Low Carbon Footprint Research Articles

Influence of the Depth of Nitrogen-Phosphorus Fertilizer Placement in Soil on Maize Yielding and Carbon Footprint in the Loess Plateau of China

Deep fertilization is a beneficial approach for reducing nitrogen losses. However, the effects of various fertilization depths on maize (Zea mays L.) productivity and environmental footprints have not been thoroughly understood. Therefore, a field experiment was conducted to investigate the effects of different fertilization depths of 5 cm (D5), 15 cm (D15), 25 cm (D25), and 35 cm (D35) on maize productivity and environmental footprints. Reactive nitrogen (Nr) losses and greenhouse gas (GHG) emissions were assessed using life cycle analysis. We hypothesized that deep fertilization can obtain lower carbon and nitrogen footprint. The results indicated that deep fertilization decreased the N2O and NH3 emissions while increasing the CH4 uptake. Compared with D5, D15 resulted in an increase in total GHG emissions and carbon footprint (CF), whereas D25 decreased by 13.0% and 23.6%, respectively. Compared with D5, the Nr losses under D15, D25, and D35 conditions was reduced by 11.3%, 17.3%, and 21.0%, respectively, and the nitrogen footprint (NF) was reduced by 16.0%, 27.4%, and 19.0%, respectively. The maize yield under D15 and D25 increased by 5.7% and 13.8%, respectively, compared with the D5 treatment, and the net economic benefits of the ecosystem increased by 7.1% and 17.1%, respectively. In summary, applying fertilizer at a depth of 25 cm can significantly reduce the environmental footprints and increase maize productivity, making it an effective fertilization strategy in the Loess Plateau region of China.

Experimental Investigation of Quasi-Static and Dynamic Impact Resistance in Thin Wood Veneer Laminates

The incorporation of sustainability into the design of transport vehicles has become increasingly important in recent years. A low carbon footprint makes wood-based structures attractive to replace other lightweight materials such as aluminum or fiber-reinforced plastics. This paper investigates and compares the static and dynamic impact behavior of thin Beech wood veneer laminates in standardized mechanical tests. The results obtained from Quasi-Static Indentation (QSI) and dynamic Low-Velocity Impact (LVI) tests reveal similarities and differences with regard to load vs. displacement behavior, damage mechanisms, permanent deformation, and energy absorption. While yield strength and damage modes are comparable in both test cases, it is found that the bending stiffness is strain-rate sensitive. Plastic deformation in compression is identified as the governing mechanism for energy absorption. These results can guide the design of sustainable wood-based structures for future transport applications where a thorough understanding of impact and crashworthiness is important.

Energy-efficient rapid additive manufacturing of complex geometry ceramics

Energy-intensive industries are one of the key greenhouse gas emitters, and decarbonization of such industries is a top priority to promote global sustainability. As one of the top energy-intensive industries, ceramic manufacturing industries are urged to boost energy efficiency in ceramic structure production. In this paper, we present a rapid and low carbon footprint strategy for freeform manufacturing spatial ceramic composites. Our approach integrates layer-by-layer deposition, photothermal in-situ solidification, and self-sustaining ceramization, enabling consolidation using only 1920 J energy. Compared to state-of-the-art processes, energy consumption can be reduced by over 100-fold, resulting in an estimated 1000-fold decrease in CO2 emissions. This energy-efficient process also demonstrates the rapid fabrication of ceramic gyroid heat exchangers, capable of withstanding extreme environments.

Accelerated carbonation curing of concrete incorporating calcium carbide residue

The synergic effect of accelerated carbonation curing and cement replacement by calcium carbide residue (CCR) on the carbon sequestration potential and performance of concrete was examined. The concrete mixes included 0, 5, 10, and 20 % (by mass) CCR as partial cement replacement and were subjected to different initial air curing durations (0, 4, and 20 h) and subsequent carbonation curing durations (4 and 20 h). The performance was evaluated based on the CO2 uptake, 1-, 7-, and 28-day compressive strengths, and volume of permeable voids. Scanning electron microscopic (SEM) imaging was used to characterize the microstructure of the carbonated concrete. The environmental footprint of concrete produced herein was assessed. The experimental results showed that using CCR enhanced the CO2 uptake of concrete, with 5 and 10 % replacement levels providing superior outcomes in concrete subjected to 4- and 20-h carbonation curing. The compressive strength and a volume of permeable voids improved upon replacing cement with 5 % CCR. Such findings were validated by examining the void space in the SEM micrographs. Furthermore, prolonging the initial air curing and carbonation durations to 20 h each and incorporating 20 % CCR resulted in the highest CO2 uptake and lowest carbon footprint. Among the developed mixes, the most suitable was the mix subjected to 20 h of each initial air curing and carbonation curing with 20 % CCR replacement by mass. Nevertheless, all developed mixes satisfy the minimum strength requirement for concrete masonry unit applications.

