position. We controlled for continent (9). The models support our predictions: Probability of occupancy decreases when temperatures rise above species’ upper thermal limits (Fig. 3A, fig. S8A, and table S2), whereas warming in regions that were previously near species’ cold limits is associated with increasing occupancy. Evidence for precipitation influencing site occupancy was mixed, but declines were more likely in sites that became drier (Fig. 3B, fig. S8B, and table S2)...


Figure 3:



The caption:

Fig. 3 Change in probability of occupancy in response to change in thermal and precipitation position from the baseline (1901–1974) to the recent period (2000–2014).

Thermal (A) and precipitation (B) positions range from 0 to 1, with 1 indicating that conditions at a site are at a species’s hot or wet limit for the entire year and 0 meaning that conditions are at a species’s cold or dry limit for the entire year during the historic period. For ease of visualizing the significant interaction between baseline thermal position and change in thermal position, the continuous baseline thermal position variable has been split at the first and third quantile to show sites that were historically close to species’ hot limits (red; n = 969 sites), cold limits (blue; n = 2244 sites), and the middle of their observed climatic limits (purple; n = 11,793 sites). Rug plots show the distribution of observations. Confidence intervals (±95%) are shown around linear trendlines.


More text:

Bumble bee species richness declined in areas where increasing frequencies of climatic conditions exceed species’ historically observed tolerances in both Europe and North America. An analysis of covariance that modeled the response of detection-corrected richness to community-averaged measures of climatic position revealed that, consistent with observed trends in species-specific occupancy change, richness was more likely to decline in regions experiencing warming, especially when species present were in the warmest parts of their historical ranges (table S2)...

...Projections suggest that recent climate change has driven stronger and more widespread bumble bee declines than have been reported previously, especially in Europe (Fig. 4). European estimates of observed richness rely particularly on observations from well-sampled regions that were cooler in the baseline period and that have experienced less warming subsequently (9), which may have contributed to underestimation of recent species richness decline across that continent (figs. S6B, S9, and S10). These findings contrast with those for other taxa that predict widespread range expansions and increasing species richness toward warming environments in the north (13, 14).


Figure 4:



The caption:

Fig. 4 Climate change–related change in bumble bee species richness from a baseline (1901–1974) to a recent period (2000–2014).

Predictions are from a model projecting percent change in detection-corrected bumble bee species richness as a function of mean community-averaged thermal and precipitation position.


Some concluding remarks from the paper:

Climate is expected to warm rapidly in the future (20). Using a spatially explicit method of measuring climatic position and its change over time, we show that risks of bumble bee extirpation rise in areas where local temperatures more frequently exceed species’ historical tolerances, whereas colonization probabilities in other areas rise as climate changes cause conditions to more frequently fall within species’ thermal limits. Nevertheless, overall rates of climate change–related extirpation among species greatly exceed those of colonization, contributing to pronounced bumble bee species declines across both Europe and North America with unknown consequences for the provision of ecosystem services. Mitigating climate change–driven extinction risk among bumble bees requires efforts to manage habitats to reduce exposure to the growing frequency of temperatures that are extreme relative to species’ historical tolerances.


The bold is mine.

...efforts to manage habitats...

Don't worry. Be happy. It's not your problem, those bumblebees. Transitional gas...solar roof...wind turbine...Elon Musk...Your SpaceX ticket to Mars...not your problem...you're for all of it. aren't you?.

You know what? Some of those bumble bees are nasty anyway. They can sting you. Some of them are boring insects and they can drill holes in the wood in your deck from which you can admire the view, and cost you thousands of dollars, way more than $2/day.

...efforts to manage habitats...

The whole world is a habitat.

I am a member of that awful Baby Boomer generation. When we were kids we used to huddle in front of black and white televisions with tiny screens and watch those Japanese monster movies - "science" fiction - where all the world's political leaders would call upon the world's scientists - who were always deeply respected and whose advice was always taken.

I actually used to believe the world worked like that, but then again, I was eight years old and now we are all eight years old, in a very different world.

Don't worry. Be happy.

History will not forgive us, nor should it.

TGIF tomorrow. Enjoy it.

