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The exponential growth in the consumption of lithium-ion batteries (LIBs) has resulted in a concomitant increase in the spent LIBs. Multi-component recycling is a highly desirable and beneficial process, yet the separator component remains overlooked. This study examined the thermal behavior, kinetics, thermodynamics, and evolved products of separator pyrolysis in N2 and CO2 atmospheres. Furthermore, the conversion was modeled using Aspen Plus and a sensitivity analysis was conducted to investigate the impact of varying operating conditions. The findings indicated that the whole degradation process could be divided into three stages: below 200 °C, 200–550 °C and 550–900 °C. The evolved products at peak temperatures of 485 °C in N2 and 500 °C in CO2 were composed of olefins and alkanes. The average apparent activation energy values were determined to be 222.78 kJ mol−1 and 159.36 kJ mol−1 in the N2 and CO2 atmospheres, respectively. Thermodynamic analysis indicated that the separator decomposition was an endothermic and non-spontaneous process. Aspen Plus modeling results were in agreement with the experimental data. The sensitivity analysis revealed that an increase in temperature lead to an increased content of lighter compounds (≤C9) and a decrease in the proportion of heavier compounds (>C10) in the pyrolysis products.

The urgency of addressing climate change has necessitated innovative and practical approaches to reducing greenhouse gas emissions. Cryogenic Carbon Capture (CCC) technology has emerged as a promising solution for capturing CO2 from industrial emissions. This study investigates a simplified design for a precooling system within CCC technology, focusing on optimizing the efficiency and reliability of the system while minimizing energy consumption. The research examines the effects of CO2 concentration in a gas mixture (simulated flue gas, nitrogen and carbon dioxide), cooling bath temperature, and gas mixture flow rate on the performance of heat exchangers in the precooling system. Theoretical, numerical, and experimental analyses were conducted to assess the system's performance. The use of liquid nitrogen at −196 °C in the cooling bath was found unsuitable due to CO2 freezing within the pipes. Instead, a mixture of dry ice and isopropyl alcohol at −78.5 °C proved effective in maintaining consistent temperature and pressure conditions without causing CO2 blockages. Numerical simulations highlighted the importance of optimizing pipe length to balance temperature control and pressure dynamics, with a 140 cm pipe length identified as optimal for heat exchanger design. Experimental results revealed that longer pipes enhance cooling performance due to increased heat exchange surface area, while higher CO2 compositions and flow rates result in higher outlet temperatures and pressures. The study emphasizes the need for further research and simulation work to refine heat exchanger designs for industrial applications, aiming to develop systems that maximize cooling efficiency while ensuring reliable operation.

In recent years, lattice structures have gained extensive attention due to their unique properties and great potential in various fields. Their effective material properties can be obtained by several means, e.g., numerical homogenization methods, finite element (FE) simulations, and experiments. Numerical homogenization methods involve certain assumptions, and thus, their applications are limited to those lattice structures satisfying all assumptions. On the contrary, although the FE simulations and experiments can be performed for all lattice structures, they are more time-consuming and tedious than the numerical homogenization methods, especially for lattice structures with complex geometry. In this study, a surrogate model is presented to address all the drawbacks mentioned above. More precisely, the effective elastic modulus of two-dimensional lattice structures with triangular unit cells is predicted by a surrogate model trained with the random forest algorithm. The dataset is generated from FE simulations. Several geometric details along with the elastic modulus of the parent material are selected as input features. These input features are varied to cover a wide range of lattice structures encountered in engineering applications. The correlation between input features is investigated to test their independence. Furthermore, the contribution of each input feature to the prediction of the surrogate models is also thoroughly examined. The accuracy of the proposed surrogate model is evaluated through comparisons with FE simulations, numerical homogenization methods, and experiments for untrained datasets.

Ni/char catalyst is one of the most promising catalysts for enhancing gas production, particularly syngas from catalytic steam gasification of biomass. In the current study, one unmodified (Ni/MMchar) and two modified catalysts (Ni/NaMMchar and Ni/NaAceMMchar) were utilized to investigate the reusability potential of Ni/char catalyst for catalytic steam gasification of bamboo in a two-stage fixed-bed reactor including the changes in catalyst characteristics. N2 adsorption-desorption by BET, scanning electron microscope connected with energy-dispersive X-ray spectrometer (SEM-EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses were utilized for examining their characteristics. The findings indicated that the three catalysts could maintain the reusability potential in catalytic steam gasification of bamboo for twice cycles. The syngas reduction percentages in the second cycles of the catalysts ranged between 11.0 and 22.8 %. H2/CO ratios of all spent catalysts lined in the range of 4.10 − 2.45. The low heating values of syngas products were in the range of 8.83–8.19 MJ/Nm3. Considering the catalyst characteristics, the increasing cycles of catalyst operations induced carbon deposition, resulting in the reduction of specific surface areas. SEM-EDS images of the used catalysts appeared the coke layer and the Ni metal sintering on the surfaces. The uses of catalysts encouraged the transformation of Ni metal active site into NiO, Ni2O3 and Ni3C forms. These phenomena were the major causes of catalyst deactivation. The changes in the characteristics and catalyst activity controlled the gasification reactions, resulting in the catalyst deactivation and gaseous products.

The objectives of this study are to evaluate the technical and cost implications of retrofitting post-combustion Carbon Capture and Storage (CCS) in existing coal-fired power plants in Thailand, with a special focus on the Mae Moh plant managed by the Electricity Generating Authority of Thailand (EGAT). We undertake a detailed analysis using AspenPlus simulation models to determine the optimum capture cost per ton of CO2 and to examine the effects of various flue gas loads on CO2 capture performance and cost-effectiveness. The research reveals a key operational insight: as the flow rate of flue gas increases, the cost to capture a ton of CO2 decreases, indicating economies of scale in CCS operations. Furthermore, the study explores the potential for integrating solar photovoltaic (PV) technology as a renewable energy source, which shows promise in lowering Thailand's power sector emissions and operational costs. By comparing the levelized cost of electricity (LCOE) for solar PV against conventional coal-fired power generation and considering the country's favorable geographic and climatic conditions, solar PV emerges as an economically viable and environmentally sustainable alternative. The findings of this research aim to inform strategic energy policy decisions in Thailand, advocating for a transition to more sustainable energy systems and emphasizing the balance between environmental responsibility and economic feasibility.

Multidimensional manganese-metal organic frameworks (Mn-MOF) are synthesized using 1,2,4,5-Benzene tetracarboxylic acid (BTTC) at various temperatures (100–160 °C). The Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques successfully confirm the formation of Mn-MOF. Among the various temperatures, the Mn-MOF synthesized at 140 °C (Mn-MOF@BTTC-140) is remarkable because it has excellent crystallinity and a unique morphology, i.e., woodchips-like structure. The synthesized Mn-MOF@BTTC materials are used in supercapacitor applications. In comparison to all materials, Mn-MOF@BTTC-140 revealed the maximum specific capacitance (Cs) of 627 F g-1 @ 1 A g-1, and it displayed 91 % capacitance retention even after the 6000 cycles at a current density of 10 A g-1. Furthermore, the supercapacitor device (SD) constructed using carbon nanofibers (CNF) as the negative electrode and Mn-MOF@BTTC-140 as the positive electrode delivered an energy density of 25 W h kg-1 at a power density of 532 W kg-1. Ultimately, LED lighting demonstrates that our fabricated materials suit practical applications.

