Primary Energy Demand Research Articles

AI-enhanced forecasting of Indian primary energy demand: Fuzzy auto-regressive distributed lag models

As the demand for energy in India continues to surge, accurate forecasting becomes paramount for efficient resource allocation and sustainable development. This study proposes an innovative approach to forecasting Indian primary energy demand by integrating Artificial Intelligence (AI) techniques with Fuzzy Auto-regressive Distributed Lag (FADL) models. FADL models, incorporating fuzzy logic, allow for a nuanced representation of uncertainties and complexities within the energy demand dynamics. In this research, historical energy consumption data is analysed using FADL models with both symmetric and non-symmetric triangular coefficients, enhancing the model’s adaptability to the inherent uncertainties associated with energy forecasting. This study addresses the urgent need for enhanced energy planning models in the context of sustainable development. Our research aims to provide a comprehensive framework for predicting future Total Final Consumption (TFC) in alignment with the Indian National Energy Plan’s net-zero emissions target by 2035. Recognizing the limitations of current models, our research introduces a novel approach that integrates advanced algorithms and methodologies, offering a more flexible and realistic assessment of TFC trends. The primary objective of this study is to develop an improved energy planning model that surpasses existing projections by incorporating sophisticated algorithms. We aim to refine

Paper: Modeling and scenario analysis of residential building energy conservation in cities of different weather

Building models are used to predict energy consumption and CO2 emissions under current and future conditions and serve as a basis for building design. The most important energy saving potentials in buildings can be achieved by improving the thermal performance of building and the efficiency of the district heating system. This study investigated energy savings in buildings in cold and hot regions of China and Africa and developed a modeling approach for energy savings in heating and cooling of residential buildings. We have provided an overview of long-term scenarios for energy demand and carbon dioxide (CO2) emissions. Using the industry-renowned software RETScreen, parameter simulations and optimizations are performed over the three time periods (currently 2030 and 2050). As a result, it was found that energy consumption has also increased and the comfort level of high-rise houses is about 10–21% higher than that of cold regions. The comfortable temperature range in these different cities is between 20°C and 29°C. We have showed the difference between the observed values and the model simulations (model bias) for HDD and CDD in cold and hot regions of China and Africa. This model represents spatial patterns and scales observed in Harbin, Shenzhen and South Africa. These features are characterized by an increased north-south gradient in eastern China, a topographically dependent distribution in western China and an associated increase in average temperature. The most commonly used types of heating in residential areas are heat pumps (31%) and district heating (21%). This is also the preferred case for condensing boilers (17%). In non-residential areas, heat pumps (32%), district heating (27%) and condensing boilers (11%) are the most commonly used heating systems. The total energy demand in Africa and China will be increased from 2020 to 2050. It is expected that the total demand for primary energy in China will be 8770 Mtoe in 2050, which corresponds to an increase in demand for primary energy of 1.9%, while Africa will see an increase of 2.7%. Final energy consumption in China and Africa will be 5776 Mtoe and 970 Mtoe respectively.

Eco-efficiency of power supply systems for offshore platforms

This study compared from an Eco-efficiency point of view three electricity supply alternatives for oil and gas extraction, preliminary treatment, and distribution activities that occur on floating production, storage, and offloading platforms (FPSO) operated off the coast of Brazil. The performance of autonomous systems (AS), in which independent open-cycle gas turbines generate electricity, was confronted with those achieved, respectively, by a Power Hub (PH) system and by an arrangement that associates the Power Hub system with an offshore wind farm (PHWE). The environmental dimension of the Eco-efficiency indicator was specified based on applying the Life Cycle Assessment technique for the impact categories of Global Warming Potential, Primary Energy Demand, and Fine Particulate Matter Formation. The economic dimension followed a similar approach based on Life Cycle costing (LCC) when considering the same units' construction, operation, maintenance, and dismantling costs. Given the characteristics of Brazilian oil fields, a comparison was made for three different stages of the operation cycle: C1: maximum extraction of oil and gas; C2: equity of volumes extracted from fuels and water + CO2; and C3: minimal extraction, but economically viable, of fuels. The results indicated that the PH and PHWE systems accumulate better environmental performance than the AS system, particularly regarding Global Warming Potential (35 % and 55 %, respectively) and Fine Particle Matter Formation (47 % and 59 % reduction). However, more than these gains are needed to compensate for the same systems' construction, operation, and maintenance investments, which were increased by up to 76 % in the case of PHWE. The study also concluded that the PH technology and its variation involving wind electrification are promising but that research efforts should be made to reduce costs. These results provide elements that can both subsidize designers from O&G companies in developing new extraction technologies and support decision processes conducted by other stakeholders and policy formulators linked to this segment.

