It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, October 08, 2021
'NEVER GIVE UP NEVER SURRENDER'
ExxonMobil and Chevron among members of newly launched Asia Pacific gas advocacy body
Advocating for industry in the Asia Pacific: ANGEA chairman Nigel Hearne is also the president of Chevron's Eurasia exploration and production business
Photo: JOSH LEWIS
Newly formed group will advocate for gas to complement new energy solutions to help accelerate the region's energy transition
US supermajors Chevron and ExxonMobil have joined forces with Jera, JGC, Mitsubishi Heavy Industries, Santos and SK E&S, to establish the Asia Natural Gas & Energy Association (ANGEA).
ANGEA, which was launched this week, claims to represent energy producers, buyers, suppliers and companies in the Asia Pacific region and aims to ensure the long-term future of natural gas and other low carbon energy sources in the region’s energy mix.
The newly formed advocacy body will look to partner with governments throughout the Asia Pacific region to advise them as they develop energy policies and solutions that are also in step with a low carbon future.
ANGEA said it would provide advice to help governments meet their national energy needs, achieve global climate goals as established by the Paris Agreement, and encourage investment to support social and economic changes needed for “a stable and consistent energy transition”.
While the group will advise on renewables and energy conservation, ANGEA noted in Tuesday’s launch statement that it recognised natural gas was complementary to new energy solutions and enabling an acceleration of the energy transition in the Asia Pacific region. Gas prices continue to surge as Europe and Asia compete for LNG cargoesRead more
“Asia Pacific will be 60% of the world’s economic growth by 2030. This will require nations to meet a significant increase in energy demand, while simultaneously switching to renewable and lower-carbon energy sources to meet energy security needs,” said ANGEA chairman, and the president of Chevron’s Chevron’s Eurasia exploration and production, Nigel Hearne.
“Effective policies, investment and regulations will be vital not only to integrate these multiple energy sources effectively, but to deliver energy efficiency improvements while transforming economies to reflect new energy, economic and environmental challenges.”
ANGEA will be overseen by a board comprising senior representatives of the founding members, while other major global and regional companies would also announce their involvement soon.
ANGEA said its members would look to utilise their expertise across the life cycle of the industry from energy development and production to transport, distribution and storage.
The founding members have also agreed to appoint an Eminent Persons Advisory Council — a group of independent and regional experts — to provide ANGEA's board and executive team with "high level expertise" across a range of policy areas.
CREATING METHANE FROM CAPTURED CARBON DIOXIDE AND THE FUTURE OF CARBON CAPTURE
There’s something intrinsically simple about the concept of carbon (CO2) capture: you simply have the CO2 molecules absorbed or adsorbed by something, after which you separate the thus captured CO2 and put it somewhere safe. Unfortunately, in physics and chemistry what seems easy and straightforward tends to be anything but simple, let alone energy efficient. While methods for carbon capture have been around for decades, making it economically viable has always been a struggle.
This is true both for carbon capture and storage/sequestration (CCS) as well as carbon capture and utilization (CCU). Whereas the former seeks to store and ideally permanently remove (sequester) carbon from the atmosphere, the latter captures carbon dioxide for use in e.g. industrial processes.
Recently, Pacific Northwest National Laboratory (PNNL) has announced a breakthrough CCU concept, involving using a new amine-based solvent (2-EEMPA) that is supposed to be not only more efficient than e.g. the previously commonly used MEA, but also compatible with directly creating methane in the same process.
Since methane forms the major component in natural gas, might this be a way for CCU to create a carbon-neutral source of synthetic natural gas (SNG)?
CARBON CAPTURE IN A NUTSHELL
Process flow diagram of a typical amine treating process used in petroleum refineries, natural gas processing plants and other industrial facilities. (Credit: Raminagrobis, CC BY-SA 4.0)
The most common type of carbon capture (CC) system is a CO2 scrubber that is used with fossil fuel power plants or similar sources of flue gas. This gas is led through the liquid solvent, typically amine-based. Amines are derivatives of ammonia, with at least one of its three hydrogen atoms having been replaced by a substituent. Monoethanolamine (C2H7NO, MEA) is a primary amine that in a water-based solution can efficiently absorb CO2 and H2S from flue gas.
