Global Warming Potential Values Research Articles

Performance optimization and environmental assessment of novel alkali-activated binders containing carbonated recycled concrete powder

This study investigates the influence of carbonated recycled concrete powder (CRCP), alkali content (AC), and silicate modulus (SM) on the compressive strength, chemical composition, and environmental benefits of CRCP-blast furnace slag blended alkali-activated binders (AABs). The results show that increasing CRCP content reduces the compressive strength of AABs due to lower geopolymeric reactivity. Using response surface methodology, the optimal values for AC and SM in AABs containing 50 wt.% CRCP were determined as 14.28% and 0.92, respectively, resulting in predicted and actual strengths of 49.9 MPa and 46.8 MPa. Chemical analyses reveal that calcite and vaterite are the predominant crystalline phases in AABs, while both Si-Al gels and calcite from CRCP participate in geopolymeric reactions. The effects of AC and SM on AAB strength are further elucidated through the combined analysis of precursor dissolution amount, geopolymeric gel formation amount, and calcium carbonate decomposition amount. Moreover, CRCP demonstrates negative carbon emissions, with a global warming potential of -0.16 kg CO2 eq/kg. The optimally proportioned AAB containing 50 wt.% CRCP shows global warming potential and carbon intensity values significantly lower than those of Portland cement, at 54.4% and 50.8%, respectively. These findings emphasize that AABs containing 50 wt.% CRCP not only meet the 43-grade strength classification but also offer notable environmental benefits. In summary, this study contributes to the development of a novel 43-graded low-carbon binder containing high-volume CRCP.

Comparative life cycle assessment of carbon-free ammonia as fuel for power generation based on the perspective of supply chains

In recent years, there has been a surge in ammonia demand due to growing interest in carbon-free fuel for decarbonization. Thus, it is crucial to identify the methods to fulfill the required demand, particularly for countries with resource scarcity or lacking well-established production infrastructure. The present study compares environmental impact analysis between domestic ammonia production and import ammonia for these countries by using life cycle assessment (LCA) methodology. In these ammonia supply paths, five different production ways were applied: gray (conventional Haber-Bosch process), blue (with carbon capture and storage), green (wind, solar, and nuclear powered water electrolysis with Haber-Bosch process). The assessment showed highest global warming potential (GWP) value at 2.64 ton CO2-eq/ton NH3 for imported gray while domestic nuclear-driven ammonia had the lowest value at 0.81 ton CO2-eq/ton NH3. In addition, contrary to expectations, the human and environment impact of green ammonias were all higher than gray and blue ammonia due to the production of raw materials. This means that environmental improvements of related production process are crucial in preparation for the coming new energy regime, which then lead to the production of environmentally friendly ammonia. Lastly, these results offer valuable guideline for future energy strategy planning.

Quantifying global warming potential variations from greenhouse gas emission sources in forest ecosystems

Forest ecosystems play a crucial role in regulating greenhouse gas (GHG) emissions and mitigating climate change. This research aimed to evaluate the GHG emissions of various sources within forested ecosystems and assess their respective contributions to global warming potential (GWP), vital for developing more targeted strategies to mitigate climate change, shaping climate policies, carbon accounting, sustainable forest management, and advancing scientific comprehension of ecosystem-climate dynamics. The study comprehensively analysed carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions EDGAR data of deforestation, fires, and natural processes such as organic soil decomposition within forested ecosystems. The assessment quantified the CO2 equivalent emissions for each category from 1990 to 2022 and forecasted till 2030. Our forecast shows that CO2 emissions from deforestation could reach between 3,990 and 4,529 metric ton (Mt) by 2030, with forest fires contributing an additional 750 Mt. Forestland CO2 absorption is expected to decline to -5134.80 Mt by 2030. There is uncertainty surrounding the forecasts for Organic soil CO2 (829.78 Mt) and Other land CO2 (-764.53 Mt). In addition, deforestation was a significant contributor to CO2 emissions, with a GWP ranging from 4000 to 4500, highlighting the complex interplay between natural processes and human activities in shaping atmospheric warming patterns. Additionally, forest fires emit a complex mix of GHGs. The potency of these gases in warming the planet varies considerably, with CH4 exhibiting a GWP range of 500 to 700 Mt CO2 equivalent, and CO2 ranging from 900 and 1350 Mt. These variations depend on fire intensity and its overall impact on the climate system. Forestland acts as powerful carbon sink, capturing atmospheric CO2 with negative GWP values between -7000 and -6000. Researchers suggest a multifaceted strategy such as stricter enforcement of sustainable forestry regulations, investing in projects that promote carbon sequestration, and reforestation. Additionally, advancements in drone technology, satellite imagery, remote sensing and advanced data analytics can aid in detecting and mitigating climate change impacts, ultimately paving the way for carbon neutrality.Graphical

