Life Cycle Assessment Results Research Articles

Poultry litter valorization by application of hydrothermal gasification: Process simulation, Economic, Energic, and Environmental analysis

Hydrothermal gasification (HTG) at supercritical water has been used to convert poultry litter into value-added products. In this research study, a process simulation model of HTG for syngas from poultry litter has been developed using Aspen Plus software, and it has been validated at four distinct temperature levels. The effects of the three parameters, including temperature, pressure, and biomass concentration on syngas quality and net heat steam have been analyzed. The results show that the model has a better yield of hydrogen and methane gas with a superior lower heating value (LHV) at 540°C, 25 MPa, and 20% feedstock concentration. Feedstock concentration is the biggest contributing factor in the production of hydrogen. Energy analysis of the HTG has been carried out using the Sankey diagrams technique, which shows that the energy efficiency of this process is about 61%. Similarly, an economic analysis of the process has been conducted based on heat steam production costs, and it reveals that the HTG method is at least 10% cost-effective than coal, natural gas, or distillated oil. In comparative results of life cycle assessment (LCA) with the HTG process and direct land disposal, the HTG process has outperformed direct land disposal. Therefore, the outcomes of this study suggest that this process is economical, environmentally friendly, and energy efficient as compared to direct land disposal.

The planetary health effects of COVID-19 in dental care: a life cycle assessment approach.

Aims COVID-19 has significantly impacted the safety guidelines for personal protective equipment (PPE) within dental services. We quantified and compared the environmental impact of different forms of PPE.Methods The PPE items were divided into three categories: 1) the body protection category, which included disposable and reusable gowns; 2) the eye protection category, which included a visor with a disposable face shield and a reusable visor; and 3) the respiratory protection category, which included respirator FP2SLw, respirator FFP2 and surgical masks. The OpenLCA software was used for analysing and comparing the environmental impact of all PPE products in the three categories.Results The life cycle assessment results of this study showed that damage to human health was more significant for the reusable gown than the disposable gown for the body-protection-category PPE. A visor with a disposable face shield had a higher environmental footprint than the reusable visor across all impact categories for the eye protection category. In addition, a visor with a disposable face shield released five times more carbon dioxide equivalent emissions and used four times more dissipated water and three times more fossil fuels than the reusable visor. A disposable gown used four times more dissipated water and three times more fossil fuels than reusable gowns. For respiratory PPE, the FP2SLw respirator had the highest burden in all 16 categories, followed by the FFP2 respirator and then the surgical mask.Conclusion The environmental impact of PPE is notable and could be reduced through using less damaging domestic products and increased usage of reusables. In addition, the selection of PPE that are reusable and made of recyclable materials can help to minimise the environmental impact and reduce environmental resource depletion.

Environmental Benefit Assessment of Blended Cement with Modified Granulated Copper Slag.

This study aimed to investigate the environmental impact of modified granulated copper slag (MGCS) utilization in blended cement production at a representative cement plant in China. Sensitivity analysis was performed on the substance inputs, and the life cycle impact assessment (LCIA) model was applied. A detailed comparative analysis was conducted of the environmental impact of cement production in other studies, and ordinary Portland cement production at the same cement plant. Results showed that calcination has the largest contribution impact of all the impact categories, especially in causing global warming (93.67%), which was the most prominent impact category. The life cycle assessment (LCA) result of blended cement was sensitive to the chosen LCIA model and the depletion of limestone and energy. In this study, producing blended cement with MGCS effectively mitigated the environmental impact for all the selected impact categories. Results also show a reduction in abiotic depletion (46.50%) and a slight growth (6.52%) in human toxicity. The adoption of MGCS in blended cement would therefore generally decrease the comprehensive environmental impact of cement, which contributes to the development of sustainable building materials.

Circular utilization of urban tree waste contributes to the mitigation of climate change and eutrophication

Circular utilization of urban tree waste contributes to the mitigation of climate change and eutrophication

The global environmental costs of mining and processing abiotic raw materials and their geographic distribution

