Waste Processing Research Articles

Mapping the Sustainability of Waste-to-Energy Processes for Food Loss and Waste in Mexico—Part 2: Environmental and Economic Analysis

Mexico generated 8.9 million tons of food loss and waste (FLW) in the year 2022, which was primarily managed through linear economy schemes where final disposal sites are predominant, leading to significant contributions to climate change and economic losses. This study, as a continuation of a prior work (Part 1), aims to evaluate the economic and environmental feasibility of implementing waste-to-energy anaerobic digestion (WtE-AD) plants for FLW management across Mexico, identifying the key factors that influence the competitiveness of these systems compared to conventional waste management practices. Using the outcomes of an energy feasibility analysis (Part 1), alongside life cycle assessment (LCA), geographic information systems, and cost engineering, this research analyzes the eco-efficiency and viability of WtE-AD for FLW valorization throughout the Mexican territory. The results indicate that, with a conventional waste management fee of USD 35.4 t−1, only the largest WtE-AD plant in the State of Mexico (treatment capacity of 2536.8 t FLW d−1) achieved a positive net present value (NPV) of USD 70.1 million, while all the other plants remained economically unviable. Conversely, under an optimistic scenario with a fee of USD 139 t−1, plants processing over 50 t FLW d−1 achieved profitability, with the largest plant reaching an NPV of USD 1.15 billion. The environmental assessment showed that larger plants effectively act as carbon sinks, with the largest plant reducing emissions by up to −89.8 kg CO₂ eq t−1 of FLW. These findings emphasize the need for appropriate waste management fees and governmental incentives to ensure the economic viability of WtE-AD plants. This study provides valuable insights for policymakers, highlighting the potential of WtE-AD technologies to contribute to Mexico’s energy transition and the shift toward a circular economy.

PELATIHAN PENGOLAHAN MINYAK JELANTAH PADA BUMDES PULOTONDO, KEC. NGUNUT – KAB. TULUNGAGUNG

The village of Pulotondo, in the Ngunut subdistrict of Tulungagung Regency, has significant potential for freshwater fish farming and horticultural plant cultivation. However, this potential remains underutilized because the marketing area is still limited to the local scope. The local BUMDes (Village-Owned Enterprises) has not seized this opportunity and is only focusing on a micro-scale LPG retail business for the surrounding community. The event can provide BUMDes Pulotondo for utilizing waste processing, specifically converting used cooking oil into scented candles. This could reduce used cooking oil waste and allow the candles to be sold, thereby boosting BUMDes's economic potential. The service method includes material presentation, discussions, and practical exercises. Making candles from used cooking oil proceeded smoothly and was well-received by 12 participants, and they can produce candles for product sale.

Automatic Waste Segregation System

The Automatic Waste Segregation System aims to enhance waste management practices by efficiently sorting waste into three categories: wet waste, dry waste, and metallic waste. Utilizing advanced sensor technologies, this system leverages an LM393 IC moisture sensor to detect the moisture content in waste, effectively identifying wet organic materials such as food scraps. Additionally, an infrared (IR) sensor is employed to distinguish dry waste, including paper, plastics, and textiles, based on the reflective properties of the materials. To further enhance the sorting process, a metal detector is integrated to identify and segregate metallic waste, ensuring that recyclables are collected accurately. The automation of waste segregation not only reduces the manual labor involved in traditional waste sorting methods but also increases the accuracy and efficiency of the process. This system is designed to operate autonomously, with real-time monitoring and feedback mechanisms that allow for seamless integration into existing waste management infrastructures. The collected data on waste types can be utilized for further analysis, enabling municipalities and organizations to develop more effective waste disposal and recycling strategies. By implementing this Automatic Waste Segregation System, we aim to address the growing challenges of waste management, reduce landfill dependency, and promote recycling and resource recovery. This innovative approach aligns with global sustainability goals, contributing to cleaner environments and enhanced waste resource management. The project has the potential to significantly improve waste processing efficiency, reduce environmental impact, and foster community awareness regarding the importance of proper waste segregation. Key Words: Arduino Mega, IR Sensor, DC Motor, Rotary Indexer, Container, etc.

