Phairat Usubharatana’s research while affiliated with Thammasat University and other places

This study develops the heliostat curve tracing parametric model (HCTPM) to predict solar energy distribution in concentrated solar power (CSP) systems with sun-tracking capabilities. HCTPM uses curve tracing techniques to visualize flux distribution on mirrors and receivers, producing results that align closely with established models like HFLCAL, which use Gaussian and Tonatiuh ray-tracing methods. Simulations revealed that deviations in energy distribution increase as Sun shape error decreases, with greater impact on flux density and sensitivity. Variations in Sun disk radius caused notable deviations, especially in elliptical projections. The model’s flexibility in adjusting mirror shapes and sizes allows for the evaluation of spill losses, optimizing mirror designs for different positions. Spill loss analysis showed that larger mirrors reduce spill loss on mirrors but increase it on receivers, particularly when mirrors deviate from the north. Although total spill loss decreases with larger mirrors, this effect weakens as receiver spill loss grows. These findings emphasize the importance of optimizing mirror and receiver design to maximize energy efficiency and minimize resource waste, contributing to more sustainable solar energy systems. The HCTPM model plays a crucial role in improving the sustainability of CSP systems by optimizing configurations based on Sun disk characteristics, reducing energy losses, and promoting efficient resource use.

This study explores the potential of sugarcane (Saccharum officinarum L.) leaves (SCLs), a significant agricultural waste, for the sustainable production of carboxymethyl cellulose (CMC) utilizing an innovative approach of carboxymethylation with monochloroacetic acid and varying sodium hydroxide (NaOH) concentrations (ranging from 20 to 60 g/100 mL). The optimal carboxymethylation condition was identified as 40 g/100 mL NaOH, which yielded the highest degree of substitution (DS = 0.86). Furthermore, a higher ash content in the obtained CMC indicated significant carboxymethyl substitution within the structure. The chemical structure of cellulose and the resulting polymers were characterized using Fourier transform infrared spectroscopy (FTIR). The FTIR spectrum exhibited characteristic peaks of carboxymethyl groups and their salts at wavenumbers of 1588–1591 cm−1 and 1413–1415 cm−1, respectively. The analyses from X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) revealed detailed insights into the crystallinity and morphology of carboxymethyl cellulose (CMC). The levels of heavy metals, including arsenic, lead, cadmium, and mercury, in the purified CMC were assessed using inductively coupled plasma mass spectrometry (ICP-MS) and were found to be within the recommended WHO/FAO limits, except for lead, which exceeded permissible levels. The prepared CMC demonstrated high purity at 99.34%, surpassing the 98.00% purity requirement for commercial-grade CMC. This product exhibits strong potential for diverse industrial applications, including paper coating, textile sizing and printing, ceramic glazing, and various uses in the oil industry.

Coal-fired power generation leads to serious environmental pollution, such as air and water pollution; thus, pollution control or treatment is necessary. However, end-of-pipe treatments are still indispensable approaches to reducing environmental stress, and focusing on each in turn leads to pollutant-by-pollutant features. The present study applies the LCA method to reveal the total direct and indirect environmental impacts from increasing significant pollution control units for a coal-fired power plant. From the results, it was found that increasing the performance of CCS and FGD units may result in higher overall environmental impacts due to their energy costs. Greater energy requirements result in greater global warming potential, human toxicity, and terrestrial acidification effects. LNB & OFA, SCR, and ESP units did not cause any other significant environmental impacts, while activated carbon used in the ACI unit is an additional source of indirect terrestrial acidification. Water depletion effects must be considered when increasing the use of CCS units. Policy makers can use the data from the present study to establish sustainable directions to resolve environmental problems at the macro-economic scale.

Thailand’s ceramic industry is one of the most important industries in the country in terms of export figures. However, production consumes a large amount of energy and raw materials, which causes adverse environmental impacts. Thus, a carbon footprint assessment of different methods of forming Thai ceramic tableware evaluated by using the life cycle assessment (LCA) as the assessment tool. The evaluation of specific energy consumption (SEC) was also conducted. The functional units were set as 1 kg and 1 L of ceramic tableware. The system boundaries included the raw material acquisition phases until the factory gate, and then being ready to ship to customers. All primary data was acquired and collected on-site through collaboration with the selected factory. The study showed that the most significant environmental impact was due to the biscuit and ghost firing processes used during the production phase, accounting for an average of 74% of the total carbon footprint. The SEC results were an average of 79 % for LPG, while electricity had a 21% share. Different forming methods did not exhibit significantly different results. Moreover, the forecasting of GHG emissions from the ceramic tableware sector by 2030 and further solution was also included in the discussion.

Environmental impacts of fishery production have resulted in increased concern and awareness. Thailand, as one of the largest global fish exporters, faces challenges related to environmental problems caused by fishery processes. Here, the environmental impact of Thai surimi production was estimated based on life cycle assessment (LCA) methodology, focusing specifically on two Thai surimi products made from goatfish and ponyfish caught within the southern region of Thailand. Three impact categories where explored: global warming, acidification and eutrophication. Life cycle impacts were calculated for one kg of product using both mass and economic allocations. Results of this study indicated that goatfish has lower impacts than ponyfish for all the impact categories. Fuel consumption during the fishery phase and electricity consumption during processing were the main parameters leading to most of the considered environmental impacts. The value of Global Warming Potential(GWP) ranged within 1.3‒3.0 kg CO2eq for goatfish and 2.2‒7.1 kg CO2eq ponyfish depending on the allocation method. The acidification impact of goatfish and ponyfish were revealed at 3.2‒7.3 gSO2eq and 12.7‒39.7 gSO2eq, respectively. The eutrophication of goatfish and ponyfish were 0.7‒1.6 gPO4eq and 2.5‒8.1 gPO4eq, respectively. Sensitivity analysis of fuel consumption, electricity consumption, product yield and allocation method were evaluated.

Taxation levying promotes and enhances the management of greenhouse gas emissions; however, its effect on product price increases for households requires clarification. The impact of a fossil fuel taxation policy on Thai household expenditure was investigated. Carbon taxation rate was based on abatement cost. An input–output price model was applied to establish economical price structures and price changes as a carbon result of implementing a carbon taxation policy. A national consumer expenditure survey and price changes were used to evaluate the carbon tax burden distribution on each households, which have different expenditure. By using marginal abatement cost curve, reduction target is 175 MtCO2e by 2030. Results indicated that achieving the reduction target by that time is possible, although welfare losses in households were inevitable. Price increases resulting from implementing carbon taxation in each product sector ranged from 0.8 to 19.6%. Commodity price changes were largest for high carbon‐intensive sectors including Public utilities (19.6%), Nonmetallic products (15.7%), and Transport & Communication (8.5%). Welfare losses per household from taxation were around 3–4% for each group, resulting from both price changes and expenditure patterns. Highest tax burden fell on the economically inactive group that spent a larger share of their income on basic survival essentials which were heavily impacted by increased prices. © 2019 American Institute of Chemical Engineers Environ Prog, 38:e13146, 2019