Assessing Hydropower Potential under Shared Socioeconomic Pathways Scenarios Using Integrated Assessment Modelling

The world is facing a global sustainability crisis affecting environmental systems and society. Addressing these issues requires a multi-dimensional approach that can integrate energy, water, and environment Systems, as well as provide scientific policy advice. In this study, an updated version of an Integrated Assessment Model (IAM) was used, together with new data compatible with Shared Socioeconomic Pathways (SSPs) projections, to significantly improve the work developed before. SSP climate data (temperature, precipitation, and total radiative forcing) and socioeconomic data (population and GDP) were loaded into the IAM, together with different scenario parameters. By analyzing varying socioeconomic scenarios, mitigation efforts, and adaptation strategies, this study assesses their impact on primary energy demand and, consequently, their impact on hydropower potential production. Our results show diverse energy paths, strongly dependent on the future scenario. Energy demand could increase up to 160%; however, several projections foresee a decline in hydropower production to minus 46% due to both climate change and socioeconomic transformation. Our findings highlight the importance of considering a range of potential future scenarios in energy planning and policy development. The varied outcomes across the considered scenarios emphasize the need for flexibility in strategies to accommodate for uncertainties and address the challenges posed by divergent trajectories in hydropower use and renewable energy shares.

Comparative life cycle assessment of light frame timber and reinforced concrete masonry structural systems for single-family houses in Luxembourg

The building sector's significant greenhouse gas emissions and energy consumption present added challenges to meeting European climate commitments amidst rapid population growth. In Luxembourg, single-family houses dominate the residential buildings, noticeably contributing to construction waste and CO2 emissions. This study compares the environmental impacts of a three-story reinforced concrete masonry single-family house and an identical timber building in Luxembourg, emphasizing greenhouse gas emissions and embodied energy. A cradle-to-grave life cycle assessment was conducted using Building Information Modelling (BIM) models to analyze the global warming potential and primary energy requirements. Environmental product declarations from the producers and the ÖKOBAUDAT German database were used to determine the environmental impacts of the materials. The results show that the timber building outperforms the concrete building with a 43.5% lower global warming potential, while the concrete building demonstrates a 15.6% reduction in primary energy demand. This aligns with the average outcomes of seven similar studies discussed in this paper, at 33.2% and 4.7%, respectively. Moreover, the timber building is 78.6% lighter than the concrete one. When evaluating benefits and loads beyond the system boundary, the timber building provides 3.6 and 4 times greater advantages in terms of global warming potential and primary energy, respectively, compared to the reinforced concrete masonry building. Additionally, the study explores the impact of reusing the floors in the timber building. The cradle-to-grave LCA reveals that reusing the timber slabs improves the building's global warming potential and primary energy by 2.4% and 1.2%, respectively. However, when considering the benefits and loads beyond the system boundary, floor system reuse exhibits a 38.9% surge in global warming advantages while reducing primary energy benefits by 28.1%. The findings advocate for a policy promoting timber construction and reuse in Luxembourg, aiming to achieve the net-zero emission target by 2050.

Impact of Covid-19 on the Demand of Coal Bulk Transportation in China

China's coal bulk transportation sector, instrumental in fulfilling 60% of the nation's primary energy demand in 2019, has been at the forefront of energy research given its criticality to China's energy matrix. Motivated by the widespread disruptions during the Covid-19 pandemic, this study employs a case-based method, focusing on the effects on both imported and domestically produced coal transportation, drawing from a plethora of references. This paper’s findings indicate that while there was an initial decline in coal sales and imports in early 2020, strategic interventions led to a 4.6% rise in coal imports by 2021, coupled with a growth of 11% in domestic coal production in 2022. Emphasizing resilience, the sector witnessed a notable rekindling of coal trade with Australia by 2023. This research not only underscores China's capacity for adaptability in its coal sector amidst global disruptions but also lays a foundational framework for future studies, accentuating the significance of understanding energy resilience in a post-pandemic world.