Treatment of Leachate Obtained in Leiras de Compostagem de Remos de Alimentos (Composting of Food Remains) by Anaerobic Biodigestion Followed by Oxygenation: a Case Study in the Federal District

Objective: During the composting process of organic waste, the leachate from the degrading windrows requires treatment processes due to its significant load of polluting substances. Frequently, the approach adopted to treat leachate involves a combination of different processes. This study aimed to evaluate the performance of a biological treatment system, consisting of anaerobic digestion followed by oxygenation, applied to leachate from a composting company of organic waste obtained from residential and commercial kitchens located in the Federal District. The outlined hypothesis is that anaerobic treatment followed by oxygenation, with the material studied and under the experimental conditions, allows for the attainment of material with characteristics that permit its discharge into water bodies, according to CONAMA Resolution No. 430/2011, which complements and amends Resolution No. 357/2005. Method: The leachate was collected from the windrows through pipes and directed to a physical treatment system composed of a sand and grease trap. After that, it was pumped into two anaerobic reactors operating in sequence, with a total retention time of 15 days. The material was then directed to a waterproof masonry tank with natural and forced aeration. Samples were taken before and after the treatment of the leachate for the determination of electrical conductivity, temperature, pH, chemical and biochemical oxygen demands, total dissolved solids, total and volatile solids, total nitrogen, N-NH4+, N-NO3-, N-NO2-, total alkalinity, total phosphorus, thermotolerant coliforms, and Salmonella. Results and Discussion: The absence of Salmonella was observed in both the samples obtained before and after the treatment. Reductions in electrical conductivity (7.6%), temperature (16.2%), total alkalinity (23.0%), chemical oxygen demand (42.3%), biochemical oxygen demand (45.5%), total nitrogen (9.3%), N-NH4+ (18.4%), total phosphorus (30.1%), total solids (16.9%), total dissolved solids (14.0%), volatile solids (21.5%), and thermotolerant coliforms (99.9%) were observed after treatment. On the other hand, increases in pH (12.3%), N-NO3- (30.4%), and N-NO2- (14.4%) were noted. However, the material treated under the experimental conditions adopted did not meet the environmental discharge requirements established by Brazilian legislation (CONAMA Resolution 430/2011), especially for the parameters biochemical oxygen demand, total nitrogen, N-NH4+, total phosphorus, N-NO₃⁻, N-NO₂⁻, and thermotolerant coliforms. Research Implications: The volume of organic waste collected and treated by composting has been increasing in recent years in Brazil, especially due to legal requirements at state (district) and municipal levels. Since organic waste generally has high moisture content, a large volume of leachate from the windrows is produced and can become a significant source of environmental contamination. Biological treatments such as anaerobic digestion followed by aeration can be an important tool to prevent this contamination, but chemical and biochemical parameters, as well as conditions like retention time, need to be evaluated to verify the efficiency of treatment systems.

Valorization of soybean by-products for sustainable waste processing with health benefits.

Soybean is a rapidly growing agricultural crop, fueled by the rising global demand for animal feed, plant-based proteins and essential nutrients for human consumption. Soybeans contain a wide range of essential nutrients that are vital for health and may play a significant role in disease prevention. Their nutritious composition has led to a diverse range of soy-based foods and derivatives available on the market. A substantial amount of soybeans is allocated to the animal feed sector, human consumption, nutraceuticals and other industrial applications. Soybean has superior protein quality and digestibility compared to other legumes. It also contains abundant amounts of isoflavones, phytosterols and minerals that augment its nutritional value as a constituent of the human diet. Many different by-products are produced during the processing of soy. Due to a lack of sustainable food manufacturing practices, a sustainable amount of these by-products is discarded as waste, posing environmental challenges. Developing an effective waste management system for soybean by-products can help address public health concerns and provide a cost-efficient way to repurpose valuable components of soy, such as soy meal, okara and soy whey. Such valorization can mitigate the environmental impact of waste and contribute to malnutrition. This study aims to evaluate the sustainable use of soy by-products to help preserve biodiversity and reduce food insecurity. This article thoroughly examines the fundamental components of soybean use in the fields of health and soybean by-product processing. It provides a summary of cost-efficient, feasible and ideal processing technologies. © 2024 Society of Chemical Industry.

