Proceedings of the 3rd International Conference on Biomass Utilization and Sustainable Energy; ICoBiomasSE 2023; 4–5 September; Kuala Lumpur, Malaysia

The problem with municipal solid waste (MSW) in Thailand necessitates the well-planned MSW management is important. The perceptive classification of waste is the effective tool to design MSW management and waste separation campaign. It was found that the perceptive classification of the waste was significantly graded in order to the characteristics of the waste. The certain numbers of the wastes were high perceptive classification to the target category. Thus, the perceptual classification of these wastes did not prevent their separation into the designated waste bin. On the other hand, careful attention was required to increase the perception classification of aluminum foil as recyclable waste. The perceptive classification of recyclable waste on aluminum foil was too low, and it was around 37.66%. Misclassification may result from a misunderstanding of the waste type. In addition, some wastes were hardly segregated to a specific category, and there were depending on the implementation process in the MSW management system. For example, the perceptive classification of tissue paper as compostable wastes was low. To design the composting process including the input of tissue paper, the campaign to improve the perceptive classification on tissue papers was recommended. In contrast, the implementation of composting without the input of tissue paper did not need the campaign to modify the perceptive classification on tissue papers. Therefore, the significant findings of this study will be the designing tools to enable the effective and sustainability MSW management.

Hydrophobic deep eutectic oil (menthol-thymol)-in-water nanoemulsion was developed to preserve the quality of banana fruit and extend their storage shelf life. Storage preservation of bananas presents several challenges due to their high respiration rate, ethylene production, and susceptibility to various physiological and biochemical changes. The storage shelf life of bananas is relatively short compared to other fruits due to the combination of rapid ripening and sensitivity to ethylene and temperature. In this study, the effectiveness of HyDEN treatment was assessed on changes in banana fruit’s physiological parameters such as firmness, weight loss, total soluble solids, titratable acidity, and colour for 14 days storage time [25 °C ± 1 °C, 67% relative humidity (RH)]. HyDEN treatment preserved the physicochemical characteristics of banana fruit and was effective in delaying the ripening process. The storage shelf life of banana fruit treated with HyDEN increased for 14 days compared to control that ripened and physically damaged after 8 days of storage. This study provided a new delivery system for applying HyDEN as an edible coating to fruit after harvest preservation.

Global demand for biofuels is predicted to upsurge in the future to unravel the scarcity of fossil fuel source and its environmental impact. Lignocellulosic biomass (LCB), derived from agricultural and industrial wastes, is a promising feedstock for biofuel production because of its advantages such as wide availability, economical, and no issue of food competition. Thus, it provides a significant contribution to meeting the biofuel demand. This study investigates the characteristics and the bioenergy potential of queen pineapple waste (QPW) from the processing facility in Camarines Norte, Philippines, for biofuel production. The physical and chemical characteristics of untreated QPW were determined via proximate and ultimate analyses, respectively. The structure of the QPW (lignin, hemicellulose, and cellulose) was determined through compositional analysis. QP waste was pre-dried at 150 °C for 5 h to lower its moisture content down to ≤ 10%. The pre-dried samples were ground and sifted to reduce the particle size. The torrefaction method was employed to produce biochar in a minimal oxidative atmospheric condition using a muffle furnace with temperature levels and reaction time as variables. Lastly, the bioenergy potential test of raw, pre-dried, and torrefied samples was carried out using a bomb calorimeter. The results revealed that the torrefaction technique increased the higher heating value of raw-dry biomass by 13–68%, depending on the reaction severity.

This study investigates thermogravimetric analysis (TGA) and kinetics study (KS) of the co-gasification of municipal solid waste (MSW) and wood pellets (WP) using flue gas as the gasification medium. Our novel decoupling gasifier design facilitates a gasification process utilizing flue gas as the reaction medium. Therefore, studying the thermal decomposition characteristics of MSW and WP during this unique gasification process is crucial. Thermal decomposition exhibited two stages based on mass loss and the rate of mass loss. The maximum mass loss rate occurred during the first stage for all samples at temperatures of 286.5/318 (two peaks), 286.5, and 293.4 ºC for 0WP100MSW, 10WP90MSW, and 20WP80MSW, respectively. The addition of WP to MSW significantly increased the DTG maximum value and eliminated the second decomposition peak of MSW. KS illustrates that the E value decreased from 19.70 to 3.35 kJ/mol under air and 64.05 to 2.12 kJ/mol under flue gas with the addition of 20%wt wood pellets.

