Waste Valorization Research Articles

Comparative Analysis of Optimal Reaction Conditions for Hydrothermal Carbonization and Liquid Hot-Water Processes in the Valorization of Peapods and Coffee Cherry Waste into Platform Chemicals

The management of coffee and peapod waste presents significant environmental challenges, with millions of tons generated annually, leading to disposal issues and resource inefficiencies. Hydrothermal processes offer a promising valorization method, though biomass characteristics significantly influence the resulting products. Biomass characterization revealed distinct profiles for coffee cherry waste (moisture: 10.94%, ashes: 7.79%, volatile matter: 79.91%, fixed carbon: 1.36%, cellulose: 27.6%, hemicellulose: 12.5%, and lignin: 13.7%) and peapods (moisture: 7.77%, ashes: 4.22%, volatile matter: 74.18%, fixed carbon: 13.0%, cellulose: 20.2%, hemicellulose: 17.4%, and lignin: 5.0%). Experiments were conducted in 100 mL and 500 mL hydrothermal reactors with varying conditions for temperature (120–260 °C), time (1–4 h), stirring (none and at 5000 and 8000 rpm), biomass/water ratio (1:5, 1:10, 1:20, and 1:40), particle size (0.5–5 mm), and catalysts (acids and bases). The results showed that peapods produced over 30 times more platform chemicals than coffee. High temperatures (over 180 °C) degraded peapods, whereas coffee yields increased. Both biomasses were influenced similarly by reaction conditions: lower biomass/water ratios, smaller particle sizes, acid catalysts, and no stirring increased yields. Peapods consistently had higher yields than coffee in all conditions. Biochar analysis revealed anthracite from coffee and coal from peapods.

Nutrient Composition and Antioxidant Potential of Rambutan (Nephelium lappaceum L) Peel

The present study was conducted to assess the nutri-chemical composition and antioxidant potential of rambutan fruit (Nephelium lappaceum L) peel. Red rambutan fruit peel was used in fresh as well as dried form for the study. The nutri-chemical profiling revealed, fresh peel had 24g/100g of carbohydrate, 2.5g/100g of protein, 0.17g/100 g of fat and 0.89g/100g starch. However, dried peel had 55.45g/100g carbohydrate, 5.25g/100 protein, 10.2g/100g fat and 1.00g/100g starch. Crude fiber content of the fresh and dried peel was 0.77g/100g and 0.068g/100g respectively. Moreover, the fresh peel had higher moisture (73%) content than dried peel (4.2%). Vitamin C being heat liable, was found higher in fresh peel (9.31mg/100g). Sodium and potassium levels was found higher in dried peel powder as 1.55mg/100g and 9.4mg/100g respectively. Phytochemical composition of rambutan peel revealed that total polyphenol was higher in dried peel (580mg/100g) when compared to fresh (310 mg/100 g), meanwhile saponin, tannin and terpenoid was found higher in fresh peel as 47mg/100g, 390mg/100g and 5.101mg/100g respectively. Flavonoid content was dominant in dried peel (20.51mg/100g) than that of fresh peel (9.6mg/100 g). The radical-scavenging activity was expressed as IC50, which reported dried peel (43.79μg/100 mL) had strong antioxidant potential than fresh peel (184.39μg/100mL). However, it is concluded that rambutan peel is a potent source of nutrients, bioactive compounds and antioxidants which in turn has immense therapeutic benefits. Furthermore, valorisation of agri-food wastes and by- products can enhance food security and promote sustainable development.

The Preparation and Characterization of an Alginate–Chitosan-Active Bilayer Film Incorporated with Asparagus (Asparagus officinalis L.) Residue Extract

The agricultural production of asparagus generates a significant number of residues rich in bioactive compounds, most of which are wasted. In this study, active edible films with antioxidant and antibacterial properties for food packaging were developed using ethanolic extracts obtained from asparagus residues. These ethanolic extracts of asparagus residue (AspE) were incorporated (1 y 4 wt%) into sodium alginate (SA) solutions for the preparation of alginate–chitosan (SA/CS) bilayer films using the casting method, and they were characterized by optical, structural, mechanical, and thermal properties. In addition, the total phenolic and flavonoid content, antioxidant activity, and antibacterial activity were determined. The results showed that the SA/CS film with 1% AspE had better optical, structural, mechanical, and thermal properties due to its color, flexibility, and homogeneity. Both films incorporated with AspE exhibited antioxidant and antibacterial activity, with higher activity in the film with 4% AspE. However, this film showed shrinkage and surface irregularities that make its application in food packaging difficult, so the formulation with 1% AspE was considered better for this type of application. This study shows that asparagus residues can be a valuable source of bioactive compounds for the food industry, indicating the potential for the valorization of this agri-food waste.