Obtaining and Characterizing New Types of Materials Based on Low-Density Polyethylene and Thermoplastic Starch

Significant interest is devoted to the development of new polymer blends by using concepts of the circular economy. Such materials have predetermined properties, are easy to recycle, ecological, and have a low carbon footprint. This research presents obtaining and characterization of polymer blends based on low-density polyethylene (LDPE) and thermoplastic starch (TPS). In the first stage, TPS was obtained through the gelatinization process, and, in the second stage, mixtures of LDPE and TPS were obtained through a melt mixing process at 150 °C for 7 min. The physical–mechanical characteristics of the samples, like hardness, elongation at break, rebound resilience, and tensile strength, were determined. The sample containing maleic anhydride grafted low-density polyethylene (LDPE-g-MA) as a compatibilizer shows improvements in elongation at break and tensile strength (by 6.59% and 40.47%, respectively) compared to the test sample. The FTIR microscopy maps show that samples containing LDPE-g-MA are more homogeneous. The SEM micrographs indicate that TPS-s is homogeneously dispersed as droplets in the LDPE matrix. From the thermal analysis, it was observed that both the degree of crystallinity and the mass loss at high temperature are influenced by the composition of the samples. The melt flow index has adequate values, indicating good processability of the samples by specific methods (such as extrusion or injection).

A New Experimental Setup to Characterize Binder–Vegetal Particle Compatibility in Plant-Based Concrete

The good insulation properties and the low carbon footprint of vegetal concretes make them promising materials whose use tends to grow continuously. To produce optimized building materials, a better understanding of the interfacial transition zone (ITZ) between vegetal particles and cement paste in terms of the reactions involved and the size of the impacted surface was investigated. This research led to the setting of a reliable visual test to observe ITZ, which enables the monitoring of its appearance and development. Different combinations of vegetal particles and cement pastes were tested to compare the formed ITZ: hemp, rapeseed, and bamboo into Portland and Prompt cement. Finally, a clear link was drawn between the sugar concentration and the size of ITZ. Thanks to image analysis, it was shown that ITZ is due to physico-chemical reactions, with the extraction of free saccharide molecules from the vegetal and water suction followed by their release into the cement paste.

Assessing the Cost of Nutritionally Adequate and Low-Climate Impact Diets in Finland

BackgroundDietary changes form an important component of the sustainability transition of food systems but could be hindered by the cost of sustainable diets. ObjectivesThis study aimed to characterize the cost of nutritionally adequate and culturally acceptable diets with low-greenhouse gas emissions (GHGEs) in Finland. MethodsTwo optimization models were built to find diets complying with nutritional and emissions requirements. The first model minimizes diet cost and the second one deviation from current diets. Both are calibrated to Finnish sociodemographic groups using dietary intake data, household budget survey data (for prices), and life cycle assessment coefficients (for GHGE). Three scenarios are simulated: “Health only” imposes only compliance with nutritional constraints, whereas “Health and GHGE-33%” and “Health and GHGE-50%” impose, in addition, minimum reductions in GHGE. ResultsMinimum cost diets have a low-carbon footprint [−65% (−73%) for females (males)] and low cost [−69% (−73%) for females (males)] when compared with current diets but lack diversity and cultural acceptability. The more culturally acceptable health-only minimum deviation diets are marginally less costly and have a lower climate impact than baseline diets across all population groups. Reducing GHGE results in a substantial decrease in the cost of the minimum deviation diets. The lower cost of the minimum deviation diets with reduced GHGE results from both intercategory and intracategory substitutions. ConclusionsAffordability is not the key obstacle to the adoption of nutritionally adequate and lower GHGE diets, but cultural acceptability is. Reducing the climate footprint of diets can generate side benefits in terms of nutrition and affordability, which confirms that dietary change should be central to the sustainability transition of the Finnish food system. However, more attention should be paid to the issues of taste, convenience, social norms, and other aspects determining the cultural acceptability of sustainable diets.

