Papers by Keyword: Lignin

Abstract: The growing energy crisis and environmental challenges have spurred the development of sustainable energy storage solutions. This study synthesizes 3D porous Orange Peel-Lignin activated carbon (OPLAC) from orange peel waste and lignin using a two-step pyrolysis process with KOH activation. The OPLAC was combined with styrene-isoprene-styrene (SIS) and SUPER P conductive carbon black to create stretchable electrode composites with varying compositions (70:20:10, 60:30:10, and 50:40:10). Mechanical testing revealed that increasing the SIS content improved stretchability, with the 50:40:10 composition achieving 300% strain and retaining 95% durability after 100 cycles. However, higher SIS content reduced electrical conductivity, with the 70:20:10 composition showing the highest conductivity (12 S/cm) and the 50:40:10 the lowest (7 S/cm). The 60:30:10 composition offered a balance between flexibility and conductivity. These results demonstrate the potential of biomass-derived activated carbon for sustainable, high-performance supercapacitor electrodes, particularly for flexible electronics and wearable devices, while highlighting the valorization of agricultural and industrial waste in energy storage applications. Keywords: Stretchable electrode, activated carbon, orange peel waste, Lignin, flexible electronics

Abstract: In this study, a bio-based slow-release nitrogen (N) fertilizer was developed using a novel composite material composed of natural rubber (NR) and lignin. To enhance its performance, the composite was further modified with epoxidized natural rubber (ENR), cassava starch (CS), and carboxymethyl cellulose (CMC). The chemical and mechanical properties of the resulting composites were thoroughly characterized using FT-IR spectroscopy and tensile strength measurements. FT-IR analysis revealed strong chemical interactions, particularly-COO stretching from CMC and-OH stretching from epoxide ring-opening and lignin, in the Lignin/NR/ENR/CMC composite. Among all formulations, the Lignin/NR/ENR/CMC film exhibited the highest tensile strength, indicating superior mechanical performance. The slow-release behavior of the composites was evaluated by monitoring cumulative nitrogen release in water. The Lignin/NR/ENR/CMC/Urea formulation demonstrated the most prolonged and controlled release profile, attributed to strong chemical interactions between CMC and the lignin matrix. SEM analysis further confirmed that CMC formed a uniform coating and potentially encapsulated lignin particles. This bio-based composite not only improves mechanical strength and chemical stability but also significantly enhances slow-release performance, making it a promising and sustainable alternative for agricultural fertilizer applications.

Abstract: Growing concerns on environmental deterioration is driving the research towards the use of renewable resources in the production of various materials. Biomass feedstocks, such as agricultural and food industry residues, present many advantages as these are widely available, can be inexpensive resources for commercial biorefineries, and can help in the waste reduction in most industries. In the Philippines, ample mango waste is generated due to its flourishing mango processing industry. Mango wastes have already shown valorization potential in numerous studies, however, studies on mango seed husk (MSH) are still limited. This study characterized the lignin found in MSH derived from kraft pulping as phenol substitute in the phenol-formaldehyde (PF) resin synthesis. During kraft delignification, the effects of alkali charge (7.3-20.7% Na₂O), temperature (130-180°C), and liquid-to-solid ratio (LSR) (6.59-23.41 w/w) on the lignin yield were examined using central composite design. The model obtained showed that lignin yield is influenced by the process variables in the following order of decreasing significance: alkali charge, LSR, and temperature. Moreover, low R² values are observed suggesting that there may be other factors affecting the response not considered in this study and that the model has low predictive power. In addition, MSH lignin was isolated from the black liquor by single-step acid precipitation at pH 2 with 20 wt% H₂SO₄. Characterization using FT-IR and difference UV spectroscopy showed that kraft MSH lignin could be a great potential as phenol substitute in PF resin production as it is mostly represented by guaiacyl units and has high total phenolic hydroxyl groups content (3.38 mmol/g). MSH lignin, with its high phenolic hydroxyl content and guaiacyl structure, has diverse industrial applications beyond resin synthesis. It can be used as a natural antioxidant in polymers, a bio-based adhesive for wood products, a UV-absorbing agent in coatings, a precursor for carbon fibers, and a surfactant in concrete and agricultural formulations. Additionally, its antimicrobial properties make it suitable for pharmaceuticals and cosmetics.

