Carbon in the Circular Economy

A topical collection in C (ISSN 2311-5629). This collection belongs to the section "Carbon Cycle, Capture and Storage".

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Editors


E-Mail Website
Collection Editor
Energy Safety Research Institute, Swansea University, Bay Campus, Swansea SA1 8EN, UK
Interests: carbon nanotube synthesis; applications and characterization; electron microscopy of carbon nanotubes; electrochemistry in organic synthesis; electro organic synthetic chemistry; catalysis and catalytic nanoparticles; nano medicine; aerospace and deep space applications; science education using nano materials
Special Issues, Collections and Topics in MDPI journals

E-Mail Website
Collection Editor
Energy Safety Research Institute, Swansea University, Bay Campus, Swansea SA1 8EN, UK
Interests: carbon dioxide capture and utilisation; sustainable and clean energy production; materials science and engineering; electrochemistry; photovoltaics; sensors; drug delivery
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

Carbon is one of the most heavily extracted materials on the planet, constituting the ingredient that serves as the basis for most of the materials of the modern world—the list ranging from fuels to medicines, solvents, plastics, rubbers, and many more. Without access to carbon and, consequently, these materials, the modern world might grind to a halt. This is especially pertinent in a peak-oil scenario. If we run out of oil and the main supply of carbon goes dry, then how will modern society continue to grow? How will it even maintain equilibrium? Yet, there is a growing body of scientific, technical, and innovative possibilities that use pre-existing materials, which are reprocessed to create the materials of our future. Materials that have been extracted, used, and then spent can be upcycled and circularized back into the economy for continued use. Additionally, materials can be created to have several lifecycles designed into their properties from the outset. In this way, the need to recycle is mitigated, and ultimately, the notion of waste is flipped on its head. Waste is a resource and a commodity, not a burden or a health hazard. Ultimately, the goal is to create materials that are designed to avoid landfill or spillage to our atmospheres at all costs. Once materials enter landfill, they historically end up in the food chain (e.g., microplastic formation from plastics), and once they end up in our atmosphere, they affect the natural environment (e.g., decreased breathing quality due to carbon particles in the air).

This Special Issue is dedicated to showcasing the various methods and materials that can be created that avoid the pathway to landfill. This is a call to action for scientists and engineers to take a cold hard look at the world in which we live. Do you really want your grandchildren to drink the microplastics that our generation created? Do you want them to live on a planet where the air is unbreathable? If such a future sounds grim to you and you have ideas and technologies to avoid it, then this Special Issue is for you. This problem is multifaceted, so the solution will require input from multiple sources and disciplines. We therefore welcome contributions from all disciplines that uncover and educate us on ways and means to keep carbon in the economy and prevent its escape into our living and breathing environment.

Dr. Alvin Orbaek White
Dr. Enrico Andreoli
Guest Editors

Manuscript Submission Information

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Keywords

  • carbon
  • carbon utilization
  • carbon recycling
  • green manufacturing
  • circular economy

Published Papers (8 papers)

