Low Carbon Materials Research Articles

Strengthen the student environmental literacy through education with low carbon education teaching materials

Science education should be able to make the students better understand and be sensitive to the environment. Nowadays, earth is affected by the greenhouse effect and global warming, which is caused by greenhouse gas emissions, especially CO2. Instil the awareness and sensitivity (environmental literacy) about the environment is very important to do. Education is the best way to grow and develop environmental literacy among the younger generation. The educational component that is very easy to be used as a means is a teaching material in the form of low carbon teaching materials. This study aims to provide a formulation of the social context associated with a reduction in CO2 emissions and its scientific explanation, as well as describe the pattern of presentation of these substances in the teaching materials. Low carbon teaching materials become a vehicle that raises the whole substance relating to CO2 emission reduction efforts. Substance in these materials taken from the contexts of everyday life, for example the CO2 emissions of various types of lamp, CO2 emissions in the type of fuel, CO2 emissions in the type of energy (LPG-LNG-Biogas), until the CO2 emissions from cigarette that burned. These contexts are given its scientific explanation (including calculations) but are presented in a simple-structured in the low carbon materials thus substantially easier to grasp. The presentation is also accompanied by analysis, stimulation of high order thinking skills, activities, and personal-contextual analysis

Life cycle assessment for masonry exterior wall assemblies made of traditional building materials

Building materials contribute a significant amount of CO2 to overall greenhouse gas emissions and this environmental impact should be reduced to improve the sustainability of the construction industry. Although new and low-carbon materials are emerging, the majority of materials used are still traditionally produced and are highly carbon intensive, such as masonry blocks and insulation slabs – rock wool or expanded polystyrene. To assess which of the traditionally used building materials are more sustainable, in this paper, wall models of the most widely used masonry blocks and insulation materials were analysed using life cycle assessment. The wall models were created to fulfil the requirements of nearly-zero energy buildings. The assessment showed that the lowest impact on the environment is from aerated concrete blocks and expanded polystyrene insulation, which is mostly due to low weight and raw materials consumption compared to other materials. On the other hand, expanded polystyrene insulation poses more danger to humans and the environment in its use phase than other materials due to emissions during fire and degradation, thus should be used with caution.

Can Governments Ban Materials with Large Carbon Footprint? Legal and Administrative Assessment of Product Carbon Requirements

This paper explores whether governments can ban carbon-intensive materials through product carbon requirements. By setting near-zero emission limits for the production of materials to be sold within a jurisdiction, governments would accelerate the phase out of carbon-intensive production processes. Their announcement could alert basic materials producers, financing institutions, and other relevant stakeholders, thus incentivising them to prepare for this shift by dedicating their innovation efforts and investments to climate friendly production processes and low-carbon materials. The paper analyses various product standards and technical regulations in the European context. The analysis of these standards and technical regulations offers an overview of the types of environmental requirements that the European Union has already adopted. Therefore, it provides a case study of the political, legal, and technical backgrounds for the development of product carbon requirements, both in the EU and beyond. Second, the paper presents an analysis of the provisions in WTO law that would apply to product carbon requirements, underlining the legal arguments in support of their adoption under international trade law.

3D hierarchical porous carbon derived from direct carbonization and in-situ chemical activation of potatoes toward high-performance supercapacitors

The construction of hierarchical porous carbon with low cost and superior performance based on biomass materials plays a significance role in application of supercapacitors. A three-dimensional Hierarchical Porous Carbon (3D HPC) was synthesized by one-step carbonization process with in situ chemical activation using potato as precursor. The 3D HPC exhibits high specific surface area and good hierarchical porous structure which can serve an excellent electrochemical performance. It can reach a high specific capacitance of 236 F g−1 at 0.5 A g−1 and a long cycle life (capacitance retention of 96% after 10000 cycles) in 2 M KOH. The 3D HPC//3D HPC symmetrical supercapacitor achieves a high energy density of 6.8 Wh kg−1 at the power density of 310 W kg−1. Meanwhile, the [BMIm]BF4/acetonitrile (AN) ionic liquid was applied to promote the energy density to supercapacitors, the higher energy density (45.06 Wh kg−1) is shown compared with that in aqueous electrolyte and most reported carbon materials in ionic liquid. The outstanding performance is attributed to the porous structure with different pore size which not only provide large surface area but also facilitate the electrolyte ions transport rapidly. This study offers a convenient and effective approach to deriving low cost and high performance carbon material for supercapacitors.