The global demand for abiotic resources is rising, and continuous extraction has adverse effects on the environment. In this study, we quantify the total global environmental costs by monetizing the life cycle assessment results of mining and processing 38 abiotic materials. Results are shown in terms of material and affected country. We assess impacts covered by the ReCiPe impact assessment method, excluding impacts on freshwater and marine ecosystems and some crucial local and cultural impacts. Furthermore, we compare the environmental costs with the mining GDP for each country. The total environmental costs range from €0.4 to €5 trillion annually. We find that the highest absolute environmental costs can be attributed to the greenhouse gases, particulate matter emissions and acidification caused by coal and steel specifically. The countries with the highest absolute costs are China and India, because China extracts and processes large amounts of materials, while India carries a large share of the climate damages that global material production causes. The countries that have the most beneficial ratio of environmental costs per GDP are countries that process materials, such as Japan and Germany (steelmaking), and countries that mostly extract oil, as Algeria, Azerbaijan and Nigeria, because they largely externalize environmental costs of upstream and downstream processes. For materials that have a worse relationship between economic gains and environmental impact, or that have high down‑stream impacts such as fossil energy carriers, circular economy, material efficiency and substitution strategies should be prioritized to reduce global environmental degradation.

Enzymes as an environmental bottleneck in cellulosic ethanol production: Does on-site production solve it?

With the progressive implementation of Low-Carbon Policies based on Life Cycle Assessment (LCA) methodologies to assess climate change mitigation, biofuels’ potential environmental advantages could finally be translated into economic revenues, especially for residue-based production chains. This implies, however, tackling environmental hotspots along the Life Cycle, such as the use of enzymes, an important input in cellulosic ethanol production. While relevant, however, aspects of enzyme manufacturing, crucial to the LCA results, are often oversimplified in databases or even undisclosed, which might render the accounting for this flow unreliable. A potential solution for this is to model enzyme production, disclosing aspects such as carbon source uptakes, energy consumption and purification steps, all of which may carry significant environmental burdens, especially for fossil-reliant procedures. Integrating these steps into the biorefinery process design as an on-site operation, however, would allow access to renewable energy and carbon sources for enzyme production, potentially reducing their burden in the final biofuel LCA profile, when compared with off-site supply. This work, then, aims to evaluate the effect of inserting on-site enzyme production within a stand-alone second-generation (2G) biorefinery, using sugarcane straw as feedstock, to produce ethanol and electricity, as opposed to off-site enzyme supply from manufacturers. The results show that adopting on-site production can reduce the overall environmental impact profile for cellulosic ethanol, in comparison to off-site supply, even though off-site data present significant variability among databases and literature. This trend persisted for varied enzyme dosages in the saccharification process and for different inventories to model off-site supply. The reference inventories for off-site supply lack transparency and details, while also displaying large discrepancies between impact indicators, indicating the need to pursue more consistent, reliable, and complete inventories for its modelling in LCA. Compared to first-generation (1G) sugarcane ethanol, 2G-ethanol (with on-site enzyme production) demonstrated a reduction in the Global Warming Potential category of around 80%. However, relevant trade-offs for 2G ethanol (with off-site enzyme supply) were observed – regarding ecotoxicity, mineral scarcity, eutrophication and even the potential GHG reduction – when different enzyme inventories are used.

Pyrolysis of engineered beach-cast seaweed: Performances and life cycle assessment

The blooming of beach-cast seaweed has caused environmental degradation in some coastal regions. Therefore, a proper treating and utilizing method of beach-cast seaweed is demanded. This study investigated the potential of producing power or biofuel from pyrolysis of beach-cast seaweed and the effect of the ash-washing process. First, the raw and washed beach-cast seaweeds (RS and WS) were prepared. Thereafter, thermogravimetric analysis (TG), bench-scale pyrolysis experiment, process simulation, and life cycle assessment (LCA) were conducted. The TG results showed that the activation energies of thermal decomposition of the main organic contents of RS and WS were 44.23 and 58.45 kJ/mol, respectively. Three peak temperatures of 400, 500, and 600 °C were used in the bench-scale pyrolysis experiments of WS. The 600 °C case yielded the most desirable gas and liquid products. The bench-scale pyrolysis experiment of RS was conducted at 600 °C as well. Also, an LCA was conducted based on the simulation result of 600 °C pyrolysis of WS. The further process simulation and LCA results show that compare to producing liquid biofuel and syngas, a process designed for electricity production is most favored. It was estimated that treating 1 ton of dry WS can result in a negative cumulative energy demand of -2.98 GJ and carbon emissions of -790.89 kg CO2 equivalence.