Characterizing the US Market for Salad Mixes through the Lens of Environmental Preferences

The consumption of salad mixes has increased because of their convenience and nutritional value, resulting in significant sales increases during the past decade. Conversely, the uses of pest-control chemicals, long-distance transportation of salad mixes, and plastic packaging have raised environmental concerns among “green consumers.” Because proenvironmental products are becoming more widespread, this study delved into market segments of salad mix consumers based on their preferences for proenvironmental labels. Data for this study were collected via a 2020 web-based survey of 2100 salad mix consumers in the United States. We performed a comprehensive two-stage cluster analysis that integrated both hierarchical and partitioning methods. This analysis was based on consumers’ preferences and evaluations of production (low energy use, low fertilizer use, low greenhouse gas emissions, low water use, and pollinator-friendly) and marketing-related (biodegradable packaging, low carbon footprint, and low food miles) proenvironmental labels. Three segments were identified. We used ordered probit regression to assess the impact of consumer demographic characteristics, market preferences, and environmental perceptions on cluster membership. The deep-rooted segment, which represented 36% of the sample, highly valued all proenvironmental labels related to salad mixes and had a particular preference for labels that included low fertilizer use, pollinator-friendly production methods, and low greenhouse gas emissions. The indecisive segment comprised 40% of the sample and moderately valued all proenvironmental labels; this group mainly comprised individuals with lower income levels and those living in rural areas. The skeptic segment represented 23% of the sample and valued environmental labels less than the deep-rooted and indecisive segments did; additionally, they reported the lowest consumption of salad mixes. These findings can help retailers and policymakers communicate information about proenvironmental labels more effectively to each segment of salad mix consumers.

Design of the Mobile Application to Reduce the Carbon Track

Climate change is impacted by global warming. As a result of climate change, some local weather patterns are gradually altering. Climate change and carbon emissions are inextricably linked and contribute to a number of phenomena, including the melting of ice at the north and south poles due to rising global temperatures. The danger of dying increases with temperature. By developing and constructing a mobile application, this study aims to promote environmental restoration efforts by providing carbon compensation, which is a carbon emissions trading system. The developed mobile application tracks carbon offsets. Users’ comments are gathered through surveys, and design and prototype are done using the Unified Modelling Language (UML). Users of mobile apps can lessen their impact on the environment, ameliorate climatic calamities, or even survive them. As a result of this application, you can lower your carbon footprint and increase your environmental consciousness by using mobile applications.

Appraisal of reclaimed asphalt pavement as coarse aggregates in cement concrete

This systematic literature review evaluates reclaimed asphalt pavement (RAP) in concrete construction, targeting reduced natural aggregate use and lower construction carbon footprint. It comprehensively covers RAP in concrete, including mechanical properties, durability, test methods, mix design, performance, influencing factors, RAP content, processing, admixtures, curing, and environmental aspects. RAP concrete matches traditional concrete mechanically while increasing sustainability through waste reduction. Durability parameters, like permeability, freeze-thaw resistance, and chloride penetration, suggest long-term structural enhancement. Reliable testing methods and standards are vital for RAP in concrete assessment. The review explores RAP in mix design, considering content, gradation, and processing. Admixtures and additives optimize RAP concrete. Curing and environmental conditions influence RAP concrete performance. Gaps indicate a need for long-term studies, understanding mechanisms, specific environmental exploration, standardized testing, and economic assessment. The study recommends future research directions to guide sustainable construction practices.