This study explores the current technology landscape and intersection of biochar and carbon capture and storage (CCS) within the engineering field, presenting a meticulous analysis gleaned from the Scopus database through bibliometric analysis. In response to the urgent need to address the escalating climate crisis, biochar, with its high carbon content, emerges as a promising and resilient tool for carbon sequestration. A literature review establishes biochar's pivotal role in mitigating climate change with contributions including substantial carbon sequestration potential, economic benefits, and positive impacts on soil structure and crop yields. Distinguishing between the applications of biochar and CCS, this paper emphasizes their complementary roles in decarbonization. By employing VOSviewer, an advanced bibliometric tool, a quantitative exploration of global connections identifying prominent authors, highly cited literature, and research trends is provided. The results reveal a substantial increase in publications related to biochar in CCS, particularly during the rapid development phase from 2016 to 2023, reflecting a growing interest in utilizing biochar as a carbon sink. Key insights from the co-occurrence analysis of keywords shed light on evolving research focuses, with three distinct clusters demonstrating the interconnectedness of adsorption, biochar, and pyrolysis. The precise method highlights a shift in research focus towards more impactful areas, particularly water pollutant removal and adsorption. The conclusion emphasizes biochar's dual role in soil carbon sequestration and carbon capture technologies, showcasing its versatility as a valuable tool in climate change mitigation efforts. Despite challenges in large-scale implementation, biochar, especially in the context of direct air capture and bioenergy CCS, emerges as a cost-effective and environmentally friendly adsorbent. In summary, this bibliometric analysis encapsulates a rigorous exploration of biochar and CCS, contributing valuable insights for researchers, policymakers and practitioners. By navigating uncharted territory, this study guides future endeavors toward impactful and relevant areas of study in the pursuit of sustainable climate change mitigation.

Abstract Sustainable urban development is an increasingly important concept as cities around the world continue to grow and face challenges related to urbanization, including environmental degradation, social inequality, and economic instability. Chiang Mai is a rapidly growing city in Thailand that steers towards sustainability. In this work, we examine the state of sustainable urban development in Chiang Mai by analyzing various indicators, including transportation, waste management, air quality, and energy consumption. A multi-dimensional framework was used to assess the sustainability of Chiang Mai. Our analysis suggests that while Chiang Mai has made progress in some areas of sustainable urban development, such as promoting green transportation and waste reduction and reduction consumption, there are still many challenges to be addressed, particularly in air pollution, water management, transportation and energy consumption. We conclude by discussing the implications of our findings for policy makers, urban planners, and other stakeholders interested in promoting sustainable urban development. This study assesses Chiang Mai’s sustainability using a comprehensive set of 35 indicators. It was found that Chiang Mai has potential for sustainable development, but some indicators require improvement. The study presents guidelines for prioritizing sustainable development, improving air and water quality, promoting sustainable tourism, enhancing waste management, transportation management and energy consumption. This research provides alternative framework for evaluating cities and presents a valuable contribution to the field of sustainable urban development.

Abstract Feedstock properties play a crucial role in thermal conversion processes, where understanding the influence of these properties on treatment performance is essential for optimizing both feedstock selection and the overall process. In this study, a series of van Krevelen diagrams were generated to illustrate the impact of H/C and O/C ratios of feedstock on the products obtained from six commonly used thermal conversion techniques: torrefaction, hydrothermal carbonization, hydrothermal liquefaction, hydrothermal gasification, pyrolysis, and gasification. Machine learning methods were employed, utilizing data, methods, and results from corresponding studies in this field. Furthermore, the reliability of the constructed van Krevelen diagrams was analyzed to assess their dependability. The van Krevelen diagrams developed in this work systematically provide visual representations of the relationships between feedstock and products in thermal conversion processes, thereby aiding in optimizing the selection of feedstock and the choice of thermal conversion technique.

Electric vehicles (EVs) are alternatives to traditional combustion engine-powered vehicles. This work focuses on a thermal management system for battery EVs using liquid cooling and a machine learning (ML) model to predict their thermal-related health. Real-world data of EV operation, battery and cooling conditions were collected. Key influencing factors on the thermal-related health of batteries were identified. The ML model’s effectiveness was evaluated against experimental test data. The ML model proved effective in predicting and analyzing battery thermal health, suggesting its potential for use with the thermal management system.

Coffee is a major industrial crop that creates high economic value in Thailand and other countries worldwide. A lack of certainty in forecasting coffee production could lead to serious operation problems for business. Applying machine learning (ML) to coffee production is crucial since it can help in productivity prediction and increase prediction accuracy rate in response to customer demands. An ML technique of artificial neural network (ANN) model, and a statistical technique of autoregressive integrated moving average (ARIMA) model were adopted in this study to forecast arabica coffee yields. Six variable datasets were collected from 2004 to 2018, including cultivated areas, productivity zone, rainfalls, relative humidity and minimum and maximum temperatures, totaling 180 time-series data points. Their prediction performances were evaluated in terms of correlation coefficient (R2), and root means square error (RMSE). From this work, the ARIMA model was optimized using the fitting model of (p, d, q) amounted to 64 conditions through the Akaike information criteria arriving at (2, 1, 2). The ARIMA results showed that its R2 and RMSE were 0.7041 and 0.1348, respectively. Moreover, the R2 and RMSE of the ANN model were 0.9299 and 0.0642 by the Levenberg-Marquardt algorithm with TrainLM and LearnGDM training functions, two hidden layers and six processing elements. Both models were acceptable in forecasting the annual arabica coffee production, but the ANN model appeared to perform better.

The transportation industry is undergoing a major shift towards electrification to mitigate carbon emissions and decrease reliance on fossil fuels in response to global climate change and greenhouse gas concerns. Recently, battery electric vehicles (BEVs) have made significant progress and are becoming a more viable option for achieving zero-emission transportation. The aim of this study is to investigate the energy consumption patterns of BEVs operating in real-world driving scenarios encompassing various route conditions. The vehicle sensor data employed in this study was acquired through onboard diagnostic devices that directly gathered raw data and subsequently transmitted it to mobile applications. Various significant factors, such as payload, road slope level, speed range, acceleration, and loads of heating, ventilation, and air conditioning, are considered as variables influencing energy consumption. By utilizing the large amount of data collected, machine learning (ML) techniques were applied to develop a predictive model of energy consumption and identify variables that influence energy consumption. The outcomes of this study hold the potential to offer guidance to transportation policymakers and furnish valuable insights for prospective buyers considering BEVs. Furthermore, the application of ML in the development of a predictive model demonstrated efficacy and exhibits promising potential for wider-ranging applications.

