Papers by Keyword: Biomass

Abstract: The conversion of biomass to graphite requires a catalyst to promote the graphitization process. Effective pre-treatment and activation of the carbon precursor are crucial for improving the efficiency and success of biomass graphitization using metal catalysts. In this work, we investigate the combined effects of HCl pre-treatment and single-step impregnation carbon with K₂FeO₄, along with KOH activation, on the graphitization process of Empty Palm Oil Fruit Bunches (EPOFB). X-ray fluorescence (XRF) data reveal that HCl pre-treatment effectively eliminates significant impurities, such as alkali metals, alkaline earth metals, and transition metals, which can hinder the graphitization process. XRD and Raman spectroscopy results indicate that the combination of HCl pre-treatment and single-step impregnation carbon with K₂FeO₄, along with KOH activation significantly improves the graphitic quality of the carbon. High-quality graphitic carbon with an IG/ID ratio of 12.35 for the sample CpreHCl_K₂FeO₄(0.07)_KOH_1200 (EPOFB carbon pre-treated with HCl, followed by impregnation with K₂FeO₄ and activation with KOH, and then pyrolyzed at 1200°C). This particular sample displays a porous surface morphology and has a surface area of 876.407 m²/g. This study underscores the importance of acid pre-treatment and chemical activation in optimizing the preparation of high-quality graphitic carbon from biomass.

Abstract: High nickel content in nickel manganese cobalt (NMC811, LiNi_0.8Mn_0.1Co_0.1O₂) resulted in high capacity but low structural stability. Surface modification of NMC811 via silica (SiO₂) coating is known to counter this problem, leading to better electrochemical performance. In this work, silica was synthesized from rice husk through sol-gel method with alkaline extraction followed by acidification process. The resulting silica was coated onto commercially available NMC811 to modify its surface via solid-state reaction method. The characterization results showed that the silica coated NMC811 demonstrated a higher conductivity and lithium diffusion coefficient of 2.85 x 10^-5 S/cm and 2.52 x 10^-14 cm²/s, respectively, compared to that of bare NMC811 (8.17 x 10^-6 S/cm and 1.75 x 10^-15 cm²/s, respectively). This result confirms that the silica derived from rice husk can be used as a potential low-cost material to modify the surface and thus to increase the electrochemical performance of commercial NMC811.

Abstract: In recent years, particular attention has been paid to the use of renewable energy, particularly biomass, for reasons related to both climate change and waste management. Biogas is frequently used in low value-added applications such as heating and fuel in engines, while it can be reformed into hydrogen, through certain process such as the process of dry reforming, of partial oxidation, of bi-reforming, or even of tri-reforming. The literature has indicated that the tri-reforming process is better than other reforming processes. Biogas tri-reforming is a simultaneous combination of endothermic dry reforming and steam reforming with exothermic methane oxidation, carried out in a single reactor to produce syngas which is an important feedstock for chemical production and energy vectors. Second, the process of tri-reforming overcomes several weaknesses of each main reform process. This article presents a new mathematical model of tri-reforming which will further optimize this type of process. The developed mathematical model was validated with literature data. Thus, the literature data used are among others, the optimal feed ratio in the tri-reforming process, CH₄/CO₂/H₂O/O₂ = 1:0.291:0.576:0.088. For optimal temperature and pressure, the data used are 1223 K and 5 bar respectively. This mathematical model makes it possible to achieve high conversion of methane (CH₄) and carbon dioxide (CO₂) coupled with high selectivity in hydrogen. The conversion rate of methane (CH₄) can reach 99% and that of carbon dioxide (CO₂) can reach 97%. The model is adapted with a high hydrogen selectivity: 2.88.

