KMITL
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Item type:Publication, Development of self-compacting mortar incorporating calcium carbonate and waste garnet: Workability, strength, and fire durability assessment(2026-06-01); Hussain, QudeerThe excessive consumption of natural sand and cement in mortar production raises environmental concerns, underscoring the need for sustainable alternatives. While the separate use of cementitious and fine aggregate substitutes has been studied, their combined effects in self-compacting mortar (SCM) remain underexplored. This study addresses this gap by investigating SCM mixes incorporating calcium carbonate (CaCO₃) as a partial cement substitute (0–20%) and waste garnet (0–100%) as a fine aggregate replacement. A total of 18 mixes were evaluated for their fresh properties, mechanical performance, durability, and residual properties after elevated-temperature exposure. The results showed that the mix with 10% CaCO₃ and 60% waste garnet exhibited the best overall performance, achieving approximately 66 MPa compressive strength and 8.1 MPa flexural strength at 90 days, representing up to a 15% improvement over the control. Water absorption was reduced to 2.42% at 90 days, while improved resistance under acidic conditions was observed, with only 7.71% mass loss after 180 days of exposure to 5% H₂SO₄ solution. Furthermore, the optimized mix retained over 65% of its compressive strength after exposure to 600 °C, indicating good residual mechanical performance at elevated temperatures. Microstructural analysis revealed a dense and cohesive matrix with a refined pore structure. These findings suggest that the combined use of CaCO₃ and waste garnet can provide a potentially eco-efficient approach for producing high-performance SCM. The improved workability, strength, and durability indicate potential suitability for applications such as repair mortars and precast elements, where both flowability and long-term performance are required.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Sequential extraction protocol for bio-calcium from saltwater crocodile (Crocodylus porosus) bone: Physicochemical and molecular studies(2026-06-01)3 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Biodiesel production from spent coffee grounds via ethanolic extraction and supercritical ethanol transesterification: technoeconomic analysis and life cycle assessment(2026-01-01); Hunsub, PanusornPrevious studies have developed biodiesel production methods from spent coffee grounds (SCGs) via ethanolic extraction and supercritical ethanol transesterification (EE-SET) to minimize the energy consumption associated with solvent evaporation. In this study, we perform a technoeconomic analysis (TEA) and a life cycle assessment (LCA) to evaluate the profitability and sustainability of EE-SET. The material and energy balances in the TEA and LCA were derived from Aspen Plus<sup>®</sup> V12 based on experimental data from previous research. The results from the base case indicated that EE-SET was unprofitable and posed a considerable environmental burden by disposing of defatted SCG (DSCG) as solid waste due to two main issues. First, the amount of DSCG was 4.8 times greater than the total biodiesel and glycerol produced. Second, landfilling DSCG incurred waste treatment costs and induced greenhouse gas (GHG) emissions simultaneously. Selling DSCG as a feedstock for solid fuel pellets offers an effective strategy for achieving profitability and sustainability. As such, EE-SET addresses the economic drawback of generating profit from selling DSCG while reducing waste treatment costs. Using DSCG as a solid fuel for environmental benefits increases ash disposal credit and substantially reduces GHG emissions. The incorporation of pelletizing units or biomass power plants into EE-SET represents a promising avenue for future research.4 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Cockle-shell biowaste as a low-cost renewable source for synthesis of calcium acetate monohydrate as a precursor of quasi-amorphous calcium pyrophosphate hydrate(2025-01-01); Calcium-rich seashell wastes can be used as renewable materials to prepare value-added compounds. This work proposed an eco-environmental preparation of calcium pyrophosphate by using cockle-shell biowaste as a low-cost renewable calcium source for the first time. Cockle shell was first ground, obtaining calcium carbonate (CaCO<inf>3</inf>) powders, which were then used as the renewable material to synthesize calcium acetate monohydrate (Ca(CH<inf>3</inf>COO)<inf>2</inf>·H<inf>2</inf>O) via acetic acid reaction. After that, cockle-derived calcium acetate monohydrate was subsequently prepared as a solution to synthesize calcium pyrophosphate (Ca<inf>2</inf>P<inf>2</inf>O<inf>7</inf>·xH<inf>2</inf>O) via a simple precipitation process with tetrasodium pyrophosphate decahydrate (Na<inf>4</inf>P<inf>2</inf>O<inf>7</inf>·10H<inf>2</inf>O). The