The effect of geosynthetic reinforcement on the load transfer mechanism of pile-supported low embankments subject to cyclic traffic loading

Pile-supported embankments are commonly employed for highways in soft soil areas. Extensive studies have been conducted on high embankments under static loading. However, low embankments with lower costs and carbon footprint have not yet been thoroughly studied. This study aims to investigate the performance of pile-supported low embankments under cyclic traffic loading by carrying out two large-scale model tests. The soft soil was constructed using Kaolin clay, and the cyclic traffic loading was simulated using a localized semi-sinusoidal function. The effect of geosynthetic reinforcement on the load transfer mechanism of pile-supported low embankments was investigated by comparing the measured data from unreinforced and reinforced cases. Test results show that geosynthetic reinforcement reduces settlement and leads to faster stabilization of settlement in low embankments. Pile-supported low embankments experience a rapid decrease followed by a stabilization in pile efficacy with increased cyclic loading, and geosynthetic reinforcement increase the pile efficacy and facilitate quicker stabilization. Geosynthetic reinforcement enhances the transfer of static and dynamic stresses to piles, resulting in less stress degradation under cyclic loading. Based on experimental results, pile-supported embankments should account for the adverse effects of cyclic loading, even if they are classified as high embankments according to existing analytical models.

Biogenic sulfur as an effective source for sulfidogenesis via sulfur disproportionation (S0Disp)

Sulfidogensis via element sulfur disproportionation (S0Disp) has been recently suggested to be a cost-effective and low carbon footprint process to produce sulfide for wastewater treatment such as denitrification and the removal of heavy metals. However, studies on this process are limited in using the industrial grade chemical sulfur (Chem-S0). In this study, biogenic sulfur (Bio-S0), a solid waste produced from biogas bio-desulfurization, was investigated for the first time in the S0Disp process with the performance compared to the Chem-S0 with identical size. The results showed that the S0Disp process driven by Bio-S0 was initiated more rapidly than that by the Chem-S0 (8 d vs 13 d) and performed a 1.2-fold higher sulfide production rate in the steady phase. A series of characterizations were conducted to elucidate the difference between using these two types of S0 in disproportionation. The faster initiation of Bio-S0 sets was suggested to correlate its hydrophilic properties, while the higher sulfide production rate was likely due to its higher reactivity as indicated by the lower crystallinity and the presence of organic polysulfane with lower dissociation energy for the S-S bond. Additional tests demonstrated that the Bio-S0 could be more readily attacked by the sulfide to produce polysulfide, a putative rate-limiting step of S0 taken by bacteria in the S0Disp process. Moreover, the sulfur-disproportionating bacteria were found to be enriched more in the Bio-S0 set, which might also contribute to the higher sulfide production rate. This study extended the knowledge of Bio-S0 in good bioavailability and offered new opportunities for reusing this solid waste.

Low‐Carbon‐Footprint Plasma‐Functionalized Coconut‐Coir‐Based Porous Carbon as an Efficient and Sustainable Adsorbent

AbstractHerein, the surface of pyrolyzed coconut coir (PCC) dust has been functionalized using atmospheric plasma under non‐equilibrium conditions without utilizing vacuum chambers. The reactive species present in the plasma such as, molecular ions, electrons, and radicals interact with PCC's surface, leading to the introduction of epoxy, carbonyl and amino functional groups on carbon surface. The resulting plasma functionalized carbon (PFC) material was characterized using several advanced material characterization techniques, including PXRD, FTIR, XPS, N2 BET specific surface area, SEM and TEM imaging techniques, etc. Moreover, it has been used in diverse applications in toxic gas removal (CO2, CO, NOx), fluoride (F−) removal from drinking water and cationic organic dye (methylene blue–MB) removal. The reported method for synthesis of functional carbon introduces a platform technology for low carbon footprint, green synthesis of advanced functional materials.

Thin-film composite membranes with contorted monomer for high-flux isothermal refining

The development of isothermal refining processes is important because of the high energy demands of crude oil separation. Membrane technology provides separation efficiency and low carbon footprint. This efficiency can be fine-tuned and enhanced by modifying the chemistry of the membrane selective layer. Herein, we describe the fabrication of membranes by interfacial polymerization using a combination of contorted fluorinated monomer bearing six fluorine atoms and trimesoyl chloride in the organic phase. A fluorinated m-phenylene diamine was added to the aqueous phase. This approach produces membranes with high surface roughness, increases their hydrophobicity and promotes the transport of hydrocarbons with high selectivity and toluene permeance (15.6 L m−2 h−1 bar−1). Successful evaluations were conducted for the fractionation of crude oil, confirming the potential for application in the petrochemical industry.