Prediction of the Spatial and Temporal Adoption of an Energy Management System in Automated Dairy Cattle Barns in Bavaria—“CowEnergySystem”

In view of rising global demand, energy is becoming a significant cost factor in industry and society. In addition to the global players China, India, and the USA, Africa will also become a driver of the world’s primary energy demand in the future due to the rapidly growing developing countries. In addition to the armed conflicts in Ukraine and the Middle East, global energy markets are tense and volatile due to inflation and higher borrowing costs. Because of society’s desire to phase out the use of fossil fuels, the use of renewable energies is increasingly taking center stage worldwide and especially in Germany. Rural areas and agriculture, especially energy-intensive livestock farms, are particularly affected by this development and are therefore faced with additional economic challenges. Additional energy can be generated by using photovoltaic systems on the roofs of farm buildings or by utilizing the liquid manure from livestock farming in biogas plants. For these farms, such alternative sources of energy could open previously untapped potential and additional synergies for using their own inexpensive energy on the farm or supplying surplus electricity directly to the public grid as a market participant. Agriculture could thus serve as an actor in a decentralized energy supply and thus build up regional energy networks. However, intelligent electricity storage concepts and a corresponding energy management system (EMS) are essential to be able to utilize the potential for renewable energy generation at all, to coordinate both internal production processes and the varying energy demand and supply on the electricity grid. As agricultural production processes differ greatly from farm to farm and region to region, the introduction of an energy management system is strongly dependent on user acceptance. The purpose of this study is to use the web-based software tool ADOPT (CSIRO 2018) to predict the level of acceptance and the duration of the market launch of an EMS based on the region of Bavaria. Individual important influencing factors for the subsequent regional marketing concept are also identified.

Structural and thermal investigation of lignocellulosic biomass conversion for enhancing sustainable imperative in progressive organic refinery paradigm for waste-to-energy applications

The depletion of finite fossil fuel reserves and the severe environmental degradation resulting from human activities have compelled the expeditious development and application of sustainable waste to energy technologies. To encapsulate energy and environment in sustainability paradigm, bio waste based energy production is need to be forged in organic bio refinery setup. According to world bioenergy association, biomass can cover 50 % of the primary energy demand of the world. Therefore, the present study focuses on reforming the energy mix for a clean energy generation, where, sample composition of cotton stalk was acidified in dilute (5% wt.) hydrochloric acid (HCL) for analyzing material burnout patterns in biomass conversion systems utilized in organic bio refinery sector. Advanced thermochemical burning technique, which includes pyrolysis and combustion was applied at four different leaching times from 0 to 180 min under nitrogen environment from 0 °C to 500 °C and air from 500 °C to 900 °C, respectively. Different analyses including proximate, ultimate, gross calorific value (GCV), thermos-gravimetric, kinetic, XRD, FTIR, SEM-EDS were used for analyzing the degradation of demineralized cotton stalk at different treatment rates. Proximate study demonstrated that cotton stalk leaching for 180 min has efficiently infused HCL, leading in a significant increase in fixed carbon and higher heating value of 20.23 % and 12.48%, respectively, as well as a reduction in carbon footprint of around 54.80%. The findings of proximate was validated by GCV analysis and CHNS analysis as value of carbon and hydrogen has shown increasing behavior with the time delay in demineralization Thermo-gravimetric and derivative thermo-gravimetric data analyses shows an increasing trend of conversion efficiency, with the maximum increase of 98 % reported for sample 3H.TT.DEM. XRD characterization has reported 23° to 25° angle for all the observed peaks. Sample 3H.TT.DEM has shown maximum angle inclination along with matured crystalline peak. The latter observations has been validated by FTIR spectroscopy as sample 3H.TT.DEM has reported maximum O–H group formation. Sample 3H.TT.DEM has reported lowest activation energy of 139.51 kJ*mole-1 and lowest reactivity of 0.000293649%*min 0C, due to moderate and stable reactiveness. In SEM examination, increment in pore size and number of pores within the structural matrix of cotton stalk was observed with the enhancement in acidulation process. Furthermore, in EDS analysis, 3H.TT.DEM has shown most balanced distribution of the elements. In this research, sustainable transformation of biomass is envisioned to improve the waste bio refinery system, significantly contributing to the achievement of Sustainable Development Goals 7, 12 and 13.