Electrochemical Molecular Switches for the Capture and Release of Uranium.

The paper I'll discuss in this post is this one: Redox-switchable carboranes for uranium capture and release (Gabriel Ménard et al, Nature volume 577, pages 652–655(2020))

According to a DOE report, DOE/EM-0275 as of 1996, the US government had in stock about 585 million kg of depleted uranium, beyond the 25 million kg enriched to about 3% in U-235, about 610 million kg.

A kg of plutonium, the starting material for which is depleted uranium, contains about 80.3 trillion joules of energy, completely fissioned.

The world was, as of 2018, consuming about 600 exajoules (600 million trillion joules) of energy each year.

Recently there have been efforts by a number of companies, one of the most well known being Bill Gates' Terrapower, to commercialize "breed and burn" type reactors that transmute depleted uranium into plutonium in situ.

It follows that this US inventory is sufficient, at current levels of energy demand to power all the world's energy for about 80 years, no dangerous natural gas, no dangerous petroleum, no coal mining for energy purposes. Of course, there are other uranium inventories elsewhere in the world. In addition, a side product of the useless wind industry and the electric car industry, both of which depend on access to iron neodymium boride magnets, often doped with dysprosium - lanthanides - is the radioactive element thorium. Collected from lanthanide mile tailings, dumps, in which the thorium has been partially refined, this thorium is also a valuable nuclear fuel. It is reasonable to say that in a "breed and burn" powered world it would be unnecessary to mine any fuels for several centuries.

Fracked rock, which has been eternally pulverized for a few decades of "good times" by all of us self declared "green" people also represents a potential source of uranium: The radon dumped by the gas industry in Pennsylvania's Reading Pronge gas fields indicates that this pulverized rock, over which water may flow for millenia upon millenia, is also a potential uranium source.

Finally, since that establishment of oxygen in the planetary atmosphere, a continuous uranium cycle has been established in the planetary oceans; they contain about 4.5 - 5 billion tons of uranium.

There has much discussion of refining uranium from dilute sources, seawater, run-off from uranium mine tailings, and natural uranium formations both for the purposes of obtaining fuel as well as to remediate areas of anthropomorphic contamination or natural uranium flows. Uranium is a chemotoxic element, notably having effects on renal and other tissues. Many thousands of papers on this subject have been published in the scientific literature; I almost certainly have hundreds in my personal electronic files. Many of these papers concern organic resins, notably amidoxime functionalized resins. There are also inorganic species that have been advanced for this purpose. What is of interest about this laboratory scale material is that it can more or less breathe uranium, in effect "inhale" and "exhale" it by the application of electrical currents.

From the introduction:

Known for over 50 years, carboranes have been extensively studied in coordination chemistry (including with U), catalysis, luminescence, and energy storage applications10,11,12,13,14,15. Studies have shown that reduction of substituted closo-carboranes to the nido-carboranes results in rupture of the C–C bond and cage opening, with a simultaneous increase in ligand bite angle, θ (Fig. 1a; closo and nido refer to 2n + 2 and 2n + 4 framework bonding electrons, respectively, where n is the number of vertices)11,14,16,17,18. We rationalized that by incorporating donating groups to ortho-carborane, we could tune the chelating properties of the cluster switching from opened to closed conformations by redox control of the reduced and oxidized states, respectively, and enable the chemical or electrochemical capture and release of uranyl in solution (Fig. 1a).


Closo and nido refer to something known as the "Wade-Mingo" rules, and refer to the presence of a complete platonic solid structure, in this case icosahedral symmetry, having all vertices represented, closo or one vertex missing, nido. (The symmetry of in these cases is not truly icosahedral, since the symmetry is "disturbed" or "degraded" by the presence of the functionalized carbon. The carbon in this boron hydride structure is functionalized with diphenylphosphine oxide.