Approaches for a low-carbon production of building materials: A review

Abstract High levels of GHG emissions are the result of the activities of the construction industry; for example, cement and steel production alone are responsible for 10–12% of global Green House Gas (GHG) emissions. In order to control climate change, while complying with the levels set by the Paris agreement and the IPCC 2018 report (a maximum of +1.5 °C above pre-industrial levels), serious measures need to be adopted so that GHG emissions can be reduced. Indeed, it is only through the adoption of the Circular Economy (CE) principles that the construction sector will be able to play a strategic role in the achievement of such reductions. Despite the importance of the topic, there are few comprehensive reviews of possible strategies to produce low-carbon materials; this paper analyses literature reviews on low-carbon material, starting from international policies on GHG emission reduction and CE principles, providing a critical summary of current knowledge. On the basis of a thorough literature review whose references have been made in accordance with the relevance of the topic of study, the approaches adopted in order to produce low-carbon materials, the materials investigated and the related issues and challenges, the work identifies in an original way eight approaches (known as Low-carbon Emission Approaches - LEAs) related to the production process that could help reduce the GHG emissions of construction materials. Comparing the results of the literature review analysis with the material life cycle by means of a matrix that relates LCA and LEAs, the paper underlines LEA's capability to reduce GHG levels. In particular, focusing on the 8 LEAs identified, it emerges that, in order to create low-carbon products for construction, it is possible to use alternative materials (up to −40% of GHG emission) and natural materials (up to −90%), to introduce secondary raw materials (up to −40/50%), to implement CCS and CCU systems in the production process (up to −70%), to increase the use of energy from renewable sources (up to −60%), and to increase product performance. The work also highlights some limitations linked to several factors, such as: the costs for initial investments, some changes in the cultural paradigm, the impossibility for the market to receive innovative products, and the lack of skills of technicians and companies, and so on; these problems need to be solved in the shortest time possible in order to achieve the goal set by the Intergovernmental Panel on Climate Change.

Compressive strength and hydration process of ground granulated blast furnace slag-waste gypsum system managed by wet grinding

Replacement of Portland cement by industrial wastes has been accepted as a potential way to reduce carbon emissions. Ground granulated blast furnace slag (GGBS), desulphurization gypsum (DG), and phosphogypsum (PG), known as the common industrial wastes, were used in this study. Binders comprised of GGBS and waste gypsum were designed to develop a novel low carbon material; in order to promote the reactivity raw materials were processed by wet grinding. Compressive strength was examined and hydration process was researched by XRD, TG, NMR, SEM, and MIP. Results showed that wet grinded PG (WGPG) and wet grinded DG (WGDG) were able to greatly augment compressive strength of wet grinded GGBS (WGS) system. The reasons were attributed to the accelerated formation of ettringite and the reduced porosity. On the one hand, the presence of ettringite could construct the crystal skeleton resulted in the hardening of system accelerated. On the other hand, the constantly produced C-S-H gel densified the microstructure and decreased the porosity significantly. Moreover, in comparison with WGDG-WGS system, the early strength of WGPG-WGS system was lower caused by the retardation effect of phosphorus in PG. Results was expected to be used for the design of low carbon materials.

