Volume 20 Issue 2

A comparative analysis of Computational Fluid Dynamics (CFD) modeling and process simulation (SIM) was carried out to evaluate biomass pyro-gasification, using experimental data from agave bagasse (AB) as a case study. Experimental data were obtained via thermogravimetric analysis (TGA) under varying conditions, including non-isothermal (700 to 1000 °C) and isothermal (900 °C and 950 °C) gasification at different air-to-biomass ratios (ABR). CFD modeling in COMSOL Multiphysics focused on micro-scale mass and heat transfer phenomena, while Aspen Plus simulations provided macro-scale process insights. Results showed that SIM closely matched experimental product yields under isothermal conditions (maximum deviation: 4.23 wt.%), while CFD excelled in predicting gas composition under non-isothermal conditions (e.g., H₂ deviation: 3.29 vol.%). Sensitivity analysis showed how temperature and ABR are critical factors that influence the product yield and gas composition, highlighting the strengths of each modeling approach. These findings underline the potential of integrating CFD and SIM approaches for improving the accuracy of biomass conversion modeling, paving the way for optimized process designs and scalable industrial applications.

The increasing amount of fly ash from daily energy combustion, coupled with land use changes from mangrove forests, has led to an increase in severe coastal erosion. This study aims to utilize fly ash by adding value to biodegradable nursery pots, which can manage fly ash and reduce the use of seedling bags. The pots also have indirect benefits in preventing coastal erosion. The seedling pots are made from rubberwood fly ash (RWFA), clay, and sand. The composition of RWFA is analyzed using X-ray diffraction and fluorescence spectroscopy. The total concentration of a specific contaminant in a waste or soil sample is measured using the total threshold limit concentration (TTLC). Hydrodynamic simulations are conducted to optimize the layout of the pots to reduce the wave velocity. This study determined that RWFA, which is composed of 38.9% CaO, 11.3% SiO₂, 8.9% organic matter, 8.8% total K₂O, 1.0% total P₂O₅, and 0.006% total N, can be used as an ingredient in pots and plant nutrients. Moreover, the seedling pot design can reduce the speed of the water velocity by placing it in a suitable position. Furthermore, the TTLC value of the pot does not exceed the standard value.

Glued wood finger-jointed panels are widely employed due to their efficient use of wood resources and the enhancement of product quality. To address defects in the quality inspection of these panels, a set of ultrasonic glued laminated wood finger-joined board inspection systems was designed using Barker Code pulse excitation. This was achieved by adopting air-coupled ultrasonic technology and incorporating phase coding technology. Relevant validation experimental research was carried out on the performance of the system. The results show that the system covered two key components, namely hardware and software, which enabled its ultrasonic transducer to realise the functions of rapid scanning of the internal and external qualities of the board and automatic C-scan inspection imaging to identify defects in the specimen without contacting the glued wood finger-joined board specimen. The validation test confirmed that the inspection system achieved good accuracy and reliability. It was concluded that this approach has potential to improve the quality inspection technology of glued laminated direct lumber and to promote the development of wood processing industry.

Lignin can be used as a natural anticancer drug because of its potential biological activity and low cytotoxicity. This research focuses on oligomeric dehydrogenation polymers (DHPs) of lignin. The lignin precursor coniferin was used to yield Zulaufverfahren dehydrogenation polymers (ZL-DHPs) and Zutropfverfahren dehydropolymers (ZT-DHPs) catalyzed by mixed enzymes. The ¹³C-NMR determination showed that the DHPs obtained were similar to natural lignin, and ZL-DHP had a slightly higher β-5 content than ZT-DHP. ZL-DHPs and ZT-DHPs were subjected to organic solvent extraction with different polarities to obtain eight fractions, i.e., ZL-1-ZL-4 and ZT-1-ZT-4. The antitumor activity showed ZL-2 (IC₅₀ 181.99 μg/mL) and ZT-2 (IC₅₀ 246.76 μg/mL) had significant inhibitory effects. Fractions ZL-2 and ZT-2 were purified through column chromatography using gradient-polarity binary eluent, and 12 purified compounds were obtained, i.e., L1–L6 and T1–T6. The results showed L2 (IC₅₀ 33.99 μg/mL) and T1 (IC₅₀ 42.08 μg/mL) had relatively high biological activity, respectively. Their structure was characterized using high-resolution mass spectrometry and ¹³C-NMR, indicating that L2 is a dimer with β-5 linkage (β-5, γ-CH₃, and γ’-CH₂OH), and T1 is also a dimer with β-5 linkage but different substituents (β-5, γ-CHO, and γ’-COOH).

It is hard to decarbonize a passenger jet. The aviation industry contributes to approximately 2.5% of global greenhouse gas emissions, underscoring the need for decarbonization to achieve net-zero emissions by 2050. Sustainable aviation fuels (SAFs) derived from conventional biomass, i.e., agricultural residues, forestry by-products, and organic waste, present a scalable solution. Conventional biomass has the potential to produce 60 to 80 billion liters of SAF annually, meeting up to 20% of current jet fuel demand. Lifecycle assessments indicate GHG emission reductions of 70 to 85% compared to fossil fuels. Advanced conversion technologies such as gasification and fermentation have achieved efficiencies exceeding 65%, demonstrating commercial viability. Case studies highlight significant CO₂ reductions of 50 to 70% per flight using SAFs. Despite its promise, biomass-based SAFs are costlier, ranging from USD 1.10 to USD 2.40 per liter. However, policy instruments such as the U.S. SAF Grand Challenge and the EU’s RED II are accelerating adoption. Beyond environmental benefits, SAFs support socio-economic development, potentially creating 1.2 million green jobs globally while addressing waste management challenges. To realize this potential, challenges in technology, economics, and policy need to be addressed. Coordinated efforts in policy, research, and investment are essential to scale SAF deployment, enabling the aviation sector to significantly reduce lifecycle emissions and achieve its net-zero ambitions.