Life cycle assessment (LCA) of thermal insulation materials: A critical review

Thermal insulation of buildings is a key factor in reducing the environmental impact of the building sector by lowering the energy demand of buildings for heating and cooling. The choice of material for the thermal insulation has become more important with the rising need for sustainability. Life cycle assessment (LCA) is a common tool to assess the environmental impact of products or services. This study reviews the available literature on LCA of building thermal insulation materials in a structured literature review. The aim was to provide an overview over the literature, critically assess the methodology used as well as the results of the LCAs, especially to identify the potential of renewable based thermal insulation. This review covered 47 studies on building thermal insulation materials in total and developed a pedigree matrix to assess the quality of the articles. The results show at times significant methodological issues and a lack of transparency on the implementation of methods within the LCA framework. For the comparative LCA results, the review suggests that among the market leading materials, EPS, Stone wool, and Glass wool are highly similar in their impact. Other materials such as XPS or PUR show overall higher impacts in the majority of categories. The results further suggest that renewable based materials tend to have a lower environmental impact, but are not necessarily better. The main cause of impact for non-renewable organic materials is the raw material and for inorganic materials the production process, while the most common main driver of impacts for renewable based materials are binders and additives. This highlights further potential for improvement for the environmental impact of renewable based thermal insulation materials by lowering the need for additives.

A Comparative Analysis of Plant-Based Milk Alternatives Part 2: Environmental Impacts

Human food production is the largest cause of global environmental changes. Environmental benefits could be achieved by replacing diets with a high amount of animal-sourced foods with more plant-based foods, due to their smaller environmental impacts. The objective of this study was to assess the environmental impacts of the three most common plant-based milk alternatives (PBMAs)—oat, soy, and almond drink—in comparison with conventional and organic cow milk. Life cycle assessments (LCA) were calculated by the ReCiPe 2016 midpoint method, in addition to the single issue methods “Ecosystem damage potential” and “Water scarcity index”. PBMAs achieved lower impact values in almost all 12 of the calculated impact categories, with oat drink and the organic soy drink being the most environmentally friendly. However, when LCA results were expressed per energy and by the protein content of the beverages, the ranking of the beverages, in terms of their environmental impacts, changed greatly, and the results of PBMAs approached those of milk, particularly with regard to the protein index. The study highlights the importance of considering a broader range of impact categories when comparing the impacts of PBMAs and milk.

Life cycle sustainable assessment of natural vs artificial lightweight aggregates

Optimal selection of concrete aggregates can promote sustainable construction practice from the bottom line, which is a feasible strategy to cope with resources crisis and solid waste pollution. In this study, a two-level tree structure framework was thus proposed for the sustainability assessment of lightweight aggregates (LWA) based on the life cycle assessment concept. The evaluation system was divided into four criteria categories marked as society demands, economic costs, environmental impacts and technical performance, and each of them was assigned a number of sub-index. A qualitative questionnaire survey with seven sub-index and a quantitative calculation with eight sub-index were executed in the target system. Sintering fly ash aggregates (SFFAA), cold-bonding fly ash aggregates (CBFAA), waste clay brick aggregates (WCBA) and natural pumice aggregates (NPA) were chosen as typical artificial and natural lightweight aggregates objectives and evaluated in the framework. Impact and sensitivity analyses were conducted to comparably discuss the sustainability of various lightweight aggregates. The impact analyses represented that the waste clay brick aggregate has better sustainability. The sensitivity analysis shows that the supply-demand relationship of raw materials greatly impacts the sustainability of lightweight aggregate, and the transportation distance of raw materials is the critical factor in the production of LWA. At the same time, artificial lightweight aggregates are sensitive to cement binder consumption, and zero cement addition or waste cement powder is an optimistic option. From the sustainable life cycle assessment results, waste clay brick aggregates, sintering fly ash aggregates and cold-bonding fly ash aggregates are suggested as the alternative to the natural pumice aggregates for the lightweight aggregates concrete production. The emphasis on the weight of the social dimension will tend to prefer the selection of SFAA, and the economic or environmental dimension will lead to the preference of CBFAA for sustainable development. The framework proposed in this work could be used in choosing other sustainable construction materials or cleaner products.

Selection of green remediation alternatives for chemical industrial sites: An integrated life cycle assessment and fuzzy synthetic evaluation approach