Dynamic evaluation of the electrical primary energy factor for building energy performance: Insights from 2022 Italian data

The primary energy factor (PEF) represents a fundamental concept for converting a final energy carrier into primary energy. Among its many areas of application, building industry is of particular interest, since primary energy demand is a representative and widespread indicator for evaluating a building’s whole energy performance. This paper starts by exploring the critical issues related to the use of PEF, which is often evaluated through outdated, static values. Through the application of one of the methods of the UNI EN 17423:2021 standard, the hourly trend of the primary energy factor for the electric carrier in Italy during the year 2022 was evaluated. Results show the strong dynamicity of the PEF and the existing relationships between its renewable and non-renewable shares, which are strongly influenced by pro-duction, import and export strategies. The obtained PEFs were applied to a case study of a residential building, evaluating the primary energy needs under different final energy conversion scenarios. This work highlights the need for an update of the PEF to dynamic values consistent with the energy context of a country to facilitate the energy transition, as well as to reduce the supply and demand mismatch, and reward the use of renewable energy.

Buildings made of massive timber logs with a derogation from the application of technical conditions for traditional masonry technologies

Timber log walls are a unique form of construction - erected from solid material, they are both a building structure and a thermal barrier. Walls of wooden logs have numerous advantages, especially favourable physical and mechanical properties, including insulation and thermal capacity. The technical conditions, which are the Polish interpretation of the Nearly Zero Energy Building (nZEB) building, which a newly designed building must meet, must meet 2 conditions simultaneously: the value of the EP index, which determines the annual calculated demand for non-renewable primary energy for heating, ventilation, cooling and preparation of domestic hot water for the entire building, and adequate thermal insulation of the external walls. Calculating the thermal insulation of a wood partition, relying only on thermal conductivity coefficients without considering other properties of the material, does not reflect the true insulating properties of wood. The lack of research on the insulating properties of wood, and thus the lack of national technical and installation requirements for log houses seriously limits the development of this type of construction and forces to undertake reliable research and development work in this area. The proposed introduction in this type of building of the methodology of the so-called Integrated Energy Design (IED) allows to carry out multi-criteria analysis of design variants at the stage of the virtual model in the BIM standard, in terms of the final energy efficiency of the building. Conducting various types of variant analyses and simulations allows to achieve optimal energy efficiency and to verify and correct the adopted solutions. The high energy efficiency of the building demonstrated by such simulations can be the basis for a deviation from the current regulations, which will allow the implementation of newly designed buildings in massive log technology, without the need for additional thermal insulation. As a result, it will be possible to preserve the unique architectural expression of buildings erected with this technology, with visible massive timber logs both on the exterior facades and on the interior.

Alternative energy-saving technologies based on low-boiling working fluids

World economic development is accompanied by an increase in the consumption of energy resources, whose potential reserves are limited. Assessments given in show that every 25 years, energy consumption in the world doubles and environmental problems increase as well. In industrial processes, a large amount of spent energy is often lost as waste heat, which is generated as a by-product and released into the atmosphere. The Global Energy Review notes that energy consumption in the form of heat released into the environment in both the USA and EU-27 is approximately 60% of all clean primary energy consumed. Currently, to reduce the global demand for primary energy, the use of energy-saving technologies is fast-growing in many countries of the world instead of direct combustion of coal, oil and gas involving low-grade coolants and environmental heat. This paper discusses low-temperature energy-saving technologies in heat and power supply systems. A technical and economic assessment of these areas is given. The results of using low-boiling liquids for power generation on the basis of hot Earth strata are reported.