When the resulting CO2 rich amine solvent is then led into a regenerator unit which heats up the rich solvent to about 118 °C at 69 kPa, it causes the absorption to be reversed and the gases to be released. Most of the MEA is recovered in this manner and can then be returned to absorb more CO2 from the flue gas.
Problems with MEA include the high water content in the solvent. Water has a high specific heat, which means it takes a lot of energy to get hot. MEA also reacts with carbonyl sulfide (COS) and carbon disulfide (CS2) to form heat-stable salts, which remove MEA from the process and require an additional process step to be removed.
After the CO2 gas has been captured this way, it is generally compressed before transport for use, storage or sequestration. The heating up of the rich amine solvent in the regeneration process, as well as the compression of the captured carbon dioxide all cost considerable amounts of energy. This is where the economics of CC are not very favorable, and prefer input gases that are already rich in the gas that is to be captured.
Mitsubishi Heavy Industries CO2 capture plant at the EOR project in Texas, USA. (Credit: Hirata et al. (2018), MHI)
Over the years, various alternatives have been developed to MEA which require less water, and processes that omit or reduce the compression step. Examples of the former are for example Shell’s Cansolv capture technology and Mitsubishi Heavy Industry’s KM CDR process with its proprietary KS-1 solvent. These all have the same goals: use less water, reduce the amount of amine solvent caught in the flue gas that’s emitted into the atmosphere and improvement of the recovery rate of the solvent while reducing energy requirements.
None of these processes are suitable for something like direct air CCS, though. Although one can technically lead atmospheric air through one of these capture plants, the difference in CO2 content in the air versus flue gas is immensely different (>9% in flue gas versus 0.04% in air), leading to a very low efficiency rating.
Even so, with flue gas the capture rate of CO2 is generally above 90%, but <99% (claimed 98% for Cansolv, >90% for KM CDR). This means that although most of the CO2 is indeed captured, some of it still is emitted with the flue gas, along with amine solvents.
PNNL’S 2-EEMPA
In PNNL’s paper by Heldebrant et al. (2021) titled Integrated Capture and Conversion of CO2 to Methane using a Water-lean, Post-Combustion CO2 Capture Solvent a number of claims are made:
>90% conversion of captured CO2 to hydrocarbons (mostly methane).
More efficient than the usual Sabatier process (skipping the CO2 compression & transport steps).
Process conditions are 170 °C and <15 bar H2 pressure with ruthenium catalyst.
Better performance of 2-EEMPA than MEA.
There are a number of steps involved in this process, from absorbing the CO2, to getting it to the point where it can react with the hydrogen that is added to create the hydrocarbons. Heldebrant et al. first describe the Sabatier process, using a combined cycle natural gas turbine plant equipped with Shell’s Cansolv (using a 50% by weight amine solvent) process as example:
CO2 captured in the absorber & released in the stripper (regenerator) at 2 bars of pressure.
Pure CO2 is compressed and mixed with hydrogen.
Mixture is added to methanation reactor for the Sabatier reaction.
The Sabatier reaction runs at 350 °C and 30 bar with an Ru/Al2O3 catalyst.
The exothermic reaction provides heat for the stripper unit and power generation.
The PNNL version does not use the proprietary Cansolv process, but instead its own 2-EEMPA (N-(2-ethoxyethyl)-3-morpholinopropan-1-amine). Heldebrant et al. claim a CO2 capture efficiency of >95% with coal-derived flue gas. 2-EEMPA-based solvent is projected to have a ~4% water content by weight in operation. At this water ratio, 74% of the CO2 captured by 2-EEMPA (as EEMPA-carbamate) is converted to hydrocarbons when hydrogen is introduced and with an Ru/Al2O3 catalyst present. Of these, 92% of these were methane.