Atmospheric chemistry of (Z)‐CF2HCF=CHCl: Kinetics and products of reaction with Cl atoms and OH radicals

AbstractLong path length FTIR‐smog chamber techniques were used to study the title reactions in 650 Torr of N2, oxygen, or air diluent at 296 ± 3 K. Values of k(Cl + (Z)‐CF2HCF = CHCl)═(6.6 ± 0.7) × 10−11 and k(OH + (Z)‐CF2HCF═CHCl)═(4.1 ± 0.7) × 10−12 cm3 molecule−1 s−1 were measured. The IR spectrum of (Z)‐CF2HCF═CHCl is reported. The atmospheric lifetime of (Z)‐CF2HCF═CHCl is determined by the reaction with OH and is approximately 2.8 days. Reaction of (Z)‐CF2HCF═CHCl with Cl atoms gives HC(O)Cl and CF2HC(O)F as major primary products. Under environmental conditions, the OH radical initiated oxidation gives CF2HC(O)F and HC(O)Cl in yields of (98 ± 8)% and (100 ± 4)%, respectively. Accounting for non‐uniform horizontal and vertical mixing leads to a 100‐year time‐horizon global warming potential value for (Z)‐CF2HCF═CHCl of essentially zero.

Structural Reuse of Decommissioned Ski Lift Steel Trusses for Load-Bearing Applications

The ongoing effects of climate change have led to a rise in global temperature, significantly reducing snow cover and resulting in the abandonment of numerous ski areas across Switzerland. As a result, many ski lifts have been decommissioned and left to deteriorate due to lenient local regulations. To address this issue, this paper presents a case study approach to repurposing steel trusses from abandoned ski lifts for a new structural application within the building industry. The design, sourcing, and construction of a new load-supporting column are described, focusing on reusing the ski lift steel trusses as a whole, without dismantling them into their components. After collection, these elements are adapted to comply with current building standards. By pouring out the hollow structure with the recently developed building material Cleancrete ©, a new load-bearing structure is developed. A comprehensive life cycle assessment (LCA) demonstrates the environmental performance of the steel–Cleancrete hybrid construction, which achieves a global warming potential (GWP) of 536.58 kg CO2-eq. In comparison, alternative designs using wood and concrete exhibited GWP values of 679.45 kg CO2-eq, +26.6%, and 1593.72 kg CO2-eq, +197.02%, respectively. These findings suggest that repurposing abandoned ski lift structures can significantly contribute to sustainable building practices, waste reduction, and the promotion of circular economy principles. The process outlined in this paper holds potential for future applications, particularly in the reuse of other steel components, ensuring continued circularity even as the supply of ski lift structures may dwindle.

Towards a national life cycle database: an LCA case study from the Czech Republic

Abstract The building sector in the Czech Republic faces several challenges, including limited availability of Life Cycle Assessment (LCA) data for building materials and products, insufficient market incentives, little institutional capacity, and some resistance from governmental entities. Therefore, this study also outlines the creation of an internal environmental dataset database designed to conduct Whole Life Carbon (WLC) assessments for 50 case studies. The database primarily sources Environmental Product Declarations (EPDs) and generic data from the Ecoinvent database, which are stored within the OneClick LCA software (OCLCA). The Global Warming Potential (GWP) is calculated for the whole life cycle of each building, using the EU Level(s) methodology. As a baseline, the datasets for materials and products with the highest GWP values were used. A sensitivity analysis was performed on the main resulting hotspots to produce results for both the so-called realistic (average GWP values) and optimistic (lowest GWP values) scenarios. The application of this methodology is demonstrated through a detailed example of one of the case studies, within the framework of the INDICATE international project. This work represents a significant step toward defining a Czech national methodology for establishing benchmarks that can be readily used by Czech practitioners and practitioners.