Efficient dye removal using manganese oxide-modified nanocellulosic films from sugarcane bagasse

Removing toxic dyes from industrial wastewater is crucial for environmental protection. This research introduced novel composite films of manganese oxide (MnO2)-modified nanocellulose (MCel) and unmodified nanocellulose (Cel) derived from sugarcane bagasse for dye removal. Nanocellulose was extracted from sugarcane bagasse and subsequently transformed into MCel through in-situ MnO2 synthesis. The MCel/Cel composites, with various MCel to Cel ratios, were fabricated into films and evaluated for their efficiency in removing methylene blue (MB). The films were characterized using Fourier transform infrared spectroscopy for functional group analysis, X-ray diffraction for crystallinity, X-ray photoelectron spectroscopy for chemical state analysis, field emission scanning electron microscopy-energy dispersive spectroscopy for morphology and elemental composition, and Thermogravimetric Analysis for thermal behaviors. Adsorption results showed that all MCel/Cel composite films achieved over 97 % removal of MB (initial concentration 100 mg L−1) within 24 h, with convenient adsorbent retrieval after adsorption. The adsorption process followed a pseudo-second order kinetic model and Langmuir adsorption isotherm. The optimal 95:5 MCel/Cel film exhibited a rate constant of 6.16 × 10−4 g mg−1 min−1 and the calculated adsorption capacity of 181.85 mg g−1. These results demonstrate significant potential for wastewater treatment and sustainable waste valorization by converting sugarcane bagasse cellulose into environmentally friendly adsorbents for contaminant removal.

Synergistic Valorisation of Fruit and Vegetable Waste for Bioenergy Production: A Review

This review provides comprehensive information on the synergistic valorization of fruit and vegetable waste (FVW) for bioenergy production, addressing the urgent need for sustainable waste management and renewable energy sources. Due to their high organic content and substantial methane formation potential, FVW presents significant challenges. This review examines anaerobic digestion, composting, and thermochemical conversion processes, including pyrolysis and gasification. The emphasis is given to the combined use of these pathways, which allows maximizing the energy recovery and the resource utilization factor as well as reducing the environmental burden. The critical analysis of the main factors influencing the effectiveness of these processes is provided waste composition, process adjustments, and technical advancements. Recent studies indicated that pre-treatment methods improved conversion efficiency by up to 30%, and integrating multiple conversion pathways enhanced energy recovery by 20-40%. This comprehensive review concludes by discussing the prospects and challenges of commercial bioenergy production from FVW, integrating findings from recent scientific investigations and technological breakthroughs. The results of this work aim to enhance sustainable waste management strategies and contribute to a holistic circular bioeconomy vision.

Additive Manufacturing of Waste Electrical and Electronic Equipment (WEEE) Produced From Acrylonitrile Butadiene Styrene (ABS)

Objective: To evaluate the feasibility of producing recycled acrylonitrile-butadiene-styrene (r-ABS) filaments from waste electrical and electronic equipment (W EEE) casings, specifically discarded monitors and televisions, and to compare their properties with those of virgin ABS. Theoretical Framework: The research was based on a literature review of additive manufacturing, WEEE recycling, and the thermal, mechanical, rheological, and microscopic characterizations of recycled polymers, with an emphasis on fused deposition modeling (FDM). Method: WEEE casings were collected and mechanically recycled to produce r-ABS filaments. These filaments were characterized and compared with virgin ABS filaments using infrared spectroscopy (FTIR), thermal analyses (TGA and DSC), rheological, mechanical, and microscopic evaluations. Results and Conclusion: The results indicated that r-ABS filaments exhibit properties comparable to those of virgin ABS. FTIR analysis revealed the presence of the main functional groups of ABS in the recycled samples. Thermal analysis showed similar behavior between the recycled and virgin materials, with a single thermal decomposition event. Rheological analysis demonstrated that r-ABS possesses viscoelastic properties suitable for the FDM process, and mechanical characterization showed that r-ABS exhibited tensile strength close to virgin ABS. Microscopic analysis revealed good layer adhesion and a low number of voids, factors that contribute to the quality of the printed objects. Research Implications: This study contributes to the valorization of polymeric waste, promoting the use of recycled materials in additive manufacturing processes, which can benefit both the environment and the 3D printing industry. Originality/Value: The research addresses a topic still underexplored in the literature, especially concerning the recycling of WEEE casings for the production of ABS filaments.