Embodied Carbon and the Nuances in Office-to-Residential Conversions

Reducing carbon emissions associated with buildings is a top priority for mitigating the human impacts from climate change. Reducing carbon emissions resulting from the manufacturing, designing, constructing, investing, owning, operating, occupying, renovating, and demolishing of buildings is essential to safeguard the environment from negative consequences. This paper relates to the environment and human influence on the climate and addresses the different amounts of embedded carbon for building activities ranging from new buildings to major renovations to minor renovations, using a methodology termed the “whole-life carbon measurement”. The data from the case studies indicate that refurbished or renovated buildings exhibit the least carbon footprint compared to other alternatives. This outcome can be attributed to the sustainable practice of reusing materials, coupled with the positive effects of retrofitting. The expectation that refurbished buildings would demonstrate a lower carbon footprint aligns with the principles of sustainability, emphasizing the environmental benefits of repurposing existing structures. While embedded carbon is currently not priced, it is important that it be accurately measured over the entire life cycle of buildings if the real estate industry is to meet sustainability goals.

Measuring the performance of CO2 injection into field-cured concrete in the Arabian Gulf climate: an experimental study

ABSTRACT Concrete has experienced significant improvements in recent decades, resulting in lower Portland cement consumption as well as a lower carbon footprint through CO2 injection while keeping comparable fresh, mechanical, and durability performance. The use of CO2 injection in concrete (CarbonCure) in the United States and Canada has enabled advances such as green concrete under normal and severe conditions. While incorporating novel developments, this study focuses on CarbonCure concrete modification in the extreme weather of the Arabian Gulf region. This is a relatively new option that has entered the field in the Middle East. The materials, process, and fresh and hardened properties of the CarbonCure concrete made and field cured in the Arabian Gulf region will be considered here and evaluated in detail. Along with adding CO2 to the mix, the cementitious material was lowered without impacting the quality or performance of the structural concrete. The developed green mix included up to 0.2% CO2 by mass of cementitious material. Because of the benefit of early carbonation, which strengthened the concrete product even with less cementitious material, this green concrete mix retained a 28% increase in slump compared to the standard concrete mix without CO2, a 28-day compressive strength of 48 MPa, low water absorption of 1.3%, and resistance to aggressive chemicals, all within the limits defined by the standard codes. Due to these benefits, and because this green concrete was tested against the severe coastal climate, it would be ideal for maritime applications.

Life cycle carbon analysis of packaging products containing purposely grown nonwood fibers: A case study on the use of switchgrass pulp for linerboard and corrugating medium

Sustainability is driving innovation in the pulp and paper industry to produce goods with lower carbon footprints. Although most of the efforts are currently focused on increasing energy efficiency or switching to renewable fuels, the attention toward alternative feedstocks has increased in recent years. Claims of nonwood fibers requiring lower use of chemicals and energy than wood fibers, along with negative consumer perceptions of tree felling, are helping purposely grown nonwoods to gain market share. The potential nonwood fiber environmental superiority over virgin or recycled wood fibers remains controversial and is often driven more by emotion and public perception rather than facts. This paper estimates the carbon footprint of corrugating medium and linerboard containing switchgrass pulp compared to analogous wood-based materials. The study includes a life cycle carbon analysis spanning from cradle to gate, which comprises stages for fiber production, pulping, papermaking, and corresponding transportation. Carbon footprints for virgin linerboard, recycled linerboard, virgin medium, and recycled medium were estimated at around 510, 620, 460, and 670 kg carbon dioxide equivalent per metric ton (kg CO2eq/t), respectively. Replacing 30% of the virgin or recycled material with switchgrass pulp translated into carbon footprint increases of around 60%, 45%, 62%, and 38%, respectively. Thus, for the proposed case study, the results suggest that switchgrass-based medium and linerboard can present a higher carbon footprint than products made from virgin and recycled wood fibers. The main driver is the production of nonwood mechanical pulp. This study was designed to mitigate part of the uncertainty around the environmental sustainability of medium and linerboard made from the selected purposely grown nonwood fibers.