Thermodynamic Performance Characterization of a Small-Scale Organic Rankine Cycle with 5 kW Net Power Output

Abstract Indonesia’s current energy landscape predominantly depends on fossil fuels and non-renewable energy sources, thereby exacerbating the issue of global warming. On the other side, geothermal utilization in the country still needs to be expanded to reduce the dependency on fossil fuels, particularly through organic Rankine cycle (ORC) systems. As an example, Ulumbu Geothermal Power Plant in Flores Island currently uses a back pressure turbine, which releases expanded steam directly into the atmosphere at 98.7°C and 0.98 bar. This paper presents a thermodynamic analysis of a small-scale Organic Rankine Cycle with 5kW Net power output based on the waste heat data of the Ulumbu Geothermal Power Plant. The study includes selecting the working fluid based on Ozone Depletion Potential (ODP) and Global Warming Potential (GWP) values, thermal efficiency, refrigerant, and steam mass flow rate calculation. Among 20 refrigerants available in Indonesia, R245fa shows promise, offering a Rankine system efficiency of 10-11%, zero ODP, a GWP of 850, and the lowest refrigerant mass flow rate. These parameters inform useful initial parameters for designing a small-scale ORC system producing 5 kW of net power, promoting cleaner and sustainable energy solutions for communities.

Thermodynamic performance and compression characteristics analysis of low GWP refrigerant in compressors: Experimental investigation and 0-D/3-D simulation

The utilization of low global warming potential (GWP) refrigerants is crucial for reducing greenhouse gas emissions. Among these alternatives for hydrofluorocarbons (HFCs), R290 stands out as a natural refrigerant with a low GWP value of 3. Therefore, it is beneficial to promote its widespread adoption and enhance the efficiency of compressors and their systems that utilize R290 to mitigate the greenhouse effect. The present study investigates and compares the thermodynamic performance and compression characteristics of a high-speed compressor employing R290 as a refrigerant with those of an R32 compressor. In contrast to previous studies, this paper presents a novel approach by developing validated the zero-dimensional (0-D) and three-dimensional (3-D) simulation model, along with experiments, to investigate the distribution of performance loss and suction-compression characteristics in high-speed R290 compressors. The results demonstrate that the R290 compressor exhibits superior volumetric efficiency, while excessive compression at high speeds leads to a noticeable reduction in indicated power. The combination of increased over-compression loss and motor loss at high speeds resulted in a 11.7% rise in input power, leading to an 8.4% decline in thermodynamic performance for the R290 compressor under standard heating compared to the R32 compressor.

Optimization of a hybrid renewable energy system for off-grid residential communities using numerical simulation, response surface methodology, and life cycle assessment

This paper presents an optimized hybrid renewable energy system tailored for off-grid residential communities, integrating wind, solar, and hydrogen technologies to meet electricity, cooling, heating, and water needs. The proposed optimization methodology combines numerical simulation, response surface methodology (RSM), and life cycle assessment (LCA), ensuring robust performance across diverse conditions. Key components include fuel cells, reverse osmosis systems, heat pumps, photovoltaic/thermal solar collectors, wind turbines, and hydrogen generation systems. The optimization process targets critical variables such as PVT panel area, the number of wind turbines, and fuel cell power. The optimal configuration was found to include 24 small-scale wind turbines, 159.46 m2 of PVT collectors, and 79.73 kW of fuel cell power. This configuration generated surplus electricity with net electricity usage (NEU) values of −123084.27 kWh/year in New York, −224245.29 kWh/year in Forks, and −215949.30 kWh/year in Santa Barbara. Additionally, the optimized systems achieved a significant reduction in life cycle cost (LCC), with Forks showing the lowest LCC at 304428.97 USD. The environmental impact was also minimized using the novel optimization approach, with the optimized systems achieving negative 100-year global warming potential (GWP100) values, indicating a net reduction in greenhouse gas emissions.