Global warming and reduced reliance on fossil fuels for electricity generation have prompted many nations to pursue sustainable energy alternatives. Singapore's future carbon tax pricing will subsequently increase in coming years; from 2019 to 2023, the initial carbon pricing scheme is set at S$5/tCO₂e and scheduled to increase by S$25/tCO₂e in 2024. The CFB boiler in Tembusu Multi-Utilities Complex consumed coal fuel in co-firing with biomass, contributing to higher carbon emission than biomass fuel. The study aims to reduce coal consumption by increasing the feed flow of palm kernel shells and woodchips fuel by improving the fuel feed ratio in coal-biomass co-firing use in the CFB boiler. The study highly safeguards the boiler's safe operating limits and reliability; the as-built and design specifications of the boiler are identified and reviewed before the adjustment test. The study assessed the effects of fuel feed ratio adjustment on the boiler's critical parameters, and no significant impact was observed. The revised 59:41 fuel feed ratio is obtained, compared to the original 80:20 design ratio. The emissions have shown promising results in reducing the following pollutants: SO₂ by 65.33%, NO_x by 5.59%, Mercury by 19.98%, CO by 36.74%, and opacity by 3.83%, while CO₂, dust, and excess %O₂ were maintained. The fly ash and bed ash physical properties are also improved and beneficial for both fly ash collectors and bed ash recycling life. The boiler efficiency increased by + 0.79% as the revised mixed fuel specific heat input and other heat credits increased.

Malaysia’s palm oil industry generates a significant amount of biomass waste, particularly empty fruit bunches (EFB). The conventional heating methods used in pyrolysis for converting EFB into value-added products are carbon-positive and decrease energy efficiency. Therefore, this study aims to explore the feasibility of solar pyrolysis using a Fresnel lens in Malaysia. The performance of the Fresnel lens-based solar pyrolysis reactor was evaluated, focusing on its thermal characteristics and biochar yield. The results indicated that, in the absence of EFB, the highest temperature within the reactor at the Fresnel lens’ focal point was 618 °C and the maximum solar irradiance value was 987 W/m². When EFB was introduced, the temperature inside the reactor was maintained at around 500 °C. Biochar yields reached 40–45% for residence times of 20–30 min. These findings demonstrate the potential of concentrated solar energy for converting EFB into renewable energy and endorse the suitability of the Fresnel lens in harnessing solar energy for the pyrolysis process in Malaysia.

Developing a briquette made from empty fruit bunch (EFB) fibers and using it as a source to produce biomass gas is one of the potential ways to solve the waste management issue of palm oil EFB in the palm oil industry. At the same time, it will also contribute to diversifying the alternative renewable energy sources in Malaysia as encouraged by the government through sustainable development goals (SDG) plans. However, briquetting raw EFB fibers is challenging due to the properties that contain lignin and cellulose content and lower combustion characteristics produced by the briquette. Therefore, thermochemical pretreatment of EFB through the carbonization process could remove this limitation. This study aims to evaluate the quality characteristics of carbonized EFB briquette and its effects on the quality of the biomass producer gas (BPG) produced. Experiments were conducted by carbonizing the raw EFB fibers with a temperature and heating time range of 350–400 °C and 40–60 min, blended with tapioca starch as a binder, and densified into a briquette. Briquettes were then combusted in the downdraft gasifier to produce the BPG. From the analysis of the carbonized EFB briquettes, results indicate the high heating value (HHV) ranged from 21.39 to 23.62 MJ/kg, and fixed carbon and ash content varied from 50.89 to 56.94% and 7.49 to 10.93%, respectively. This study also discussed the relationship of the HHV with fixed carbon and ash content in producing BPG. Overall, carbonization treatments reduce the generation of tar, and the quality of BPG increases when the carbonized EFB briquettes are gasified.

