Enhancing recycled-paper quality using cellulose nanocrystals from pineapple leaf waste Averroes Piliang, Nico Sihotang, Muhammad Ibadurrahman, Sri Rahayu, Zhihao Yen, Ronn Goei, Refi Ikhtiari, Alfred Tok, Saharman Gea Nordic Pulp and Paper Research Journal, 2026 Pineapple leaves, often found as waste in North Tapanuli District, Sipahutar District, contain high levels of cellulose, making them a potential source for extracting cellulose nanocrystals (CNC). This study employs the acid hydrolysis method, followed by ultrasonication, to produce CNC, a process known for its simplicity and effectiveness in removing amorphous cellulose. The Fourier transform infrared spectroscopy (FTIR) analysis at a wavenumber of 1,358 cm −1 , associated with S=O vibrations, indicates esterification during hydrolysis. Transmission electron microscopy (TEM) reveals that the extracted CNCs exhibit a rod-like structure with a diameter of 5.18 ± 1.61 nm. X-ray diffraction (XRD) results show a crystallinity index of 78 % and a crystal size of 2.35 nm. The CNCs were incorporated into used newspaper pulp at varying concentrations (0, 1.5, 3, 5, and 8 |wt%). The findings demonstrate that CNC addition enhances the mechanical properties of the paper, including grammage, tensile strength, tear index, and crack index, primarily due to hydrogen bonding interactions between CNCs and pulp fibers. The optimal improvement was observed with a 5 | wt% CNC addition, significantly increasing tensile strength, tear index, and crack index of the recycled paper.
Biochar-Based Catalysts in Hydrogen Production: Mechanisms, Activation, and Efficiency Ricky Andi Syahputra, Muhammad Irvan, Andriayani Andriayani, Basuki Wirjosentono, Karna Wijaya, Shiplu Sarker, Saharman Gea Trends in Sciences, 2026 Biochar, a carbon-rich material derived from biomass, has emerged as a promising catalytic platform owing to its low cost, wide availability, structural tunability, and environmental compatibility. This review provides a critical and mechanistically integrated assessment of biochar-based catalysts for sustainable hydrogen production across thermochemical and photochemical pathways. Rather than cataloging reported yields, the analysis adopts a standardized normalization framework, expressing hydrogen productivity primarily as mmol H₂ g⁻¹ catalyst h⁻¹ to enable reliable cross-study comparison. The review introduces a unified structure–property–performance perspective linking feedstock chemistry, activation strategy, and metal–carbon interactions to pathway-specific hydrogen productivity. Evidence indicates that feedstock-derived chemistry often exerts a stronger influence on catalytic behavior than pyrolysis temperature alone, while controlled metal doping—particularly with Ni, Fe, and Co—enhances active-site accessibility and stability. Activation treatments modulate porosity and surface functionality, yet excessive modification may induce structural degradation or catalyst deactivation. Beyond catalytic efficiency, biochar-based systems offer sustainability advantages through biomass valorization, reduced reliance on critical raw materials, and compatibility with circular carbon strategies. By integrating mechanistic insight, normalization rigor, and sustainability considerations, this review positions biochar not merely as a low-cost alternative support, but as a tunable catalytic platform for next-generation hydrogen technologies. HIGHLIGHTS Biochar provides a tunable catalytic platform for sustainable hydrogen production from biomass resources. Metal–carbon interactions significantly enhance catalytic activity, stability, and coke resistance. tructural tuning of biochar optimizes porosity, surface functionality, and thermal durability. Normalized hydrogen productivity enables consistent comparison across heterogeneous studies. A unified mechanistic framework guides rational design of next-generation biochar catalysts. GRAPHICAL ABSTRACT