Abstract: As the world shifts from a fossil-based to bio-based economy, energy production via the valorization of biomass residues is promising. However, raw biomass utilization for energy production proves to be challenging owing to their low bulk densities and hygroscopic nature. These problems are addressed through briquetting. This work focuses on the utilization of sugarcane bagasse (SCB) – an abundant agricultural residue in the Philippines – with lignin as a binder for solid fuel briquettes. The effects of SCB-to-lignin ratio and compaction pressure on the fuel characteristics and quality of the briquette were investigated. Briquetting experiments were carried out in a Carver press at a constant pressing temperature of 150°C and varying compaction pressures (CP = 5, 8 and 11 MPa) and binder content (BC = 4, 8 and 12%). Briquetting of SCB resulted in an increase in bulk density by 7 to 8 times (0.817 ± 0.006 - 0.974 ± 0.029 g/cm³) compared to loose SCB (0.110 ± 0.000 g/cm³). From ANOVA, it was found out that CP significantly affects bulk density (p < 0.05). The higher heating value (HHV) and compressive strength (CS) rose to as high as 19.7 ± 0.1 MJ/kg_db, and 113.14 ± 2.81 MPa, respectively. It was found out that BC significantly affects the HHV (p < 0.05) but has an insignificant effect on the CS (p > 0.05) while CP has insignificant effects on both HHV and CS (p > 0.05). Overall, SCB-lignin briquettes are able to overcome storage and handling challenges through improved bulk density, stacking capability of up to ~550,000 briquettes at the lowest achieved CS, retarded moisture uptake rate (0.0611 ± 0.0017 wt% per hr) and an equilibrium moisture content of 8.02 ± 0.15 wt%, making this fuel viable for domestic usage as determined by current briquetting standards.

Abstract: Traditional deflocculants containing chromium in high-temperature and high-pressure (HTHP) wells present health hazards due to chromium toxicity. This study aims to tackle this issue by creating a heat-resistant diluting ingredient for water-based drilling mud (WBM) produced from easily accessible natural resources. The synthesized compound demonstrated exceptional heat resistance by employing an organosolv extraction method using formic acid, followed by cross-linking with tannin. It maintained stability even at a high temperature of 150 °C. Adding the agent to mud formulations significantly resulted in superior rheological properties, as 0.6 w/w % agent ratios led to greater thinning and control of viscosity. The study found that increasing tannin-lignin content effectively reduced plastic viscosity at higher temperatures, mitigating viscosity buildup. Apparent viscosity was highest at 0.2 w/w % tannin-lignin but decreased with rising temperatures, improving mud circulation for deep-well applications. While tannin-lignin from oil palm biomass fiber exhibited the highest yield point at 100 °C, the yield points generally declined at 150 °C, reaching a moderate value beneficial for hole cleaning. A slight pH reduction with temperature-affected rheology, with an optimal pH range (8.0–10.5), is required for effective WBM performance. This environmentally conscious solution has a considerably diminished ecological impact compared to chrome-based alternatives, promoting safer and more sustainable drilling methods. It enhances resource efficiency by harnessing biomass resources, reduces the use of hazardous chemicals, and facilitates safer operations due to its non-toxic composition. Later research may concentrate on enhancing the utilization of agents and investigating alternate biomass sources to achieve broader applicability. This sustainable thinning agent represents a possible alternative for HTHP WBM applications, facilitating a more environmentally friendly and safer future in the drilling sector.

Abstract: The Philippines still relies heavily on oil and coal as energy fuel sources, contributing to approximately 63.21% of the energy mix. It is crucial to seek alternative feedstock that can comply with the increasing demand. This study thus investigated the energy potential of bolo (Gigantochloa levis (Blanco) Merrill) along the bottom, middle and top culm height portions, for bioenergy applications. The top culm was consistently observed to have the lowest moisture contents and the highest relative (0.4757 g/mL) and bulk (0.2003 g/mL) densities. Proximate analysis revealed a significant increase in average fixed carbon (FC) content from top (19.18%) to bottom (20.88%), while ash content showed the opposite trend, ranging from 3.59% to 5.92%. The average volatile matter (VM) content (74.90% - 75.53%) showed no significant variation along the culm. Lignin content was also analyzed and its correlation with FC and VM reveal a parabolic relationship with R² values of 0.84 and 0.63, respectively. Despite the top section having the lowest higher heating value, its higher density and lower moisture content resulted in the highest calculated energy density (8.13 GJ/m³ in chipped form), suggesting that the top portion has the best potential as a biomass energy source for direct combustion.