This research aims to design and test automatic auxiliary heating unit for solar dryer cabinets to improve drying performance. The auxiliary heating unit utilizes an infrared furnace with cooking gas, a fin heat exchanger, and a blower. It is equipped with an automatic control system to regulate the temperature of the dryer. An agricultural product used in the experiment was fresh pineapple slides. The experimental test was divided into three cases; using (i) solar dryer, (ii) hot air dryer from the automatic auxiliary heating unit and, (iii) combined solar dryer with auxiliary heating unit. Temperature of the automatic auxiliary heating unit was controlled at 55.0 ± 3.0 °C and the air flow speed in the dryer cabinet was 1.5 ± 0.2 m/s. The thermal output from the automatic auxiliary heating unit was more than 2700 W. From the tests, it was shown that the drying time could be reduced to 12.5 h from 32 h, when the solar dryer was combined with the automatic auxiliary heating unit, compared to using only solar dryer. Dried pineapple products showed good quality. Comparative analysis of CIELAB color properties indicated low pigmentation. From a simple economic analysis, return on investment was less than 3.0 months. The use of automatic auxiliary heating units to the solar dryer enabled reduction in drying time and improved product quality.

Biomass can be converted to bio-fuels and bio-chemicals via many thermo-chemical conversion platforms such as hydrothermal liquefaction (HTL) which occurs at high temperature and pressure conditions. HTL can be used for converting wet or high moisture content biomass to biocrude oils effectively. There are wide variety of relevant parameters affecting the system of biomass HTL, for example, operating conditions, biomass characteristics, solvent properties, or catalyst identities used. This brings about the difficulty in making highly accurate prediction of biocrude oil yields from biomass HTL. In this work, a gradient tree boosting machine learning (GTB-ML) model with principal component analysis (PCA) was applied to predict the yields of biocrude oils from biomass HTL, using 15 input variables from biomass characteristics, operating conditions, and solvent properties. PCA is a statistical method to find correlations in multivariate data, and it can be used to specify highly influential variables in input datasets for ML models. PCA results confirmed that input variables from biomass characteristics were as important as those from HTL operating conditions. The GTB-ML developed from principal components 1 to 8, representing about 90% of the whole original dataset can be used to predict the yields of bio-crude oils from biomass HTL at acceptable accuracy with correlation coefficient, R2=0.8and root mean square error = 0.005.

The present study reports on an investigation of teak sawdust pyrolysis oil blended with commercial diesel in a small four-stroke compression ignited engine. The engine performance and emissions were evaluated. The teak sawdust pyrolysis oil was obtained from a single-stage fixed bed pyrolysis reactor at 600 °C. Its physicochemical properties were characterized and found to be acceptable for the engine. Teak sawdust pyrolysis oil blends with diesel at the ratios of 10%, 25%, and 50% by mass were utilized. The small engine was tested at constant speeds from 800 to 2600 r/min. 25% teak sawdust pyrolysis oil blend at 2000 r/min was found to have better brake thermal efficiency with lower brake-specific fuel consumption compared to the other teak sawdust pyrolysis oil blends. Meanwhile, the highest engine load was obtained at 50% teak sawdust pyrolysis oil blend and 2600 r/min to be 8 kW. Furthermore, the emissions of CO, CO 2 , and hydrocarbon at 50% teak sawdust pyrolysis oil and 2000 r/min were slightly lower than other teak sawdust pyrolysis oil blends, no NO x detection in tested fuels, moreover, at 2600 speed, the smoke opacities of the fuels show lower than those the others. It was noted that a blend of 25% teak sawdust pyrolysis oil with diesel was suitable for the small engine (at 2000 r/min) in terms of performance and CO, CO 2 , and NO X emission for sustainability in agriculture and rural areas.

AbstractThailand is among high-ranking coffee-exporting countries in the world. This study investigated, analyzed and proposed ideas for improved production of coffee to meet the demands from the local and international market. Using data collected from site visits, observation and interviews, value stream mapping analysis was used to identify the activities in the coffee production process. Automated machine deployment was used to improve the performance of coffee production. From the findings, it was shown that the total cycle time could be reduced by more than 82 %, the profit of sorted cherry coffee could be increased by 80%, and the processing time of green bean coffee could be reduced by almost 97%. An automated color sorting machine was deployed to improve the production process. With integrated lean and automated mechanization techniques, farmers can gain several benefits and become more responsive to future customer demands.

Cities around the world have expanded and consumed many resources. The expansion of these cities has had a huge impact on our planet. There are many ideas about sustainable urban development around the world to slow down or stop the destruction of the environment. Sustainable urban development is a concept that allows the economy, society, and environment to grow together in a balanced and sustainable manner. Chiang Mai in Thailand is considered a city with much potential. It currently has good city planning. However, indicators to evaluate the potential of sustainable cities are still lacking. Hence, this work aims to develop appropriate indicators for assessing the sustainability of Chiang Mai city using the Delphi method of panel surveys. At least 20 experts in various fields were selected to take the Delphi surveys conducted in three rounds. The results of the Delphi processes showed that there were 35 indicators suitable for assessing Chiang Mai's potential as a sustainable city and helping with the development planning of Chiang Mai in the future.

Open burning of agricultural residues as a means of disposal causes massive atmospheric air pollution in northern Thailand. Converting this agricultural residual biomass to clean energy can help reduce this problem. They may be utilized as solid fuel for electrical power generation, where cost is one of the major factors affecting long term success in the use of biomass and bioenergy. In this work, a cost optimization model was developed for Thailand scenario by considering two parts of total cost: biomass and transportation costs. Ten potential agricultural residual biomass materials which were the most abundant in Thailand were taken into account. For transportation cost, K-means clustering was applied to group a number of supplies and demands, and to identify centroids of each cluster to use them as representatives in calculating the transportation cost from a supply to a demand point. Each kind of biomass was gathered into six different types of power plant. It was transported by 10-wheel trucks. A wide range of input data (biomass and transportation costs) from a supply to demand was also evaluated. From a case study considered, it was demonstrated that reduction of the total costs by more than 50% could be achieved. These results were from only biomass and transportation costs without taking other factors such as seasonal conditions or process limitations into consideration. Different input parameters can change the finalized total cost.