Abstract: The present research focuses on the development of highly efficient and lightweight electromagnetic wave (EMW) absorbers to address the growing issue of electromagnetic pollution. We investigate the use of carbon derived from biomass, specifically durian husks, to create carbon-based microwave absorbers with enhanced performance. A two-step process involving carbonization followed by potassium hydroxide (KOH) activation was employed to synthesize porous carbon materials. The microwave absorption properties were then analyzed using a vector network analyzer across a frequency range from 2 to 18 GHz, with a focus on key parameters such as reflection loss and complex permittivity. The sample, which was 2.0 mm thick and had 15% carbon nanomaterials mixed in with paraffin wax, had an optimal reflection loss of -30.8 dB at 12.8 GHz with an effective absorption bandwidth of 9.0 GHz, highlighting its strong electromagnetic wave absorption performance. The porous structure and large specific surface area significantly contributed to the material’s ability to absorb electromagnetic radiation. These findings highlight the potential of durian husk-derived carbon material as a highly effective and lightweight EMW absorber for practical applications.

Abstract: Coffee grounds are an abundant biomass rarely used and often thrown away for nothing. On the other hand, pyrolysis is an alternative technology for utilizing biomass such as coffee grounds into biochar, syngas, and bio-oil. The bio-oil resulting from pyrolysis can then be mixed with dexlite in a 1:1 ratio, which is then called B50. This paper aims to analyze the performance of a Diesel generator driven by a motor fueled by Dexlite (a Diesel fuel variant that has a minimum CN of 51 and contains a maximum of 1200 ppm sulfur) and a mixture of bio-oil resulting from the pyrolysis of coffee grounds at a temperature of 500 °C with Dexlite (B50), with variations in load power of 300 Watt, 1100 Watt, and 1300 Watt. Generator set performance analysis includes effective power, torque, specific fuel consumption, generator efficiency, and exhaust emissions. At a load of 1300 W with a rotation of 1600 rpm, the maximum effective power obtained is the same, whether the generator is fueled with dexlite or B50, around 1,440 kW. The maximum torque value for dexlite and B50 fuel is 8.6 Nm. The maximum specific fuel consumption (SFC) for dexlite fuel at a load of 300 W at 1600 rpm is 645.25 g/kWh. The maximum air and fuel ratio (AFR) is on the B50 with a load of 300 W at 2000 rpm, which is 1:47. The maximum thermal efficiency is at the B50 at 1600 rpm, around 66.6%. The maximum generator efficiency is 48% with dexlite fuel and B50. Regarding exhaust gas analysis, the maximum CO exhaust emission level is 475 PPM on dexlite. In contrast, the maximum H₂S level is 347 PPM on Dexlite, whereas the maximum O₂ concentration is 20.6% when the generator operates on B50. The analysis found that the performance of diesel generator engines with B50 fuel was better than pure Dexlite.

Abstract: The generation of organic waste has increased globally in recent years. One way to degrade waste more quickly and carry out the bioconversion process of organic waste is to use insects. This BSF has attracted researchers to cultivate and utilize this biomass to extract biochemicals. However, in this research, pupal skin melanin (PSM) from BSF waste is used to obtain melanin. Melanin is a group of blackish-brown pigments with strong physical, chemical, and antimicrobial properties. These properties can be used as an alternative biopolymer material for various environmental sustainability purposes. The melanin extraction method consists of three main steps, namely demineralization, deproteination, and deacetylation, which will be compared with the results of melanin purification from Sepia officinalis melanin (SOM). Characteristics using FTIR, SEM, and EDS to determine the comparison of the quality of melanin obtained from the extraction of pupal skin with commercial melanin from Sepia officinalis. The research results obtained from FTIR analysis show that there are distinctive peaks that correspond to the structure of melanin, including hydroxyl groups (-OH), amine groups (-NH), carboxyl groups (-COOH), and aromatic groups. For SEM analysis, the morphology of PSM and SOM shows differences in surface condition. The melanin resulting from Sepia officinalis is not homogeneous and contains many lumps or aggregates. Whereas the surface of melanin from pupal skin is more homogeneous or looks smoother, but there are still small aggregates on the surface. Furthermore, from the EDS analysis, the total pure concentration was 99.33% for SOM and 69.78% for PSM.