Integration of Teaching Laboratory Activities Based on the Valorization of Industrial Waste into Chemical Education to Address the Emerging Sustainable Development Goals

Integration of Teaching Laboratory Activities Based on the Valorization of Industrial Waste into Chemical Education to Address the Emerging Sustainable Development Goals

Conversion of glycerol into value-added products

Biomass residues and industrial waste are of great interest for their potential to produce a wide range of bioenergy and value-added products. Crude glycerol can be valorized into value added products by several microorganisms through microbial fermentation. Thus, Significant efforts have been made to develop biological methods to convert crude glycerol into various valuable chemicals and fuels, including 1, 3-propanediol, hydrogen and ethanol.In this context, our work have use glycerol medium as source of carbon for investigate bioethanol and 1, 3-propandiol production, using a microbial consortium. All experiments was carried out in sealed bottles, the reaction medium is placed in the shaker incubator at 37°C with stirring at 130 rpm. . Nitrogen gas was injected to create anaerobic conditions. The highest concentration of ethanol and 1,3 – propanediol obtained were 3.47 (g/l) and 4.8 mg/l respectively . These results highlight promising avenues for the valorization of biomass residues and industrial wastes in sustainable bioenergy production.

Use of CO2 for enhanced carbon recovery in thermochemical processing of fruit peel waste

To address a supply variability associated with biomass, utilization of food waste provides a practical approach to consistently obtain carbon–neutral energy resource. Despite the technical merits of conventional biological process, the inevitable generation of less useful by-products, such as carbon dioxide (CO2) and sludge, remains a primary constraint. As an alternative, thermochemical process, such as pyrolysis, presents a promising solution for the comprehensive valorisation of food waste. In this study, citrus peel, one of the fruit processing wastes, was used as a model food waste. To enhance the eco-friendliness of the pyrolysis system, CO2 was introduced as a medium gas given the uncertainty regarding its behaviour as an inert or reactive agent at the pyrolysis temperatures. The pyrolysis approach demonstrated that CO2 interacts with volatile pyrogenic products, resulting in an increased formation of carbon monoxide (CO). Notably, this enhancement was observed at ≥ 400 °C, suggesting that CO2′s reactivity is limited at lower temperatures. To maximize the utility of CO2, the pyrolysis setup was modified by incorporating a heating block at 600 °C and a nickel-based catalyst (Ni/Al2O3). While these adjustments accelerated the thermal cracking of citrus peel, test setup modification led to an aromaticity increase of the resulting pyrogenic products. However, integrating CO2 into the catalytic pyrolysis created favourable conditions for detoxifying these aromatic compounds and further boosting CO production. Syngas productivity from catalytic pyrolysis in the presence of CO2 was 35.2 wt%, showing 3.67 times increase over that from conventional pyrolysis. In conclusion, CO2-assisted catalytic pyrolysis of the citrus peel offers significant technical benefits: it enhances carbon recovery in the form of CO and reduces the formation of undesirable aromatic pyrogenic products.

Valorization of food waste into hydrogen energy through supercritical water gasification: Generation potential and techno-econo-environmental feasibility assessment

Food waste (FW) is a significant portion of the solid waste produced by cities, and it has become a global problem due to the poor management of food distribution and consumption. The improper disposal of FW in landfills precipitates pervasive global environmental predicamentsHowever, effective management strategies have the potential to convert this large amount of garbage into a very effective renewable energy source, particularly through the generation of environmentally friendly hydrogen. This study examines the capacity for energy generation and the practicality of hydrogen production in Bangladesh using supercritical water gasification technology. The findings indicate that approximately 489 MW of electricity can be extracted from approximately 23 million tons (Mt) of FW in 2023, with a projected escalation to around 2042 MW by 2042, coinciding with an anticipated surge in FW generation to approximately 110 Mt. Moreover, the study delves into the economic feasibility of these gasification endeavors, employing diverse metrics encompassing total life cycle cost, net present value, investment payback duration, levelized cost of energy, and internal rate of return. Technoeconomic analyses divulge an investment with a net present value of 11,669.4 M$M$, an 11-year payback period, and an internal rate of return of 14 %. In addition, the research assesses the technological, economic, and environmental viability inherent in the establishment of gasification-based electricity-generating facilities in Bangladesh's preeminent eight cities by 2023. This examination postulates that a transition from coal-based power plants to those powered by food waste would precipitate an annual reduction of 3.59 Mt in carbon dioxide emissions.