2024

Jump to: 2023, 2021, 2020, 2019

27 pages, 13944 KiB  
Article
How to Compute Whether Biomass Fuels Are Carbon Neutral
by Gilbert Ahamer
C 2024, 10(2), 48; https://doi.org/10.3390/c10020048 - 22 May 2024
Cited by 1 | Viewed by 1381
Abstract
Based on recent interest and on the importance of the ongoing climate change catastrophe, this article provides the basics of global carbon cycle modelling as required for the assessment of the degree of carbon neutrality of biomass energy, and its underlying dynamics. It [...] Read more.
Based on recent interest and on the importance of the ongoing climate change catastrophe, this article provides the basics of global carbon cycle modelling as required for the assessment of the degree of carbon neutrality of biomass energy, and its underlying dynamics. It is aimed at clarifying the question “Are biomass fuels carbon neutral?”. The “Combined Energy and Biosphere Model” (CEBM) computes annual carbon flows including growth and decay of plants on 2.5 × 2.5° grid elements of the continents’ surface and offers detailed results on the changes of after implementation of large-scale biomass energy strategies worldwide. The main (and possibly unexpected) effect is the long-term depletion of the soil organic compartment after extraction of biomass fuels. When comparing CEBM model runs using (i) biomass energy sources and (ii) carbon-free energy sources (such as solar or wind), it becomes quantitatively clear already on the theoretical level (i.e., even without taking into account efficiency losses) that biomass is only “half as carbon neutral” as ideally assumed, to express a rule of thumb—mainly because of soil carbon depletion. Still, biomass energy will play an important role when fighting global warming, even if efforts to lower energy demand are preferable as a fundamental strategy. Full article
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21 pages, 2270 KiB  
Review
Carbon Capture, Utilization, and Storage Risks from Supply Chain Perspective: A Review of the Literature and Conceptual Framework Development
by Md Ainul Kabir, Sharfuddin Ahmed Khan and Golam Kabir
C 2024, 10(1), 15; https://doi.org/10.3390/c10010015 - 31 Jan 2024
Cited by 2 | Viewed by 3665
Abstract
The technology called carbon capture, utilization, and storage (CCUS) is important for capturing CO2 emissions before they enter the air. Because everyone wants to stop global warming by reducing CO2 emissions, CCUS is an important and emerging technology that can help [...] Read more.
The technology called carbon capture, utilization, and storage (CCUS) is important for capturing CO2 emissions before they enter the air. Because everyone wants to stop global warming by reducing CO2 emissions, CCUS is an important and emerging technology that can help slow down climate change, lower emissions in many areas, and support the move toward a sustainable and carbon-neutral future. As CCUS technology and its adaptation increases, it is very important to pay attention to the CCUS risks from a supply chain (SC) point of view. The goal of this study was to identify CCUS supply chain risks and develop a conceptual framework (CF) that provides a structured approach to ensure safe and reliable CCUS supply chain operations. Therefore, this study analyzed the literature related to the SCs of different sectors and identified the SC risks, which was the foundation for CCUS SC risk identification. This study demonstrates that there is no research article that provides a comprehensive CCUS SC risk management framework that connects with risk management strategies. The conceptual framework that is proposed in this study connects CCUS SC functions, risks, and risk management strategies to construct a complete CCUS supply chain risk management system. Moreover, the CF provides guidelines for future research, which will enrich the CCUS supply chain risk management system as well as fight climate change. Full article
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2023

Jump to: 2024, 2021, 2020, 2019

12 pages, 1093 KiB  
Article
Carbon Capture and Storage through Upcycling of Suberinic Acid Residues in Wood Composites Finishing
by Aleksandra Jeżo and Grzegorz Kowaluk
C 2023, 9(3), 80; https://doi.org/10.3390/c9030080 - 25 Aug 2023
Cited by 4 | Viewed by 1618
Abstract
Finishing coatings used in the wood-based composite industry play a key role in the final appearance of the finished product. However, the use of such coatings is not only for aesthetic purposes, but also to protect the product against surface damage and moisture [...] Read more.
Finishing coatings used in the wood-based composite industry play a key role in the final appearance of the finished product. However, the use of such coatings is not only for aesthetic purposes, but also to protect the product against surface damage and moisture or to minimize the emission of harmful substances. The latter is an extremely important factor in terms of safety for both the manufacturer and the user, which is why the emissivity test is one of the most important tests conducted in this case. Carbon-rich materials, such as those remaining from the extraction of birch bark, can fulfill the role of minimizing the emission of harmful substances. In this article, an attempt to create coatings in the form of a film by combining a biopolymer with suberinic acid residues (SARs) was made. Two types of biopolymers were used, polylactide (PLA) and polycaprolactone (PCL), in various polymer–SAR ratios. Suberinic acid as a residue is a raw material that can potentially contribute positively to the fixing of CO2 from the atmosphere, which creates the possibility for further use. As part of this study, the obtained coatings were tested in terms of scratch resistance, relative hardness, cold liquids, total volatile organic compounds (TVOCs), formaldehyde emission, surface absorption, etc. Differences between the polymers used and the effect of the SAR additive on selected surface properties were demonstrated. The addition of carbon-rich SAR significantly improves gas barrier properties of the PLA- and PCL-based surface finishing materials. The relative hardness and scratch resistance also increased with rising SAR content. However, the increasing content of SAR filler acts as a limiter in the depth of penetration of the deposited surface finishing materials onto the wood surface. It is possible to state that this innovative approach regarding (1) the utilization of biopolymers as a matrix, instead of conventional, crude oil-based resins, and (2) the incorporation of post-processed carbon-rich waste lignocellulosic materials to produce the surface finishing and/or protective films has been confirmed. Full article
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2021