MD2 pineapple is one of the most popular pineapples because of its sweetness. The sweetness of the MD2 pineapple varies depending on the geographical location and cultivation technique, fruit parts, and maturity at harvest. This study focuses on the effect of maturity at harvest and the fruit parts used on the physicochemical and phytochemical properties of the MD2 pineapple. The pineapples were harvested at three different maturity stages, i.e. mature-green, ripe (50% yellow peel), and over ripe (100% yellow peel). Then, each pineapple was cut horizontally to obtain three different parts of the pineapple, namely the top, middle, and bottom and the juice was extracted from each part. The volume recovery percentage, total soluble solids (TSS), and pH were found to increase for each part from mature-green to overripe except for titratable acidity (TA) which decreases. Total phenolic content (TPC) and total flavonoid content (TFC) were found to increase from mature-green to ripe but decrease from ripe to over ripe fruit. The proteolytic activity increases, while vitamin C content decreases with fruit maturity. The total protein was found to be not significantly affected by fruit maturity. TSS, pH, and proteolytic activity show an increasing trend from the top to the bottom of the pineapple, while TA and vitamin C content show the opposite trend. The middle and bottom parts of the pineapple were found to have the highest proteolytic activity.

Bioresorbable functional particles offer unique advantages based on different synthetic strategies, with the activated moiety may achieve various targeted drug delivery to minimize side effects. Thus, in this study, a highly MO-loaded adsorptive smart-assembled natural clay (montmorillonite, MMT) dispersion onto poly (ε-caprolactone) nanoparticles matrix (hereafter known as MO-loaded MMT/PCL NPs) is formed by solvent displacement method. MMT is selected due to its great drug loading ability due to high specific surface area and grants mucoadhesive properties with tortuous pathway needed for drug delivery across the gastrointestinal barrier. The MO-loaded MMT/PCL NPs are synthesized by self-solvation interaction between the organic phase that composed of dissolved 1 g L⁻¹ PCL, 2–20 wt % of MMT, and 0.6–3.0 g L⁻¹ of MO in acetone and the aqueous phase consisted of 0.2 wt% poly (vinyl alcohol) surfactant solution. The injection rate of organic phase was fixed at 5 mL min⁻¹ with volume ratio aqueous phase to organic phase (V_aq/V_or) between 3–10, and 600–1200 rpm of stirring speed. The inclusion of MMT in polymer was found to improve the entrapment of hydrophilic MO, hence hindering untimely drug leakage. Particle size decreased with increasing the stirring rate and the aqueous-to-organic volumetric ratio as well as the concentration MMT, thus resulting in drug encapsulation efficiency and drug loading up to 30–50 and 5–10%, respectively. The encapsulation of MMT and MO in the NPs was confirmed by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy.

This study investigated the co-composting of food waste and cow manure and the resulting compost product properties. Food waste composition and the source of waste were also studied. Food waste composition survey showed that carbohydrate was the main constituent of food waste. The composting experiment was conducted by using an aerobic method at 45–60 °C for 24 h to achieve maximum thermophilic microbe activity. It was found that addition of 30% cow manure produced compost with pH of 6.17, moisture content of 27.4%, as well as having high phosphorus (P) and potassium (K) content at about 1.48% and 2.13%, respectively. Overall, it was found that short composting time could still produce high-quality compost by applying proper heat and environment control to optimize the aerobic digestion process.

Synthesis parameters such as cellulose (1–5% w/v) and surfactant (0–6% w/v) concentrations are investigated and optimized on controlling the mean diameter of cellulose beads. Cellulose fibers from printed paper wastes are extracted and used to prepare cellulose beads via a water-in-oil (W/O) microemulsion and precipitation techniques. Different cellulose solutions of concentrations were prepared by dissolving cellulose fibers in NTU solvent (NaOH: thiourea, urea, 8:6.5:8% w/v). Cellulose beads were precipitated out by dilute acetic acid solution. Under FESEM, it was observed that smaller cellulose beads (≤ 1 µm) were formed with and without surfactant, which in this case, Span 80 (Sorbitan monooleate). Spherical beads with porous surfaces were shown when surfactant concentration increased. The smallest mean diameter was 0.166 µm at 1% w/v cellulose concentration without Span 80, while the largest mean diameter of 1.153 µm obtained from 5% w/v cellulose concentration and 6% w/v Span 80 concentration. Hence, small size cellulose beads of high specific surface area, low-cost and environmentally friendly are potentially useful as control release carriers.