At the same conditions, MEA showed a conversion ratio to hydrocarbons of <20%. The entire process chain can be summarized as in the following graphic:
Proposed FG-to-SNG process with the IC3M technology. (Source: Heldebrant et al. (2021))
The benefits compared to the traditional Sabatier process are a lower reaction temperature (170 °C instead of 350 °C), lower pressure (15 vs 30 bar) and lower cost for constructing and maintaining the equipment.
A STORY OF EXTERNAL FACTORS
As alluded to earlier in this article, a major consideration with carbon capture is the efficiency of the process. If we consider that CCU as proposed here relies on a rich source of CO2, as well as a pure source of hydrogen, it would appear that the former would have to come from flue gas and similar waste streams from the fossil fuel industry. For the latter, things are more problematic if we wish to not create additional waste.
Currently virtually all hydrogen on the market is produced through steam reforming (SMR) of natural gas. This makes it not carbon-neutral: if it requires natural gas as input for SMR to create the hydrogen needed to create the SNG, one may as well directly use the natural gas.
This is further illuminated by Howarth et al., whose recent study details the effectiveness of so-called ‘blue hydrogen’, which uses CCS with SMR of NG and came to the conclusion that it’s more effective to just burn the NG directly. This leaves then only so-called ‘green’ hydrogen as viable input for this SNG process to conceivably make it carbon-neutral.
In 2020, only 4% of worldwide hydrogen was produced via electrolysis, some of it from low-carbon power sources. Even if all hydrogen at these SNG production facilities came from electrolysis facilities powered by VRE or nuclear power, that would still leave the CO2 as an issue. If this came from fossil fuels, then it merely postpones the moment this carbon enters the atmosphere to when the SNG is burned.
True carbon-neutral fuel is conceivable, but so far no viable source of carbon has been found. Carbon from flue gas costs about $7.5 per ton, extracting carbon from sea water as carbonic acid would cost about $50 per ton and direct air carbon capture between $94 and $232 per ton. This then leaves PNNL’s process primarily as a way to use the carbon from fossil fuels (coal or NG) twice, though at a considerable energy investment.
NO FREE LUNCH
In light of these considerations and also based on PNNL’s own press release, it would seem clear that the ability to generate methane using this method is mostly transitional, to support the transition to low-carbon ways to power the modern world. The only likely exception to this is probably extra-terrestrial exploration, where in-situ resource utilization (ISRU) is likely to become a big thing.
One of the reason why SpaceX’s Mars-bound Raptor rocket engines are methane-fueled is due to the relative ease with which methane can be produced even on locations like the surface of Mars. When the nearest source of terrestrial methane is suddenly a planet away, the electrical and others costs of even DACC and electrolysis of water to slowly create a trickle of methane fuel for the trip back or to sustain a colony do not seem as outrageous any more.
One major benefit of water-lean solvents like 2-EEMPA is also likely to be the more efficient capturing of CO2 at fossil fuel plants. Whether this is enough to make big players like MHI and Shell sit up and pay attention is still anyone’s guess, but it’s hard to deny the benefit of more efficient CCS at fossil fuel plants.
Buying a gadget made with recycled plastic instead of brand-new materials might sound like an environmentally friendly investment, but it does very little to cut down on the heaps of plastic pollution and electronic waste that are trashing the environment and ending up everywhere — including in our own bodies.
Think of plastic pollution like an overflowing tub in your bathroom, says Josh Lepawsky, a professor at Memorial University of Newfoundland who maps the international movement of electronic waste. “If you walked into that, probably the first thing you would do would be to turn off the tap — not grab a bucket and a mop, if you think of the bucket and the mop as recycling,” Lepawsky says. Turning off the tap equates to staunching the production of plastic goods. Trying to clean up a growing mess won’t address the root of the problem. “It doesn’t mean, don’t use a bucket and a mop. But that’s not turning off the tap.”
CUTTING DOWN WASTE MEANS CUTTING DOWN CONSUMPTION
Cutting down waste means cutting down consumption. That’s something that can’t be solved with flashy new product offerings, even if those products are made with recycled materials. Companies need to sell fewer products that last longer so that gadgets aren’t so disposable in the first place. Hyping up recycling can actually stand in the way of that.