Optimization of a proposed biomass generator: Harnessing citizen waste with electric vehicle charging infrastructure

Global municipal solid waste production is rising, causing significant environmental, health, and economic issues. Developed countries have advanced recycling technologies, but cities like Dhaka, Bangladesh—among the most densely populated-struggle with inadequate waste management. This feasibility study aims to improve environmental protection and create new energy sources by proposing a waste management system across Dhaka, focusing on waste valorization for bioenergy with optimized efficiency and minimal impact. The study includes design and optimization of a biomass-based power plant to meet the energy needs of EV charging stations and the national grid, evaluating its economic performance through discounted cash flow and payback period analyses. The paper explores the integration of an EV charging station powered by biogas, addressing the growing need for EV infrastructure in Dhaka. By evaluating biomass generators as a greener alternative to fossil fuels, the study analyzes the technical, economic, and environmental feasibility, including CO2 emissions, using HOMER Pro.

Valorization of Food Waste Using Pulsed Electric Fields: Applications in Diverse Food Categories

Valorization of Food Waste Using Pulsed Electric Fields: Applications in Diverse Food Categories

Valorization of agro-industrial waste for pectinase production and its influence on circular economy

Pectinases are a diverse group of enzymes that play a crucial role in modifying or breaking down complex pectic substances. Pectinases are widely distributed among bacteria, fungi, and plants. The global demand for microbial pectinase has significantly increased due to its broad applicability and efficient catalytic capabilities across multiple industries including food processing, textiles, and biofuel production. Their commercial production often relies on expensive substrates, contributing to economic inefficiency and environmental burdens. Utilizing agro-industrial waste and microorganisms for pectinase production offers a rational solution to two interconnected challenges: the cost-effectiveness of enzyme production and the environmental impact of waste generation. Moreover, the valorization of waste materials not only contributes to efficient enzyme production but also exemplifies a circular approach by minimizing environmental impact and promoting sustainable resource efficiency to bioprocessing. This review offers a thorough examination of microbial pectinases, including their production from agro-industrial waste, their various industrial applications, and the current market landscape. It also delves into recent advancements in enzyme development and optimization techniques that have significantly boosted the efficiency and cost-effectiveness of pectinase production. By highlighting these developments, the review emphasizes the potential for this approach to enhance industrial practices and contribute to environmental sustainability.

Valorization of polyurethane foam waste through the decoration with nano-polyaniline for dye decontamination from polluted water.

Two polyurethane polyaniline nanocomposites have been synthesized using two in situ polymerization routes of dried and wet bases to valorize the polyurethane waste. The physical and chemical properties of polyurethane-based nanocomposites were compared using SEM, XRD, FTIR, and Zeta potential. SEM images showed that the average particle size of the dried-based composite was 56 nm, while the wet-based composite had an average size of 75 nm. The separation efficiency for methylene blue (MB) and Congo red (CR) dyes was evaluated against free polyurethane foam waste. It was evident that pure polyurethane (PPU) achieved only 4.79% and 16.71% removal for MB and CR, respectively. These dye decontamination efficiencies were enhanced after nano polyaniline decoration of polyurethane foam either through dried base polymerization (DPUP) or wet base polymerization (WPUP). WPUP composite records 11.23% and 85.99% for MB and CR removal, respectively, improved to 26.69% and 90.07% removal using DPUP composite for the respective dyes. The adsorption kinetics, isotherms, and thermodynamics were investigated. The experimental results revealed the pseudo-second-order kinetic model as the most accurately described kinetics model for both CR and MB adsorption. The Langmuir model provided the best fit for the data, with maximum adsorption capacities of 110.98 mg/g for CR and 26.86 mg/g for MB, with corresponding R-squared values of 0.9974 and 0.9608, respectively. Regeneration and reusability studies of PPU, WPUP, and DPUP showed effective reusability, with DPUP displaying the highest adsorption capacity. These results aid in creating eco-friendly and cost-efficient adsorbents for dye removal in environmental sanitation.