Abstract: The growing rise in agricultural activities has resulted in an increase in unutilized waste which is a significant contributor to greenhouse gas emissions. This has led to a need for sustainable methods to add value to such waste. This work focused on the transformation of agricultural waste into usable products through alkaline treatment to obtain lignin and cellulose, and the evaluation of the derived lignin as a viable carbon precursor in energy storage applications. Laser scribing was used as a fast and simple strategy in producing laser-induced graphene (LIG) electrodes. Lignin was isolated from wheat straw using sodium hydroxide treatment. The pulp from the treatment was subjected to bleaching with sodium chlorite followed by acid hydrolysis to extract microcrystalline cellulose. Fourier-transform infrared spectroscopy (FTIR), Transmission electron microscopy, and Xray diffraction were used for characterization of the materials produced. The fabricated supercapacitor could achieve an areal capacitance (C_A) of 5.12 mF/cm² (0.02 mA/cm²). This study illustrated the successful valorization of wheat straw residue into microcrystalline cellulose and the use of extracted lignin in producing graphitic carbon electrodes for supercapacitors.

Abstract: Lignin is the largest component of biomass and the second most abundant natural polymer. Lignin-based products are commonly applied as binders, and are utilized for polymer applications. The purpose of this study is to use lignin as an admixture in mortar. The lignin dissolved in 1M NaOH solution, and the ratio was 1:5 by weight. The lignin contents utilised in this study were 1%, 2%, 3% by weight of cement and a cement water rasio of 0.4. Lignin as an admixture in mortar increased the flowability value. The flowability value increased as the lignin content rose. the highest compressive strength and flexural strength occured at 1% lignin content. They were 35.71 MPa and it was 5.49 MPa, at the age of 28 days. The longest setting time was obtained at 3% lignin content for initial setting time of 285 minutes, and final setting time of 540 minutes. Based on the results of the setting time test, it has been determined that the more lignin was mixed in, the longer the setting time will be. Therefore lignin as an admixture to the mortar makes changes its characteristics.

Abstract: Sugar palm fruit shell is one of the biomass wastes that contains lignocellulose. Lignin is a valuable material that can be earned from the isolation of lignocellulosic material. In this work, lignin was isolated from palm fruit shell waste by Klason method with 72% sulfuric acid after removing free extractive by soxhlation process. The isolated lignin was analyzed to determine the functional groups, surface morphology, and thermal stability using Fourier Transform Infrared spectroscopy, Scanning Electron Microscopy and Energy Dispersive X-ray. This work aimed to isolate and characterize lignin from palm sugar fruit shells. The yield of lignin in this experiment was 27%. The water content, ash, and lignin pH obtained were 4.50%, 3.41% and 9.98. The Fourier Transform Infrared spectroscopy spectra showed the many functional groups contained in lignin, such as carbonyl, hydroxyl, amine, ether, methoxy, and aromatic components. The Scanning Electron Microscopy showed a rough and porous surface. The Energy Dispersive X-ray showed the elemental composition in lignin, such as carbon, oxygen, and some inorganic elements. The Thermogravimetric Analysis showed that weight loss of lignin reached 47.948 % or 5.082 mg at 600°C. The characteristics of lignin obtained from sugar palm fruit shell by Klason showed that it had potency as a good material for further application.

Abstract: The high difference in surface tension between the filler and the polymer often constrains membrane compatibility. To reduce the surface tension, organosilane such as GPTMS is usually used to improve miscibility. In this study, GPTMS was introduced to produce lignin-GPTMS (LG) and lignosulfonate-GPTMS (LsG). The modification was done by reacting lignin and lignosulfonate with GPTMS using ethanol as the media. The product was characterized using Fourier Transform InfraRed (FTIR), X-ray Diffraction (XRD), Particle Size Analyzer (PSA), Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX) and microscope. The success of functionalization was shown in FTIR spectra with the vibration of Si-O at 1034 cm^-1 and 528 cm^-1. The XRD analysis presents that the filler material has an amorph and crystalline structure. The functionalization using a 2:1 ratio increases zeta potential absolute and particle size due to the silane being a bridge and making a larger macromolecule. For a ratio of 1:1, a higher organosilane compound results in breaking siloxane linkages and making smaller molecules. Mixed LG and LsG into PVDF membrane conducted to analyze filler compatibility. The sulfonation and functionalization of GPTMS increase the compatibility of lignin in PVDF membrane with the best homogeneity achieved by a membrane with the addition of LsG 1:1.