The impact of green roofs’ composition on its overall life cycle

Green roof systems have been developed to improve the environmental, economic, and social aspects of sustainability. Selecting the appropriate version of the green roof composition plays an important role in the life cycle assessment of a green roof. In this study, 10 compositions of an intensive green roof for moderate zone and 4 green roof compositions for different climatic conditions were designed and comprehensively assessed in terms of their environmental and economic impacts within the “Cradle-to-Cradle” system boundary. The assessment was carried out over a 50-year period for a moderate climate zone. The results showed that asphalt strips and concrete slab produced the highest total emissions. It was found that most greenhouse gases emissions were released in the operational energy consumption phase and in the production phase. The energy consumption phase (48.78%) for automatic irrigation and maintenance caused the highest Global Warming Potential (GWP) value (758.39 kg CO2e) in the worst variant, which also caused the highest life cycle cost (878.47€). On the contrary, in the best variant, planting more vegetation and lower maintenance and irrigation requirements led to a reduction in GWP (445.0 kg CO2e), but in terms of cost (506.6€) this composition didn't represent the best variant. The Global Warming Potential Biogenic (GWP-bio) compared to the Global Warming Potential Total (GWP-total) represents a proportion ranging from 0.8% to 78% depending on the proposed vegetation. Overall higher biogenic carbon values (up to 1525 kg CO2e) were observed for the proposed tall vegetation of Magnolia, Red Mulberry, Hawthorne, Cherry, and Crab-apple Tree. Based on the results of the multicriteria analysis, which included core environmental & economic parameters, biogenic carbon emission levels, the outcome of this paper proposed optimal green roof composition. Optimal intensive green roof composition was subjected to a sensitivity analysis to determine the impact of changing climatic conditions on CO2 emissions and life cycle costs. The results of the sensitivity analysis show that the optimal variant of the green roof can be implemented in the cold and subtropical zone with regard to CO2 emissions, but not with regard to life cycle costs.

Investigation of mechanical, durability, and thermal properties of sustainable self-compacting mortars containing construction demolition waste and supplementary cementitious materials

This study aims to produce sustainable self-compacting mortar (SSCM) to provide solutions to the waste generation caused by the construction industry and to provide alternative solutions to the increasing consumption of natural resources and cement. In SSCM designed as 12 different mixtures; recycled sand (RCS) and pumice were used as aggregate and silica fume (SF) and fly ash (FA) were used as supplementary cementitious materials (SCM). The mechanical, durability, and thermal properties of the produced SSCM were investigated. Compressive and flexural strengths were determined at age of 7, 28 and 90 days. Significant increases in flexural and compressive strengths were observed for 10 % SF and 10 % FA substitutions. After 90 days of water curing, the specimens were exposed to high temperature. A decrease of up to 93.4 % in flexural strength was observed after high temperature effect. Sorptivity, water absorption and porosity values were determined. Thermal conductivity test was also performed on the specimens. Significant changes were observed due to the use of SCM. The global warming potential (GWP), and energy consumption (EC) were considered to evaluate environmental properties. Significant reductions in GWP and EC values were observed for mortar series with 30 % SCM. Significant gains were achieved in economic properties due to the use of SCM, with total costs decreasing by approximately 10 %, especially in series with 30 % SCM. SSCM produced using recycled aggregates and SCMs have provided significant contributions to sustainability.

Performance profile of Cold Storage Using R32 as Refrigerant for Traditional Fishing Boat with Photovoltaic as Energi Source

This paper discusses the performance of cold storage using R32 refrigerant. R32 is one of the recommended refrigerant with the main advantage low ODP and GWP (Global Warming Potential) value of around 0 and 675. However, because of this refrigerant classified as a new refrigerant, the implementation is limited to air conditioning and heat pump. In this paper, R32 will be tested for cold storage applications. The cold storage performance will be studied about the achieved temperature, power consumption, cooling capacity and Coefficient of Performance without load. The testing was carried out in 2 ways, cold storage testing on a lab scale and direct testing on a 5 GT fishing boat. The performance results show that both tests on a lab scale and tests directly on a fishing boat without a load can reach a cold storage room temperature of -18oC. Meanwhile, the compressor power consumption supplied by photovoltaic is 0.653-0.776 kW. Based on the test results, shows that R32 has a positive possibility of being applied to cold storage.