Ultra-Narrow Alkane Product Distribution in Polyethylene Waste Hydrocracking by Zeolite Micropore Diffusion Optimization.

Plastic pollution poses a pressing environmental challenge in modern society. Chemical catalytic conversion offers a promising solution for upgrading waste plastics into valuable liquid alkanes and other high value products. However, the current methods yield mixed products with a broad carbon distribution. To address this challenge, we introduce a tandem catalytic system that features matched acidic sites and confined metals for the conversion of low-density polyethylene (LDPE) into liquid alkanes. This system achieves a liquid alkane yield of 94.0%, with 84.8% of C5-C7 light alkanes. Combined with in situ FTIR and molecular dynamics simulation, the shape-selective mechanisms is elucidated, which ensures that only olefins of the appropriate size can diffuse to the encapsulated Pt sites within the zeolite for hydrogenation, resulting in an ultra-narrow product distribution. Furthermore, due to the rapid diffusion of olefins within the hierarchical zeolite, the catalyst exhibits higher catalytic efficiency and resistance to coking tendency. Our findings contribute to the design of efficient catalysts for plastic waste valorization.

Extracts from Wheat, Maize, and Sunflower Waste as Natural Raw Materials for Cosmetics: Value-Added Products Reaching Sustainability Goals.

Agricultural waste is underutilized, and sometimes burning them has a negative impact on the environment and human health. This research investigates the untapped potential of extracts from maize, wheat and sunflower waste as natural materials for cutaneous, specifically, cosmetic application. The possibility of incorporating lipid and ethanol extracts from wheat, maize, and sunflower into creams was investigated together with their potential contribution to the structural and functional properties of the topical formulations. Results of the physicochemical characterization show that investigated extracts can be successfully incorporated into creams with satisfactory stability. All extracts showed a desirable safety profile and good antimicrobial activity against various microorganisms. Lipid extracts have proven to be promising structural ingredients of the oil phase, contributing to the spreadability, occlusivity, and emollient effect. Ethanol extracts influenced washability and stickiness of the formulation and could be considered as prospective ingredients in self-preserving formulations. The extracts affected the sensory properties of the creams, mainly the smell and color. These results suggest that the extracts from wheat, maize, and sunflower waste could be used as multifunctional natural ingredients for cosmetic formulations which can replace less sustainable raw materials. This also represents a valorization of waste and is in line with broader sustainability goals.

Mining of thermophilic biosurfactant producers for solid-state fermentation

Solid-state fermentation (SSF) is an emerging technology for organic waste valorisation to marketable bio products. SSF scale-up is hindered by heat transfer problems that could be diminished operating under thermophilic conditions. Compost samples collected from food waste composting facility in a primary school in Barcelona and textile industry sample from Faisalabad Pakistan were subjected to isolation of thermophilic biosurfactant producing microorganisms. Altogether 43 isolates were screened through biosurfactant qualitative screening, but 18 isolates dominated with promising results which were further shortlisted under solid-state culture to select the five significant performers belonging to Bacillus sp., Aspergillus sp., and Streptomyces sp. The performance of the five isolates in SSF was assessed in time course studies in 0.5-L packed bed bioreactor using winterization oil cake (WOC), wheat bran and glucose as substrates combined with wheat straw as support material. All five isolates colonized the substrate well in SSF systems and exhibited considerable glucose consumption and adaptation within the SSF setup. The fermentation extracts indicated promising surface-active properties as observed by emulsification and oil displacement analysis. These findings provide an effective enrichment strategy for screening of thermophilic biosurfactant producers and can aid establishment of the scale up for the enhanced metabolite production.