The successful use (for performance predictions, in previous work) of process modeling and simulation of fast pyrolysis plants has made these techniques imperative in the design and operation of the pyrolysis plant itself. The current work proposes an expansion of pyrolysis simulation in the Aspen Plus® model for lignocellulosic biomass, which is based on the kinetic reaction mechanisms of different materials under varied operational settings. This simulation allows the yield prediction for both slow pyrolysis at 350–450 °C, with residence times in the range 30–50 s, and fast pyrolysis at 450–600 °C, 1–5 s residence time. The comparison between simulation and experimental results was performed, focusing on the product yields and components. The results revealed a significant correlation between the two sets of results, not only for slow pyrolysis but also for quick pyrolysis processes of biomass, with less than 8% difference error when compared to the pilot plant and earlier experimental work. The simulation model was proven to be suitable for predicting pyrolysis yields and products within the common temperature and residence time ranges, and it was discovered to be ideal for predicting the outcomes of fast pyrolysis products within the specific scope of operation. The results from the model showed a high level of reliability in estimating the composition of different compounds obtainable, not only from slow pyrolysis but also from fast pyrolysis, with a 0.99 Pearson’s correlation coefficient.

Abstract In this study, the effects of print parameters on the mechanical properties of additively manufactured metallic parts were investigated using a tensile test. The 17-4 PH stainless steel specimens with two print parameters, including infill density and pattern orientation, were fabricated by additive manufacturing (AM) using the bound metal deposition (BMD) technique. The mechanical properties considered in this study are the Young’s modulus and ultimate tensile strength. The results demonstrate that the pattern orientations do not affect the Young’s modulus of the infill specimen with the triangular pattern. In contrast, the ultimate strength significantly varies depending on the pattern orientations, where the samples with the pattern orientation of zero degrees yield the best ultimate strength. In fact, the mechanical properties of infill specimens increase with their infill density. However, when operating cost and time are considered, an index for estimating performance and sustainability is consequently established. The relationship between the normalized ultimate strength of an infill specimen and the relative density is defined as the weight efficiency. The index for assessing a sustainable product is characterized by the weight efficiency versus sustainable parameter(s). The index can help end users select an appropriate infill density for AM products by considering the operating cost and time. Different cost models, including material-only costs, direct costs, and total costs, can be included in the index model to assess a sustainable product in a particular cost context.

Among renewable and sustainable energy resources, biomass plays a vital role. Agricultural residues/wastes, energy crops, and lignocellulosic biomass could potentially be major feedstocks for biorefineries. In Thailand, one of the most interesting energy crops is hybrid giant Juncao grass (GJG) or Pennisetum purpureum × Pennisetum typhoideum. GJG can be easily grown and has relatively high yields under tropical climates. Herein, conversion of GJG to biofuels via hydrothermal liquefaction (HTL) was investigated using batch reactors under varying reaction temperatures of 250–350 °C and biomass-to-deionized water concentrations of 15–25 wt% at a fixed residence time of 30 min. Changes in temperature and GJG-to-deionized water concentration were found to markedly affect the yields and distribution of products from HTL of GJG. Yields of the liquid product, or bio-oil, can be up to 50 wt% at 350 °C and 25 wt% GJG-to-deionized water concentration. The yields of solid char and gas products fluctuated within 10–25 wt% and 30–45 wt%, respectively. Higher heating values of the resulting bio-oil and char were remarkably better than those of the raw material. An energy recovery of over 50% from the bio-oil, as well as about 35% from the char, can be obtained. By gas chromatograph-mass spectrometry and nuclear magnetic resonance, the bio-oil obtained was found to be a complex chemical mixture, consisting mainly of phenols, nitrogenous compounds, aliphatic compounds, ketones, carboxylic acids, and aldehydes. The finding is useful in future utilization of GJG via HTL for biofuel and/or biochemical production.

Fossil fuels are the primary source of energy for a long period in spite of excessive environmental hazards, such as greenhouse gas emissions. Production of energy and fuel from lignocellulosic biomass has been the goal of the study in pursuit of renewable alternatives to fossil materials. Corncob is common agricultural biomass waste found in many countries. It can be utilized to produce bioenergy, but the conversion efficiency is limited. Pretreatment may be applied to improve the efficiency of corncob conversion; for example, by the fractionation of lignocellulosic biomass. Choline chloride (ChCl) and glycerol are considered as synthetic deep eutectic solvents (DESs), also known as green solvents. DESs are expected to fractionate hemicellulose and lignin from raw biomass, and the accessibility of cellulose may be enhanced. In this work, pretreatment of corncob with DES prepared from ChCl and glycerol was investigated at varying reaction temperatures (60–150 °C), residence times (6–15 h), and ChCl-to-glycerol molar ratios (1:0.5-4). The results showed that hemicellulose and lignin were effectively extracted from the raw corncob, and therefore, cellulose content in the remaining solid residue, known as cellulose-rich material (CRM), can be improved by least 140%. The reaction temperature, residence time, and presence of ChCl in the DES influenced the pretreatment of corncob significantly. Increases in reaction temperature and residence time led to a higher cellulose content in CRMs and an increased extraction of hemicellulose and lignin from the raw corncob. Without the ChCl in DES, the cellulose content in CRMs and the extraction of hemicellulose and lignin from the sample were decreased markedly. The optimal condition at 150 °C, 12-h residence time, and 1:4 ChCl-to-glycerol molar ratio could be used to improve the cellulose content of CRMs from the raw corncob by more than 150%. The CRM with improved lignocellulosic properties can be used as a feedstock in further bioenergy/fuel application.

With rapidly depleting fossil fuels and growing environmental alarms due to their usage, hydrogen as an energy vector provides a clean and sustainable solution. However, the challenge lies in replacing mature fossil fuel technology with efficient and economical hydrogen production. This paper provides a techno-economic, and environmental overview of H2 production technologies. Reforming of fossil fuels is still considered as the backbone of large-scale H2 production. Whereas renewable hydrogen has technically advanced and improved, its cost remains an area of concern. Finding alternative catalytic materials would reduce such costs for renewable hydrogen production. Taking a mid-term timeframe, a viable scenario is replacing fossil fuels with solar hydrogen production integrated with water splitting methods, or from biomass gasification. Gasification of biomass is the preferred option as it is carbon neutral and cost-effective, producing hydrogen at 1.77 – 2.77 $/kg of H2. Among other uses of hydrogen in industrial applications, the most viable approach is to use it in hydrogen fuel cells for generating electricity. Commercialization of fuel cell technology is hindered by a lack of hydrogen infrastructure. Fuel cells and hydrogen production units should be integrated to achieve desired results. Case studies of different fuel cells and hydrogen production technologies are presented at the end of this paper, depicting a viable and environmentally acceptable approach compared with fossil fuels.

Abstract Crop yield and its prediction are crucial in agricultural production planning. This study investigates and predicts arabica coffee yield in order to match the market demand, using artificial neural networks (ANN) and multiple linear regression (MLR). Data of six variables, including areas, productivity zones, rainfalls, relative humidity, and minimum and maximum temperature, were collected for the recent 180 months between 2004 and 2018. The predicted yield of the cherry coffee crop continuously increases each year. From the dataset, it was found that the prediction accuracy of the R2 and RMSE from ANN was 0.9524 and 0.0784 tons, respectively. The ANN model showed potential in determining the cherry coffee yields.