Figure 1:



The caption:


a, General chemical or electrochemical mono- or bi-phasic capture of uranyl from UO2X2L2 (X = Cl−, OAc−; L = THF, Ph3PO) using the reduced ‘open’-cage nido-carboranes (2a/2b) generated by reduction (for example, CoCp∗2CoCp2∗ or negative bias) of the ‘closed’-cage closo-carborane (1). The corresponding relative bite angles (θ are also shown. Oxidation (for example, [FeCp2][PF6] or positive bias) of the captured products 3/4 or 3N/4N leads to UO22+ release. Compounds labelled in green have been chemically isolated, whereas compounds in orange are proposed electrochemical products (see Methods). Blue and red pathways represent UO22+ capture and release, respectively. b, c, Solid-state molecular structures of 4 (b) and 3 (c) obtained from XRD studies. H atoms, [CoCp∗2]+[CoCp2∗]+ counter cations, phenyl C–H linkages and all co-crystallized solvent molecules are omitted for clarity. See Extended Data Fig. 1for the structures of 1 and 2a.


Many of the experiments described in the full paper take place in organic solvents, which of course, is not seawater, but nevertheless the system is definitely quite interesting, and one can imagine modifications.

Anyway, the system operates electrochemically.

Figure 2:



The caption:

a, Illustration of the H-cell used, incorporating excess Fc/Fc+ (left) and 1, TPO and [UO2Cl2(THF)2]2 (right) in a 3:1 PC:benzene solvent mixture. Charging the cell (blue) leads to the capture of UO22+, converting 1 to 4N (major product) and 3N (minor product, not shown). b, Quantification of products and reactants by 31P{1H} NMR spectroscopy against an inert internal standard, [Ph3PNPPh3][PF6] (not shown). The initial spectrum is shown in grey, whereas spectra acquired during charge and discharge cycles (1–6) are shown in blue and red, respectively. c, Bottom, applied galvanostatic potentials for charge (blue) and discharge (red) cycles. Dashed lines represent wait periods, which were necessary for 31P{1H} NMR data acquisition. Each cycle is 24 h. Top, instrumental measure of delivered charge (teal) versus charge used for the reduction of 1, measured by quantifying the total reduced products, 3N and 4N, by 31P NMR spectroscopy. See Methods and Extended Data Figs. 6, 8 for additional experimental details and data.


The issue of organic solvents is addressed as shown in figure 3, which essentially is an extraction procedure.

Figure 3:



The caption:

Fig. 3: Simplified depiction of half H-cell and spectroscopic measurements for the biphasic electrochemical capture/release of dissolved UO22+ (yellow sphere) from/to buffered aqueous solutions. See Methods and Extended Data Fig. 7 for an expanded stepwise figure and all experimental details. a, Biphasic mixture of UO2X2 dissolved in a NaOAc-buffered aqueous solution (pH 5.4) and of electrochemically generated 2bfrom 1 (X = OAc− or NO3−. Inset, aqueous UV-Vis and organic 31P{1H} NMR spectra after reduction of 1 to 2b, but before phase mixing. Residual 1 is observed in the latter owing to the set SOC. b, Simplified depiction of the captured UO2X2 in the form of 3N and/or 4N. Inset, aqueous UV-Vis spectrum showing the capture of UO2X2 by the 2b/DCE layer (top); the corresponding 31P{1H} NMR spectrum of the DCE layer showing the captured major product (3N/4N) and minor residual 1 (bottom). c, Biphasic release of UO2X2 from the DCE layer to a fresh NaOAc-buffered solution (pH 5.4), following electrochemical oxidation of 3N/4N. Inset, aqueous UV-Vis and organic 31P{1H} NMR spectra of free UO2X2 and 1, respectively—both consistent with the release of captured UO2X2 from the DCE to the aqueous phase. A small amount (~20%) of unknown byproducts (marked by asterisks) is also observed in the 31P{1H} NMR spectrum.


Note that exposure to organic solvents would not be acceptable unless the organics were destroyed by subsequent processing. One such available approach to processing would involve subjecting the resultant aqueous solution to supercritical conditions, whereupon the solvent residues would be oxidized to carbon dioxide and the water reduced to hydrogen.

