Tag Archives: coal

Making graphite from coal and a few graphite facts

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Canada is the 10th largest (1.2%) producer of graphite in the world with China leading the way in the top spot at 68.1%. That’s right, 1.2% can get you into the top 10.

If you’re curious about which countries fill out the other eight spots, The National Research Council of Canada has a handy webpage titled, Graphite Facts,

Graphite is a non-metallic mineral that has properties similar to metals, such as a good ability to conduct heat and electricity. Graphite occurs naturally or can be produced synthetically. Purified natural graphite has higher crystalline structure and offers better electrical and thermal conductivity than synthetic material.

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Among the many applications, natural and synthetic graphite are used for electrodes, refractories, batteries and lubricants and by foundries. Coated spherical graphite is used to manufacture the anode in lithium-ion batteries. High-grade graphite is also used in fuel cells, semiconductors, LEDs and nuclear reactors.

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The Lac des Iles mine is the only mine in Canada that is producing graphite. However, many other companies are working on graphite projects.

Canada’s graphite shipments reached 11,937 tonnes in 2020, up slightly from 11,045 tonnes in 2020 [sic].

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Global production and demand for graphite are anticipated to increase in the coming years, largely because of the use of graphite in the batteries of electric vehicles. In 2020, global consumption of graphite reached 2.7 million tonnes. Synthetic graphite accounted for about two-thirds of the graphite consumption, which was largely concentrated in Asia.

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In 2020, the value of Canada’s exports of graphite was $31.6 million, a 9% decrease compared to the previous year. Imports also decreased in 2020, by 33% to $20.9 million.

Natural graphite accounted for 46.7% ($14.8 million) of the value of Canada’s exports of graphite and 13.5% ($2.8 million) of Canada’s imports of graphite in 2020. Synthetic graphite accounted for 53.3% ($ 16.9 million) of Canada’s exports of graphite and 86.5% ($18.0 million) of Canada’s imports of graphite in 2020.

In 2020, the United States was the primary destination for Canada’s exports of natural and synthetic graphite, accounting for 85% and 42% of the total exports, respectively.

…

I think the writer meant that shipments were up slightly from 2019. The page was last updated on February 4, 2022.

The news from Ohio

A June 10, 2022 news item on Nanowerk about research into a new type of graphite (Note: A link has been removed),

As the world’s appetite for carbon-based materials like graphite increases, Ohio University researchers presented evidence this week for a new carbon solid they named “amorphous graphite.”

Physicist David Drabold and engineer Jason Trembly started with the question, “Can we make graphite from coal?”

“Graphite is an important carbon material with many uses. A burgeoning application for graphite is for battery anodes in lithium-ion batteries, and it is crucial for the electric vehicle industry — a Tesla Model S on average needs 54 kg of graphite. Such electrodes are best if made with pure carbon materials, which are becoming more difficult to obtain owing to spiraling technological demand,” they write in their paper that published in Physical Review Letters (“Ab initio simulation of amorphous graphite”).

Ab initio means from the beginning, and their work pursues novel paths to synthetic forms of graphite from naturally occurring carbonaceous material. What they found, with several different calculations, was a layered material that forms at very high temperatures (about 3000 degrees Kelvin). Its layers stay together due to the formation of an electron gas between the layers, but they’re not the perfect layers of hexagons that make up ideal graphene. This new material has plenty of hexagons, but also pentagons and heptagons. That ring disorder reduces the electrical conductivity of the new material compared with graphene, but the conductivity is still high in the regions dominated largely by hexagons.

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A June 10, 2022 Ohio University news release (also on EurekAlert), which originated the news item, delves further into the research (Note: Links have been removed),

Not all hexagons

“In chemistry, the process of converting carbonaceous materials to a layered graphitic structure by thermal treatment at high temperature is called graphitization. In this letter, we show from ab initio and machine learning molecular dynamic simulations that pure carbon networks have an overwhelming proclivity to convert to a layered structure in a significant density and temperature window with the layering occurring even for random starting configurations. The flat layers are amorphous graphene: topologically disordered three-coordinated carbon atoms arranged in planes with pentagons, hexagons and heptagons of carbon,” said Drabold, Distinguished Professor of Physics and Astronomy in the College of Arts and Sciences at Ohio University.

