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 หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Life Cycle Energy Consumption and Greenhouse Gas Emissions of Polylactic acid (PLA) and Polystyrene (PS) Trays) ผู้เขียน: อัญชลี สุวรรณมณี, Thanawadee Leejarkpai, Yosita Rudeekit,  ดร.ธำรงรัตน์ มุ่งเจริญ, รองศาสตราจารย์ สื่อสิ่งพิมพ์:pdf AbstractThis study aimed to assess the energy consumption and greenhouse gas (GHG) emissions of three types of materials used for tray production in Thailand. The materials studied were a polystyrene (PS) tray produced in Thailand and derived from petroleum, a polylactic acid (PLA-baseline) tray, which was produced in the USA and derived from corn, with the third one being a PLA tray with process improvement (PLA-improved). The improvements to the hypothetical PLA-improved tray included using PLA pellets produced in Thailand, using biomass feedstocks for PLA pellet production and reducing the amount of raw materials used in the forming process. The functional unit (FU) was 1,000 units of trays, with each tray being 20 ? 14 ? 1.5 cm. The first part of the study considered the production of PS trays, PLA trays (PLA-baseline) and PLA trays with process improvement (PLA-improved). The energy consumption and GHG emissions of PLA-improved trays was 51.38% and 63.2% lower than that of PS and PLA-baseline trays, respectively. Consequently, PLA-improved trays generated lower GHG emissions than PS trays by 16.04%, but the energy consumption to produce PLA-improved trays was slightly higher (4.06%) than that for PS trays. In the second part of the study, different waste management scenarios using PS, PLA-baseline and PLA-improved trays were considered. It was found that incineration with energy recovery was suitable with PS trays because it could reduce energy consumption and GHG emissions by 22.7% and 3.4%, respectively, whereas, composting and landfill with energy recovery from methane collection were suitable with PLA-baseline and PLA-improved trays. Composting of PLA-baseline and PLAimproved trays produced a reduction in energy consumption of 6.5% and 12.0%, respectively, while GHG emissions were reduced by 267.7 and 253.9 kg CO2 equivalent/FU, respectively. Landfill with energy recovery from methane collection from PLA-baseline and PLA-improved trays resulted in energy consumption reductions of 17.2% and 31.8%, respectively, with reductions in GHG emissions of 138.3 and 114.3 kg CO2 equivalent/FU, respectively. |
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หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Separation of Light and Middle-Heavy Rare Earths from Nitrate Medium by Liquid-Liquid Extraction) ผู้เขียน:Palakorn Satusinprasert, อัญชลี สุวรรณมณี, ดุษฎี รัตนพระ สื่อสิ่งพิมพ์:pdf AbstractSeparation of light (LREEs) and middle-heavy (M-HREEs) rare earths from a nitrate medium was studied using a liquid-liquid extraction technique. Tri-n- butyl phosphate (TBP) in kerosene was used as the extractant. The effect of the TBP concentration (30–80% volume per volume; v/v), contact time (3–10 min) and shaking speed (100–200 rpm) on rare earth extraction were investigated. The distribution ratio and separation factor were determined to evaluate the extraction behavior and the separation possibilities of M-HREEs from LREEs. The results showed that the distribution ratio increased with increasing TBP concentration. The concentration of rare earth in the aqueous phase decreased as the contact time and shaking speed increased. The separation factor values for M-HREEs/LREEs markedly increased as the atomic number of the LREEs decreased. High separation factor values were observed for Y/Nd, Y/Pr, Y/La of 6.35, 11.15 and 13.95 respectively. The best conditions for the separation in this study were found to be: a TBP concentration of 50% v/v, a contact time of 5 min and a shaking speed of 200 rpm. Under these conditions, it was possible to separate M-HREEs (Sm, Gd, Y) from LREEs (La, Pr, Nd). |
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