Identifikasi Pemborosan dalam Proses Produksi Pakan Ternak Ayam di PT.XYZ dengan Menggunakan Metode Value Stream Analysis Tools (VALSAT)

This research aims to identify various types of waste in the chicken feed production process at PT. XYZ and provide improvement recommendations to reduce production costs. The method used is the Value Stream Analysis Tools (VALSAT) to map and analyze the value stream in the production process. This research includes direct observation and data analysis to find the main wastes. The results show seven main types of waste in the chicken feed production process: waiting time, unnecessary movements, product defects, excess inventory, inefficient processes, overproduction, and transportation. However, the research encountered several challenges, such as data limitations and difficulties in collecting accurate data. The largest waste found was excess inventory, with an average score of 9.13. This research provides clear insights into areas in the production process that require improvement. The implementation of the improvement recommendations is expected to increase the company's efficiency and productivity. Despite facing some challenges, the use of VALSAT proved effective in identifying and analyzing waste. It is hoped that the provided improvement recommendations can reduce waste and enhance operational efficiency at PT. XYZ.

An infrared radiation-responsive high-entropy CoCaMgMnAlFe-LDHs for controllable hydrogen generation via NaBH4 hydrolysis: Utilization of steel slag and lithium-ion battery liquid waste

Green processing of steel slag and lithium-ion battery liquid waste poses a global environmental challenge. This study utilizes waste acid (containing Co2+, H+ and NO3–) and alkali solutions (containing Li+, Na+, OH– and CO32–) from lithium-ion battery manufacturing to recover metal cations from steel slag (containing Ca2+, Mg2+, Al3+, Fe3+, and Mn2+), preparing high-entropy CoCaMgMnAlFe-LDHs catalysts for controllable hydrogen generation via NaBH4 hydrolysis. The ultimate residue, without any residual hazardous metal cations, enabling safe reintroduction into the natural environment. The presence of Co2+ endows the CoCaMgMnAlFe-LDHs catalyst with rapid photo-thermal conversion capability, enabling it to rapidly heat up under infrared radiation and efficiently catalyze the reaction of NaBH4 hydrolysis. The hydrogen generation rate reaches 1.12 mol·h−1·g−1·W−1 driven by 1050 nm infrared radiation. This study provides a novel approach to the environmentally friendly treatment and high-value utilization of steel slag and lithium-ion battery liquid waste.

RECYCLING OF LITHIUM ION BATTERIES: THE BLACK SPOT OF THE GREEN DEAL

Progress towards a decarbonized economy is dependent on the development of energy storage devices enabling the deployment of new strategies in the transport and energy sectors. Lithium-Ion Batteries (LIBs) play a key role in facilitating the shift from fossil fuels to renewables based on ubiquitous sources of decentralized energy. However, the rapidly increasing demand for batteries has generated environmental concerns regarding recycling, and raw materials depletion and exhaustion. Moreover, the level of extraction and processing of battery raw materials from local resources is almost negligible, inducing geopolitical concerns regarding potential threats to production and the stability of local manufactures. Finally, the storage and processing of hazardous wastes remains a difficult challenge in the circular economy concept. Recycling, therefore, is beneficial to the environment and has a high economic value via strengthening local supply chains. This work presents an alternative, comprehensive, and holistic review of LIB recycling technologies; from traditional metallurgy strategies to innovative, direct recycling methods and pioneering in-production and design-for-recycling approaches. It identifies new directions for making recycling efficient and techno-economically profitable and sustainable - including the vital role of robotics, artificial intelligence, and machine learning. Keywords: Lithium Ion Batteries, Recycling, Design for Recycling, In-production Recycling, Artificial Intelligence

Exploring Gumuruh Village's Upcycling Potential Using Creative Innovation To Turn Plastic Waste Into Commercial Products

Plastic waste presents a major environmental challenge worldwide, with improper disposal endangering ecosystems. Upcycling offers a solution by conserving natural resources, reducing carbon emissions, and minimizing waste, all while lowering the demand for new production. Additionally, recycling generates significant economic benefits, particularly by producing high-quality commercial products in sectors like furniture. In Gumuruh Village, Bandung, the community actively participates in recycling efforts, including the processing of organic waste, to create sustainable products. Through the Design Thinking approach and Service Learning, academics and local SMEs collaborate to design and develop products that directly benefit the community.