“Since this phase is topologically disordered, the usual ‘stacking registry’ of graphite is only statistically respected,” Drabold said. “The layering is observed without Van der Waals corrections to density functional (LDA and PBE) forces, and we discuss the formation of a delocalized electron gas in the galleries (voids between planes) and show that interplane cohesion is partly due to this low-density electron gas. The in-plane electronic conductivity is dramatically reduced relative to graphene.”

The researchers expect their announcement to spur experimentation and studies addressing the existence of amorphous graphite, which may be testable from exfoliation and/or experimental surface structural probes.

Trembly, Russ Professor of Mechanical Engineering and director of the Institute for Sustainable Energy and the Environment in the Russ College of Engineering and Technology at Ohio University, has been working in part on green uses of coal. He and Drabold — along with physics doctoral students Rajendra Thapa, Chinonso Ugwumadu and Kishor Nepal — collaborated on the research. Drabold also is part of the Nanoscale & Quantum Phenomena Institute at OHIO, and he has published a series of papers on the theory of amorphous carbon and amorphous graphene. Drabold also emphasized the excellent work of his graduate students in carrying out this research.

Surprising interplane cohesion

“The question that led us to this is whether we could make graphite from coal,” Drabold said. “This paper does not fully answer that question, but it shows that carbon has an overwhelming tendency to layer — like graphite, but with many ‘defects’ such as pentagons and heptagons (five- and seven-member rings of carbon atoms), which fit quite naturally into the network. We present evidence that amorphous graphite exists, and we describe its process of formation. It has been suspected from experiments that graphitization occurs near 3,000K, but the details of the formation process and nature of disorder in the planes was unknown,” he added.

The Ohio University researchers’ work is also a prediction of a new phase of carbon.

“Until we did this, it was not at all obvious that layers of amorphous graphene (the planes including pentagons and heptagons) would stick together in a layered structure. I find that quite surprising, and it is likely that experimentalists will go hunting for this stuff now that its existence is predicted,” Drabold said. “Carbon is the miracle element — you can make life, diamond, graphite, Bucky Balls, nanotubes, graphene, [emphasis mine] and now this. There is a lot of interesting basic physics in this, too — for example how and why the planes bind, this by itself is quite surprising for technical reasons.”

Here’s a link to and a citation for the paper,

Ab Initio Simulation of Amorphous Graphite by R. Thapa, C. Ugwumadu, K. Nepal, J. Trembly, and D. A. Drabold. Phys. Rev. Lett. 128, 236402 DOI: https://doi.org/10.1103/PhysRevLett.128.236402 Published 10 June 2022 © 2022 American Physical Society

This paper is behind a paywall.

There is an earlier version of the paper which is open access at ArXiv (hosted by Cornell University),

[Submitted on 22 Feb 2022 (v1), last revised 23 Apr 2022 (this version, v2)]

Ab initio simulation of amorphous graphite by Rajendra Thapa, Chinonso Ugwumadu, Kishor Nepal, Jason Trembly, David Drabold

About graphite and Canadian mines

A July 25, 2011 posting marks the earliest appearance of graphite on this blog. Titled, “Canadians as hewers of graphite?” It featured Northern Graphite Corporation, which today (June 21, 2022) is the largest North American graphite producer according to the company’s homepage,

  • Only North American producer
  • Will be 3rd largest non-Chinese producer
  • Two large development projects
  • All projects:
    • In politically stable countries
    • Have “battery quality” graphite
    • Close to infrastructure

There’s also this from the company’s homepage,

Northern owns the Lac des Iles (LDI) mine in Quebec, the only significant graphite producer in North America. Northern plans to increase production and extend the mine life.

Northern is currently upgrading its Okorusu processing plant in Namibia. It will be back on line in 1H 2023 and make Northern the third largest non Chinese graphite producer.

Northern plans to develop its advanced stage Bissett Creek project in Ontario which has a full Feasibility Study. It has been rated as the highest margin graphite deposit in the world.

The Okanjande deposit in Namibia has a very large measured and indicated resource. Northern intends to study building a 150,000tpa plant to supply battery markets in Europe.

I notice the involvement in Namibia. I hope this is a ‘good’ mining company. Canadian mining companies have been known to breach human rights and environmental regulations when operating internationally. There’s a recent tragedy described in this June 20, 2020 news article on the Canadian Broadcasting Corporation (CBC) online news site (Note: A link has been removed),

Trevali Mining Corp. says it has recovered the bodies of the final two of eight workers killed after its Perkoa Mine in Burkina Faso flooded following heavy rainfall on Apr. 16 [2022].

