ผลงานตีพิมพ์ทั้งหมด

Modeling Thailand's Municipal Solid Waste Decarbonization: A System Dynamics Approach to Aligning MSW Management with NDC 3.0 and Net Zero 2050 Goals

Nattarat Phaingam, Phairat Usubharatana, Harnpon Phungrassami

Engineering Technology & Applied Science Research · 2026

This study applied a System Dynamics (SD) model to simulate Municipal Solid Waste (MSW) generation and Greenhouse Gas (GHG) emissions in Thailand through to 2050. Calibrated with 2008-2024 data, the model uniquely incorporated tourism-related demand shocks and post-COVID recovery patterns alongside population, GDP, and urbanization drivers. Four scenarios were evaluated: Baseline Dynamic (BD), National Roadmap (NR), Circular Resilience (CR), and Net Zero Alignment (NZA). The results indicate that under BD, emissions reach 19.9 Mt CO2e by 2050, failing national climate targets. Meanwhile, NR moderates growth (16.4 Mt CO2e) and only CR (6.5 Mt CO2e) and NZA (4.6 Mt CO2e) achieve substantial reductions. Notably, the NZA scenario demonstrated alignment with Thailand’s ambitious NDC 3.0 target of a 47% reduction by 2035. Landfill diversion of biodegradable waste was identified as the primary leverage point, minimizing methane generation at the source. This research provides a strategic framework to synchronize circular economy policies with explicit decarbonization objectives, supporting Thailand’s transition toward Net Zero 2050.

Greenhouse Gas Emissions from Fossil Fuel Combustion in the Paper Products Industry of Thailand: An Input-Output and Structural Path Analysis

Kullawut Karoonwattana, Harnpon Phungrassami, Phairat Usubharatana

Chemical engineering transactions · 2026

This study examines greenhouse gas (GHG) emissions from fossil fuel combustion in Thailand’s paper sector using Input–Output Analysis (IOA) together with Structural Path Analysis (SPA). The assessment draws on Thailand’s 2015 national input–output table, fossil fuel consumption records, official emission factors from the Thailand Greenhouse Gas Management Organization (TGO, 2022), and production statistics reported by the Office of Industrial Economics (OIE, 2021). The findings indicate that direct emissions from paper manufacturing are relatively modest, while embodied emissions reveal strong dependencies on upstream sectors, particularly the public utilities and transportation sectors. The revised assessment distinguishes between direct and indirect emission intensities within the IOA–SPA framework. Direct emission intensity was normalized using total paper product output, whereas indirect embodied emission intensity was evaluated using pulp production as a proxy material-flow reference for upstream supply-chain dependencies. The resulting fossil fuel combustion–related GHG emission intensity indicators showed reasonable consistency with weighted national benchmarks derived from official TGO emission factors for paper products, supporting the applicability of the IOA–SPA framework under Thailand’s current data constraints. The framework provides a practical basis for evidence-based policymaking, sectoral decarbonization strategies, and Thailand’s transition toward net-zero emissions.

Sustainable Synthesis and Characterization of Carboxymethyl Cellulose from Agricultural Byproducts: Corn Leaf and Rice Straw

Teerapong Churam, Phairat Usubharatana, Harnpon Phungrassami

Engineered Science · 2025

This study explores the sustainable production of carboxymethyl cellulose (CMC) from corn (Zea mays L.) leaf (CL) and rice (Oryza sativa L.) straw (RS), two abundant agricultural byproducts. A novel carboxymethylation method was employed, using sodium hydroxide (NaOH) concentrations of 20–60 g/100 mL. Optimal conditions were determined at 40 g/100 mL NaOH, yielding degrees of substitution (DS) of 0.87 for CL and 0.89 for RS. The DS significantly enhances CMC properties, such as water solubility and viscosity, making it suitable for applications in pharmaceuticals and food industries. Fourier transform infrared spectroscopy confirmed the presence of carboxymethyl groups, while thermogravimetric analysis (TGA), X-ray diffraction, and field emission scanning electron microscopy revealed structural and morphological characteristics. Heavy metal analysis via inductively coupled plasma-mass spectrometer (ICP-MS) showed compliance with World Health Organization (WHO)/Food and Agriculture Organization (FAO) limits, except for lead. The high purity of CMCCL and CMCRS (99.35% and 99.36%) exceeds commercial-grade standards, emphasizing their industrial potential in sectors such as paper, textiles, and ceramics.

