Browsing by Author "Jayasinghe, TK"

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    item: Conference-Full-text
    Investigation of co2 sequestration possibility via indirect mineral carbonation using waste coal fly ash
    (IEEE, 2020-07) Senadeera, KR; Jayasinghe, TK; Jayasundara, PM; Nanayakkara, G; Rathnayake, M; Weeraddana, C; Edussooriya, CUS; Abeysooriya, RP
    Mineral carbonation is recognized as a significant method for CO2 sequestration using waste coal fly ash. Naturally available free lime in coal fly ash can be extracted to an aqueous solution before reaction with CO2, which could produce precipitated calcium carbonate (PCC), i.e., indirect mineral carbonation. In this study, fly ash samples were collected from Lakvijaya Coal Power Plant (LCPP) in Sri Lanka and tested for their chemical/physical properties and the possibility of calcium extraction. The average calcium oxide (CaO) content in LCPP fly ash was 5.81 wt%. Laboratory experiments were performed to determine the possibility for indirect carbonation, varying the residence time, quality of mixing, solid-liquid ratio, and salinity of water. Under the specific conditions, the maximum calcium extraction efficiency of 9.65% was obtained within 45 minutes, which stayed constant against time, thereafter. Effect of improved mixing using baffles was minor, where similar variations were observed for both baffled and non-baffled configurations against mixing time. Increased salinity significantly improved the calcium extraction efficiency by 71.1% when the salinity got increased from 0 g/L to 50g/L, which highlights the potential of sea water as an effective solvent for indirect mineral carbonation process using coal fly ash for CO2 sequestration.
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    item: Conference-Extended-Abstract
    Life cycle assessment-based process analysis for fuel-grade bioethanol production using rice straw
    (Department of Chemical & Process Engineering University of Moratuwa, 2020-03) Jayasundara, PM; Jayasinghe, TK; Rathnayake, M; Rathnasiri, PG
    Rice straw is a major biomass residue from rice cultivation, which reaches to a world average of 740 million tonnes/year generation. Open burning of rice straw in paddy fields is the common practice, which could result in an average greenhouse gas emission of 92 kg of CO2 eq/tonne of dry rice straw and other harmful airborne emissions. Existing studies indicate that bioethanol production from rice straw is more environmentally benign, compared to alternative options, such as gasification for combined heat and power generation and dimethyl-ether production. This study analyses the net energy indicators and carbon footprint of fuel-grade bioethanol production processes from rice straw comparing three dehydration techniques: 1. Extractive distillation, 2. Azeotropic distillation, and 3. Pressure swing distillation. Chemical process simulations using the Aspen Plus software were utilized to evaluate the bioethanol production process from rice straw, with a plant output capacity of 222 litres/hr of fuel-grade bioethanol (99.7 vol% ethanol). The results show that the most environmental benign dehydration technique is extractive distillation. The findings from this study can support decision making for future wasteto- biofuel plants using waste rice straw in the world.