Collaboration and shared logic for creating value-added in three Finnish wooden multi-storey building projects

ABSTRACT Increasing societal interest towards sustainable and low-carbon materials contributes to demand for wood-based materials and modern solutions for urban construction. Wooden multi-storey construction (WMC), however, is a relatively new phenomenon in the construction business, and collaborative business models in projects that adopt such novel building techniques are yet to develop. Shared logic is a key concept shaping the development of well-functioning business ecosystems, even though actor priorities may vary between the WMC business ecosystem members. This study examines the applicability of business ecosystem concept based on actor perception involved in three Finnish WMC projects. The results suggest that elements from the business ecosystem thinking can be identified in all the cases. Moreover, network collaboration created benefits to the ecosystem, such as reference value and new insights from research and development. For some companies, engagement in the business ecosystem created financial and employment benefits, while some interviewees perceived these projects also to create immaterial value, such as awareness on sustainability issues in their business, marketing gains, or in the form of mutual learning effects.

Primary energy and CO2 emissions implications of different insulation, cladding and frame materials for residential buildings

In this study, we analyse and compare the primary energy use and carbon dioxide (CO2) emissions associated with different insulation, cladding and frame materials for a constructed concrete frame multi-storey residential building in Sweden. Our approach consists of identifying individual materials giving the lowest primary energy use and CO2 emissions for each building envelope part and based on that, modelling different material combinations to achieve improved alternatives of the concrete frame building with the same operation energy use based on the Swedish building code or passive house criteria. We analyse the complete materials and energy chains, including material losses as well as conversion and fuel cycle losses. The analysis covers the primary energy use to extract, process, transport, and assemble the materials and the resulting CO2 emissions to the atmosphere. The results show wide variations in primary energy and CO2 emissions depending on the choice of building envelope materials. The materials for external walls contribute most to the primary energy and CO2 emissions, followed by foundation, roof and external cladding materials. The improved building alternatives with wood construction frames, wood external cladding, expanded polystyrene as foundation insulation and cellulose insulation in the external walls and roof result in about 36 - 40% lower production primary energy use and 42 – 49% lower CO2 emissions than the improved concrete alternative when achieving the same thermal performance. This study suggests that strategies for low-energy buildings should be combined with resource-efficient and low carbon materials in the production phase to mitigate climate change and achieve a sustainable built environment.

How interlayer twist angles affect in-plane and cross-plane thermal conduction of multilayer graphene: A non-equilibrium molecular dynamics study

Graphene, a kind of emerging low dimensional carbon material, has admirable thermal properties with potential applications in the thermal management of aerospace and microelectronics fields. In recent studies, thermal properties of both conventional single-layer and multilayer graphene were extensively studied. However, few studies focused on that of multilayer graphene with twist angles, whose thermal properties are different from that of conventional graphene because of the existence of interlayer twist angles. Such knowledge gap hinders the potential applications. Therefore, the thermal conductivity of bilayer, 4-layers and 6-layer zigzag graphene with various twist angles is investigated utilizing non-equilibrium molecular dynamics at the typical temperature region in this study, and both in- and cross-plane thermal conductivity are investigated. The size of the studied graphene is 10 nm × 22 nm in the x-y plane, and the size in the z-direction depends on the number of layers. Moreover, the phonon vibrational density of state is also analyzed for mechanisms behind the thermal transport. The result indicates that a local maximum value can be found with the twist angle of 30° for in-plane thermal conduction. The results also suggest that the highest thermal conductivity could be reached without any twist angles for both in and cross-plane conduction. The observation would provide an opportunity to study the characteristics of in-plane and cross-plane thermal transport of twisted multilayer graphene.