Harumanis mango is one of the best mangoes in the world, and it is only produced in Perlis, Malaysia. Pruning of the Harumanis plant is an important and routine step to maximize both the quantity and quality of the fruits. During pruning season, a lot of leaves and branches are typically discarded. The leaves can however be upcycled into a source of phytochemicals and antioxidants, and this may be used to partially offset the cost of producing the Harumanis. Therefore, in line with zero waste practice, this study examines the phytochemical content and antioxidant activity of young and matured pruned Harumanis leaves. Microwave-assisted extraction (MAE) with water as the solvent was used to extract the phytochemical and antioxidant compounds. The total phenolic compounds (TPC) and total flavonoid compounds (TFC) were then quantified, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay was used to determine antioxidant activity. It was found that ground leaves sieved to a particle size of 200 mesh, a sample-to-solvent ratio of 2:50 (g/mL), and a sample size of 2 g yielded the best results for extracting antioxidants and phytochemical compounds from young and matured leaves. The matured leaves were found to contain higher TPC and TFC values (11.05 ± 1.10 mg GAE/g and 46.98 ± 0.03 mg QE/g, respectively) compared to young leaves (10.30 ± 0.03 mg GAE/g and 39.34 ± 0.05 mg QE/g, respectively). However, DPPH activity was found to be higher in young leaves compared to matured leaves (75.78 ± 0.48% and 70.52 ± 0.83%, respectively). It is concluded that both young and matured Harumanis leaves are a good source of phytochemicals and antioxidants.

The presence of nickel in industrial waste has emerged as a significant environmental concern, predominantly attributed to the plating industry. The significant objective of this study is to optimize the precipitation and leaching method to extract valuable nickel from the waste material. The high concentration of nickel found in the waste makes it a potentially valuable resource. To explore its potential extraction, the precipitation and leaching processes were optimized using a simulated Watts bath solution which is widely employed in the industry. This study focuses on examining the influence of pH, contact time, and sulfuric acid concentration on the extraction of nickel concentration during the precipitation and leaching processes. To develop a prediction model for the process, three models were taken into consideration: quadratic, linear, and 2F1. The quadratic model exhibited the greatest adjusted R² value, suggesting a superior level of fit in comparison with the linear and 2F1 models. The predicted R² value of 0.8169 exhibits a satisfactory level of concordance with the adjusted R² value of 0.9737. The recommended optimal conditions proposed by response surface methodology (RSM) consisted of a pH value of 10.56, a contact time of 16.52 h, and a sulfuric acid concentration of 1.80 M in order to achieve a nickel concentration of 28,415 mg/L.

Used cooking oil (UCO) is a vegetable or animal-based oil that is generated from cooking and frying foods at room temperature. The UCO which mainly consists of fats and oils is originating from the commercial or industrial food processing operation, including the restaurants. The growing of human population has induced a large quantities of UCO. In Malaysia, the disposal of UCO from the households and restaurants into the drainage and soil has become a major problem, which has caused the blockage of drainage and sewer system due to improper disposal of practices of UCO wastewater. Therefore, a study was conducted in order to remove the oil from the UCO wastewater by using the modified kapok fibre (MKF) through the esterification reaction. In this study, the effect of calcium oxide (CaO) catalyst percentages added in the esterification was investigated. Based on the results, the adsorption capacity showed that the MKF was able to adsorb UCO up to 12.46 ± 0.5 (SE) g of oil/g with the oil removal of 27.25% by using 5 wt% CaO. As the percentages of CaO increased to 10 wt% CaO and 15 wt% CaO, both of adsorption capacity and oil removal were increased at 15.26 ± 0.6 (SE) g oil/g (33.37%) and 19.93 ± 1.3 (SE) g oil/g (43.58%), respectively. Therefore, it was found that the increasing in CaO percentages resulted in higher adsorption of UCO and percentage of oil removal. The maximum percentages of CaO was obtained by using 15 wt% CaO, where it gave the highest adsorption capacity and oil removal efficiency.