The concept of green site remediation calls for a model that can consider environmental impacts in the selection of site remediation alternatives. In this study, an integrated life cycle assessment (LCA)-fuzzy synthetic evaluation (FSE) model is developed to help practitioners select the optimal site remediation plan by incorporating life cycle impacts into the comprehensive suitability evaluation. The LCA module quantifies environmental and economic impacts using ReCiPe and Input-Output LCA methods, respectively. The impacts are evaluated along with other suitability considerations, presented in 32 indicators under ten criteria, by practitioners through a questionnaire survey. FSE is used to process the collected subjective judgments and generate a suitability index for informed selection. The integrated model is applied to a case study of an abandoned chemical industrial site contaminated by various organic chemicals and mercury. Four remediation alternatives, designed as the combined uses of ex-situ thermal desorption, in-situ thermal desorption, and in-situ containment, are evaluated. The LCA results show that the alternative with extensive use (treating 93.8 % of the contaminated soil) of in-situ thermal desorption is associated with the highest environmental and economic impacts, followed by the alternative with less extensive use (6.2 %) of in-situ thermal desorption. The FSE results show that the economic, technical, and environmental impact considerations are the top three important criteria. The integrated LCA-FSE results indicate that the alternative with mixed use of ex-situ thermal desorption and in-situ containment could be the optimal plan. Excluding LCA results could alter the suitability ranks of the alternatives.

Life Cycle Environmental Impacts of Wastewater-Derived Phosphorus Products: An Agricultural End-User Perspective.

Recovering phosphorus from wastewater in more concentrated forms has potential to sustainably recirculate phosphorus from cities to agriculture. The environmental sustainability of wastewater-based phosphorus recovery processes or wastewater-derived phosphorus products can be evaluated using life cycle assessment (LCA). Many LCA studies used a process perspective to account for the impacts of integrating phosphorus recovery processes at wastewater treatment plants, while some used a product perspective to assess the impacts of producing wastewater-derived phosphorus products. We demonstrated the application of an end-user perspective by assessing life cycle environmental impacts of substituting half of the conventional phosphorus rock-based fertilizers used in three crop production systems with wastewater-derived phosphorus products from six recovery pathways (RPs). The consequential LCA results show that the substitution reduces global warming potential, eutrophication potential, ecotoxicity potential, and acidification potential of the assessed crop production systems in most RPs and scenarios. The end-user perspective introduced in this study can (i) complement with the process perspective and the product perspective to give a more holistic picture of environmental impacts along the “circular economy value chains” of wastewater-based resource recovery, (ii) enable systemwide assessment of wide uptake of wastewater-derived products, and (iii) draw attention to understanding the long-term environmental impacts of using wastewater-derived products.

Dynamic simulation and lifecycle assessment of hydrogen fuel cell electric vehicles considering various hydrogen production methods

In this research study, a real model of a hydrogen fuel cell vehicle is simulated using Simcenter Amesim software. The software used for vehicle simulation enabled dynamic simulation, resulting in more precise simulation. Furthermore, considering that fuel cell degradation is one of the significant challenges confronting fuel cell vehicle manufacturers, we examined the impact of fuel cell degradation on the performance of hydrogen vehicles. According to the findings, a hydrogen vehicle with a degraded fuel cell consumes 14.3% more fuel than a fresh fuel cell hydrogen vehicle. A comprehensive life cycle assessment (LCA) is also performed for the designed hydrogen vehicle. The results of the hydrogen vehicle life cycle assessment are compared with a gasoline vehicle to fully understand the effect of hydrogen vehicles in reducing air emissions. The methods considered for hydrogen production included natural gas reforming, electrolysis, and thermochemical water splitting method. Furthermore, because the source of electricity used for electrolysis has a significant impact on the life cycle emission of a hydrogen vehicle, three different power sources were considered in this assessment. Finally, while a hydrogen vehicle with a degraded fuel cell emits lower carbon dioxide (CO2) than a gasoline vehicle, the emitted CO2 from this vehicle using hydrogen from electrolysis is approximately 25% higher than that of a new hydrogen vehicle.

Life Cycle Sustainability Assessment of Wastewater Systems under Applying Water Demand Management Policies

Sustainability assessment of urban water and wastewater infrastructures, especially when it comes to managing existing systems, is of paramount importance. Hence, this study presents a comprehensive approach to investigate the sustainability of a real wastewater system under different water demand management policies (WDMPs) in the operation and maintenance stage. In this regard, life cycle sustainability assessment (LCSA) is used through its three main pillars, which are (1) environment, (2) economy, and (3) society. Accordingly, (1) Environmental assessment is conducted using life cycle assessment (LCA) considering a thorough inventory dataset; (2) The economic assessment results are analyzed by the life cycle cost (LCC) method; and (3) Social life cycle assessment (SLCA) is conducted using the analytic hierarchy process (AHP) method, in which three main stakeholders “public and local community”, “workers and employees”, and “treated wastewater and sludge consumers” are considered. Finally, to prioritize scenarios, the results of LCA, LCC, and SLCA for every scenario are aggregated to account for the sustainability score using the AHP. The results of applying the proposed method to a real case study show that scenarios leading to less reduction in wastewater production are more sustainable options as they represent better performance regarding economic and social aspects. The proposed framework provides a better insight into the integrated sustainability analysis of urban water infrastructures. In addition, it can be used as a guideline for exploring the effects of WDMPs on wastewater systems in different study areas.