Enzymatic hydrolysis of corn crop residues with high solid loadings: New insights into the impact of bioextrusion on biomass deconstruction using carbohydrate-binding modules

Lignocellulosic biomass is a sustainable source of renewable substrate to produce low carbon footprint energy and materials. Biomass conversion is usually performed in two steps: a biomass pretreatment for improving cellulose accessibility followed by enzymatic hydrolysis of cellulose. In this study we investigated the efficiency of a bioextrusion pretreatment (extrusion in the presence of cellulase enzyme) for production of reducing sugars from corn crop agricultural residues. Our results demonstrate that bioextrusion increased the reducing sugar conversion yield by at least 94% at high solid/liquid ratio (14%–40%). Monitoring biomass surface with carbohydrate-binding modules (FTCM-depletion assay) revealed that well known negative impact of high solid/liquid ratio on conversion yield is not due to the lack of exposed cellulose which was abundant under such conditions. Bioextrusion was found to be less efficient on alkaline pretreated biomass but being a mild and solvent limiting pretreatment, it might help to minimize the waste stream.

Testing the greenhouse gas emissions reduction potential of alternative strategies for the english housing stock

Buildings account for around a third of global energy and process emissions, but have been delivering much smaller emissions savings than other sectors. Although clear standards of new building construction and retrofitting options have been developed and are able to reduce building emissions, there is need for a clear prioritisation of policy options capable of delivering the greatest reduction in emissions at minimal costs. This requires an assessment of the trade-offs between new construction and retrofitting in terms of the pace of adoption of improved building standards and the emissions savings achieved to meet current climate targets. In this paper, a dynamic material flow analysis is used to explore the impact of combined mitigation strategies on both new and existing buildings capable of reducing embodied and operational emissions in the English domestic housing stock. The results show that progress in the use of low carbon materials in construction and the deployment of zero-carbon buildings at scale would not be enough to deliver a reduction of building emissions of the scale required nationally (–66% from current levels by 2050). Improvement in building standards for both new and pre-existing construction is essential to meet targets, but its costs are likely to be unreasonable without a reduction in the demand for floor area per capita by promoting flexible design of buildings, house sharing or telecommuting, which are likely to produce far-reaching implications in social organisation and urban planning.

Development and application of a hybrid prestressed segmental concrete girder utilizing low carbon materials

A hybrid prestressed segmental concrete (HPSC) girder utilizing low carbon materials was developed in this paper. This paper introduces the hybrid prestressing concept of pre-tensioning the center segment and assembling all segments by post-tensioning, as well as the development process of the low carbon HPSC girder. First, an optimized mix proportion of 60 MPa high strength concrete containing high volume blast furnace slag was developed, then its mechanical properties and durability characteristics were evaluated. Second, the mechanical properties of 2,400 MPa high strength prestressing strands and the transfer length characteristics in pre-tensioned prestressed concrete beams were evaluated. Third, using those low carbon materials and the hybrid prestressing concept, the HPSC girders were manufactured, and their structural performance was evaluated. A 30-m long HPSC girder for highway bridges and a 35-m long HPSC girder for railway bridges were designed, manufactured, and structurally confirmed as having sufficient strength and safety. Finally, five 35-m long HPSC girders were successfully applied to an actual railway bridge for the first time.

Modified potential for atomistic simulation of the growth of carbon materials from binary alloy catalysts.

A new hybrid bond order potential has been developed and implemented to describe carbon-bimetallic alloy interactions, which are involved in the catalytic growth of carbon materials such as graphene and carbon nanotubes on the surface of binary alloy catalysts. In carefully adjusting the parameters, the potential energy fitting correlated with the results calculated from the density functional theory (DFT) method leads to a high quality empirical force field with an average error of <4.5% only. With the PES accuracy, in total 16 (n,m) have been successfully obtained from the MD trajectories in this work, and the structural evolution including random chirality and diameter formation has been identified. The newly modified force field is expected to be useful for modelling the spontaneous growth of carbon materials, particularly tubes on binary alloy clusters, giving an idea of how these C-C, C-M, and M-M interactions affect the growth behavior of carbon nanotubes. In addition, the new FF is only valid for liquid alloy nanoparticles at this time, but the use of solid alloy nanocatalysts with the new FF can be further employed for 2-D material growth such as graphene layer growth.