Oceans of plastic
The scale of the plastics problem is massive. As of 2017, humans had produced 8.3 billion metric tons of plastic (for comparison, a rhinoceros weighs about 1 metric ton) — much of which can persist in the environment or in landfills for hundreds of years. Recycling has done little to stop that mess. Only 9 percent of plastic waste has ever been recycled, research has found. People send at least 8 million tons of plastic into the ocean every year, where it might end up in giant garbage patches, arctic ice, the bellies of sea life, and back inside our bodies.
“We can’t recycle our way out of this problem—acute reduction of plastic products, recycled or not, is the solution,” Max Liboiron, an associate professor of geography at Memorial University who researches plastic pollution, said in an email to The Verge. “Even the production of new plastic items that use some of these ocean plastics as feedstock will result in a net increase in plastic pollution.”
“WE CAN’T RECYCLE OUR WAY OUT OF THIS PROBLEM.”
Take Microsoft’s new “Ocean Plastic Mouse,” which has a shell made with 20 percent recycled plastic. Any potential environmental gains that might come with that 20 percent recycled material could potentially be wiped out if the company sells 20 percent more mice, says Lepawsky. It’s a pitfall ecological economists describe as the “rebound effect” or “Jevon’s paradox.”
To have the most impact, products should be made with 100 percent recycled materials. But that’s nearly impossible with plastic, which is why it’s pretty typical for companies to only use a small percentage of rehashed plastic in their products. Plastic quality deteriorates with each use. Because of that, it’s difficult to make a new bottle out of an old bottle or a new mouse out of an old mouse. Microsoft’s mouse, for example, required the company to create a new plastic resin that’s only partly reclaimed plastic and combines those beads of recycled plastic with new plastic, too. When all’s said and done, it’s more likely that a product will be downcycled rather than recycled. That means it’s used to make something that doesn’t require high-quality plastic. Plastic bottles, for instance, are often turned into thin fibers used in carpeting and fleece.
Even using 30 or 40 percent dirty plastic in the mouse probably wouldn’t be feasible, according to Claire Barlow, deputy head of the engineering department at the University of Cambridge who specializes in materials engineering and industrial sustainability. The quality of the dirty plastic just isn’t good enough, she says. It might not have the strength or durability required for the product, or it could just be too difficult to process. So the fresh plastics are used to make up the difference.
All those weaknesses with plastic also make it more difficult to recycle something that’s already been made with recycled materials. There comes a point when plastic can’t even be downcycled anymore. When it reaches that point, it’s typically incinerated or sent to landfills. Plastic greenwashing
Microsoft is far from alone when it comes to making new environmental claims with recycled materials. Logitech has made a big push to sell items with post-consumer recycled plastic. Samsung is even making watch bands with “recyclable” and supposedly eco-friendly materials, including apple peel. The trend also extends far outside of tech to food packaging, fashion, and even toys.
Several factors could be driving that trend. The sheer magnitude of the plastics problem has brought it to more consumers’ attention. Plastics, which are made from fossil fuels, are also tied to another environmental crisis that’s come to the forefront more lately: climate change. Recent research shows that shoppers are thinking more about the sustainability of the brands they buy. Tech companies have come under a lot of pressure lately for the harm they do to the environment — particularly when it comes to their air pollution, greenhouse gas emissions, waste, and water use. Employees at Microsoft, Amazon, Google, and other tech giants have published letters pushing their companies to stop polluting and to stop working with fossil fuel companies altogether. While companies have announced smaller steps like using more recycled materials or fully offsetting their emissions — they haven’t agreed to meeting their employees’ more ambitious demands.
WITHOUT TURNING OFF THE TAP FOR PLASTICS WASTE, SMALLER ACTIONS COULD AMOUNT TO MERE GREENWASHING
Without turning off the tap for plastics waste, smaller actions could amount to mere greenwashing — a term used to describe efforts to make something (like a brand) seem more eco-friendly than it really is while glossing over the real environmental harm for which it’s responsible.