SOSIALISASI PENGOLAHAN SAMPAH BERBASIS SUMBER DAN PRAKTEK PEMBUATAN ECO-ENZYME DAN KOMPOS DI DESA ADAT SABA

The population of Indonesia and the very rapid development of industry have caused the amount of waste to increase or increase and it has not been managed well by the government and society, so waste has become a problem that can damage the environment. Of the total waste produced, around 80% is dominated by organic waste which is only seen as residual waste that has no economic value and causes environmental pollution. In accordance with the circular letter from the Governor of Bali regarding source-based waste management which has not been implemented effectively by every traditional village, through the KKN UNHI activities of Saba Village Group 10, socialization of source-based waste management and the practice of making compost and eco enzymes was carried out. This activity aims to socialize the waste management process and practice processing organic waste by making compost and eco-enzymes. Socialization and practical activities for making composters and eco enzyme liquids were carried out at the Banjar Hall of Saba Traditional Village, Blahbatuh District, Gianyar Regency which was attended by PKK throughout Saba Village, KWT Lestari Saba and STT Saba Traditional Village. Eco enzymes produced from organic waste, namely leather and vegetables, mixed with sugar and water and fermented for 3 months have benefits as house cleaning agents, effective natural fertilizers and pesticides, farming and purifying water, air and soil. Apart from being useful in helping the community in processing organic and inorganic waste, it also has economic value and helps government programs in preserving the environment in order to save the earth from global warming.

The production systems green development: Waste logistics and data-driven waste management

Increasing the environmental friendliness of production systems is largely dependent on the effective organization of waste logistics within a single enterprise or a system of interconnected market participants. The purpose of this article is to develop and test a methodology for evaluating a data-based waste logistics model, followed by solutions to reduce the level of waste in production. The methodology is based on the principle of balance between the generation and beneficial use of waste. The information base is data from mandatory state reporting, which determines the applicability of the methodology at the level of enterprises and management departments. The methodology is presented step by step, indicating data processing algorithms, their convolution into waste turnover efficiency coefficients, classification of coefficient values and subsequent interpretation, typology of waste logistics models with access to targeted solutions to improve the environmental sustainability of production. The practical implementation results of the proposed approach are presented using the production example of chemical products. Plastics production in primary forms has been determined, characterized by the interorganizational use of waste and the return of waste to the production cycle. Production of finished plastic products, characterized by a priority for the sale of waste to other enterprises. The proposed methodology can be used by enterprises to diagnose existing models for organizing waste circulation and design their own economically feasible model of waste processing and disposal.

Consumer liking of steamed green Chinese cabbage (Brassica rapa ssp. chinensis) cultivated in formulated vegetable waste-based organic hydroponic solutions

Chinese cabbage or pak choy (Brassica rapa ssp. chinensis) is often consumed because of its high nutritional content and several health advantages. Due to their promotion as being healthier and more ecologically friendly, hydroponic vegetables have seen a recent spike in consumer interest. The production of Chinese cabbage involved the processing of the vegetable waste to create various hydroponic solution formulations (F1 = banana peels, eggshells, and bean sprouts; F2 = banana humps, onion peels, bean sprouts, and moringa leaves; F3 = moringa leaves, onion peels, and bean sprouts; and F4 = AB Mix solution). They were applied at concentrations of 600, 900, 1,200, and 1,500 parts per million. The aim of this study was to investigate the relationship between the type of hydroponic growth solutions and Chinese cabbage customer acceptance. As a result, using a hedonic test of consumer liking, a panel of 32 untrained individuals was asked to show their liking score on sensory attributes of Chinese cabbage. There was a significant difference in the color liking of Chinese cabbage as an effect of hydroponic solution formulation. However, both organic vegetable waste-based formulations did not statistically substantially affect consumer acceptance, which includes color, taste, flavor, texture, and overall liking. Ultimately, vegetable waste-based organic formulations can be used to produce Chinese cabbage that is as acceptable to customers as those prepared with inorganic AB-Mix solution.

Artificial intelligence and IoT driven system architecture for municipality waste management in smart cities: A review

Numerous devices, including sensors, RF ID, and other types of smart devices, have been developed as a result of the Artificial Intelligence (AI), and Internet of Things (IoT) revolution. Urban areas can become smart by monitoring and collecting data about their surroundings through the deployment of technologies with powerful computational capabilities and those that are converted into intelligent things. Waste management is among the most significant issues in smart cities, a rise in metropolitan regions and faster increases in population are the main reasons. When it comes to gathering data about waste management, intelligent services can serve as the front line. Waste management with IoT support is a common example of a service offered by smart cities. Various duties, like gathering, processing, and use of waste in appropriate facilities, are included in waste management. The present study proposed an updated waste management system architecture design after reviewing existing artificial intelligence and IoT-based waste management systems and automation in smart cities. The proposed system architecture deals with the automation of municipality trash in smarter urban areas, using IoT technology and sending notification messages based on sensor data relating to the dustbin state, such as full or empty. The notifications are sent simultaneously to the municipality office and the waste carrier vehicle driver, so that waste can be emptied on time. The proposed system architecture represents a scalable and adaptable model for municipalities that aim to transform their waste collection processes and play a key step in minimizing municipality waste in smart cities. By deploying this proposed system architecture with smart sensors and IoT devices, municipalities can monitor waste levels to ensure that bins are emptied when it is necessary. This reduces the frequency of waste collection, lowers fuel consumption, and minimizes operational costs. The Route optimization algorithms further enhance efficiency by determining the most efficient paths for waste collection trucks, so they can reduce travel time and fuel emissions.