Model Based Design of Composite Carbonaceous Anode for Li-Ion Battery for Fast Charging Applications

Blending of the popular anodic material graphite with hard carbon is one of the suggested way to improve the rate capability and cycle life performance in Lithium ion batteries. Based on this concept, this work proposes a high-rate battery with optimal blend composition, which can undergo high charge rate with high cycle life durability. This is done by suitably blending the existing graphite based anode with low cost hard carbon material, which improves the rate limiting solid phase diffusion. In this paper, an electrochemical model is developed for cell comprising of electrode with multiple active materials. Simulation study confirms that the hard carbon layer on graphite matrix facilitates charge transfer and creates additional electronic conduction pathways. Electrochemical model is used to devise a generic methodology to optimally design lithium ion cell comprising of anode with multiple active materials. In particular, the optimal composition of 30% hard carbon (HC) and 70% natural graphite (NG) exhibits high rate charging capability compared to pure NG. Efficacy of the proposed solution is also shown by demonstrating the high rate capability of the battery fabricated in the laboratory and prediction from proposed model are in good quantitative accord with the test result.

Assessment of Paint Layers Quality 3. Analysis by SEM-EDAX and XRF techniques of the paint layers applied on a railway bridge

In order to identify the premature biodegradation causes of paint applied in 2013 on a railway bridge, top coat layers applied have been investigated by XRF and SEM-EDAX techniques after 32 years, corresponding to periods of operation under identical climatic conditions of 4.5 years and 3.5 years respectively. By analysis of the experimental results obtained, it has been found that by using suitable painting materials (titanium content of about 7.5 % - TiO2 for UV protection) an exploitation period of more than 30 years could be obtained. Low-carbon (low polymer) and titanium dyeing materials with significant content of soluble salts have a low durability and anticorrosive protection capability. They degrade relatively fast both by top coat degradation and by intense increases of biofouling.

Engineered hybrid fibre reinforced composites for sound absorption building applications

The sound absorption was investigated in a series of 21 isotropic Hybrid Fibre Reinforced Composite (HFRC) prototypes, using the impedance tube method. The composite blends were engineered targeting the recovery of highly-available natural and synthetic fibrous polymeric materials —thermoplastic, ligno-cellulose, keratin, alginate bio-polymer—sourced locally from the post-consumer and end-of-life waste streams. Two major environmental pollution problems are discussed, such as urban noise and waste fibres, and how to transfer this waste into building materials, targeting a two-fold solution with environmental, economic, and social benefits. The diversion of valuable fibrous resources from landfill disposal is pursued, promoting multi-stage cascading use of raw materials as local industrial feedstock, through the development of high-end non-toxic products, for acoustic building applications. The noise absorption properties of the HFRCs is the focus of the study, since urban noise is considered by the World Health Organization amongst the major sources of anthropogenic environmental pollution of global industrialized urban settlements. The experimental results indicated low absorption coefficient at mid-frequencies (500 Hz–2.5 kHz) and a higher absorption (2.5–6.4 kHz) coefficient at higher frequency ranges. Peak sound absorption values of ±0.78 were achieved by the low-density prototypes with minimal filler-matrix interfacial voids and in which the filler phase was constituted by natural fibres with intricate hierarchical intraparticle microstructure. These series of innovative low-carbon materials from wastes introduce a sustainable alternative to traditional commercial synthetic products, for the improvement of the indoor quality by a significant noise reduction, particularly targeting dwellings in densified urban zones.