Hydrogen generation from coconut shell bio-oil via steam reforming incorporating energy–energy analysis R.A. Syahputra, B. Wirjosentono, K. Wijaya, H. Susilo, D.H. Sinaga, et al. Global Journal of Environmental Science and Management, 2026 BACKGROUND AND OBJECTIVES: Tropical biomass residues like coconut shells are abundant and relevant for the transition toward low-carbon hydrogen. However, coconut shell bio-oil is rich in oxygenated aromatics that complicate reforming and accelerate catalyst deactivation. While many studies focus on catalyst performance, system-level assessments that jointly quantify process performance together with energy–exergy behavior, preliminary environmental indicators, and techno-economic implications for coconut shell bio-oil remain limited. The objectives of this study were to address this gap by comprehensively evaluating hydrogen production from coconut shell bio-oil via an integrated steam reforming process. METHODS: Process simulation was conducted in Aspen Plus V11 using the Peng–Robinson method. The bio-oil feed was represented by five compounds based on fast pyrolysis data: phenol (45.42 mole percent), guaiacol (34.34 mole percent), catechol (10.09 mole percent), vanillin (6.38 mole percent), and furfural (3.77 mole percent). Steam reforming was integrated with water–gas shift and pressure swing adsorption. Operating conditions were screened from 600 to 1000 degree Celsius and 5 to 9 bar. Energy–exergy analysis, a gate-to-gate environmental assessment, and a techno-economic evaluation were performed.FINDINGS: Hydrogen production increased sharply from 600 to 700 degree Celsius and then plateaued at 0.2332 to 0.2338 kilograms per hour above 800 degree Celsius, while pressure provided only modest gains. Heat integration shows that water–gas shift heat release (2.564 kilo Watt) nearly offsets the reformer/pre-heater duty (2.620 kilo Watt), increasing exergy efficiency from 46.7 percent to 54.3 percent. The environmental assessment reports a net carbon intensity of 8.5 kilograms carbon dioxide equivalent per kilogram hydrogen with water consumption of 18.5 liters per kilogram hydrogen. The techno-economic assessment indicates strong scale sensitivity, with capital cost of 2,743,530 United States Dollar and annual operating cost of 1,292,780 United States Dollar under the stated basis. CONCLUSION: The screening supports a practical operating window around 700 to 800 degree Celsius. Further gains are better targeted through improved heat recovery, steam management, purification recovery, residue valorization, and scale-up assessment rather than further temperature escalation beyond the plateau region.
Graphene oxide–bacterial cellulose composites for enhanced adsorption of rhodamine B from aqueous solutions A. Muhammad Afdhal Saputra, Farda Nata Syakira, Salwa Aqilah Luthfiyah, Safira Azkia, Muhammad Irvan Hasibuan, Marpongahtun, Andriayani, Ronn Goei, Sumiyyah Sabar, Saharman Gea Water Science and Engineering, 2025 Industrial effluents pose significant environmental challenges due to the presence of water-soluble organic dyes such as rhodamine B (RhB), necessitating the implementation of effective removal strategies. Although adsorption is recognised as a promising alternative to conventional dye removal methods, developing cost-effective, sustainable, and highly efficient adsorbents remains challenging. This study investigated RhB adsorption using the bacterial cellulose (BC)/graphene oxide (GO) composite. GO was incorporated to enhance adsorption capacity by improving electrostatic interactions and introducing additional functional groups. The methodology involved synthesising GO from Sawahlunto coal, preparing BC/GO composites with varying GO contents, and conducting RhB adsorption experiments across different pH levels. Comprehensive characterisation confirmed successful GO synthesis and integration into the BC matrix. While pristine BC exhibited limited RhB removal efficiency and adsorption capacity (42.04% and 0.093 4 mg/g, respectively), BC/GO demonstrated significantly improved performance. The optimal composite containing 50 mg of GO achieved a removal efficiency of 98.91% and an adsorption capacity of 0.219 mg/g. Further optimisation at a pH value of 3 enhanced adsorption efficiency and capacity to 99.50% and 0.221 mg/g, respectively. Langmuir isotherm analysis with a coefficient of determination of 0.934 revealed a monolayer adsorption mechanism, highlighting the potential of BC/GO for advanced environmental remediation in industrial wastewater treatment.