An Ab initio based OH initiated oxidation kinetics of glycerol carbonate: A promising biofuel component

The global energy demand is steadily increasing because of the population explosion and economic growth. Fossil fuels supply around 85 % of global primary energy demand. On one hand, fulfilling the increasing energy demands is a big challenge for the next few decades. On the other hand, the continued burning of fossil fuels leads to higher CO2 emissions, severely impacting global warming. Therefore, the policymakers vow to shift from conventional fuels to renewable resources for economic, environmental, and future energy security reasons. In this context, biofuels from lignocellulosic biomass and/or carbon-neutral fuels produced in the sustainable carbon cycle can close the carbon cycle and reach net zero-carbon emission. Recently, glycerol carbonate has been proposed as a promising fuel or fuel additive for future sustainability. Therefore, we investigated the hydrogen abstraction reactions of glycerol carbonate (GC) by OH radicals using high-level ab initio and variational transition state theory calculations. We mapped out the potential energy surface using the CCSD(T)/cc-pV(D, T)Z//MP2/cc-pVTZ level of theory. We used the ab initio parameters to obtain the site-specific rate coefficients by employing the variational transition state theory. We observed that every hydrogen atom in GC displays a unique reactivity with OH radicals. We derived branching ratio of each channel that are difficult to access experimentally. The overall rate coefficients exhibit a strong non-Arrhenius behaviour, which can be represented as:kovCVT/SCT(T)=3.39×10−20×T2.659×e−750.0Jmol−1RTcm3moleculesThis is the first reported rate data for the glycerol carbonate and OH radicals reaction.

Potential of Energy Saving of Propane Heat Pump as replacement of gas boilers with low and high temperature emitters

This work deals with the analysis of the energy performance and the environmental impact of a Heating, Ventilation and Air Conditioning (HVAC) system based on an innovative Air-to-Water electrical Heat Pump (AWHP) using propane (R290) as the refrigerant. A building of the University of Bologna located in Forlì (North of Italy) is considered for replacing a condensing gas boiler and a conventional chiller with an AWHP using R290. To evaluate the efficiency of the existing heating system and the potential savings linked to the adoption of the propane AWHP, the building energy model was created and calibrated by collecting monthly thermal and electrical consumptions as a function of the actual climate data. In this paper, the main features of the R290-based AWHP are described in detail by emphasising the device performance as a function of the operating conditions (i.e., air and water temperature and speed of the scroll compressor). A series of scenarios have been studied to evaluate the energy performance of the propane AWHP with respect to the reference scenario under various operating conditions. The results show that while the total primary energy demand increases adopting the propane AWHP with respect to the case of a gas boiler, the non-renewable primary energy fraction decreases significantly, with a dramatic increase in the renewable quote. From an economic point of view, lower annual costs are obtained by adopting a propane AWHP coupled to fan coils, mainly when the electrical heat pump is used in a thermally insulated building in which a photovoltaic system is installed.

Readiness of Zero-Emission Buildings (ZEBs) implementation in the European Union

The building sector plays a central role in the reduction of greenhouse gas (GHG) emissions in the European Union (EU). The revision of the Energy Performance of Buildings Directive (EPBD) sets out ambitious requirements to make the EU building stock decarbonised by 2050. The proposal for a recast EPBD introduces Zero-Emission Building (ZEB) as the building target for all new buildings as of 2030. This paper offers insights into the concept of ZEB, analysing its key methodological aspects, with a focus on ambition, the role of energy efficiency, and the role of renewable energy. Additionally, the paper evaluates the performance levels of new buildings in EU Member States, highlighting the gaps between current Nearly Zero-Energy Buildings’ performance levels and potential ZEB performance levels, specifically in terms of primary energy demand and renewable energy contribution. The findings emphasise the necessity to enhance initiatives aimed at improving energy efficiency and harnessing renewable energy sources to adopt the ambitious ZEB concept as of 2030. Additionally, the paper highlights the importance of addressing GHG emissions comprehensively, extending beyond the operational phase of a building to include embodied impacts, in order to achieve a life-cycle zero-emission building stock.