Gasification of biomass is an industrial process utilized to produce product gas that can be used in electrical power generation with internal combustion engines. However, there remain huge challenges with regards to tar and other pollutants, thus their removal before further use is necessary. Non-thermal plasma method can be considered as a novel and efficient way for treatment of tar from product gas. In this work, a laboratory-scale, reverse vortex flow gliding arc plasma reactor was developed and tested for the removal of tar model compound using naphthalene as surrogate. Effects of total gas feed rate in the range of 20–60 L/min, applied voltage in the range of 50–220 V, hence, power input in the range of 300–460 W with initial naphthalene concentration of 610 ± 50 mg/m3 on removal and energy input were investigated. It was found the tar removal efficiency increased with increasing applied voltage. Maximum naphthalene removal efficiency of 85% was achieved at applied high voltage of 15 kV and specific energy input of 0.13 kWh/m3 with energy utilization efficiency of about 4.60 g/kWh. From the findings, non-thermal plasma technology appeared to offer great potential in the removal of biomass tar from gasification. The technology may be promising for possible application to real biomass tar cracking and upgrading of product gas from gasification.

Transport electrification, which entails replacing fossil fuel-powered engines with electric drivetrains through the use of electric vehicles (EVs), has been identified as a potential strategy for reducing emissions in the transportation sector. As the adoption of EVs increases, there is a growing need to understand their performance and characteristics, particularly the factors that influence energy consumption under actual driving conditions. This study sought to investigate the actual energy consumption of commercial battery electric vehicles (BEVs) in Thailand by conducting real-world driving tests under various route conditions, including urban and rural route modes. Data collection was performed through the use of onboard diagnostics and global positioning system devices. The result shows that the average energy consumption of the BEVs in this study was 148.03 Wh/km. Moreover, several machine learning (ML) techniques were utilized to analyze the collected dataset to predict energy consumption and identify the key factors influencing energy consumption. A comprehensive investigation of factor significance was carried out by employing a specific algorithm in conjunction with the SHapley Additive exPlanations (SHAP) approach. This investigation provided insights into the influence of battery current and vehicle speed on the energy consumption of BEVs, particularly in the context of urban route conditions. The results of this study provide valuable insights into the energy consumption of BEVs and the factors affecting it, which can aid in improving energy efficiency and informing policy decisions related to transport electrification.

A vaccine storage employing a compact refrigeration module for remote area use was proposed and realized in laboratory setting. The module was based on a passenger car air-conditioner driven by a biodiesel powered small engine. The engine used was of single-cylinder, direct-injection, and compression-ignited type with swept volume of about 0.30 dm3 and compression ratio of 20:1. The biodiesel powered engine was tested to drive the air-conditioning system at normal operation over various speeds and loads. The refrigeration module was found to operate well with low specific fuel consumption at optimal speed ratio between the engine and the compressor. At this setting, the engine thermal efficiency was 28% and the refrigeration COP was about 1.8. With regards to energy saving, the modular system appeared to offer a satisfactory outcome, in which the vaccine storage was able to maintain the temperature below 8 °C for about 4.5 h after the engine stop.

Mitigating CO2 emissions is an important clean energy research topic. Post-combustion carbon capture is a well established and vital carbon capture technology for existing fossil-fueled power plants. In this work, monoethanolamine (MEA) based carbon capturing unit was designed using AspenPlus V.10 software for a 300 MWe power unit of Mae Moh power plant in Thailand. Technical and economic analysis of retrofitting a lean aqueous MEA system was investigated. From the simulation study, it was revealed that the optimal lean CO2 feeding for the amine-based carbon separation plant was about 0.2 mol/mol using packed columns with Sulzer Mellapak 250Y product. The optimal liquid-to-gas ratio with a flue gas containing 15% CO2 was approximately 3.0. Furthermore, the optimal total costs of the plants were less than 55 $/ton of CO2 captured.

Hot air and solar drying are among the most popular preservation methods for fresh fruits. Ultrasonic technology could enable a faster dehydration rate at low temperatures, hence, preserving vitamins and nutrients in fruits. In this work, the application of ultrasonic vibration to pineapple drying was investigated. Experiments were conducted in hot air as well as direct solar dryers. The temperature in the hot air dryer was controlled at 60 °C, with an applied vibration frequency of 40 kHz. Three cycles of 10, 20, and 30 min with 1 min ultrasonic operation per interval were tested. The results showed that for the cycle of 10 min with 1 min vibration applied, the moisture content of pineapple slices was decreased from 87 to

Conversion of Pennisetum purpureum × Pennisetum americanum (Napier Pak Chong1) press cake into biobutanol using Clostridium beijerinckii TISTR 1461 was proposed as an alternative to combustion in this study. The optimum conditions for biobutanol fermentation were determined using a full factorial design and a central composite design of experiment. The studied factors were initial pHs (5.50–6.50) and sugar concentrations (40–60 g/L), while butanol yield (g/g reducing sugar utilized) was specified as the optimization response. The results showed that the suitable enzyme loading of alkali-pretreated press cake (at 3% w/w NaOH, 10% substrate loading, boiling at 90 °C, with a reaction time of 1 h) was 10 FPU/g biomass, which provided a glucose yield of 345 mg/g pretreated press cake. The optimized pH and reducing sugar concentration were 6.08 and 43 g/L, respectively. At these conditions, the maximum butanol yield from the hydrolysate of NaOH-pretreated press cake was 0.135 g/g reducing sugar utilized (0.30 g/g glucose utilized). Apart from the possibility of generating much less pollution, it was estimated that using the same amount of press cake, butanol production could possibly have a value comparable to that obtained from combustion for electricity production. A new concept for overall Napier Pak Chong1 grass utilization was also presented.

Bio-oil produced from biomass fast pyrolysis process is an organic liquid that can be transformed into high quality biofuel through upgrading process. Bio-oil comprises a large amount of carboxylic acids, which cause its corrosiveness, hence, difficulty for storage and utilization. Esterification may be considered as an intermediate upgrading method to convert the acids in bio-oil into esters by reacting with alcohol. This work presents kinetic studies of the esterification of a bio-oil model compound in ethanol catalyzed by 12-tungstosilicic acid. Oleic acid was used to represent the main component of bio-oil derived from agro-residues. Conditions considered were the molar ratio of ethanol to oleic acid of 9.11:1, catalyst loading of 10 wt%, and reaction temperatures in the range of 35-75 °C. It was found that the pseudo-homogeneous kinetic model was suitable to represent the esterification of the bio-oil model compound. Average reaction order n = 1.9, activation energy Ea=50.1kJ/mol, and pre-exponential factor A = 11.11×103 min−1 were obtained by fitting the kinetic model with experimental results.