An Italian case study of life cycle assessment for a drinking water dispenser

The goal of this article is the comparison of global warming potential, estimated according to IPCC 2013 methodology, between bottled water and a drinking water dispenser made of pine wood. The functional unit is 1 L of water. Two cases are considered: in the first case is considered 1 L of refrigerated water supplied by a water dispenser, in the second case, it is also considered how users come back home with their water. The global warming potential for bottled water packed in polyethylene terephthalate is taken by literature, its average value is equal to 0.16 kg CO2 eq./L. In the first case, the water dispenser has a global warming potential value equal to 6.89 × 10−2 kg CO2 eq./L, the percentage difference between bottled water and water dispenser is about 43% in 100 years. In the end, a comparison of vehicles used by users to come back home is performed. The comparison shows that the use of bikes has a lower impact than cars.

A comprehensive assessment of mechanical and environmental properties of waste basalt powder-modified high strength mortars exposed to high temperature

Waste Basalt Powder (BT) is a stone cutting workshop waste. The BT was recycled in the high strength mortars by Portland cement (PC). High temperature performance of the mortars were determined up to 800 ºC by in terms of weight and strength losses. The global warming potential (GWP) and Primary Energy (PE) of the mortars were calculated by Life Cycle Assessment (LCA) for the mortars and their environmental impacts were evaluated. GWP and PE decreased up to 23.9 % and 22.4 % in BT-containing mortars compared to the control group, respectively. Lower CO2 emission and PE values were determined in all the BT-containing mortars compared to the control group. Mortars containing 15 % BT had 9.92 % higher compressive strength than the control group with 14.35 % and 13.44 % lower GWP and PE values, respectively. The optimum BT content is 15 % in terms of strength, high temperature resistance and environmental impact. As a result, it is possible to successfully recycle BT material in the production of high-strength mortar that is more resistant to high temperatures.

A comparative assessment of the capabilities and success of the wood construction industry in Slovakia and Ukraine based on life cycle assessment certification standards

This study assessed the possibility of using wood as a building material for the construction of houses. A comprehensive method was used, which consisted of analysing environmental management regulations, applying the life cycle assessment method to minimise the carbon footprint; using software to calculate the carbon footprint of a wooden house at different stages of the life cycle. The object of study is the carbon footprint of a house built of wood. The Life Cycle Assessment method was used as a methodology for assessing the life cycle. Using the One Click Life Cycle Assessment and Life Cycle Cost software, the carbon footprint of a log house was calculated for the product life cycle stage mentioned above (A1-A3). When calculating the carbon footprint of wood-based building materials, carbon emissions were taken into account not only from the finished products, but also from all other products obtained as a result of logging. When calculating the carbon footprint, greenhouse gas emissions from all activities are estimated. We have obtained data on the life cycle cost of a wooden house in terms of electricity use. Accordingly, we obtained a value of global warming potential (A1-A3) of 0.51 kg CO2 e/kWh. We also obtained data on the life cycle cost of a wooden house in terms of diesel consumption. According to the results of the LCA, the value of the global warming potential due to meeting the water supply/sewage needs is (A1-A3) 0.69 kg CO2 e/m3. The value of the global warming potential due to meeting the heat supply needs of production needs is (A1- A3) 0.13 kg CO2 e/kWh. Based on the information obtained, we can conclude that it is advisable to use a wooden log house as a building material, as the carbon footprint is smaller than that of a brick building. The final section presents the results of calculating the life cycle cost of a wooden house by discount factor and inflation, the results of the life cycle cost of a wooden house by percentage of energy costs, and the results of assessing the life cycle cost of a wooden house (displaying parameters according to the European energy certification scale). Based on the carbon footprint assessment (using the Life Cycle Assessment methodology), economic comparison (Life Cycle Cost and total construction costs), and expert assessment (based on technical and ergonomic parameters) of the two construction technologies, the feasibility and possibility of using wood as a building material was established. The study proves the feasibility of applying the LCA method in the construction industry.