A synthesis of graphene oxide/bacterial cellulose nanocomposites Natural Resources Environment and Food and Energy Security Updates in North Sumatra, 2025
Temperature-dependent etherification of cassava starch with CHPTAC for cationic starch production Sri Rahayu, Basuki Wirjosentono, Evi Oktavia, Cut Fatimah Zuhra, Khatarina Meldawati Pasaribu, Averroes Fazlur Rahman Piliang, Nico Setyawan Sihotang, Juliati Br Tarigan, Jonathan Siow, Ronn Goei, Alfred Iing Yoong Tok, Saharman Gea Case Studies in Chemical and Environmental Engineering, 2024
The Effect of Concentration Based on Etching Time of Hydrofluoric Acid on Shear-Bond Strength of Porcelain Repair Material on Cohesive Fractures of Porcelain Fused to Metal Restoration Journal of International Dental and Medical Research, 2024
The Effect of Fluoride Acid Etching Times on the Adhesive Behaviours of Porcelain Restorative Materials on the Cohesive Fractures of Porcelain Fused to Metal Restoration Journal of International Dental and Medical Research, 2023
Compression Strength of Metal-Ceramic Fixed Dental Prostheses Reinforced by Nanoparticle Silica from Rice Husks Journal of International Dental and Medical Research, 2023
Talenta M K M Nasution, Runtung Sitepu, Rosmayati, M F Ganis Siregar, Bustami Syam, Luhut Sihombing, Farhat, A S Rambe, Budiman Ginting, Hasanuddin, Seri Maulina, Ramli, Trelia Boel, Budi Agustono, Kerista Sebayang, Muriyanto Amin, Ida Yustina, Masfria, Zulkarnain, Setiawan, O S Sitompul, Siti Latifah, Robert Sibarani, Erman Munir, Tulus, I Budi Putra, Zaimah Z Tala, D Keumala Sari, Saidin, P Melati Hasibuan, Jelly Leviza, Hamidah Hanum, Jonatan Ginting, Tavi Supriana, Johannes Tarigan, Syahrizal, Irvan, Prihatin Lumbanraja, H Sakti Siregar, A Nurbaity Lubis, Sondang Pintauli, R O Nasution, Mohammad Zulkarnain, Mauly Purba, Heristina Dewi, Ikhwanuddin Nasution, Nursahara Pasaribu, Pengarapen Bangun, Saharman Gea, Husni Thamrin, M Arifin Nasution, Hendra Harahap, Nurmaini, S Indra Chahaya, Heru Santosa, P A Zaitun Hasibuan, Khairunnisa, Marianne, E D Jaya Ginting, Ferry Novliadi, Rika Eliana, S Eka Wahyuni, C Trisa Siregar, S Saidah Nasution, E Muisa Zamzami, M F Syahputra, M Silvi Lidya, Rudi Hartono, Samsuri, A Heri Iswanto, Dwi Suryanto, Suwardi Lubis, R P Wibowo, Muhammad Husni, G A W Siregar, Erwin Sitorus, Hakim Bangun, Rina Bukit, E Pascawira Sinulingga, Fadli, Darma Bakti, Chairani Hanum, Irnawati Marsaulina, Himsar Ambarita, Elvina Herawati, Onrizal, Iskandar Muda, Yuandani, P C Eyanoer, Rondang Tambun, R F Rahmat, Ridwan Siregar, Jonner Hasugian, Diana Chalil, T I Nasution, Indra Surya, Rosmalinda, M A Muchtar, T H Nasution, Maria Elfida Journal of Physics Conference Series, 2018
The manufacture of palm oil-based polyurethane nanocomposite with organic montmorillonite nanoparticle as paint coatings International Journal of Chemtech Research, 2015
Mechanical properties of oil palm trunk by reactive compregnation methode with dammar resin International Journal of Pharmtech Research, 2015
Preparation and characterization of nanocrystalline cellulose from sugar palm bunch (Arenga pinnata (Wurmb) Merr.) International Journal of Pharmtech Research, 2014
Mechanical properties of nanocrystal cellulose reinforced polystyrene with glycerol monostearic as antistatic agent International Journal of Chemtech Research, 2014