This is a lab scale procedure, and it seems to me that a number of issues need to be addressed before anything like this could be run on an industrial scale. Then again, as stated at the outset, the "breed and burn" concept means that there is really no need to obtain more uranium than has already been mined, at least for several centuries, so there's plenty of time to do that, to make nuclear energy essentially inexhaustible. (At the end of my life, it does seem that ultimately fusion energy may be viable, but current isolated uranium might make the world survivable in the interim.

It's a nice little interesting paper, I think.

Have a nice day tomorrow.

My wife made me watch a wonderful movie with her yesterday.

My wife loves movies; I'm sort of "so-so" on watching movies; I generally refuse to watch horror movies, disaster movies, and the like.

(My wife likes to watch movies that put her to sleep, at least after the sixth or seventh time she's seen them. It's a joke in our family.)

We had some rare time alone together to enjoy one another yesterday, and she insisted I watch a movie with her, a romantic comedy.

It was a wonderful film, touching in a fairly profound way on the cultural clashes that can take place in immigrant communities with the American culture. (My father-in-law experienced this as he was first generation Italian American, something that had effects on my marriage to a second generation half Italian American.)

This film was particularly poignant because it was made before the age of the racist idiot "pResident" in the White House, because the immigrant culture in question was Islamic, Pakistani in fact.

It was a very sweet and in someways profound romantic comedy. It is also a true story, and if you watch it on DVD it is definitely worth watching the extra features.

This is the movie in question:

The Big Sick

The biggest star in it is Holly Hunter, and she does an outstanding job. In the role she plays, mother of the native American in the love object in the film, her character is also dealing with a cultural clash in her marriage, a clash between a right wing North Carolina culture with the New York culture of her husband.

A lovely film.

Separation of Three Phases, Gas, Liquid and Solid Using a Cyclone Injected with Hot Hydrogen.

The paper I'll discuss in this post is this one: Hydrocyclone Settler (HCS) with Internal Hydrogen Injection: Measure of Internal Circulation and Separation Efficiencies of a Three-Phase Flow (Roberto Galiasso Tailleur, Andres G. Peretti, Ind. Eng. Chem. Res. 2020, 59, 3, 1261-1276) Dr. Tailleur is a Chemical Engineer whose affiliation in the paper is listed as Simon Bolivar University in Miranda Venezuela. Venezuela, for those who do not know, is a large producer of the dangerous fossil fuel petroleum, which is toxic in not only environmental and epidemiological sense, but is also toxic in an economic and political sense. This has certainly been true in Venezuela. Venezuela is a case in point that political and economic absolutism on the far left is not particularly less odious and less destructive than political and economic absolutism on the right. The main product of the country these days is economic refugees.

This paper is about the processing of dangerous fossil fuels, and concerns the catalytic alkylation of C2 and C3 alkenes, ethylene and propene, with isobutane, presumably to make the dangerous fuel gasoline.

As an opponent of the use dangerous fossil fuels, on the grounds that they are destroying a future that does not belong to us, that it is not our right to destroy, it may seem strange that I am as interested as I am in this kind of technology. Nevertheless I have been recently emphasizing that many of the technologies in industries that should be abandoned on the grounds they are not sustainable, have use in other industries, or in new uses for expansion of applications of extant industries. Indeed this was historically true of the dangerous petroleum industry. The original purpose for the distillation of dangerous petroleum which was industrially pioneered by John D. Rockefeller, was to make lamp oil to replace whale oil as the over hunting of whales was leading to the decline of the species that had nothing to do intrinsically with pollution, making whale oil expensive and difficult to obtain. The development of the distillation process led to a search for what was then a by product of distillation, gasoline. The destruction of the planetary atmosphere followed in the following century and a half.

I have been making this point as well about the useless solar thermal industry, another so called "renewable energy" industry dependent upon turning huge pristine ecosystems into industrial parks that have low capacity utilization, in this case desert ecosystems. The solar thermal industry will never be able to make economically viable hydrogen to replace the source of more than 98% of the current source of the world's hydrogen, dangerous natural gas and dangerous coal, but the technologies explored in papers around thermochemical water and carbon dioxide splitting cycles that are often described in papers as being applicable to solar thermal technology are equally viable to sustainable and low environmental impact nuclear systems.