LOW CARBON FOOTPRINT ALUMINIUM COMPONENTS FOR E-MOBILITY

In the fast-evolving E‐mobility transformation, the circular economy is one of the key factors to make Europe carbon neutral by 2050, together with sustainability, achievable only with a synergic approach, from raw material choice to recycling, through product design for re‐purposing. Secondary aluminium alloys have a twenty times lower carbon footprint than primary metals, leading to significant CO2 savings. Their properties can satisfy engineering targets through optimized product design. Adopting a smart system layout, in which functions are assigned to assemblies, some of the low‐end mechanical properties of secondary alloys can be offset. Design for easy disassembling can then guarantee a selective re‐purposing and, finally, an environmentally friendly recycling of components. Innovative products in this field have been developed and successfully produced by means of an optimized high-pressure die casting (HPDC) technology, adopting low carbon footprint raw materials supplied in alternative to ingot format. In this work, the characterization of a component for e-mobility has been conducted, evaluating both the characteristics of the scrap alloy used to produce the castings and the casting itself. The results demonstrate a fine and high-quality microstructure of the casting, proving the feasibility of the production process using exclusively scrap alloy.

Editorial: Special issues in March and May TAPPI Journal focus on the latest pulp manufacture and engineering research

This issue, organized by Editor-in-Chief Peter Hart, features content from the 2023 PEERS/IBBC Conference that has been peer reviewed for publication in TAPPI Journal. The papers encompass a range of topics:œ Two papers, from researchers Suarez et al. at WestRock, examine pulp from nonwoods like wheat straw and sugar-cane bagasse using a holistic life cycle analysis approach to project environmental performance in packaging products. The results can help mills make decisions about which fibers ensure a low carbon footprint.

Four chemometric models enhanced by Latin hypercube sampling design for quantification of anti-COVID drugs: sustainability profiling through multiple greenness, carbon footprint, blueness, and whiteness metrics

Montelukast sodium (MLK) and Levocetirizine dihydrochloride (LCZ) are widely prescribed medications with promising therapeutic potential against COVID-19. However, existing analytical methods for their quantification are unsustainable, relying on toxic solvents and expensive instrumentation. Herein, we pioneer a green, cost-effective chemometrics approach for MLK and LCZ analysis using UV spectroscopy and intelligent multivariate calibration. Following a multilevel multifactor experimental design, UV spectral data was acquired for 25 synthetic mixtures and modeled via classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), and genetic algorithm-PLS (GA-PLS) techniques. Latin hypercube sampling (LHS) strategically constructed an optimal validation set of 13 mixtures for unbiased predictive performance assessment. Following optimization of the models regarding latent variables (LVs) and wavelength region, the optimum root mean square error of cross-validation (RMSECV) was attained at 2 LVs for the 210–400 nm spectral range (191 data points). The GA-PLS model demonstrated superb accuracy, with recovery percentages (R%) from 98 to 102% for both analytes, and root mean square error of calibration (RMSEC) and prediction (RMSEP) of (0.0943, 0.1872) and (0.1926, 0.1779) for MLK and LCZ, respectively, as well bias-corrected mean square error of prediction (BCMSEP) of -0.0029 and 0.0176, relative root mean square error of prediction (RRMSEP) reaching 0.7516 and 0.6585, and limits of detection (LOD) reaching 0.0813 and 0.2273 for MLK and LCZ respectively. Practical pharmaceutical sample analysis was successfully confirmed via standard additions. We further conducted pioneering multidimensional sustainability evaluations using state-of-the-art greenness, blueness, and whiteness tools. The method demonstrated favorable environmental metrics across all assessment tools. The obtained Green National Environmental Method Index (NEMI), and Complementary Green Analytical Procedure Index (ComplexGAPI) quadrants affirmed green analytical principles. Additionally, the method had a high Analytical Greenness Metric (AGREE) score (0.90) and a low carbon footprint (0.021), indicating environmental friendliness. We also applied blueness and whiteness assessments using the high Blue Applicability Grade Index (BAGI) and Red–Green–Blue 12 (RGB 12) algorithms. The high BAGI (90) and RGB 12 (90.8) scores confirmed the method's strong applicability, cost-effectiveness, and sustainability. This work puts forward an optimal, economically viable green chemistry paradigm for pharmaceutical quality control aligned with sustainable development goals.