Solar-Powered Parboiling Rice Machine and its Relevance to Sustainability

Given that rice stands as one of Africa's most widely consumed cereals, serving as a primary dietary energy source, both its production and demand have seen a steady rise over the years. In line with other sub-Saharan African nations, Guinea has witnessed a surge in rice consumption, driven by various factors, particularly the significant energy challenges it faces, compounded by the fact that approximately 70% of its population lacks access to electricity. The prevalent reliance on firewood for boiling paddy rice has significantly contributed to deforestation, as there is a growing demand for fuelwood and various forms of wood fuel for energy. This study seeks to explore the reasons behind the reluctance of people to embrace climate action with solar-powered parboiling rice machines (SPPRM). It also aims to identify the underlying causes of this disinterest. Based on the conducted survey, a total of 500 residents in the Basse-Guin?e region were sampled, revealing that a significant majority (92%) of the respondents are already aware of the environmental impacts associated with their daily cooking activities. The results further indicate that approximately 25% of the respondents were unable to adopt new machine technology due to a lack of government consumption subsidies, while the remaining 45% cited a lack of access to new machines as the primary hindrance. Consequently, the study concludes that, despite the potential benefits that could arise from adopting SPPRM for sustainable development, financial barriers and limited access to the machines pose significant challenges for the respondents.

A Multi-Objective Optimization Method for the Design of a Sustainable House in Ecuador by Assessing LCC and LCEI

The building industry significantly contributes to global warming, driving the demand for sustainable construction and green buildings. However, barriers like cost concerns and limited knowledge persist. Previous studies have used multi-objective optimization (MOO) to minimize life cycle cost and environmental impact, often emphasizing energy efficiency. In equatorial climates, unique factors like material selection must be considered. This study assesses the cost-effectiveness of sustainable materials, focusing on envelope materials in Ecuador. The case study is a single-family house in the equatorial climate, optimized using Building Information Modeling (BIM), Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA). In this study, a MOO process using the weighted sum approach (WSA) identifies sustainable house designs. The sustainable houses achieve a 98% decrease in Ozone Depletion Potential, a 75% reduction in Global Warming Potential, and a 45% drop in Primary Energy Demand, although they still incur a 30% increased cost. The results offer a foundation for cost-effective, eco-friendly housing solutions. Bamboo emerges as a promising material with local acceptance. This research highlights the significance of material selection in sustainable construction and provides a replicable approach for diverse settings. It aims to promote sustainable housing solutions in Ecuador and beyond.

A Systematic Review of Climate Change Implications on Building Energy Consumption: Impacts and Adaptation Measures in Hot Urban Desert Climates

The climate change–built environment nexus is complex and intertwined. Recognizing the rising air temperatures and solar radiations owing to climate-induced global warming, it is critical to manage the increased building energy and cooling loads in the Middle East Gulf states’ hot desert climates (Bwh). One of the top climate priorities is to promote climate resilience by reducing risks and enhancing adaptation options. This study aims to systematically review the existing literature to document building energy performances in and the associated adaptation measures of the Middle East Gulf states, regarding the implications of climate change. It is accomplished by answering the following questions: ‘How well do we understand the effects of climate change on building energy use in hot urban deserts?’ and ‘What are the most appropriate adaptation strategies to reduce energy use in hot urban deserts?’. Using the Preferred Reporting Items for Systematic review and Meta-Analysis protocols (PRISMA), 17 studies on the influence of present and future weather scenarios on building performance are examined, considering variations in typology, methods, and input variables. Finally, the paper identifies the preferred methods and input variables for modelling building energy performance under predicted climatic changes. Passive design considerations are considered highly effective in mitigating and adapting to climate change implications. Thermal insulation and efficient window glazing are identified as the best-performing strategies, while the use of solar Photovoltaic (PV) is considered efficient in meeting the primary energy demands. The study’s findings can assist planners and designers in projecting future climatic influences on the energy usage of existing buildings.

ANALYSIS OF THE IMPACT OF LEED CERTIFICATION TECHNICAL REQUIREMENTS ON CALCULATED ENERGY PERFORMANCE OF AN OFFICE BUILDING

The article presents an analysis of the impact that meeting LEED certification criteria hason the calculated energy performance of a building based on Polish regulations regarding themethodology for determining the energy performance of a building, taking into account thetechnical modernization that affects the final result of the analysis. Calculations were carried outon the example of an office building. The analysis covered scope that combines LEED certificationand energy performance, such as water use and indoor lighting. The calculations were made ina program designed for energy performance calculations. The use of energy-saving lamps (46%lower energy use in relation to standard lamps) or fittings limiting the water flow from the tap(26% lower water use) did have a positive impact on the final calculation of post-modificationenergy performance, according to which the demand for primary energy was reduced by 36%.The static analysis was performed using commercial software for preparing energy performancecertificates and on the basis of formal guidelines set out by the LEED certification.