According to the reference in the paper, the compounds in the three phases described in this paper for which this hydrocyclone was developed are as follows: The solid is a platinum sulfate-titanium-zirconium catalyst supported on silica, SiO2, basically sand. The gases are isobutane, propene and butene, as described above, and the liquid is the condensate, dangerous alkanes that are components of dangerous gasoline.

Be this as it may, I am always thinking about ways that future generations will clean up the mess that our generation produced in a kind of drunken sybaritic ecstasy of material consumption, albeit the ecstasy in question being distributed among parties in an ever less judicious way.

The biggest mess we leave of course, is a destroyed atmosphere. Among the engineering routes to removing the dangerous fossil fuel waste carbon dioxide from the atmosphere, all of which will be challenging, I personally regard reformation of biomass with supercritical water, supercritical seawater, or supercritical carbon dioxide to be potentially viable routes. These technologies will involve three phase (actually four phase) separations, and thus my interest in the technology. Many, most, if not all, will involve hot hydrogen.

From the introduction of the paper:

Figure 1 shows the new alkylation–regeneration process scheme that is described in detail in refs (1) and (2); it consists of a slurry transport reactor (STR, used for alkylation), two stages of gas–solid–liquid separation in a hydrocyclone stripper (HCS1 and HCS2), and a fluidized bed reactor (FBR, employed for catalyst regeneration). The HCS of Figure 1 is used to separate gases, liquids, and solids from the stream that left the alkylation reactor at 360 K and 1.4 MPa. It delivers solids to the FBR and gases and liquids to other separation stages.(1) The solid obtained (spent alkylation catalyst) in the two HCS stages must be stripped of adsorbed hydrocarbons by hot hydrogen before being fed to a fluidized bed catalyst regenerator. Ninety-five percent of the regenerated catalyst is sent back to the STR. Catalyst purge and make up is a function of catalyst deactivation, HCS efficiency, and fines produced in the process.


Figure 1:



The caption:

Figure 1. Hydrocyclone–settler system.


The introduction continues:

The feed of the HCS is composed of hydrogen soluble in light alkylate and 8% by weight of the catalyst; the latter contains less than 2% of 1–10 μm and more than 97% of 40–60 μm in particle diameter. More than 98% of the solids and less than 10% of liquids must be recovered at the underflow (UF) stream. In this process scheme, two stages are used to obtain the maximum recovery of solids and liquids and deliver preheated solids into the regenerator (Figure 1).
Hydrocyclones have been successfully used in the industrial separation of solids for more than 40 years. The design is simple, easy to operate, and of low operating and maintenance costs; these devices are very important to perform solid separations; nevertheless, high solid efficiency in hydrocyclones is difficult to achieve when there are small differences between liquid and solid densities in the feed and they contain very fine particles. In conventional (isothermal) liquid–solid separation, the average cut size dp50 is related to the inlet pressure at an order of 0.25 and to the hydrocyclone diameter, according to Bradley(2) and Rietema(3) equations...

...Previous experiments with a small hydrocyclone and the study done for the spouted bed reactor development were used to select current base case (BC) dimensions and operating conditions for the new hydrocyclone settler (HCS1). Then, the HCS1 was tested to mainly explore the effect of lower cone lengths, feed and hydrogen flow rates, and temperatures using five types of sensors: ECT, differential pressure, pressure, and temperature as well as by sampling. In addition, other amounts and particle size distributions were used to compare with BC. These sensors were calibrated using a well-known flow vessel at similar operating conditions to those of the HCS; data were consolidated, and the methodology was used in the current study of HCS1.
There are several characteristics of this device that are not mentioned in the literature about conventional three-phase cyclones:

(1) radial and axial gas, liquid, and solid heating by hot hydrogen,

(2) vaporization of hydrocarbons,

(3) slurry lift in the riser by effects of hydrogen injection through a nozzle,

(4) tangential and axial flows of gases in the riser that have a divergent outlet,

(5) different types of gas cores (formed hydrogen plus vaporized hydrocarbons),

(6) gas core positions controlled by the settler level of wet solids,

(7) tailpipe discharge into a settler with controlled levels of solids, and

(8) use of high-pressure metallic hydrocyclones with the flow, level, and pressure controlled by three automatic loops.