The bodies of the other six workers were recovered by search teams late last month.

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The Vancouver-based zinc miner says it is working alongside Burkinabe authorities to coordinate the dewatering and rehabilitation of the mine.

The flooding event is under investigation by the company and government authorities.

MiningWatch Canada, an Ottawa-based industry watchdog, has questioned how well the company was prepared for disaster and criticized the federal government’s lack of regulations on how Canadian mining companies operate internationally. [emphasis mine]

They say tighter rules are necessary for companies operating abroad. 

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A May 10, 2022 article by Amanda Follett Hosgood about the disaster for The Tyee provides more details and asks some very pertinent and uncomfortable questions. (Yes, The Tyee is a very ‘left wing’ journalistic effort and they have a point where Canadian mining companies are concerned.)

Getting back to Northern Graphite, there’s this from their Governance page,

Northern Graphite is committed to conducting its activities in a manner that meets best international industry practices regardless of the country or location of operation.  The Company will operate with the highest standards of honesty, integrity, and ethical behaviour.  It will conduct its business in a manner that meets or exceeds all applicable laws, rules, and regulations and meets its social and moral obligations.  This policy applies to all Board members, officers and other employees, contractors, and other third parties working on behalf of or representing the Company.

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The company gets more specific, from their Governance page,

  1. …
  2. Taking all reasonable precautions to ensure the health and safety of workers and others affected by the Company’s operations.
  3. Managing and minimizing the environmental impact of the Company’s operations by following best international practices and standards and meeting stakeholder expectations while recognizing that mining will always have some unavoidable impacts on the environment. 
  4. Utilizing practices and technologies that minimize the Company’s water and carbon footprints.
  5. …
  6. Respecting the rights, culture and development of local and Indigenous communities.
  7. …
  8. The elimination of fraud, bribery, and corruption.
  9.  The protection and respect of human rights.
  10. …
  11. Providing an adequate return to shareholders and investors while ensuring that all stakeholders benefit from the extraction of the earth’s resources through fair labour and compensation practices, local hiring and contracting, community support, and the payment of all applicable government taxes and royalties.

There are two other Canadian mining companies (that I know of) in pursuit of graphite, Lomiko Metals (British Columbia) and Focus Graphite (Ontario). All the mines in Canada, whether they are producing or not, are in either Québec or Ontario.

As for the research team in Ohio, congratulations on your very exciting work!

Do you want that coffee with some graphene on toast?

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These scientists are excited:

For those who prefer text, here’s the Rice University Feb. 13, 2018 news release (received via email and available online here and on EurekAlert here) Note: Links have been removed),

Rice University scientists who introduced laser-induced graphene (LIG) have enhanced their technique to produce what may become a new class of edible electronics.

The Rice lab of chemist James Tour, which once turned Girl Scout cookies into graphene, is investigating ways to write graphene patterns onto food and other materials to quickly embed conductive identification tags and sensors into the products themselves.

“This is not ink,” Tour said. “This is taking the material itself and converting it into graphene.”

The process is an extension of the Tour lab’s contention that anything with the proper carbon content can be turned into graphene. In recent years, the lab has developed and expanded upon its method to make graphene foam by using a commercial laser to transform the top layer of an inexpensive polymer film.

The foam consists of microscopic, cross-linked flakes of graphene, the two-dimensional form of carbon. LIG can be written into target materials in patterns and used as a supercapacitor, an electrocatalyst for fuel cells, radio-frequency identification (RFID) antennas and biological sensors, among other potential applications.

The new work reported in the American Chemical Society journal ACS Nano demonstrated that laser-induced graphene can be burned into paper, cardboard, cloth, coal and certain foods, even toast.

“Very often, we don’t see the advantage of something until we make it available,” Tour said. “Perhaps all food will have a tiny RFID tag that gives you information about where it’s been, how long it’s been stored, its country and city of origin and the path it took to get to your table.”

He said LIG tags could also be sensors that detect E. coli or other microorganisms on food. “They could light up and give you a signal that you don’t want to eat this,” Tour said. “All that could be placed not on a separate tag on the food, but on the food itself.”