Environmental Impact Assessment of Building Materials Using Life Cycle Assessment

In pursuit of environmental sustainability in the construction sector, this study employs a comprehensive life cycle assessment (LCA) approach to evaluate the environmental impact of widely used building materials in Iran, with a particular focus on energy consumption and carbon footprint. The investigation encompasses 22 widely used building materials, utilizing the Ecoinvent v3 database and Simapro8 software to assess critical environmental variables, including carbon dioxide (CO2) emission, required primary energy, water consumption, and thermal conductivity. The findings unveil the diverse environmental profiles of these materials, with thermal conductivity typically hovering around zero to 2 W/m.K for most, but with exceptions such as lime, aluminum, rebar, and steel exhibiting significantly higher values. Moreover, aluminum, ceramics, PVC pipe, and expanded polystyrene (EPS) foam are identified as higher energy consumers during their life cycle, in contrast to concrete and cement mortar characterized by lower primary energy demands. The materials identified as high-carbon building materials are steel, stone, plaster, rebar, bitumen, concrete, glass, cement, gravel, and EPS foam. On the other hand, the materials identified as low-carbon building materials are masonry blocks, wood, tiles, bricks, drywall, MDF, and cement mortar. This research provides valuable insights for material selection and sustainable construction practices, emphasizing low-carbon materials to reduce environmental impact and contribute to the global effort to mitigate climate change through responsible construction choices.

Technology transition strategies for textile-dyeing sludge management in China from the environmental and economic perspectives

Textile-dyeing sludge reutilization is considered as an effective management scheme in the transition to low-carbon and sustainable development from the conventional incineration or landfilling. However, few studies have focused on its assessment from environmental and economic perspectives. In this study, a bin-to-grave life cycle thinking is applied to compare the environmental and economic performances of four promising and newly industrialized sludge reutilization technologies (i.e., pyrolysis-gasification-incineration, co-combustion in coal-fired power plants, sludge-to-brick, and sludge-to-biochar) with the traditional landfill option. Results indicate that technology transition to sludge-to-biochar option outperforms other transition strategies. The sludge-to-biochar option could gain environmental benefits in 7 categories i.e., primary energy demand (−6.1 × 103 MJ/t sludge), abiotic depletion potential (−4.9 × 10−4 kg antimony eq./t sludge), eutrophication (−0.15 kg PO43− eq./t sludge), ozone depletion(−1.67 × 10−5 kg CFC-11 eq./t sludge), photochemical ozone formation (−2.25 kg NMVOC eq./t sludge), ionizing radiation-human health effects (−3.1 kg U235 eq./t sludge), and ecological toxicity (14.4 CTUe/t sludge). Direct emissions of GHG in sludge reutilization technologies contribute to >70 % of the global warming potential category. Adopting the preferred sludge-to-biochar option at the provincial scale could mitigate approximately 0.81 million t of CO2 eq./year, which is equivalent to the amount of CO2 annually absorbed by 44.1 million trees in China. Feedstock (i.e., chemicals) contributes to about 77.9 %–97.9 % of toxicity-related environmental loads (i.e., human toxicity-cancer effects and ecological toxicity) for sludge-to-biochar, whereas in other utilization technologies, the key factor is heavy metal emission. The sludge reutilization technologies could break even within 3 years except pyrolysis-gasification-incineration (7 years). Meanwhile, contribution, sensitivity, and scenario analyses indicate that reducing primary energy consumption and improving the product quality and yield could effectively alleviate environmental burdens. A reasonable sludge disposal fee could help with the circular regeneration of textile-dyeing sludge. Despite that sludge-to-biochar stands as the foremost advantageous option for the technology transition in managing textile-dyeing sludge, certain aspects (for example, product quality and feedstock consumption) still necessitate further enhancements before its large-scale application in China.