The main objective of this device is to maximize the separation of coarse (>10 microns) and minimize that of fines particles (<10 microns) and liquids going into the regenerator operating at a 1.4 MPa inlet pressure; a secondary objective is to preheat the catalyst for regeneration in the fluidized bed, and the third one is to minimize the delta of pressure, erosion, vibration, and pressure oscillation in a steady-state operation.

The streams were characterized by their particle size distribution, pressure, temperature, amount and type of solids, and gas and liquid content. Gas–liquid equilibria were calculated using the Peng–Robinson state equation.

More than 1800 experimental points were used to calibrate the sensors. The results are reported in the Supporting Information. A total of 2800 points were obtained with HCS1 using nine high-pressure prototypes. The separation efficiencies and internal circulation were measured, and the results were compared to the values predicted by known published equations.


(Yesterday I attended a wonderful lecture, in the context of the development of understanding fusion plasmas, on the use of "artificial intelligence" in the processing and weighting of fairly extreme multivariate analytical inputs, which I might imagine would have application for a system of measurements for this dangerous fossil fuel technology. It was unbelievably fascinating. It may be available as a video at the above link in a few weeks.)

Figure 2 in the paper shows the types of analytical tools used in the analysis of this device:



The caption:

Figure 2. (a) Global scheme of slurry preparation and HCS1 and HSC2 with secondary hydrogen preheating and injection at the inlet of riser. (b) Five ECT sensors located in the cone with capacitance, temperature, and pressure detectors and an imaging processor system; (c) hydrocylone dimensions; and (d) list of sensors (see location in (a)) connected to a data logger and processing computer.



Figure 3 shows the types of readouts being processed:




The caption:

Figure 3. Different variables plotted as functions of operational time (minutes). Upper part: inlet feed and hydrogen mass flow rates. Middle part: delta of pressure and gas temperatures at the outlet. Lower part: slurry mas flow rates at the UF and OVF streams. HCS1 at base-case operating conditions.


(These inputs are considerably of lower dimensionality than the measurements of fusion plasma devices, but depending on the time resolution can still be quite complex.)

Two tables describing the inputs and dimensions of the pilot device:





Some overview remarks of the conduct of experiments:

The pilot plant was continuously operated, and the flow rate, temperature, vibration, and pressure were recorded (Figure 3); mass balances were performed every 10 min. The results are reported in Table3 as an example. Internal circulation obtained by the sensors is shown in Figure 4, and the radial profiles of pressure, temperature, and solid content are in Figure 5. The flow in the apex and tail pipe is depicted in Figures 6 and 7, and the effect of apex and vortex finder diameters is in Figure 8.


Table 3:



The figures:




The caption:

Figure 4. (a) Half-HCS1 with the spires going downward (yellow) by the wall and going upward (green) around the gas core. (b) Radial distribution of solids (ECT) at z = 0.5 and z = 0. (c) Profiles of temperature (red), vaporization (purple), solid concentrations (green), and pressure near the external wall. (d) PSD in the feed and OVF and UF streams (%, with respect to the stream).




The caption:

Figure 5. (a) Radial profile of temperature (red, thermocouple) and the core radius (yellow, ECT); (b) radial distribution of pressure; (c) radial distribution of delta pressure; and (d) ECT measure of solid distribution. Operating conditions for HCS1: FH2 = 0.4 kg/s, TH2 = 560 K, Lc1 = 0.5 m, uo1 = 4 m/s, Lc1 = 0.4 m, and Do/Dc = 0.4.




The caption:

Figure 6. (a, b) ECT spaced by 8 cm in the connecting (tail) pipe during circulation (circ) and spray modes of discharge. (c) Twin-plane Cs/Cs,av ratio measured by ECTV as a function of delay time for circulating and circulating-spray-circulating types of discharge in the tail pipe.




The caption:

Figure 7. Effect of hydrogen in the oscillation of the core and frequency of circ and circ-spray-circ mode of solid discharge. (a) ECT at z = 0.5 and z = 0 as a function of time; (b) amplitude of the vibration at the apex (10 kHz) as a function of time.