Biomass torrefaction is a simple and appropriate thermo-chemical treatment/conversion process for upgrading agricultural residues to a high-quality fuel, which could be used as an alternative energy resource to replace fossil fuels. In this paper, reaction kinetics for torrefaction of pelletized agro-residues biomass under dry flue gas conditions were investigated. The two-step mechanism model was used to describe the biomass torrefaction decomposition, and with the experimental data, the kinetic parameters of this model were analyzed. The torrefaction reactions were found to occur in a narrow period of reaction time, and the kinetic parameters were affected by dry flue gas conditions. The model predictions can imitate the thermo-chemical degradation well, and the predicted torrefied solid was shown to contain not only chars but also some intermediate and unreacted fractions. This work provides further insights for understanding torrefaction kinetics of agricultural biomass pellets which are important in designing and operating industrial biomass conversion equipment and apparatus.

Torrefaction combined with densification for upgrading biomass to torrefied biomass pellets is increasingly of great interest since torrefied biomass pellets are considered as a major renewable energy source. Especially in the application of co-firing with coal, torrefaction may be easily integrated into an existing co-firing power plant, whose flue gases from the power plant could be used to torrefy biomass pellets. This could also help to improve the overall carbon efficiency of the power plant and reduce emissions of greenhouse gases. In the present work, a torrefaction plant for corn residue pellets to produce torrefied solid fuels using flue gases as a main heat source was simulated in Aspen Plus® software. Torrefaction module was successfully modelled by an RYield reactor, which was programmed with the two-steps-in-series kinetic for the decomposition of biomass pellets as well as the volatile formation for by-products. The model can, therefore, provide the distribution and yield of both torrefied biomass pellets and volatile by-products. From the validation, the simulation results appeared to show good agreement with available experimental data in the literature. At the suggested conditions of 260 °C wet flue gas and 20 min residence time, thermal energy of 460 J/g and 380 J/g were required for the drying and the torrefaction modules, respectively. At these conditions, the performance of the whole process was found to be almost 95%. This plant produced 75% w/w torrefied biomass pellets yield with HHV of 21.9 MJ/kg. The by-products mainly included 10.7% w/w water, 7.4% w/w CO2, and 1.7% w/w CO. Our findings provide a feasible outlook for integrating a torrefaction process of biomass pellets into a co-firing power plant, utilizing a realistic heat of waste flue gases for the process.

This research aimed to develop a cost model in acquiring various agricultural residues as fuels for biomass power plants and to investigate cost differentiation when sources of biomass materials were changed or combined to produce electricity. Database of agricultural residues including location, availability and price throughout Thailand was accumulated based on top seven highest availability sources. Cost model was developed to compare cost when different types of agricultural residues were utilized to generate either electricity or heat. Cluster analysis was applied in the demand side analysis by clustering biomass power plants which were located within 50 km radius from the same centroid. Transportation cost was estimated from the biomass source to the corresponding demand centroid. The cost model for transporting agricultural residues to the demand location was then proposed. From the cost model of transporting agricultural residues, a biomass power plant was chosen as examples. It was shown that when the biomass power plant replaced eucalyptus barks with corncobs, the production cost could be reduced by more than 60%. From the analysis, it was also revealed that the most important factors that a biomass power plant should consider were energy content and cost of the raw material, as well as availability of the nearest supply source.

In many counties, hemp is becoming a high-valued economic crop. Post-processing, more than 65% w/w of its starting material becomes waste. Herein, pyrolysis of hemp hurds/residues was investigated under low (10–50 °C/min) and intermediate (100–150 °C/min) heating rates using a discrete distributed activation energy model (DAEM). Thermochemical decomposition of hemp hurds occurred in three stages: drying, active pyrolysis, and char formation, accounting for 70–80% w/w overall weight loss. With the discrete DAEM, the model can be utilized for predicting pyrolysis behaviors of hemp hurds accurately with correlation coefficient of over 0.99. Different reaction mechanisms appeared between the low and intermediate heating rates with 60 and 25 parallel first-order pyrolytic reactions detected, respectively. Under low heating rates, the pyrolysis showed high reactivity. The activation energy (E) and enthalpy change (ΔH) varied within 240–320 kJ/mol. The Gibbs free energy (ΔG) was 120–200 kJ/mol. The entropy change (ΔS) was 120–300 J/mol∙K. Under intermediate heating rates, the reactions were close to thermodynamic equilibrium and stability. The E and ΔH fluctuated from 80 to 250 kJ/mol. The ΔG was within 160–200 kJ/mol. The ΔS was between −100 and 100 J/mol∙K.

In this work, the catalytic upgrading of a bio-oil model compound via esterification with ethanol was studied using 12-tungstosilicic acid as the catalyst. The response surface method was used to investigate and optimize the process variables, which include the ethanol to acid molar ratio, catalyst loading, reaction temperature, and reaction time for maximum conversion of the organic acid for esterification under atmospheric conditions. The effect of high He pressure on acid conversion for esterification was also studied. The maximum acid conversion was almost 90%, which can be achieved at reaction temperature of 77 °C, ethanol to acid molar ratio of 5:1, catalyst loading of 4.0% w/w, and reaction time of 8.3 h. Pressurizing the reaction with inert He did not have any effect for acid conversion at this optimum condition and had a slight negative effect under the studied conditions. After upgrading, the esterified products were found to improve the heating value from 17.6 to 23.2 MJ/kg and appeared to enhance fuel properties.

Used cooking oil is unsuitable to use again in the food process, but it may be harnessed as raw material in biofuel production. In this work, used palm oil was reactedvia cracking over mechanically mixed catalystsbetween ZSM-5 and Y-Re-16to generate organic liquid products (OLP). The catalysts used were known for highacidity and lowcost for decomposition, degradation,and deoxygenation of triglycerides. The cracking experiments were conducted in a flow reactor. The experimental variables included reaction temperature between 300-500°C, catalyst loading between 5-20 % w/w, and ratio of mixed catalyst between ZSM-5 and Y-Re-16 from 0-100 % w/w. They were setvia response surface methodology and central composite design of experiments. Both catalysts showed good cracking reaction. The optimum condition for generating the OLP of about 85 % w/w was found at 300°C, 5 % catalyst loading, 97 % ratio of mixed catalyst. The OLPs with different short-chain hydrocarbons between C7-C21 were identified. The main components were 71.43% of diesel, 12.11% of gasoline, and 8.95% of kerosene-like components.