One example of greenwashing, according to Cambridge’s Barlow, is the emergency of bio-sourced plastics that can be just as bad or even worse than traditional plastics. A majority of bio-sourced plastics, made with things like corn instead of oil, still aren’t biodegradable, she says. And raising the crops those materials are derived from might actually lead to more water use and greenhouse gas emissions than traditional plastics. “There’s a big question mark on those. When you probe, sometimes it’s fine, but most of them, it’s greenwash,” she says.
Vague terms like “recyclable” also raise red flags for experts with whom The Verge spoke. Razer announced a goal earlier this year to make all of its products with recycled or recyclable materials by 2025. But a lot of things might be recyclable in theory but not in practice — like Amazon’s plastic shipping envelopes. Most municipal recycling programs won’t actually accept them, so consumers need to take the packaging to drop-off points for it to be recycled. Few people actually do that, according to at least one survey by ocean advocacy group Oceana.
Meaningful action on the plastics problem will require much bigger changes. When companies try to tackle huge problems like climate change and plastic pollution with small announcements about recycling and changes to individual devices, Lepawski says, “It’s nibbling around the edges, dealing with symptoms and not systems.”
The Product Stewardship Institute and other environmental advocates are pushing for policies that would force companies to take greater responsibility for what happens to the devices they sell after customers are done with them. Companies would be required to take back items or shoulder the costs associated with responsibly disposing of them. In the absence of those policies, municipalities and taxpayers wind up carrying the financial burden — or the environment pays the ultimate cost if that’s where trash winds up. Municipal recycling programs are still recovering from the global shock in 2018 when China stopped accepting most recyclable goods. With no one to sell dirty plastics to, some curbside recycling programs in the US shuttered or started sending more materials to landfills and incinerators.
Ocean Plastic Mouse and recycled plastic pellets Image: Microsoft
Still, experts worry that a hot market for recycled materials could keep the incentives and infrastructure in place for producing more plastics — whether they be recycled or not. Microsoft partnered with Saudi Basic Industries Corporation (SABIC), a subsidiary of oil company Saudi Aramco, for its Ocean Plastic Mouse. Big Oil has tried to push its plastics business as a growing line of revenue as efforts to reduce greenhouse gas emissions cut into its fuel business.
Microsoft’s new webpage for the Ocean Plastic Mouse tells consumers that they can recycle their old mouse by mailing it into Microsoft — although there’s a disclaimer at the bottom that says its recycling program is only available in certain countries. Consumers concerned about the environment would be better off keeping their old mouse rather than recycling it and buying a new one, says Sydney Harris, policy and programs manager at the Product Stewardship Institute.
“They’re creating new demand for a flashy new product that I don’t need because I have a perfectly functioning mouse right now,” says Harris. “That is not sustainable, inherently. I should be holding on to my mouse until it’s on its very last legs and stops working.” But even that can be hard to do when companies continually release new devices that might be incompatible with old accessories — like new laptops or phones with missing headphone jacks and different designs for chargers.
When tech companies design things that quickly become obsolete, they drive another growing disaster: e-waste. E-waste contains materials beyond plastic like mercury and lead that can be toxic to people and the environment. Affluent countries like the US send much of their e-waste abroad, where it often winds up in makeshift recycling facilities that can put workers’ health at risk.
“IT’S ACTUALLY VERY USEFUL TO BRANDS TO KEEP THE ATTENTION DOWNSTREAM.”
The focus on post-consumer recycling ultimately shifts responsibility from companies to their customers. That will never lead to the type of deep, systemic change needed to stem the world’s waste problems, says Lepawsky. “Individual consumer action will never match the scale of the problem,” he says. Typically across industries, he says, there’s way more waste generated during the manufacturing process — before a product ever gets to market — than trash that consumers throw out. “It’s actually very useful to brands to keep the attention downstream on post consumer waste, because then it means the regulatory eye is kept off of their manufacturing process.”
There’s a lot of other things that big tech companies might also want to hide from prying regulatory eyes — from privacy and moderation concerns to employees coming forward about prejudice and abuse. But, hey, at least they can say they recycled something, right?