The caption:

Figure 8. Effect of Du and Dr in coarse solid separation efficiency at optimal hydrogen flow rates. Delta of pressure of vortex–apex of −4 ± 0.5 kPa and vibration frequency of 20 ± 4 Hz.




The caption:

Figure 9. (a) Effect of PSD in the feed in solid distributions at the outlet streams. Feed A (black dashed lines), UF (red dashed lines), and OVF (green dashed lines). Feed B (violet dashed lines), UF (gray dashed lines), and OVF (blue dashed lines). (b) 2D ECD image of radial particle distribution at z = 0.5 for A and B solid distributions in the feed. (HCS1 base-case dimensions and operating conditions.)


Some discussion of the results:

The main difference between HCS1 and previous hydrocyclone technology is the use of hot hydrogen that “complements” the effects of centrifugal force in the separations of gas, liquid, and solid from the stream that leaves the alkylation reactor. Both liquid and solid separations (efficiencies) need to be maximized because they affect the economy of the process.
Sensors (ECT, differential of pressure, pressure, and temperature) and sampling allow determining the flow pattern of solids in different areas of the hydrocyclone. The tests found that hydrogen produces a different type of fluid circulation in the lower cone, riser, and apex than that reported for conventional hydrocyclone, desander, and deoiling devices. Hydrogen produced important hydrocarbon vaporization that changes slurry properties (density and viscosity), radial and axial distributions of solids, temperature, and delta of pressure and produces a carry-over of slurry through the riser. Hydrogen injection is responsible for pressure oscillation and additional vibration of the HCS.

The simulation of HCS1 using published correlations show important deviation. For example, the calculation presents a deviation higher than 38% in the prediction of for HCS1 operating with cold hydrogen (363 K and 1.4 MPa), but the differences are higher when using hot (530 K) hydrogen. Reynolds numbers of the feed (inlet), required to produce high solid/liquid separation at the apex in HCS, are half those measured by other authors in isothermal hydrocyclones (see, for example, the value used by Wang and Yu(30)); these authors observed a shorter reverse core in flooded hydrocyclones at almost twice the inlet Re number needed for solid separation than that calculated for the isothermal HCS1 device. The HCS operates at a relatively low inlet Re number with a shorter cone and broader vortex finder and underflow diameters than those of conventional isothermal hydrocyclones. There is no correlation between d50 and the inlet Re number as it was for conventional devices (see Gu and Liow(39)).


An excerpt of the authors conclusions:

________________________________________
A total of 2800 experimental points have been obtained for HCS1 to determine the best dimensions and operating conditions for gas, solid, and liquid separation. Stability, efficiency, delta of pressure, catalyst attrition, and the effect of hydrogen flow and temperature were studied using BC dimensions, selected based on previous studies; the effect of some critical dimensions were studied by departing from BC. The objectives of the separations are imposed by the economy of the process. Minimum vibration and pressure fluctuations and pressure losses are operational requirements. The results demonstrate that

(1) the solid separation efficiency increases sharply from fines (0–10 microns) to coarse particles (40–70 microns) as expected. The efficiency for fine-particle separation is higher than that observed in conventional hydrocyclones.

(2) The solid separation mainly occurred in the shorter than conventional lower cone where coarse particle tangential and radial velocities are accelerated by centrifugal forces and hydrocarbon vaporization. There is a nonlineal radial profile of temperature, pressure, and solid concentration across and along the lower cone. Without hot hydrogen injection, there is not enough centrifugal forces to separate solid and liquid for BC dimensions.

(3) In steady-state conditions, the slurry, high-in-solid, moves downward, rotating against the internal wall in the lower cone, axis, and tail pipe. The level of solids at the settler ropes the discharge and induces the upward movement of low-in-solid slurry that helps the separation at the apex and seals the bottom of the gas core...


Additional points are made in the conclusion, and the paper features extensive discussion of these engineering parameters.

These sorts of things, I know, are very esoteric, but these are the types of things about which future generations will need to know to address the consequences our irresponsibility.

Enjoy your Sunday.




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