The objective of this wok was to develop the high energy performance standards (HEPS) for oil-injected air-cooled screw air compressors in Thailand. Based on the data from the Customs Department in 2018, it was found that Thailand imported a great number of air compressors with total value of more than 60 million USD. In this study, the energy performance of the air compressors was evaluated from standardized tests, and the energy performance data was used to analyze the energy efficiency standards using statistical principles of normal curves and standard scores. The criteria used in determining the HEPS was that about 30% of the products must have the specific power higher than the HEPS value. The HEPS value was shown in the form of equations to be able to use with all the power input. If it is promoted to adopt this HEPS, Thailand will have the potential to save energy by about 37,305,000 kWh/year. Keywords: Energy efficiency, Screw air compressor, Air-cooled oil-injected, HEPS

Utilization of agro-residues from maize production as biorenewable energy source is considered to be a very good and sustainable waste management method. Hydrothermal carbonization (HTC) is a thermochemical conversion process for solid organic materials at elevated temperature and pressure in the presence of water. Through hydrolysis, dehydration and decarboxylation, a solid hydrochar as well as gaseous and aqueous products are generated. The energy density and the macromolecular structure of the solid product are improved, giving rise to a carbonized product that is simpler to convert to heat, power or fuel than the starting materials. This study was about applying HTC to upgrade maize residues. The residues used were cobs derived from a maize processing factory. The HTC experiments were carried out in a batch 10-dm3 pressure reactor equipped with 14 kW heaters and internal temperature control. About 0.5 kg of biomass was loaded with 5 dm3 of deionized water into the reactor. The effects of temperature (180–250 °C) and time (60–360 min) were examined. The hydrochar was recovered by filtration and dried for subsequent analyses. With increasing temperature and time, the amount of hydrochar was found to decrease, while the gaseous and aqueous products increased. Hydrochar yields were in the range of about 35%–72%. From the analysis result, hydrochar produced was found to have improved fuel qualities Its elemental composition was coalified with H/C and O/C atomic ratios moving towards that of lignite. Keywords: Agricultural waste, Biomass conversion, Hot compressed water, Renewable energy, Wet pyrolysis

Open burning of agricultural residues after harvesting season is usually practiced as a disposal means for highland farms. The practice has partially contributed to the haze problem in the northern region of Southeast Asia during February to April every year. This can drastically affect human health in the long run. In this work, alternative means to utilize maize residues as a bio-renewable fuel source is explored. These maize residues can potentially be used as a raw material to substitute or partially replace wood chips in production of smokeless charcoal. Local charcoal producers in Maehongson, northern Thailand have recently looked into alternative raw materials for smokeless charcoal production since the demand for domestic and aboard has shoot up to about 6000 tons this year. Possibility of using maize residues is paramount. According to such requirement, this work focused on cost analysis of transforming maize residues into high-added-value smokeless charcoal. The analysis covered from maize harvesting and residue collection methods, logistics approach to charcoal production site, production cost and product transportation cost. Primary and secondary data collection, site survey, interviews with stakeholders and cost modeling were performed. It was found that the maize farmers could earn up to 15 USD/ton from sales of the maize residues to charcoal production plants, while the plants remain profitable. Keywords: Agricultural residues, Smokeless charcoal, Cost analysis, Environmental policy, Sustainable waste management

Operational management of multiple reservoirs and hydropower plants based on Nam Ngum river basin near Vientiane, Laos PDR was investigated for optimal power generation. The system consists of three reservoirs namely Nam Ngum1, 2 and 5. Analysis of water balance, storage and discharge relationship for each reservoir was carried out using the HEC-ResSim 3.0 simulation software package. Historical monthly records of these reservoirs between 1975 to 2018 were used to derive representative dry, normal and wet years to be input for the simulation. Operational management of available water was optimized for maximum power generation based on particle swamp optimization technique. From the simulated results, it was possible that for a representative wet year, electricity production of Nam Ngum1 hydropower plant can be increased from 1217 to 1348 GWh/y, an increase of about 11%, compared to current operational practice. Total power production of all three reservoirs of 4380, 3816 and 3400 GWh/y could be increased to 4727, 3860, and 3426 GWh/y, respectively. The technique proved to be useful in the operation of reservoirs and hydropower plants. Keywords: Multi-reservoirs, Hydropower, HEC-ResSim, Optimization, Renewable energy

Oily sludge is a hazardous waste stream of oil refineries that requires an effective process and an environment-friendly route to convert and recover valuable products. In this study, the pyrolytic conversion of the wet waste oil sludge was implemented in an autoclave pyrolyzer and a thermogravimetric analyzer (TGA) at 5°C/min, 20°C/min, and 40°C/min, respectively. The kinetic analysis was performed using model-free methods, such as Friedman, Kissenger–Akahira–Sunose (KAS), and Ozawa–Flynn–Wall (OFW) to examine the complex reaction mechanism. The average activation energy of wet waste oil sludge (WWOS) estimated from Friedman, KAS, and OFW methods was 198.68 ± 66.27 kJ/mol, 194.60 ± 56.99 kJ/mol, and 193.28 ± 54.88 kJ/mol, respectively. The activation energy increased with the conversion, indicating that complex multi-step processes are involved in the thermal degradation of WWOS. An artificial neural network (ANN) was employed to predict the conversion during heating at various heating rates. ANN allows complex non-linear relationships between the response variable and its predictors. nH, ΔG, and ΔS were found to be 191.26 ± 2.82 kJ/mol, 240.79 ± 2.82 kJ/mol, and −9.67 J/mol K, respectively. The positive values of ΔH and ΔG and the slightly negative value of ΔS indicate the endothermic nature of the conversion process, which is non-spontaneous without the supply of energy.

Based on a prior demonstration of the high activity of a homogeneous tungstosilicic acid catalyst for the esterification of acetic acid as bio-oil model compound, a further study has been undertaken in an attempt to heterogenize the catalyst. Tungsten oxide was supported on amorphous silica (W/A150) using incipient wetness impregnation and incorporated into the structure of structured silica (W-KIT-5) via a one-step hydrothermal synthesis. The catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), physisorption (BET), and temperature-programmed desorption of ammonia (NH3-TPD). Both series were evaluated for the esterification of acetic acid with ethanol and compared with the homogeneous 12-tungstosilicic acid catalyst. The result of XRD analysis suggests the average crystallite size of the W oxide nanoparticles on both supports to be less than 2 nm, while XPS analysis revealed that all W existed in the W 6+ oxidation state. From the BET and NH3-TPD analyses, it was shown that the KIT-5 series had higher surface area and acidity than the W/A150 catalyst. The 10% W-KIT-5 was shown to be the best heterogeneous catalyst with the highest activity and acid conversion of about 20% and 93% of the homogeneous catalyst. Significant leaching of tungsten from both the supports occurred and will have to be solved in the future.