Volatile compounds are emitted as gases from certain solids or liquids. These compounds are important in agricultural production as plant growth enhancers, fruit ripening agents, and pesticides. Ca-alginate beads have been used to control the release of volatile compounds. This study aims to investigate the effects of process variables on gas release (carbon dioxide gas was used as a model gas) from free and latex-coated floating calcium alginate beads. Floating beads were prepared from a sodium alginate solution containing calcium carbonate (CaCO₃) as a gas-forming agent. The resulting solution was then extruded into a calcium chloride (CaCl₂) solution and coated with latex solution. The effect of alginate concentration and extrusion tip diameter on beads size was investigated. The results indicated that increasing alginate concentrations and the extrusion tip diameter led to the formation of larger beads. Moreover, the gas (CO₂) released from free and latex-coated beads was studied. It was observed that the release rate of CO₂ from free-floating beads increased with the increased extrusion tip diameter but decreased with increasing alginate concentration. Instead, applying latex coating on floating calcium alginate beads could provide the controlled release of CO₂.

Spent mushroom medium and dried sludge from bioethanol industry can be utilized into beneficial organic compost after completion the composting process. Food waste fermented liquid and commercially effective microorganisms (EM) from EMRO Sdn. Bhd. were used as the microbial inoculant for the aerobic composting. Three kg of composting pile made of spent mushroom and dried sludge are used to obtain a 23.07 C/N ratio at the initial composting process. In order to ascertain the impact of composting process in seven days, the sample from each of the composting beds for analysis of temperature, pH, moisture, and total organic matter was assessed. Food waste fermented liquid and commercial EM composts reached the thermophilic phase (40 °C) after a day of the composting process. Moisture content showed a significant result for both composting piles on day 1 due to the highest evaporation of water at the thermophilic phase. The composting process was not extended until reached stability and maturity phases; thus, the pH for both composting piles was recorded at 9, which is far from the stable compost normally at neutral pH (~7). The organic matter content of each composting pile showed gradually decreased during the composting process. The degradation rate for the composting pile using food waste fermented liquid showed slightly higher than commercial EM which was 0.0363 and 0.0232 day 1, respectively. In conclusion, food waste fermented liquid shall be used as a replacement for EM commercial as a microbial inoculant for the composting process based on the results shown in this study.

Wood is an important raw material, especially for construction and industrial scale activities which have resulted in a large amount of wood waste (WW). The accumulation of industrial WW has led to serious environmental issues; hence, the utilization of the industrial WW is being studied by researchers due to the rich content of cellulose. This study investigated the physicochemical properties of cellulose nanofibrils (CNFs) derived from industrial WW. The preparation of the CNFs involves the pretreatment of WW with an alkaline deep eutectic solvent (DES) and bleaching with peracetic acid, followed by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated oxidation and mechanical post-treatment. Interestingly, the yield of the CNFs produced was 52%, which is half of the raw material used. Furthermore, the morphology of the WW-derived CNFs was analyzed from scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The WW-derived CNFs showed a uniform size with a width of around 20–100 nm and a length of several micrometers. Moreover, the production of WW-derived CNFs was further verified by Fourier transform infrared spectroscopy (FTIR) for the surface functional groups, X-ray diffraction (XRD) for the crystallography, and thermal gravimetry analysis (TGA) for thermal stability. The results obtained from these characterization methods have proved the successful transformation of the industrial WW into a high-potential nanomaterial, which is the CNFs that can be used for further applications in paper making, composites, packaging, textiles, biomedicine, energy storage, and electronics.

Electricity demand in islands and remote areas is generally supplied by diesel generators or other fossil fuels because they are far from the utility grid. Nevertheless, the research trends nowadays are to reduce the reliance on fossil fuels by working on renewable energy. Renewable energy sources provide numerous benefits to rural and remote areas, including sustainability, environmental tolerance, low pollution, and economic advantages. However, the majority of renewable energy sources are uncontrolled and unpredictable. To address these drawbacks, hybrid systems involving the use of multiple types of renewable energy resources and/or traditional energy resources and/or storage systems have been developed. However, sizing for hybrid renewable energy can be difficult due to a number of factors, such as the sizing of system components and the integration of each component to optimize system performance. As a result, the primary purpose of this work is to conduct a review of the most recent configuration of HRES, techniques to addressing optimization issues, and evaluation indicators of hybrid renewable energy system (HRES).