Jump to: 2024, 2023, 2020, 2019

43 pages, 3477 KiB  
Review
Towards Controlled Degradation of Poly(lactic) Acid in Technical Applications
by Stefanie Teixeira, Katarzyna Morawa Eblagon, Filipa Miranda, M. Fernando R. Pereira and José Luis Figueiredo
C 2021, 7(2), 42; https://doi.org/10.3390/c7020042 - 30 Apr 2021
Cited by 115 | Viewed by 19552
Abstract
Environmental issues urge for the substitution of petrochemical-based raw materials with more environmentally friendly sources. The biggest advantages of PLA over non-biodegradable plastics are that it can be produced from natural sources (e.g., corn or sugarcane), and at the end of its lifetime [...] Read more.
Environmental issues urge for the substitution of petrochemical-based raw materials with more environmentally friendly sources. The biggest advantages of PLA over non-biodegradable plastics are that it can be produced from natural sources (e.g., corn or sugarcane), and at the end of its lifetime it can be returned to the soil by being composted with microorganisms. PLA can easily substitute petroleum-based plastics in a wide range of applications in many commodity products, such as disposable tableware, packaging, films, and agricultural twines, partially contributing to limiting plastic waste accumulation. Unfortunately, the complete replacement of fossil fuel-based plastics such as polyethylene (PE) or poly(ethylene terephthalate) (PET) by PLA is hindered by its higher cost, and, more importantly, slower degradation as compared to other degradable polymers. Thus, to make PLA more commercially attractive, ways to accelerate its degradation are actively sought. Many good reviews deal with PLA production, applications, and degradation but only in the medical or pharmaceutical field. In this respect, the present review will focus on controlled PLA degradation and biodegradation in technical applications. The work will include the main degradation mechanisms of PLA, such as its biodegradation in water, soil, and compost, in addition to thermal- and photo-degradation. The topic is of particular interest to academia and industry, mainly because the wider application of PLA is mostly dependent on discovering effective ways of accelerating its biodegradation rate at the end of its service life without compromising its properties. Full article
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2020

Jump to: 2024, 2023, 2021, 2019

16 pages, 2307 KiB  
Article
Achieving Climate Targets via the Circular Carbon Economy: The Case of Saudi Arabia
by Yousef M. Alshammari
C 2020, 6(3), 54; https://doi.org/10.3390/c6030054 - 31 Aug 2020
Cited by 8 | Viewed by 4521
Abstract
Clean hydrocarbon technologies have a key role to play in achieving the circular carbon economy while meeting climate targets in many countries around the world. The aim of this work is to assess which technology, or combination of technologies, is the most cost-effective [...] Read more.
Clean hydrocarbon technologies have a key role to play in achieving the circular carbon economy while meeting climate targets in many countries around the world. The aim of this work is to assess which technology, or combination of technologies, is the most cost-effective in achieving climate targets by 2030 leading to a quick and smooth transition to a low carbon energy system in Saudi Arabia and similar oil-based economies. We find that low carbon policy support by banning crude oil in power generation, leads to accelerated underground oil gasification, in the absence of carbon prices. We also find that setting a policy for carbon reduction targets leads to a more flexible energy system transition enabling more technologies in the mix with an increasing transition period. Our results also show that clean hydrocarbon technologies may be sufficient to achieve new climate targets, as shown by the stabilised emissions in scenario 3 by 2025, without the implementation of renewable sources of energy which most studies do not include. We propose that by investing in clean hydrocarbon technologies over the short term, the transition towards a low carbon economy will be accelerated while developing renewable sources of energy over the long term. Full article
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2019