Opportunities to reduce environmental burden by recycling fabric waste in a woollen fabric company

PurposeWool fiber is accepted as one of the natural and renewable sources and has been used in the apparel and textile industry since ancient times. However, wool fiber has the highest global warming potential value among conventional fibres due to its high land use and high methane gas generation. This study aimed to recycle the wool fabric wastes and also to create a mini eco-collection by using the produced yarns.Design/methodology/approachThis manuscript aimed to evaluate the fabric wastes of a woolen fabric producer company. Fabric wastes were opened with two different opening systems and fiber properties were determined. First, conventional ring yarns were produced in the company’s own spinning mill by mixing the opened fibres with the long fiber wastes of the company. In addition, opening wastes were mixed with different fibres (polyester, long wool waste, and Tencel fibres) between 25% and 70% in the short-staple yarn spinning mill and used in the production of conventional ring and OE-rotor yarns. Most of the yarns contained waste fibres at 50%. Recycled and virgin yarns were used as a weft and warp yarn and a total of 270 woven fabric samples were obtained and fabric properties were examined. Also, a fabric collection was created. A life cycle assessment (LCA) was made for one of the selected yarns.FindingsAt the end of the study, it was determined that it was possible to produce yarn and fabric samples from fiber blends containing high waste fiber ratios beyond 50%. All the woven fabric samples produced from conventional ring and OE-rotor yarns gave higher breaking, tearing and stitch slip strength values in the weft and warp direction than limit quality values of the company. In addition, abrasion resistance and WIRA steam stability properties of the fabric samples were also sufficient. Environmental analysis of the recycling of the wastes showed a possible decrease of about 9940034.3 kg CO2e per year in the global warming potential. In addition, fiber raw material expenses reduced yarn production cost about 50% in case of opened fabric waste usage. However, due to insufficient pilling resistance results, it was decided to evaluate the woven fabrics for the product groups such as shawls and blankets, where pilling resistance is less sought.Originality/valueThe original aspects of the article can be summarized under two headings. First, there are limited studies on the evaluation of wool wastes compared to cotton and polyester fibres and the number of samples examined was limited. However, this study was quite comprehensive in terms of opening type (rag and tearing), spinning systems (long and short spinning processes), fiber blends (waste 100% and blends with polyester, long wool waste and Tencel fibres) and yarn counts (coarser and finer). Recycled and virgin yarns were used as a weft and warp yarn and a total of 270 woven fabric samples were obtained using different colour combinations and weave types. All processes from fabric waste to product production were followed and evaluated. Life cycle assessment (LCA) and cost analysis was also done. The second unique aspect is that the problem of a real wool company was handled by taking the waste of the woolen company and a collection was created for the customer group of the company. Production was made under real production conditions. Therefore, this study will provide important findings to the research field about recycling, sustainability etc.

Environmental Sustainability and Physicochemical Property Screening of Chitin and Chitin-Glucan from 22 Fungal Species.

Thanks to its biobased character with embedded biogenic carbon, chitin can aid in the transition to a sustainable circular economy by replacing fossil carbon from the geosphere. However, meeting current demands for material availability and environmental sustainability requires alternative methods limiting conventional chemical and energy-consuming chitin extraction from crustaceans. To assist future chitinous bioproduct development, this work analyzes the physicochemical properties and potential environmental sustainability of fungal chitin-glucan complexes. A conventional isolation procedure using sodium hydroxide, a weak acid, and short reaction times are applied to the fruiting body of 22 fungal species. Besides, the valorization of underutilized waste streams including Agaricus bisporus and Agaricus brunnescens stipes is investigated. The carbohydrate analysis renders chitin fractions in the range of 9.5-63.5 wt %, while yields vary from 4.2 to 29.9%, and the N-acetylation degree in found in between 53.0 and 98.7%. The sustainability of the process is analyzed using life cycle assessment (LCA), providing impact quantification for global warming potential, terrestrial acidification, freshwater eutrophication, and water use. With 87.5-589.3 kg·CO2-equiv per kilo, potentially lower global warming potential values in comparison to crustacean chitin are achieved. The crystallinity degree ranged from 28 to 78%, while the apparent chitin crystalline size (L020) is between 2.3 and 5.4 nm. Ten of the species yield α-chitin coexisting with semicrystalline glucans. Zwitterionic properties are observed in aqueous solutions, shifting from cationic to anionic at pH 4.5. With its renewable carbon content, fungal chitin is an environmentally sustainable alternative for high-value applications due to its balance of minimal treatment, low carbon footprint, material renewability, ease of isolation, thermal stability, zwitterionic behavior, biodegradability, and noncytotoxicity.