physicochemical characteristics of the synthesized calcium acetate precursor and its calcium pyrophosphate product were investigated by X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry, and scanning electron microscopy. The characterization results demonstrate that cockle shell powder (CaCO<inf>3</inf>) is a potentially renewable source for the preparation of triclinic calcium acetate with the chemical formula of Ca(CH<inf>3</inf>COO)<inf>2</inf>·H<inf>2</inf>O, which was further used as the precursor to form value-added amorphous calcium pyrophosphate with the chemical formula of Ca<inf>2</inf>P<inf>2</inf>O<inf>7</inf>·4H<inf>2</inf>O. This approach not only demonstrates the feasibility of using biogenic Ca-sources for material synthesis but also offers an environmentally friendly process with potential long-term benefits in reducing environmental issues, promoting sustainable chemical production, and increasing value to the underused biowaste.1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Biodiesel Production from Spent Coffee Grounds by Using Ethanolic Extraction and Supercritical Transesterification(2024-12-01); Sawangkeaw, RuengwitThis work presents a way to use ethanol and spent coffee grounds (SCG) as feedstocks for biodiesel production to solve ethanol overproduction in Thailand and biodiesel feedstock shortage problems together. Waste coffee oil (SCGO) was ethanolic extracted from SCG; then, ethanol-SCGO mixture was transesterified in supercritical condition without ethanol removal. The ethanolic extraction curves of SCG at a temperature range of 50–70 °C were constructed. Transesterification experiments were studied in a batch reactor and a continuous reactor at various temperatures (275–350 °C) and reaction time (5–40 min) under 15.0 MPa. The molar ratio of ethanol-oil mixture was set at 30:1. The highest ester content of 88.37 ± 3.00 wt% was found in biodiesel obtained at a temperature of 275 °C and a reaction time of 40 min in a batch reactor. Furthermore, excess temperature (< 300 °C) and reaction time (< 20 min) induced thermal degradation and promoted the loss of ethyl linoleate. For continuous reactor, the maximum ester content of 83.38 ± 5.86 wt% was observed at 325 °C and 29.4 min of residence time. Unlike in batch reactors, thermal degradation of ethyl linoleate was not observed in a continuous reactor. The results showed that ethanolic extraction and supercritical transesterification are alternative ways to produce biodiesel from SCG without removing extractant and using catalyst. From a prospective point of view, techno-economic analysis (TEA) and life-cycle assessment (LCA) of invented process should be conducted to ensure profitability and environmental benefits, respectively. Graphical Abstract: (Figure presented.)1 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Carbon-neutral synfuel production via continuous solar H2O and CO2 gasification of oil palm empty fruit bunch(2023-10-15); Abanades, StéphaneSolar gasification offers a promising carbon-neutral pathway to thermochemically convert waste biomass and solar energy into synfuel. In this study, a thermodynamic analysis of solar gasification of oil palm empty fruit bunch (EFB) with H<inf>2</inf>O and CO<inf>2</inf> gasifying agents was first performed to predict equilibrium product distribution. Subsequently, on-sun continuous solar gasification of EFB was experimentally carried out in a solar particle-fed gasifier to evaluate the influence of gasifying agent types (H<inf>2</inf>O and CO<inf>2</inf>), gasifying agent/EFB molar ratios (1.8–3.4), temperatures (1050–1350 °C), and to assess overall process feasibility and reliability. As a result, solar EFB gasification performed efficiently with both H<inf>2</inf>O and CO<inf>2</inf> gasifying agents under continuous on-sun operation. Syngas product composition and gasification reaction rate strongly depended on gasifying agent type. Increasing temperature enhanced syngas yield and quality, and changed the CO/H<inf>2</inf> mole ratio, especially in EFB + CO<inf>2</inf> gasification. A gasifying agent/EFB molar ratio of 2.6 (slight excess of gasifying agents) and a temperature of 1300 °C were shown to be optimal for continuous solar EFB gasification. The maximum total syngas yield above 76 mmol/g<inf>dry_EFB</inf>, syngas lower heating value above 22 kJ/g<inf>dry_EFB</inf>, and energy upgrade factor above 1.37 were achieved from both EFB + H<inf>2</inf>O and EFB + CO<inf>2</inf> gasification, which closely approached their theoretical equilibrium values. The maximum carbon conversion exceeding 93% and solar-to-fuel energy conversion efficiency up to 19.3% were achieved, demonstrating efficient EFB-to-synfuel conversion performance. Continuous solar EFB gasification with both H<inf>2</inf>O and CO<inf>2</inf> was thus established to be a reliable process for EFB waste biomass valorization into high-quality and carbon-neutral synfuel.