Multiple laser passes with a defocused beam allowed the researchers to write LIG patterns into cloth, paper, potatoes, coconut shells and cork, as well as toast. (The bread is toasted first to “carbonize” the surface.) The process happens in air at ambient temperatures.

“In some cases, multiple lasing creates a two-step reaction,” Tour said. “First, the laser photothermally converts the target surface into amorphous carbon. Then on subsequent passes of the laser, the selective absorption of infrared light turns the amorphous carbon into LIG. We discovered that the wavelength clearly matters.”

The researchers turned to multiple lasing and defocusing when they discovered that simply turning up the laser’s power didn’t make better graphene on a coconut or other organic materials. But adjusting the process allowed them to make a micro supercapacitor in the shape of a Rice “R” on their twice-lased coconut skin.

Defocusing the laser sped the process for many materials as the wider beam allowed each spot on a target to be lased many times in a single raster scan. That also allowed for fine control over the product, Tour said. Defocusing allowed them to turn previously unsuitable polyetherimide into LIG.

“We also found we could take bread or paper or cloth and add fire retardant to them to promote the formation of amorphous carbon,” said Rice graduate student Yieu Chyan, co-lead author of the paper. “Now we’re able to take all these materials and convert them directly in air without requiring a controlled atmosphere box or more complicated methods.”

The common element of all the targeted materials appears to be lignin, Tour said. An earlier study relied on lignin, a complex organic polymer that forms rigid cell walls, as a carbon precursor to burn LIG in oven-dried wood. Cork, coconut shells and potato skins have even higher lignin content, which made it easier to convert them to graphene.

Tour said flexible, wearable electronics may be an early market for the technique. “This has applications to put conductive traces on clothing, whether you want to heat the clothing or add a sensor or conductive pattern,” he said.

Rice alumnus Ruquan Ye is co-lead author of the study. Co-authors are Rice graduate student Yilun Li and postdoctoral fellow Swatantra Pratap Singh and Professor Christopher Arnusch of Ben-Gurion University of the Negev, Israel. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice.

The Air Force Office of Scientific Research supported the research.

Here’s a link to and a citation for the paper,

Laser-Induced Graphene by Multiple Lasing: Toward Electronics on Cloth, Paper, and Food by Yieu Chyan, Ruquan Ye†, Yilun Li, Swatantra Pratap Singh, Christopher J. Arnusch, and James M. Tour. ACS Nano DOI: 10.1021/acsnano.7b08539 Publication Date (Web): February 13, 2018

Copyright © 2018 American Chemical Society

This paper is behind a paywall.

h/t Feb. 13, 2018 news item on Nanowerk

Building a wrench 1.7 nanometres wide

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A blue wrench (of molecules) to adjust a green bolt (a pillarene ring) that binds a yellow chemical “guest.” It’s a new tool — just 1.7 nanometers wide — that could help scientists catalyze and create a host of useful new materials. Image courtesy of Severin Schneebeli

A blue wrench (of molecules) to adjust a green bolt (a pillarene ring) that binds a yellow chemical “guest.” It’s a new tool — just 1.7 nanometers wide — that could help scientists catalyze and create a host of useful new materials.
Image courtesy of Severin Schneebeli

So, if you can imagine 1.7 nanometers, that’s what the wrench would look like without all the colour effects. A Sept. 25, 2015 news item on Nanotechnology Now describes the scientific breakthrough,

University of Vermont chemist Severin Schneebeli has invented a new way to use chirality to make a wrench. A nanoscale wrench. His team’s discovery allows them to precisely control nanoscale shapes and holds promise as a highly accurate and fast method of creating customized molecules.

This use of “chirality-assisted synthesis” is a fundamentally new approach to control the shape of large molecules–one of the foundational needs for making a new generation of complex synthetic materials, including polymers and medicines.

A Sept. 24, 2015 University of Vermont news release (also on EurekAlert) by Joshua E. Brown, which originated the news item, expands on the theme,

Experimenting with anthracene, a substance found in coal, Schneebeli and his team assembled C-shaped strips of molecules that, because of their chirality, are able to join each other in only one direction. “They’re like Legos,” Schneebeli explains. These molecular strips form a rigid structure that’s able to hold rings of other chemicals “in a manner similar to how a five-sided bolt head fits into a pentagonal wrench,” the team writes.