Evaluation of Greenhouse Gas Emission Assessment Resulting from Processing Municipal Organic Waste into Bahan Bakar Jumputan Padat for Co-firing in Power Plants; Case Study: Bagendung Landfill Cilegon City

One type of biomass that can be used as fuel for co-firing in power plants is Bahan Bakar Jumputan Padat (BBJP)/Solid Waste Fuel. BBJP is a non-hazardous waste derivative that cannot be recycled. The production process of BBJP is strictly regulated by the Indonesian national standard (SNI) 8966:2021. The definition, characteristics and specifications of BBJP are much closer to Solid Recovered Fuel (SRF) than Refuse Derived Fuel (RDF). The utilization of BBJP reflects the dedication to reducing waste in landfills with a circular economy concept approach as well as the transition of the energy mix in Indonesia. To the present day, the production capacity of BBJP at Bagendung landfill in Cilegon City, Banten Province, has successfully produced 30 tons/day of organic municipal waste with an average BBJP product yield ranging between 11-15 tons/day. This research is intended to assess the Greenhouse Gas emissions (GHG) generated from the processing of municipal waste into BBJP. There are three main processes that produce GHG emissions, namely during bio drying processing, the use of machinery that produces emissions from electricity and the transportation process that produces combustion emissions in diesel fuel. As a result, direct GHG emissions arising from all waste processing activities into BBJP consist of 10 pollutants, namely CH4, N2O, CO, NH3, CO2, NOX, SO2, NVMOC, PM2.5 and ID(1,2,3,c,d)P. CO2 emission is the largest pollutant, accounting for 96.70% of the entire BBJP process.

Phase equilibria and thermodynamic analysis of liquid–liquid immiscibility in the system SiO2–Na2O–MoO3

AbstractPhase equilibrium experiments were carried out in the SiO2–Na2O–MoO3 system at 1200ºC and 1000ºC. We found that immiscible phase region in this system is narrower than that reported previously. By combining phase relationship and thermodynamic data and assuming associate species model, interaction parameters to describe enthalpy of mixing of SiO2–Na2O–MoO3 liquid were optimized by CALPHAD methodology. The thermodynamic database can be applied to thermodynamic calculations of silicate systems containing molybdenum, such as the vitrification process of high-level radioactive waste.

Treatment of Bottom Ash Medical Waste (BAMW) from Hospital Infectious Waste into Paving Block Products

Hospital solid waste is infectious waste, so it is included in the category of hazardous and toxic waste. One method of processing hospital solid waste is by burning it in an incinerator. The result of burning B3 waste at high temperatures is ash or known as bottom ash medical waste (BAMW). Ash from hospital waste processing is included in hazardous and toxic materials, so it needs to be handled properly. This study aims to process BAMW using the solidification/stabilization method. The BAMW processing product is paving blocks. The study was conducted by varying the composition of paving blocks. The variations carried out were the percentage of BAMW and its particle size. In addition, a Total Organic Carbon (TOC) level test was carried out on the water used to soak the paving blocks after being stored for 27 days. The results of the study showed that the higher the percentage of BAMW, the lower the compressive strength of the paving blocks, while the ability to absorb water and wear increased. The size of the BAMW particles also affects the quality of the paving blocks. The smaller the particle size, the better the quality of the paving blocks. Higher compressive strength indicates better quality of the paving blocks. The results of the analysis of the water used to soak the paving blocks showed that the TOC concentration was higher if the compressive strength decreased. BAMW can be used as an additional material for making paving blocks, but the composition should not be large.