Glued-laminated timber (glulam) is a structural wood-based composite widely used in construction. One of the constraints to its production is the requirement that lamellae must have the same moisture content before bonding. This study analyzed the effect of joining lamellae having different moisture content levels on the bonding performance of glulam elements. Black spruce [Picea mariana (Mill.) B.S.P.] wood with different levels of moisture content (11%, 13%, and 15%) were bonded with two component polyurethane and placed in three different environments with different relative humidities. Block shear and delamination tests were performed according to ASTM D905-08 (2021) and EN 302-2 (2013), respectively, and the glue line profile was assessed with a micro-CT scanner. The results showed that the relative humidity had more influence on the results than the initial moisture of the wood. The results obtained for block shear and delamination tests respected the limits of the standard, but the adhesive profile of mixed moisture glulam presented some undesirable characteristics (thinner and irregular adhesive distribution). Micro-CT scan reconstructed images were found to be an interesting tool for this type of evaluation.

This study aimed to enhance rotational wood welding technology by developing a simplified prediction model for pull-out strength. The key findings can offer a robust evaluation framework to advance rotational wood welding and expand its applications in woodworking. For instance, (1) A comprehensive database of 689 previously published trials was curated to identify key factors: substrate diameter, effective welded length, and substrate density. (2) Comparative analysis of test outcomes and predictive models revealed consistent trends, suggesting that modeling techniques for self-tapping wood screws could be applied to rotational wood welding joints. (3) Univariate linear regression validated the primary factors, leading to a multivariate model for predicting withdrawal capacity. Theoretical predictions closely matched empirical data, highlighting the model’s industrial applicability.

To ensure the environmentally safe usage of copper amine-based wood preservatives in aquatic environments, it is necessary to minimize copper leaching from treated wood. In this study, alkaline copper quat (ACQ) was reformulated to enhance resistance to copper leaching by adjusting the proportions of copper, didecyldimethylammonium chloride (DDAC), and mono-ethanolamine (Mea) solvent. The copper proportion in the formulation was decreased 40% while maintaining the total retention of active ingredients through increasing DDAC. The molar ratio of Cu to Mea in the formulation was then adjusted from 1:4 to 1:2.75. This reformulation shortened the time to copper stabilization from 15 to 6 days, and reduced cumulative copper leaching by 75%, compared to a control formulation. These fixation properties were further improved with just a 30-min hot-air post-treatment at 100 °C. Wood treated with the reformulated ACQ exhibited comparable performance in biological efficacy against fungi and termites compared to wood treated with commercial ACQ.

5-Ethoxymethylfurfural (5-EMF) is a promising liquid fuel or fuel additive due to its high energy density and stability. The conversion of glucose to 5-EMF involves a three-step tandem reaction: isomerization, dehydration, and etherification. However, low catalytic efficiency in these steps has limited 5-EMF yields. To address this, a Fe/ZSM-5 bifunctional catalyst with both Brønsted and Lewis acid sites was developed and characterized using XRD, SEM, XPS, BET, Py-FTIR, and NH₃-TPD techniques. The catalyst’s performance in glucose conversion was systematically evaluated. Optimal conditions—20 wt% Fe loading, 180 °C reaction temperature, 10 h reaction time, and a catalyst-to-glucose mass ratio of 1:1—resulted in 97.1% glucose conversion and a 38.4% 5-EMF yield. Reaction kinetics followed a first-order model with an activation energy of 32.6 kJ/mol. The catalyst maintained over 94% glucose conversion after five cycles, demonstrating its stability. These findings underscore the potential of the Fe/ZSM-5 bifunctional catalyst for efficient glucose valorization to 5-EMF and provide key insights for process optimization.

This study integrates the Fuzzy Analytic Hierarchy Process (AHP) with the Failure Mode and Effects Analysis (FMEA) to enhance risk prioritisation in wood-based manufacturing. Traditional FMEA methods face challenges in handling subjective evaluations and complex environments. By incorporating fuzzy logic, this study refines the Risk Priority Number (RPN) calculation, enabling a more nuanced assessment of failure modes. Critical failure points, such as delays in order processing, production, and delivery, were identified, highlighting their impact on operational efficiency, customer satisfaction, and financial outcomes. Using the Pareto principle, it was revealed that addressing the top 20% of the identified risks could mitigate approximately 80% of the overall risk exposure. Proposed corrective measures, including enhanced employee training, streamlined workflows, and improved communication protocols, provide actionable strategies to optimise processes and ensure sustainability. Conducted within a Croatian wood-manufacturing company, this framework demonstrated its efficacy in refining risk assessments and supporting continuous improvement. The findings advance risk management methodologies and showcase the potential for broader applications in dynamic and complex industrial environments.