Abstract: This research aims to identify chemical composition and it’s leaching from concrete mixed with sugarcane bagasse ash. By manipulating percent of slump flow at 110±5%, sugarcane bagasse ash was employed as a pozzolanic material to partially replace cement at 0, 10, 20, 30, 40, and 50 percent by weight of binder in concrete. Cube specimens were cast and cured in water for 3, 7, 14 and, 28 days, respectively. The patterns of sugarcane bagasse ash morphology were performed by using Scanning Electron Microscope (SEM) to analyze physicochemical characteristics. Results of tests on the X-ray fluorescence (XRF) analysis from the ash and curing water at various times revealed that SiO₂ made up half of the components in sugarcane bagasse ash. Al₂O₃, CaO, Fe₂O₃, K₂O, P₂O₅, and MgO were the minor components. The calcium content from the 14-day period at 50% by weight of the sugarcane bagasse ash binder was higher than that of the other elements, according to the results of curing water. According to the results of 28-day water curing, potassium outnumbered all other elements in the replacement of sugarcane bagasse ash in every ratio.

Abstract: Sorghum (Sorghum bicolor (L.) Moench) is an agricultural commodity that produces waste, including stems, during its cultivation. Sorghum stems can be used as an alternative precursor for forming activated carbon (AC) with a high surface area by utilizing ZnCl₂ as an activator and followed by a pyrolysis process at 750 °C under N₂ gas. In this study, AC from sorghum stems was sequentially used as an adsorbent for heavy metals in wastewater, as well as applied as an anode material for lithium-ion batteries. From the characterization analysis, the synthesized AC has an amorphous structure, a high carbon content of > 90%, and a surface area of 1189 m²/g. AC was applied to adsorb 10, 50, and 100 ppm of metal cobalt (Co) at 30 °C. The adsorption isotherm and kinetics of metal Co showed an adsorption capacity of around 28.2 mg/g. The Langmuir isotherm model also describes Co adsorption and follows the pseudo-first-order equation. As for the Li-ion anode material, the ACs material is fabricated on a cylindrical battery with LiNi_0.8Co_0.1Mn_0.1O₂ as the counter cathode material. The specific discharge capacity results are 104 mAh/g at the voltage window of 2.7-4.3 V. The sequential utilization of sorghum stem-derived activated carbon can improve the product’s sustainability, and such an approach is promising to be applied in other biomass-based waste treatments.Keywords: Activated carbon, adsorption, battery, biomass, sorghum

Abstract: Nanocarbon synthesis from diverse sources has garnered significant attention, with a particular focus on materials derived from biomass. Carbon dots (CDs), due to their water solubility, low toxicity, and biocompatibility, have emerged as promising candidates for a wide range of applications. In recent years, CDs have found utility in several applications such as bioimaging, drug delivery, and biosensors. In this study, we present an eco-friendly, straightforward, and cost-effective technique for the synthesis of carbon dots through a hydrothermal reaction, utilizing peeled date palm midribs as the source material. High-resolution transmission electron microscopy, X-ray diffraction, UV-visible absorption spectroscopy, photoluminescence analysis, Fourier-transform infrared spectroscopy, and zeta potential measurements services to investigate the synthesized carbon dots' morphology, crystal and structure, and optical properties. The results show that the carbon dots had a size distribution ranging from 2.5 to 6 nm, and a crystallographic interplanar distance of 0.23 nm corresponding to the graphitic structure. When excited at a wavelength of 340 nm, the synthesized dots exhibited a prominent bluish emission at 420 nm, highlighting their potential for use in optical and biological applications. This work underscores the feasibility of harnessing sustainable biomass sources, such as date palm midribs, for the green synthesis of carbon dots with desirable properties, opening up new avenues for their utilization in cutting-edge technologies.

Abstract: Biomass waste is one of the promising resource for the production of bio oil. In this study, a mixture of biomass waste will be pyrolyzed in the presence of activated carbon and zeolite as the catalyst. The catalyst concentrations were varied at 2%, 4%, 6%, respectively. While, the pyrolysis process was carried out at 500°C, for 60 minutes, with a nitrogen flow of 3 L/min. The highest bio oil yield was obtained the pyrolysis process by using zeolite with 35% at 4% w/w of the catalyst concentration. The lowest acid number obtained was 42.92 on 4% zeolite catalyst with rice husk biomass as the raw material, the best viscosity was obtained on 4% activated carbon multi feedstock with a viscosity value of 4.96 cP. The best density was obtained in multi feedstock with 4% zeolite catalyst and rice husk with 4% zeolite of 0.996 g/mL.