This work studied generation of producer gas using oxygen-enriched air and steam mixture as gasifying medium. Corn residues consisting of cobs and stover were used as biomass feedstock. Both corn residues were pelletized and gasified separately with normal air, oxygen enriched air and steam mixture in a fixed bed reactor. Effects of oxygen concentration in enriched air (21-50%), equivalence ratio (0.15-0.35), and steam to biomass ratio (0-0.8) on the yield of product gas, the combustible gas composition such as H2, CO, and CH4, the lower heating value (LHV), and the gasification efficiency were investigated. It was found that the decrease in nitrogen dilution in oxygen enriched air increased proportion of combustible gas components, improved the LHV of producer gas, but gasification efficiency was not affected. The increase in equivalence ratio favoured high product gas yield but decreased combustible gas components and LHV. It was also observed that introduction of steam enhanced H2 production but excessive steam degraded fuel gas quality and decreased gasification efficiency. The highest gasification efficiency of each oxygen concentration was at equivalence ratio of 0.3 and steam to biomass ratio of 0.58 for cob, and 0.22 and 0.68 for stover, respectively. ©2019. CBIORE-IJRED. All rights reserved

Municipal solid waste (MSW) and charcoal can be used as a substitute fuel in a gas engine. In this work, performance of a downdraft gasifier and gas engine system operated on MSW briquette fuel was investigated. Experimental test was carried out on a 62 kW, four-cylinder, naturally aspirated engine coupled to a 20 kW dynamometer. The downdraft gasifier was used to generate producer gas from MSW briquettes and charcoal. The engine load was varied between 1.5-9.0 kW. Biomass consumption, producer gas production, cold gas efficiency, thermal efficiency of the gas engine, carbon monoxide (CO), hydrocarbon (HC) emissions and exhaust temperature were evaluated. The MSW briquette fuelled operation was compared against that with charcoal. It was found that, the use of MSW briquette led to lowering performance of the downdraft gasifier and gas engine system, in comparison with the use of charcoal. Maximum cold gas and thermal efficiencies obtained were 64.6% and 16% at 4.5 kW and 9 kW loading, respectively. The CO and HC emissions of the gas engine operated on MSW briquettes were higher than that on charcoal, while the exhaust temperatures were similar. ©2019. CBIORE-IJRED. All rights reserved

Thailand has great potential to usebiomass from agricultural wastes for renewable fuels and energy. However, its current utilization is rather low due largely tothehigh moisture content and low energetic densityof these materials. A simple thermal pretreatment such as torrefaction may be useful in adding value tothese solid agricultural wastes. The objective of this work was to investigate effect of torrefaction temperature and time on the yields and physico-chemical properties of agricultural wastes (wood chips and oil palm fronds). The torrefaction experimental workwas carried out in a laboratory reactor with varying temperaturesof 200 to 400°C and reaction timesof 20 to 60 min. A 5 kW electrical heater was used to heat the reactor. From the results obtained, it was found that torrefaction temperature and time affected the solid product proximate and energy properties. The higher heating value of torrefied fuel was increased with torrefaction temperature and time. Optimum torrefaction temperature for wood chips and oil palm frondswas identified at 200°C, while optimum timeswere20 and 40 min, respectively, for maximum mass and energy yields. At these conditions, the energycontent of both biomass materials was improved to 17.65 MJ/kg and 16.34 MJ/kg, 20-30%higher than theoriginal values. The value and energy yield of wood chips and oil palm fronds could be improved through torrefaction.

Non-thermal plasma technology is an interesting method for removalof tar from gasified biomass. In this study, AC gliding-arc reactors with a reverse vortex flow configuration were developedfor biomass tar treatment. Successful generation of plasma discharge was obtained at high volume flowsof treated gas. Preliminary experimental results showed that the onset of electric discharge occurred at about 10 kV. A large numberof plasma discharges was evident. For our developed prototype, electric power input, total gas feed rate, and variouscarrier gases(Air, N2, N2+C10H8) were adjusted to investigate their effects on the dischargephenomena.The reverse vortex flow gliding arc discharges showed high residence timesfor potential chemical reactions inside the reactor. From preliminary tests, maximum removal efficiency of a representative tar compoundof more than 93%was found, atanenergy utilization efficiencyof about 30 g/kWh.

Application of advanced pyrolysis processes to agricultural waste for liquid production is gaining great attention, especially when it is applied to an economic crop like tobacco. In this work, tobacco residues were pyrolyzed in an ablative reactor under vacuum. The maximum bio-oil yield of 55% w/w was obtained at 600°C with a particle size of 10 mm at a blade rotation speed of 10 rpm. The physical properties of the products showed that the oil produced was of high quality with high carbon, hydrogen, and calorific value. Two-dimensional gas chromatography/time-of-flight mass spectrometric analysis results indicated that the oils were complex mixtures of alkanes, benzene derivative groups, and nitrogen-containing compounds. In addition, 13C NMR results confirmed that long aliphatic chain alkanes were evident. The alkanes were likely converted from furans that were decomposed from hemicelluloses. Ablative pyrolysis under vacuum proved to be a promising option for generating useful amount of bio-oils from tobacco residues.

Maize is a popular field crop in Thailand for animal feed production. The country dedicates more than six million hectares to maize cultivation, and its total output amounts to about five million tons. The harvest of maize results in three primary residues: roots, stalks, and leaves. Over 80 % of these residues are disposed of in the cultivated area itself, usually by open burning. This practice releases large amounts of pollutants (such as the hazardous particulate matter known as PM2.5) into the atmosphere. Pelletisation represents one promising alternative to such strategies as open burning. The main objective of this study is to provide an overview of the pelletisation process in order to guide future attempts to increase efficiency and sustainability in maize pellet production. Thai standards for the production of pellets are compared with international standards, and the effects of differences in pellet composition on combustion efficiency are discussed. The results of this study can serve as a guideline for spearheading zero-waste agriculture initiatives and promoting the use of renewable resources like pellets for utilisation in biomass power plants, per the recommendations in the Alternative Energy Development Plan (AEDP 2012-2021).

Biodiesel is a renewable, carbon neutral liquid fuel produced from vegetable oils or animal fats with alcohol via catalytic transesterification reaction. Conventionally, alkaline-catalysed transesterification using convective heating takes long time to complete. Alkaline catalysts used are usually non-recyclable, environmentally unfriendly and could react with free fatty acids to form soap. Recently, ionic liquids have been shown to be effective in catalyzing transesterification. Furthermore, microwave irradiation has been shown to boost heat transfer to the reactants, making the reaction time shorter than the conventional heating. In this work, biodiesel production from microwave-irradiated transesterification of palm oils with methanol using a green ionic liquid was investigated. The ionic liquid (ChOH) was synthesized from choline chloride (ChCl) with potassium hydroxide (KOH) and characterized by Fourier transform infrared spectroscopy. The batch experiments were setup and carried out in an 800 W microwave oven with a flask reactor connected to a condenser. The continuous experiments were setup and carried out with a polytetrafluoroethylene (Teflon) tubing connected to a Teflon valve and a pump. Operating condition was oil to methanol ratio (1:15), reaction time (8 min), power of microwave (800 W), and catalyst loading (4 wt%). Methyl ester content was determined by gas chromatography and mass spectrometer. From the findings, it was shown that the ionic liquid was effective in catalysing transesterification of palm oils. Microwave heating proved to accelerate the reaction in short time. The methyl ester content was found to be 87 and 82 % for the batch and continuous experiments. The ester content was quite low, compared to the conventional heating. Further investigation was needed to find high biodiesel yield. The ChOH could also be reused several times but its effectiveness to produce biodiesel may be degraded, in comparison with the fresh catalyst.