Development and characterization of sustainable PLA/Olive wood waste composites for rehabilitation applications using Fused Filament Fabrication (FFF)

An understanding of how the construction industry can support the transition towards a Circular Economy (CE) of the built environment plays a key role in rehabilitation processes that often require skilled labor.Fused Filament Fabrication (FFF), an Additive Manufacturing (AM) technique, is a new technology recently proposed for this purpose. In recent years, a number of studies have been presented to improve the sustainability of the main materials used in 3D printing (e.g. PLA filament), suggesting, in particular, some interesting composite filaments.The present paper is related to the development and characterization of sustainable materials, able to reduce the environmental impacts of the conventional materials for FFF. More specifically, various composite filaments based on polylactic acid (PLA) and different amounts of olive wood scraps were produced by an extrusion process and fully characterized from a physical, thermal and mechanical point of view. As they are suitable for application in a low-cost 3D printing machine, these filaments are used to build simple 3D printed models as a first exploitation of architectural building elements based on wood powder.In addition, in order to evaluate the environmental advantages of the wood waste derived composite filaments, the impact indicators were also quantified by Life Cycle Assessment (LCA). LCA results showed environmental benefits resulting from the inclusion of wood scraps in PLA filaments (20% of wood corresponds to 10% impact reduction) supporting further research in this area.

Energy-Model and Life Cycle-Model for Grinding Processes of Limestone Products

Fine and ultrafine grinding of limestone are frequently used in the pharmaceutical, chemical, construction, food, and cosmetic industries, however, research investigations have not yet been published on the combination of energy and life cycle modeling. Therefore, the first aim of this research work was the examination of main grinding parameters of the limestone particles to determine an empiric energy-model. Dry and wet grinding experiments have been carried out with a Bond mill and a laboratory stirred ball mill. During the grinding processes, the grinding time and the filling ratio have been adjusted. The second goal of this research assessed the resources, emissions and environmental impacts of wet laboratory grinding with the help of life cycle assessment (LCA). The life cycle assessment was completed by applying the GaBi 8.0 (version: 10.5) software and the CML method. As a result of research, the determination of an empiric energy-model allowed to develop an estimated particle size distribution and a relationship between grinding fineness and specific grinding energy. The particle size distribution of ground materials can be exactly calculated by an empirical Rosin–Rammler function which represented well the function parameters on the mill characters. In accordance with LCA results, the environmental impacts for the mass of a useful product for different levels of specific energy with the building of approximation functions were determined. This research work sets up a new complex model with the help of mathematical equations between life cycle assessment and specific energy results, and so improves the energy and environmental efficiency of grinding systems. This research work facilitates the industry to make predictions for a production-scale plant using an LCA of pilot grinding processes.

Comparative performance and cost-integrated life cycle assessment of low impact development controls for sustainable stormwater management

Climate change and urbanization have led to an increase in the frequency and intensity of floods in urban regions. To cope with such extreme events, low impact development (LID) has been adopted as a sustainable alternative to conventional stormwater management systems. LID controls mitigate runoff and manage flooding at the source by providing additional storage, filtration, and infiltration of stormwater. This study aims to investigate the techno-economic and environmental performance of multiple LID controls: bioretention cells (BC), infiltration trenches (IT), and permeable interlocking concrete pavement (PICP) compared to a conventional stormwater pipe drainage system. A cost-integrated life cycle analysis was conducted to assess the environmental impacts and evaluate the financial feasibility of the examined stormwater management systems. An eco-efficiency analysis (EEA) was carried out to quantify the environmental costs of LID controls by incorporating the results of a life cycle assessment (LCA) and life cycle cost analysis (LCCA). The technical analysis showed that LID controls significantly reduced runoff by 67%, 53%, and 36% for IT, BC, and PICP, respectively compared to the conventional system. Moreover, the LCA results revealed that the pipe drainage system was the least favorable with a single score of 191 mPt, followed by PICP (188 mPt), BC (40 mPt), and IT (30 mPt). Over a 30-year assessment period, the LCCA findings indicated that the IT and BC controls had the lowest net present costs of $11.6 and $14.5 million, respectively, compared to the PICP ($17.0 million) and conventional ($19.5 million) systems. The EEA revealed that IT was the most eco-efficient (EI = 0.34 Pt/$) among the LID systems, whereas PICP was the least cost-efficient (EI = 0.97 Pt/$). It was also found that applying hybrid LID models further reduced the runoff, environmental impacts, and financial burdens by up to 79%, 84%, and 48%, respectively. Overall, these findings emphasized the potential environmental and financial benefits of implementing integrated LID controls as sustainable stormwater management systems.