The C-shaped strips can join to each other, with two bonds, in only one geometric orientation. So, unlike many chemical structures–which have the same general formula but are flexible and can twist and rotate into many different possible shapes–“this has only one shape,” Schneebeli says. “It’s like a real wrench,” he says–with an opening a hundred-thousand-times smaller than the width of human hair: 1.7 nanometers.

“It completely keeps its shape,” he explains, even in various solvents and at many different temperatures, “which makes it pre-organized to bind to other molecules in one specific way,” he says.

This wrench, the new study shows, can reliably bind to a family of well-known large molecules called “pillarene macrocycles.” These rings of pillarene have, themselves, often been used as the “host,” in chemistry-speak, to surround and modify other “guest” chemicals in their middle–and they have many possible applications from controlled drug delivery to organic light-emitting substances.

“By embracing pillarenes,” the Vermont team writes, “the C-shaped strips are able to regulate the interactions of pillarene hosts with conventional guests.” In other words, the chemists can use their new wrench to remotely adjust the chemical environment inside the pillarene in the same way a mechanic can turn an exterior bolt to adjust the performance inside an engine.

The new wrench can make binding to the inside of the pillarene rings “about one hundred times stronger,” than it would be without the wrench, Schneebeli says.

MAKING MODELS

Also, “because this kind of molecule is rigid, we can model it in the computer and project how it looks before we synthesize it in the lab,” says UVM theoretical chemist Jianing Li, Schneebeli’s collaborator on the research and a co-author on the new study. Which is exactly what she did, creating detailed simulations of how the wrench would work, using computer processors in the Vermont Advanced Computing Core.

“This is a revolutionary idea,” Li said, “We have 100% control of the shape, which gives great atomic economy–and lets us know what will happen before we start synthesizing in the lab.”

In the lab, post-doctoral researcher and lead author Xiaoxi Liu, undergraduate Zackariah Weinert, and other team members were guided by the computer simulations to test the actual chemistry. Using a mass spectrometer and an NMR spectrometer in the UVM chemistry department, the team was able to confirm Schneebeli’s idea.

CREATIVE SIMPLICITY

Sir Fraser Stoddart, a world-leading chemist at Northwestern University, described the new study as, “Brilliant and elegant! Creative and simple.” And, indeed, it’s the simplicity of the approach that makes it powerful, Schneebeli says. “It’s all based on geometry that controls the symmetry of the molecules. This is the only shape it can take–which makes it very useful.”

Next, the team aims to modify the C-shaped pieces–which are tied together with two bonds formed between two nitrogens and bromines–to create other shapes. “We’re making a special kind of spiral which is going to be flexible like a real spring,” Schneebeli explains, but will hold its shape even under great stress.

“This helical shape could be super-strong and flexible. It could create new materials, perhaps for safer helmets or materials for space,” Schneebeli says. “In the big picture, this work points us toward synthetic materials with properties that, today, no material has.”

Here’s a link to and a citation for the paper,

Regulating Molecular Recognition with C-Shaped Strips Attained by Chirality-Assisted Synthesis by Dr. Xiaoxi Liu, Zackariah. Weinert, Mona Sharafi, Dr. Chenyi Liao, Prof. Jianing Li, and Prof. Severin T. Schneebeli. Angewandte Chemie DOI: 10.1002/anie.201506793 Article first published online: 9 SEP 2015

© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Coal, methane, and nanotech in Alberta

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The title of the May 5, 2011 news item on physorg.com looked promising, Turning coal into methane using nanotechnology. From the news item,

Mechanical engineering professor Sushanta Mitra wants to adapt a bioconversion process that occurs naturally over millions of years into a fast-moving production that breaks down coal and captures methane gas in storage tanks. Mitra says bioconversion of coal to methane has great potential for improving the environment globally.

“The standard practice of burning coal for power generation could be reduced and possibly eliminated,” said Mitra. “Bioconversion will reduce carbon dioxide emissions from power generation by 25 per cent.”

The process by which coal is changed to methane is called methanogenesis. The researchers are experimenting with a variety of microbial materials, which will be mixed with water and piped underground into coal seams. The research could be applied to coal-based energy production anywhere in the world, says Mitra, and could be of special importance here in Alberta.

I was hoping for a few more details about the nanotechnology aspect of the project but there wasn’t anything more other than Mitra received a $1.92M grant from Carbon Management Canada and he’s hoping to be testing his methane conversion process in a underground coal seam by 2015.