Approach to establish carbon emission benchmarking for construction materials

The construction industry will play a crucial rule in global carbon emission reduction as the embodied carbon of construction materials shares an increasing portion of a building’s life-cycle carbon dioxide (CO2) emissions. In order to reduce CO2 emissions by selecting low-carbon construction materials, it is inevitable that a proper benchmarking mechanism and severity representation of different emission levels should be established, as benchmarking is a useful tool for pursuing consumer purchasing habits toward selection of low-carbon materials. In addition, high variation of carbon emissions is observed among the large number of studies and databases, and there is no consensus on how these should be used in practice. Therefore, standardization and benchmarking of emissions for construction materials are essential. In this study, a novel benchmarking approach was developed for embodied carbon emissions of commonly used construction materials by applying a fuzzy set theory. Given that a reliable local database is lacking, the benchmark was developed by referring to the existing carbon inventories, linguistic variables of severity levels from a questionnaire survey, and the fuzzy set analysis. A six-step method was proposed based on a horizontal and graphical approach. This study offers an alternative approach in benchmarking where a database or a set of real data is not available. It is expected that the developed benchmarks will help practitioners and decision-makers compare the embodied CO2 emissions of a specific batch of construction materials and select low-carbon materials in construction projects.

Direct Electricity Generation Mediated by Molecular Interactions with Low Dimensional Carbon Materials—A Mechanistic Perspective

AbstractNext‐generation off‐the‐grid electronic systems call for alternative modes of energy harvesting. The past two decades have witnessed the evolution of a wide spectrum of low dimensional carbon materials with extraordinary physical and chemical properties, ideal for microscale electrical energy storage and generation. Tremendous progress has been made in harnessing the energy associated with the interactions between these nanostructured carbon substrates and the surrounding molecular phases, subsequently converting them into useful electricity. This review summarizes the important theoretical and experimental milestones the field has reached to date, and further classifies these energy harvesting processes based on underlying physics, into five mechanistically distinct classes—phonon coupling, Coulombic scattering, electrokinetic streaming, asymmetric doping, and capacitive discharging. With a special mechanistic focus, the authors hope to resolve the fundamental attributes shared by this diverse array of molecular scale energy harvesting schemes, offer perspectives on key challenges, and ultimately establish design principles that guide further device optimization.

Use of innovative low carbon materials for sustainable energy-efficient housing in Nigeria

Sustainable energy-efficient housing is environmentally-conscious housing. Energy efficient houses consume less energy while maintaining or improving the comfort conditions of occupants. This paper examines low carbon initiatives in housing construction in Nigeria based on the use of stabilized soil blocks, solid interlocking blocks, and supplementary cementitious materials such as fly ash, rice husk ash, palm oil fuel ash, and their various combinations in concrete production as low carbon materials. These are materials readily available in Nigeria and can be useful for sustainable housing construction. Their use is for the purpose of reducing embodied energy in construction of houses and reduction of operational energy in housing use. Owing to the poor state of energy generation and transmission in Nigeria energy efficiency measures are imperative to reduce the energy required in houses. The paper thus affirms the need to adopt energy efficiency strategies in housing in order to achieve eco-friendly and sustainable environment in Nigeria.

Cradle-to-gate life cycle assessment of energy and carbon of a residential building in Sri Lanka

The growing concerns over the environment have led to increasing demand for environmentally-friendly buildings. So far, only a few studies on environmental impacts of buildings have been conducted in the context of Sri Lanka. Reliable data sources that match the specific conditions of the country are limited. Using the life cycle assessment (LCA) methodology, this paper presents a cradle-to-gate energy and carbon emission study of a multi-storey residential building in a Sri Lankan university. The total embodied energy and carbon of the building are 3.84 GJm-2 and 229.34 kgCO2m-2, respectively, which are comparable with results of similar studies found in literature. Reinforced concrete, the main structural material, contributed to 61 % of total embodied energy and 71 % of total embodied carbon of the building. Despite the relatively low material quantity used, aluminium, ceramic tiles and paint shared 18.67 % of total embodied energy. In order to achieve low-energy and low-carbon buildings in Sri Lanka, several strategies were identified; suitable construction practices and building designs to reduce quantities of mass materials, use of alternative materials with low energy and carbon intensities, material recycling and reuse, use of clean and renewable energy for production processes and popularising the concept of eco-labels for building materials. The reduction of embodied energy and carbon is expected to lighten the environmental footprint of buildings.