The Valorization of Fruit and Vegetable Wastes Using an Anaerobic Fixed Biofilm Reactor: A Case of Discarded Tomatoes from a Traditional Market

Tomato waste, characterized by high organic matter and moisture content, offers a promising substrate for anaerobic digestion, though rapid acidification can inhibit methanogenic activity. This study investigated the performance of a 10.25 L anaerobic fixed biofilm reactor for biogas production using liquid tomato waste, processed through grinding and filtration, at high organic loading rates, without external pH control or co-digestion. Four scouring pads were vertically installed as a fixed bed within a fiberglass structure. Reactor performance and buffering capacity were assessed over three stages with progressively increasing organic loading rates (3.2, 4.35, and 6.26 gCOD/L·d). Methane yields of 0.419 LCH4/gCOD and 0.563 LCH4/g VS were achieved during the kinetic study following stabilization. Biogas production rates reached 1586 mL/h, 1804 mL/h, and 4117 mL/h across the three stages, with methane contents of 69%, 65%, and 72.3%, respectively. Partial alkalinity fluctuated, starting above 1500 mg CaCO3/L in Stage 1, dropping below 500 mg CaCO3/L in Stage 2, and surpassing 3000 mg CaCO3/L in Stage 3. Despite periods of forced acidification, the system demonstrated significant resilience and high buffering capacity, maintaining stability through hydraulic retention time adjustments without the need for external pH regulation. The key stability indicators identified include partial alkalinity, effluent chemical oxygen demand, pH, and one-day cumulative biogas. This study highlights the effectiveness of anaerobic fixed biofilm reactors in treating tomato waste and similar fruit and vegetable residues for sustainable biogas production.

A CASE STUDY OF IMPLEMENTATION OF CIRCULAR ECONOMY PRINCIPLES TO WASTE MANAGEMENT: INTEGRATED TREATMENT OF CHEESE WHEY AND HI-TECH WASTE

In a global context characterized by severe environmental problems and increasing resource scarcity, waste represents both a challenge and an opportunity. This study aims to demonstrate with a real case the potential for optimizing the waste valorization action attainable through the synergic application of different treatments to residues of equally different nature and origin. In particular, bio-chemical (dark fermentation), chemical-physical (selective leaching) and thermo-chemical (hydrothermal carbonization) treatments were applied for the integrated valorization of whey from sheep cheese production and Hi-Tech waste (discarded electrical and electronic equipment). The treatments were applied at a laboratory scale on real samples of these residues. The organic acids used for selective leaching of valuable metals from Hi-Tech waste were obtained by dark fermentation of the cheese whey, while hydrothermal carbonization was used to convert the waste from previous stages into hydrochar feasible as solid fuel or soil improver. The dark fermentation tests have highlighted the possibility of recovering ≈ 100 g of organic acids from 1 L of whey; furthermore, it is also possible to recover bio-hydrogen depending on the operating conditions applied and the type of targeted organic acids. The leaching tests have demonstrated how the organic acids from whey fermentation have selective and quantitative mobilization capacities comparable to those of the same acids available on the market. The carbonization tests produced carbon-enriched hydrochar with promising fuel properties, as well as process waters suitable for anaerobic digestion with methane production. The results of the project led to the filing of an international patent.

Enhancing the performance of paraffin's phase change material through a hybrid scheme utilizing sand core matrix

Smart waste management and valorisation is presented in the current investigation. Iron is collected from mining wastewater stream and augmented with sand as a supporting material to produce sand core. The sand core pellets encapsulated in paraffin’s to enhance its feasibility as phase change material (PCM). Sand core was characterized using X-ray diffraction and Scanning Electron Microscope (SEM) augmented with energy dispersive X-ray spectrum analysis. Experimental test is achieved by mixing sand core/iron and paraffin that is signified as an encapsulated phase change material. The encapsulated sand core-PCM is embedded in varies mass weights of percentages of 0.5, 1.0, 1.5 and 2.0% and labeled as 0.5%-sand core-PCM, 1.0%-sand core-PCM, 1.5%-sand core-PCM and 2.0%-sand core-PCM. The encapsulated sand core-PCM is embedded into a heat exchanger of the vertical type model that is connected with a flat plate solar collector. Such collector is heating the heat transfer carrier, which is exposed to the heat exchanger for melting the PCM. The experimental work is conducted across the solar noon where the solar intensity in the region is reached to 1162 W/m2 at the time of conducting experiments. Water is applied and supposed as the working heat transfer fluid transporter and pumped into the system at the rate of 0.0014 kg per second. The experimental result revealed that the heat gained recorded an enhancement from 7 to 48 kJ/min when the 1.5%-sand core-PCM system is applied. Thus, the results showed the system is a good candidate by increasing the system efficiency with 92% as a potential solution of solar energy storage at the off-time periods.