Study reveals abundance of microscopic paint flakes in the North Atlantic
IMAGE: A MICROSCOPIC PAINT FLAKE, MEASURING AROUND 320ÎœM IN DIAMETER, COLLECTED DURING A CPR SURVEY IN THE SOUTHERN NORTH SEAview more
CREDIT: ANDREW TURNER, UNIVERSITY OF PLYMOUTH
Flakes of paint could be one of the most abundant type of microplastic particles in the ocean, new research has suggested.
Through a range of surveys conducted across the North Atlantic Ocean, scientists estimated that each cubic metre of seawater contained an average of 0.01 paint flakes.
This, they say, suggests the material is second only in terms of recorded abundance to microplastic fibres, which have an estimated concentration of about 0.16 particles per m3.
A detailed chemical analysis of some of the flakes, conducted on some of the particles gathered during the surveys, also revealed high quantities of copper, lead, iron and other elements.
This is because they are designed to have antifouling or anti-corrosive properties, with the researchers saying it could pose an additional environmental threat to both the ocean and many species living within it when they ingest the particles.
The study, published in Science of the Total Environment, was carried out by scientists from the University of Plymouth and the Marine Biological Association (MBA).
Dr Andrew Turner, Associate Professor (Reader) in Environmental Sciences at the University of Plymouth, is the current study’s lead author. He said: “Paint particles have often been an overlooked component of marine microplastics but this study shows that they are relatively abundant in the ocean. The presence of toxic metals like lead and copper pose additional risks to wildlife.”
The study is based around data gathered by the MBA’s Continuous Plankton Recorder (CPR), which is fitted with silk meshes and towed in surface waters similar to the spaces occupied by marine mammals.
Over the course of 2018, it was used to sample sea water right across the North Atlantic region, from the Arctic Ocean to Spain, and from the eastern United States to Sweden.
More than 3,600 samples were collected during that time and flakes were reported in about 2.8% (102) of all silks analysed. That compares with fibres or strands being observed in 48.8% (1763) of silks over the same period.
Paint flakes also appeared to be more densely distributed around the shelf seas of northwest Europe than in the open, or more remote, ocean environments.
An analysis of the paint particles was carried out in labs at the University using X-ray fluorescence (XRF) spectrometry, with their chemical composition consistent with that found on the hulls and other painted components of ships mobilised in the Atlantic region.
Dr Clare Ostle, the co-ordinator of the Pacific Continuous Plankton Recorder (CPR) Survey at the MBA and co-author on the study, added: “We now know that plastics are everywhere, and that most organisms are likely ingesting them, however there is less known about how harmful this ingestion might be. This study has highlighted that paint flakes are an abundant form of microplastic that should not be overlooked, particularly as some may have toxic properties.”
CAPTION
The Continuous Plankton Recorder (CPR) is fitted with silk meshes and towed in surface waters similar to the spaces occupied by marine mammals
Researchers at the Chinese University of Hong Kong have developed a polymer-based 3D printing material that can be dissolved almost entirely on-demand.
Made up of plant leaves and plastic waste, the team’s ‘Planstic’ filament features high-entropy fibers, designed to attract natural enzymes that accelerate its rate of degradation once disposed of. After just 8 weeks’ soil decomposition, the scientists say their material completely degrades leaving very few microplastic particles behind, potentially making it an eco-friendly alternative to mainstream PETs.
“The main problem with biodegradable plastics is that plastic items marked ‘biodegradable’ can only be broken down into smaller pieces. This is not an improvement on traditional plastics,” say the team in their paper. “Planstic solves this problem by enzyme degradation, making the degradation reaction of microplastics take place more efficiently, thus accelerating their degradation.”
“PLANSTIC CAN REDUCE THE COSTS OF DEALING WITH SECONDARY POLLUTION, AND CAN BE USED GENERALLY IN DAILY LIFE TO SOLVE THE PLASTIC DEGRADATION PROBLEM WORLDWIDE.”