Jump to: 2024, 2023, 2021, 2020

9 pages, 1870 KiB  
Article
From Newspaper Substrate to Nanotubes—Analysis of Carbonized Soot Grown on Kaolin Sized Newsprint
by Bruce E. Brinson, Varun Shenoy Gangoli, Anjli Kumar, Robert H. Hauge, W. Wade Adams and Andrew R. Barron
C 2019, 5(4), 66; https://doi.org/10.3390/c5040066 - 29 Oct 2019
Cited by 1 | Viewed by 7858
Abstract
Herein, we report the successful use of newspaper as a substrate for the growth of single-walled carbon nanotubes (SWCNTs) by chemical vapor deposition (CVD) with intriguing results demonstrating that (a) the large surface area of newspaper stock allows for SWCNT growth and (b) [...] Read more.
Herein, we report the successful use of newspaper as a substrate for the growth of single-walled carbon nanotubes (SWCNTs) by chemical vapor deposition (CVD) with intriguing results demonstrating that (a) the large surface area of newspaper stock allows for SWCNT growth and (b) only newspaper produced with kaolin clay sizing allowed for SWCNT growth. Kaolin newsprint was impregnated with Al2O3 and Fe(NO3)3·9H2O (as precursors to FexOy nanoparticles), and calcined (30 min at 400 °C). The subsequent char residue was loaded into a CVD chamber and used as a substrate for SWCNT growth at 750 °C, using H2, C2H2, and water vapor as the growth gas. Samples of raw carbon soot exhibiting fluorescence spectra, indicative of SWCNTs, were further evaluated by resonant Raman spectroscopy, and by transmission electron microscopy (TEM). The calcinated substrate remnants were evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Experiments utilizing paper substrates produced with kaolin filler resulted in hybridized sp2–sp3 bonded carbon species. The soot was found to consist primarily of carbon nanotubes and bi-layer graphene in the form of collapsed nanotubes, also known as graphene nanoribbons (GNR). Full article
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9 pages, 5220 KiB  
Article
The State of HiPco Single-Walled Carbon Nanotubes in 2019
by Varun Shenoy Gangoli, M. Anto Godwin, Gadhadar Reddy, Robert Kelley Bradley and Andrew R. Barron
C 2019, 5(4), 65; https://doi.org/10.3390/c5040065 - 28 Oct 2019
Cited by 10 | Viewed by 11656
Abstract
High-pressure carbon monoxide (HiPco)-synthesized single-walled carbon nanotubes (SWCNTs) have been a widely studied carbon nanomaterial for nearly two decades. It has been the de facto standard for SWCNT research, be it functionalization, separation and purification, or composites, as a result of the consistent, [...] Read more.
High-pressure carbon monoxide (HiPco)-synthesized single-walled carbon nanotubes (SWCNTs) have been a widely studied carbon nanomaterial for nearly two decades. It has been the de facto standard for SWCNT research, be it functionalization, separation and purification, or composites, as a result of the consistent, high-quality material that was made available at an affordable price to researchers worldwide. The recent shutdown of the HiPco reactor at Rice University has resulted in a scarcity of HiPco material available to the research community, and a new source of similar SWCNTs is desperately needed. Continued research and development on the design, materials used, and the overall process have led to a new HiPco material, referred to as NoPo HiPCO®, as an alternative to the erstwhile Rice HiPco SWCNTs. In this work, we have compared the two HiPco materials, and aim to provide more clarity for researchers globally on the state of HiPco SWCNTs for research and applications alike in 2019. Full article
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7 pages, 1265 KiB  
Article
Chemical Recycling of Consumer-Grade Black Plastic into Electrically Conductive Carbon Nanotubes
by Ali Hedayati, Chris J Barnett, Gemma Swan and Alvin Orbaek White
C 2019, 5(2), 32; https://doi.org/10.3390/c5020032 - 12 Jun 2019
Cited by 17 | Viewed by 11926
Abstract
The global plastics crisis has recently focused scientists’ attention on finding technical solutions for the ever-increasing oversupply of plastic waste. Black plastic is one of the greatest contributors to landfill waste, because it cannot be sorted using industrial practices based on optical reflection. [...] Read more.
The global plastics crisis has recently focused scientists’ attention on finding technical solutions for the ever-increasing oversupply of plastic waste. Black plastic is one of the greatest contributors to landfill waste, because it cannot be sorted using industrial practices based on optical reflection. However, it can be readily upcycled into carbon nanotubes (CNTs) using a novel liquid injection reactor (LIR) chemical vapor deposition (CVD) method. In this work, CNTs were formed using black and white polystyrene plastics to demonstrate that off-the-shelf materials can be used as feedstock for growth of CNTs. Scanning electron microscopy analysis suggests the CNTs from plastic sources improve diameter distribution homogeneity, with slightly increased diameters compared with control samples. Slight improvements in quality, as determined by Raman spectroscopy of the D and G peaks, suggest that plastics could lead to increased quality of CNTs. A small device was constructed as a demonstrator model to increase impact and public engagement. Full article
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