Mineral concentration in citrus peel flours

Citrus fruits are known for their health benefits but managing processing waste is a challenge. Extracting bioactive compounds from these residues to create new products is promising, but mineral analysis is essential for food safety. The objective of this study was to analyze how the methodology for obtaining flour from sweet passion fruit peel, Tahiti lime, Murcott tangerine, and pearl pineapple influences the amounts of minerals Fe, Zn, Mn, Cu, Cr, and to determine the presence of these minerals in flours according to the defined limits. Maceration demonstrated a significant reduction in mineral content, such as iron, zinc, manganese, copper, and chromium, in the flours of lime and tangerine peels and passion fruit albedo. There was an increase in mineral levels after this process, such as zinc in passion fruit flavedo flour and manganese in tangerine and pineapple peels. Fe, Zn, Mn, Cu, Cr were respectively determined in 100g-1 in flours, from lime peel: 3,696mg; 1,273mg; 22,834mg, 0.422mg; 1104.945 μg; tangerine peel: 1,322mg; 2,560mg; 13,571mg; 0.236mg; passion fruit albedo: 8,596mg; 6,480mg; 76,003mg; 1,031mg; passion fruit flavedo 8,609mg; 3,363mg; 86,167mg; 2,317mg; in pineapple skin: 12,181mg; 0.704mg; 71,018mg; *mg; 2224.215 μg. Cr was not determined in the flours: albedo and flavedo from passion fruit, and tangerine and Cu from pineapple peel. Flours are sources of minerals but must be consumed with caution due to high quantities that can exceed the maximum tolerable intake limits.

Application of the Clark–Wright Method to Improve the Sustainability of the Logistic Chain

The incessant consumption of goods and materials underscores the need to address the growing problem of waste generation and its profound impact on environmental sustainability. The problem of waste removal can be approached in different ways, whether it is the routing of vehicles, the work of drivers, the optimal distribution of waste bins, or other matters in the entire waste process. The aim of this study is to investigate the possibilities of optimizing waste collection processes in the region using a slightly modified Clark–Wright method. Optimal waste collection routes are defined with a focus on cost reduction and overall optimization of logistic chain processes. The established mathematical model for the capacitated vehicle routing problem includes the principles of sustainability and environmental friendliness. The results indicate that the largest messenger of all the newly proposed routes are the routes containing the surrounding settlements. Newly designed routes lead to significant reductions in fuel consumption and vehicle maintenance, which has a positive impact on financial and environmental resources. The conclusion indicates that by applying the Clark–Wright method, we have achieved a reduction in the number of routes of twenty fewer routes. This study provides regions with a detailed plan to improve waste management practices, contributing to a future of increased sustainability and environmental awareness.

Sustainable and Environment-Friendly Management of Shrimp Processing Waste through High-Quality Chitosan Production

The shrimp processing industry generates substantial waste, including shells, heads, and tails, which, if not properly managed, can contribute to significant environmental issues, such as pollution and disease transmission. This study explores the conversion of shrimp waste into chitosan, a valuable biopolymer with applications across multiple industries, by utilizing its chitin, protein, and mineral content. The extraction process involved demineralization with 1M HCl, deproteinization with 3.5% NaOH, and deacetylation with 60% NaOH. The resulting chitosan exhibited high quality, characterized by a crystal structure, white color, odorless powder form, 73.7% degree of deacetylation (DD), 64% yield, solubility in acetic acid, and water content of 1.5%. This research highlights an environmentally responsible approach to shrimp waste management, providing a method for repurposing waste into a high-value material that meets industry standards, supporting environmental sustainability and circular economy practices.

Miracle in the evening: Explaining the boundary condition of consumer's self-control on purchase intention of near-expired products

Due to consumers' misunderstanding of product expiration dates, huge amounts of food waste and retail losses have been recognized as a worldwide problem. This research explores a solution to mitigate such waste and losses in the consumer purchase decision-making process of near-expiry products. Drawing from the literature on expiration date-based pricing (EDBP) and self-control, we propose that consumers' purchase intention for near-expiry products vary depending on the time of day (morning vs. evening). The results from mixed methodologies, including an analysis of actual sales data from an online retailer (Study 1) and randomized controlled experimental studies (Studies 2 and 3), reveal that consumers are less sensitive to near-expiry products when purchasing EDBP products in the evening compared to the morning. Furthermore, we examine how self-control mediates the interaction effects of the nearness of the expiration date and the time of day on the purchase intention of near-expiry EDBP products. A novel perspective on understanding consumers’ dynamic evaluations of sales promotions over time and managerial implications for promotional strategies to promote products approaching their expiration date are discussed.