The production method behind the researchers’ ‘Planstic’ 3D printing filament. Photo via the ACS Applied Polymer Materials journal. Microplastics: a global menace
Despite their inherent versatility, cheapness and corrosion-resistance, it is well-documented that plastics can take thousands of years to degrade. This means that once polymer-based products are discarded, they become an enduring pollutant to the environment, and this is particularly problematic when they break down into the toxic microplastics that are increasingly entering the human diet.
While degradable plastic bags are becoming the norm at Western supermarkets, the Hong Kong-based scientists point out that these still cause secondary pollution, via the raw materials and high energy consumed in the process of making them.
Similarly, although disposable food-related packaging, cutlery and containers are often marked as being made from biodegradable plastics, in reality, they can only be broken down into smaller pieces. As a result, many such polymeric goods still contribute to a growing microplastic problem that, according to recent research, now leads the average American to eat 39,000-52,000 polymer particles per year.
The Planstic filament being degraded over an eight-week period.
Images via the ACS Applied Polymer Materials journal.
Introducing a ‘Planstic’ solution
To help the world wean itself off its microplastic diet, the Hong Kong team has formulated a low-cost plant-infused plastic, that harnesses natural enzymes to degrade tiny polymer particles much more efficiently. Nicknamed Planstic, the researchers’ novel material was created via the combination of redbud leaves and ground PET, which were mixed, plasticized and made printable in a ‘Chembox.’
In the process of creating their material, the scientists found it possible to integrate leaves from the short-growth cycle Cercis chinensis, which naturally includes long fibers that lend themselves to degradation. The team also discovered that reinforcing these fibers at intersections improved the resulting filament’s properties, while each ingredient’s dosage could be optimized to minimize energy loss.
Once they’d finalized their material, deciding on a mix of 80% fibers and 20% PET, the researchers deposited it using a NanoscribePhotonic Professional GT2 3D printer, into a series of microstructures. After SEM imaging had shown that it could be 3D printed into parts with fine features as small as 160 nm, Planstic then proved itself to be more flexible but less strong than normal plastic bags under stress testing.
In order to assess their filament’s biodegradability, the team later deposited it into composted soil, finding that the enzymes within its leaf base decomposed “hard-to-degrade substances” like cutin. Interestingly, the material’s less stable surface also improved decomposition rates, as it allowed microorganisms to contact with it and accelerate the process, helping achieve “nearly total plastic degradation.”
Following the success of initial trials, the researchers say their Planstic material proves that “attracting microbials” can “accelerate plastic degradation.” Moving forwards, the team suggest that such closed-loop recycling methods could even replace landfill or incineration disposal methods, “reducing the energy pressure of nanotechnology and [helping] build an environmentally-friendly society.”
Bio-based 3D printing has continued to scale in recent years.
Photo shows WASP’S ‘TECLA’ eco-habitat. Photo via WASP.
Advancing bio-based AM
Given that many 3D printing polymers are as much part of the world’s microplastic problem as any other plastic, researchers continue to develop bio-alternatives that incorporate various natural elements, ranging from soil to insect faeces.
Scientists at the Massachusetts Institute of Technology (MIT) have turned to lab-grown wood cells as a means of producing a sustainable 3D printable biomaterial of their own. By cultivating their material, in a method akin to culturing meat, the team believe that it could be turned into a wood replacement with the potential to be 3D printed into home-made furniture.
On a commercial level, Desktop Metal has also begun binder jetting wooden parts via its Forust wood 3D printing subsidiary. The company is now upscaling waste byproducts from the wood manufacturing and paper industries such as sawdust and lignin, before mixing these with a bio-epoxy resin for architectural additive manufacturing applications.
Elsewhere, in the construction industry, WASP has utilized natural materials such as soil, rice, husk and lime to 3D print an entire eco-friendly organic house. Finished earlier this year, the self-supporting carbon-neutral ‘TECLA’ home, is designed to act as a proof-of-concept for a sustainable new house building model.
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Are you looking for a job in the additive manufacturing industry? Visit 3D Printing Jobs for a selection of roles in the industry. Featured image shows a breakdown of the production method behind the researchers’ ‘Planstic’ 3D printing filament. Photo via the ACS Applied Polymer Materials journal.
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