Global Warming Potential of Electricity from Sodium Hydroxide Pretreated Napier Grass Biogas: a Cradle-to-Gate Life Cycle Assessment

Phairat Usubharatana, Atitaya Kuwalairat, Harnpon Phungrassami

Chemical engineering transactions · 2025

Napier grass was investigated as a bio-energy feedstock for Thailand. Laboratory anaerobic digestion and cradle-to-gate life cycle assessment (LCA) determined electricity generation’s global warming potential (GWP). Untreated and 1 % w/v NaOH pretreated biomass were digested. Pretreatment significantly increased cumulative biogas yield by up to 49 %, with 538.9 ± 22.3 mg/gVS at the highest F/I ratio. The LCA, based on primary experimental data and adjusted secondary data for the 2019 Thai electricity mix, characterized GWP per 1 kWh. Untreated systems exhibited GWP between 2.86–3.82 kg CO2e/kWh. However, pretreatment raised emissions to 7.01–8.26 kg CO2e/kWh; this was primarily due to the high emissions from NaOH manufacture and neutralization. Substituting 40 % of synthetic nitrogen fertilizer with cattle manure nearly halved both footprints, and a fully organic regime resulted in the untreated system’s GWP being reduced to 0.57 kg CO2e/kWh, which falls below the 2019 Thai grid factor of 0.599 kg CO2e/kWh. These findings indicate that while reactor performance is improved by NaOH pretreatment, climate benefits are offered only when aggressive fertilizer optimization.

Development and Analysis of the Heliostat Curve Tracing Parametric Model (HCTPM) for Sustainable Solar Energy in Sun-Tracking Concentrated Solar Power Systems

Harnpon Phungrassami, Phairat Usubharatana

Sustainability · 2024

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.

Sustainable Production of Carboxymethyl Cellulose: A Biopolymer Alternative from Sugarcane (Saccharum officinarum L.) Leaves

Teerapong Churam, Phairat Usubharatana, Harnpon Phungrassami

Sustainability · 2024

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.

Life Cycle Assessment of Biogas Production from Mixtures of Vinasse and Concentrated Latex Wastewater

Kanjana Chongchit, Thiwawan Sakdamnoensakul, Phairat Usubharatana, Harnpon Phungrassami

International Journal of Environment and Waste Management · 2022

Life cycle assessment of biogas production from mixtures of vinasse and concentrated latex wastewater

Phairat Usubharatana, Thiwawan Sakdamnoensakul, Kanchana Chongchit, Harnpon Phungrassami

International Journal of Environment and Waste Management · 2022

Environmental impacts of biogas production were evaluated by a life cycle assessment (LCA) of mixtures of vinasse and concentrated latex wastewater (CLWW) as: 1) single-stage and two-stage anaerobic digestion with different ratios and initial pH; 2) LCA of thermal energy from biogas. Results showed that almost all two-stage anaerobic digestion processes produced higher amounts of biogas and methane than the single-stage. Environmental impact was assessed for 1 MJ of thermal energy production. Two-stage anaerobic digestion produced less environmental impact in terms of global warming potential (GWP), acidification (AD) and energy use (EU) than single-stage at 64.82, 64.86 and 64.72%, respectively. Anaerobic digestion significantly contributed to environmental impact using sodium hydroxide solution for pretreatment.

Effect of functional unit and processing types on carbon footprint and specific energy consumption assessment of Thailand tableware products

Phairat Usubharatana, Harnpon Phungrassami

International Journal of Sustainable Engineering · 2021

Thailand’s Table 5ceramic 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 Problem Shifting Analysis of Pollution Control Units in a Coal-Fired Powerplant Based on Multiple Regression and LCA Methodology

Harnpon Phungrassami, Phairat Usubharatana

Sustainability · 2021

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.