Ornamental Stone Processing Waste Incorporated in the Production of Mortars: Technological Influence and Environmental Performance Analysis

The technological performance and environmental advantages of replacing sand by ornamental stone processing waste (OSPW) in the production of mortars for civil construction were studied. Technological properties associated with the standard consistency index, squeeze flow and bulk densities as well as the determination of water retention and calorimetry analysis were evaluated in the mortars’ fresh state, whereas capillarity tests as well as mechanical resistance by flexural and compression tests were determined in the hardened state for mortars incorporated with 10, 30 and 60 wt.% of OSPW substituting sand. Three different types of Portland Cements were considered in the incorporated mortars production. For these mortars environmental analysis, their corresponding life cycle assessment results were compared to that of conventional waste-free (0% OSPW) control mortar. It was found that the OPSW incorporation acts as nucleation sites favoring a hydration process, which culminates after 28 days of curing in the formation of more stable phases identified as hydrated calcium silicates by X-ray diffraction (XRD) amorphous halo. It was also revealed that both flexural and compression improved resistance for the incorporated mortars after 28 curing days. In particular, the calorimetry and XRD results explained the better mechanical resistance (12 MPa) of the 30 wt.% OSPW incorporated mortar, hardened with Portland Cement V, compared not only to the control, but also to the other incorporated mortars. As for the environmental analysis, the replacement of sand by OSPW contributed to the reduction in associated impacts in the categories of land use (−5%); freshwater eutrophication (−9%); marine eutrophication (−6%) and global warming (−5%).

Life Cycle Risk Assessment Applied to Gaseous Emissions from Crumb Rubber Asphalt Pavement Construction

Asphalt mixtures for road pavements are produced and laid at high temperatures, producing gaseous emissions that contain polycyclic aromatic hydrocarbons and volatile organic compounds that paving workers are exposed to. This paper aims to combine the effects of gaseous emissions on human health with the life cycle impacts of wearing courses. The results of sanitary-environmental risk analysis and life cycle assessment were combined in an integrated approach, the life cycle risk analysis, to evaluate the environmental performance of road pavements and local cancer and toxicological effects on workers. Two asphalt mixtures modified with crumb rubber (CR) from end-of-life tires (gap and dense graded) were compared to standard, unmodified asphalt mix. Air samples were collected at the screed and the driver’s seat of a paver during the construction of a full-scale trial section in Turin, Italy. The CR wearing course with a higher asphalt binder content (gap-graded) had a cancer effect on workers 3.5 and 2.9 times higher than the CR mixture with a lower asphalt binder percentage (dense-graded) and the standard mixture, respectively. Instead, the toxicological effects were 1.3 and 1.2 times higher for the gap-graded mixture than the dense-graded and the standard mix, respectively.

Comparative life cycle assessment of cement, sintered bricks and non-sintered bricks manufacturing using water-based drilling cuttings from shale gas production in the Sichuan Basin, China

This study determined the environmental impacts of three recycling pathways for water-based drilling cuttings (WDC), namely cement, sintered bricks, and non-sintered bricks, based on the life cycle assessment (LCA) method. A life cycle inventory was developed with based on the resource utilization of 1t drilling cuttings as the functional unit, and a sensitivity analysis was conducted to identify the essential materials and energy consumption. The results showed that the sequence of the environmental impact index for the three recycling pathways was cement, non-sintered brick and sintered brick. Primary energy demand and direct emissions were the main reasons for this difference. Direct emissions, electricity, and binder were the largest contributors to the inventory of cement, sintered bricks, and non-sintered bricks, accounting for 54%, 33.4%, and 62.1% of the environmental impact burden, respectively. Furthermore, a 5% reduction in direct emissions, electricity, and binder decreased the integrated impact index by approximately 2.67%, 3.04%, and 3.38% for cement, sintered bricks, and non-sintered bricks, respectively. Based on the LCA results, strategies for reducing emissions and conserving energy were proposed. These results provide a useful reference for creating a sustainable system for recycling water-based drilling cuttings.