Properties and environmental sustainability of fungal chitin nanofibril reinforced cellulose acetate films and nanofiber mats by solution blow spinning

Materials from biological origin composed by renewable carbon facilitate the transition from linear carbon-intensive economy to a sustainable circular economy. Accordingly, we use solution blow spinning to develop fully biobased cellulose acetate films and nanofiber mats reinforced with fungal chitin nanofibrils (ChNFs), an emerging bio-colloid with lower carbon footprint compared to crustacean-derived nanochitin. This study incorporates fungal ChNFs into spinning processes for the first time. ChNF addition reduces film surface roughness, modifies film water affinity, and tailors the nanofiber diameter of the mats. The covalently bonded β-D-glucans of ChNFs act as a binder to improve the interfacial properties and consequently load transference to enhance the mechanical properties. Accordingly, the Young's modulus of the films increases from 200 ± 18 MPa to 359 ± 99 MPa with 1.5 wt% ChNFs, while the elongation at break increases by ~45 %. Life cycle assessment (LCA) is applied to quantify the environmental impacts of solution blow spinning for the first time, providing global warming potential values of 69.7–347.4 kg·CO2-equiv.·kg−1. Additionally, this work highlights the suitability of ChNFs as reinforcing fillers during spinning and proves the reinforcing effect of mushroom-derived chitin in bio-based films, opening alternatives for sustainable materials development beyond nanocelluloses in the near future.

Thermodynamic and environmental analysis of integrated supercritical water gasification of sewage sludge for power and hydrogen production

Supercritical water gasification is a promising process for treating sewage sludge (SS) to obtain hydrogen and electrical energy. Here, a novel thermodynamic equilibrium model for supercritical water gasification of sewage sludge was developed and the thermodynamic and environmental effects of operating parameters on the system were investigated. The sensitivity analysis revealed that the optimum reaction condition for the system was: reaction temperature of 750 °C, preheated water to SS ratio of 1, and SS concentration of 25 %. Under this condition, the system energy efficiency and exergy efficiency were 44.74 % and 46.51 %, respectively, with H2 production of 103.19 kg/h and power generation of 2526.2 kW. The energy and exergy efficiencies could be improved by reducing the preheated water to SS ratio and increasing the reaction temperature and SS concentration. The heat exchangers and the heater were the key units causing exergy losses, accounting for 40.3 % and 19.5 % of the total exergy losses, respectively. When utilizing carbon capture and storage (CCS), the global warming potential (GWP) value was only 0.31 kg CO2-eq under the optimal operating parameters, which was 61.44 % less than without CCS.

Environmental impacts of materials in masonry residential house

AbstractThis study aims to quantify the environmental impact of a specific family home, with a particular focus on its contribution to climate change. To achieve a more precise assessment, the family home was dissected into various components based on the materials’ function and their location within the structure. The evaluation was conducted using the life cycle assessment (LCA) methodology, considering the “cradle to site” boundaries and utilizing the IPCC GWP100 method. The cumulative contribution of the materials used in the selected house to climate change was found to be 125,000 kg CO2 equivalent (CO2eq). When analyzing the global warming potentials (GWP100) of individual building structures, the calculated values ranged from 3.8 to 62.2 kg CO2eq. The results indicate that the materials for horizontal structures had the lowest global warming potential values, while materials for vertical structures had the highest values. Particular attention was paid to comparing three different ways of transporting materials to the site. The portion of climate change attributable to transportation fell within a range of 10.9–12.3%. Findings verified that road transportation consistently made the greatest contribution to the overall GWP100, regardless of distance, with rail transportation yielding the lowest values. Discrepancies between the highest and lowest values of transport-related GWP100 were determined to be as much as 9.1%. Opting for the most environmentally friendly option, namely rail in this study, could result in savings of 4.9 kg CO2eq per 1 km of transportation distance for the analyzed building materials used per family house.