The Front Cover encapsulates our narrative: an aspen tree is a lignin source, while structural details appear on the blackboard. Visual elements illustrate the lignin extraction process: wood chips, ...extraction setup, and resulting powder. A figure holds the culmination of research—a cartridge, symbolizing the chemical evolution of lignin. The filled cartridge is placed on a table and ready for deployment. More information can be found in the Research Article by Y. Karpichev and co‐workers. Cover art by Mahendra K. Mohan.
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•NiFe2O4 acted as a novel effective heterogeneous catalyst for the biomass SCWG.•Addition of NiFe2O4 catalyst provided an increase in H2 production up by 60%.•About 66 mol% of gas ...products were achieved at 500 °C, 60 min and 2 g of catalyst.•Liquid organic products were mostly composed of methyl derivatives.
Eucalyptus wood chips were reacted under supercritical water conditions to evaluate the effect of a NiFe2O4 catalyst, residence time and temperature parameters. Experiments were performed in a batch reactor at 400 °C , 450 °C and 500 °C using three different amounts of catalyst (0, 1.0, 2.0 g) and three different residence times (30, 45, 60 min). Results showed that eucalyptus wood chips reacted and produced CO2 as the dominant gas in all cases, followed by H2 and CH4. However, the presence of NiFe2O4 catalyst led to a 60% increase in H2 produced, while significantly reducing the solid residue and enhancing the percentage of methyl derivatives in the organic liquid products. The highest H2 mol% was at 450 °C, 2 g of catalyst and 60 min of residence time. Analysis of the derived oils showed that they were mostly composed of ketones, aldehydes, methylbenzenes and alkylated phenols. Increasing the reaction temperature to 500 °C increased the molar composition of methane by 62% compared to its yield at 450 °C. In generally, this work showed that NiFe2O4 acted as an effective heterogeneous catalyst for improved production of H2 and CH4 via supercritical water gasification process.
•Wood chips from spruce were mixed with calcium hydroxide to raise the pH.•Three piles (250 m3) with 0, 1.5 and 3.0% Ca(OH)2 have been stored for 4 months.•Storage characteristics and cultivable ...members of the microbiota were investigated.•Ca(OH)2 was able to decrease the dry matter loss significantly.•The additive led to 5 °C higher maximum pile temperatures (sanitization effect).
The objective of this study was to investigate the effect of an alkaline additive on the storage of wood chips from Norway spruce forest residues. Piles of untreated and calcium hydroxide treated wood chips (250 m3) were set up and investigated for four months. It was demonstrated that adding Ca(OH)2 to moist wood chips decreased the dry matter loss by 6%. This was attributed to the increase of the pH to a level of 8, rendering the habitat less suitable for fungal colonisation. The results suggest the set-up storage strategy as a potential alternative method for preserving wood chips when long term storage is required.
In this contribution coupled DEM–CFD simulations of convective drying of wood chips in a baffled laboratory rotary dryer are presented. Due to the anisotropy of the biogenous (fibrous) material a ...three-dimensional spatial resolution of inner particle transport processes within the DEM code has been incorporated. The drying law is based on a diffusion approach. The simulations show that L-shaped baffles lead to higher drying rates than straight baffles. L-shaped baffles lead to a more even distribution of the particles across the cross-section of the drum where a larger amount of the wood chips are located in regions of hot, unsaturated air. However, the assumption of anisotropic transport properties within the wood chips and the subsequent solving of the associated differential equation of the three dimensionally resolved particle requires high computational effort. Therefore, the second purpose of the paper is to propose a model reduction method for single particle DEM-models based on proper orthogonal decomposition to reduce computation times. Specifically, we assess the impact of these methods on the computational complexity of the single particle models. The results show that even with a basic implementation a considerable reduction can be achieved on the single particle level. While our results only apply to the specific example treated here, it is evident that the effect of model reduction grows with grid size.
Commercial mushrooms are produced on lignocellulose such as straw, saw dust, and wood chips. As such, mushroom-forming fungi convert low-quality waste streams into high-quality food. Spent mushroom ...substrate (SMS) is usually considered a waste product. This review discusses the applications of SMS to promote the transition to a circular economy. SMS can be used as compost, as a substrate for other mushroom-forming fungi, as animal feed, to promote health of animals, and to produce packaging and construction materials, biofuels, and enzymes. This range of applications can make agricultural production more sustainable and efficient, especially if the CO
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emission and heat from mushroom cultivation can be used to promote plant growth in greenhouses.
Incorporation of biochar in cementitious materials is a promising solution in the mitigation of environmental pollutants by partially cutting off the consumed ordinary Portland cement and reducing ...the amount of waste disposal in landfills. This work studied the partial replacement of cement by biochars having a different chemical composition and its effect on the performance of cement mortars. The feedstocks for biochar production were selected from biomass wastes produced in agro-industrial and forestry sectors in Portugal. They included olive stone, rice husk and wood chips from residual forest biomass. Biochars were produced at 500 ℃ using a slow pyrolysis process. The biochars were added at different cement replacement rates; 0.5, 1, 2 and 4 wt% of cement weight. XRD and TGA were used to elaborate the effect of biochar on the hydration products. Effect of biochar addition on the capillary water absorption, compressive and flexural strength of cement mortar was analyzed. The results suggested that the biochars contributed to the promotion of hydration products. Cement replacement with 4 wt% olive stone and rice husk biochars was associated with a slight increase of 28-days compressive strength. Rice husk biochar showed the best long-term mechanical performance due to its pozzolanic reaction in the matrix. No significant changes were observed in the water absorption of cement mortar after the addition of 4 wt% biochar as cement replacement. The research outcomes suggested the beneficial effect of cement replacement with biochars from olive stone and rice husk up to 4 wt% with comparable properties.
This study highlights the opportunities and challenges of pomegranate wood chips (PWC) gasification in a pilot-scale multi-reactor gasification system integrated with an internal combustion engine ...for combined heat and power generation. PWC with a higher heating value of 19.54 MJ/kg were converted into syngas in a downdraft gasifier and then the resultant syngas was utilized to generate power at two electrical power loads of 7 and 10 kW. The experimental results showed that lower electrical output (7 kW) leads to syngas production with higher H2 and CO molar concentrations (21.5% H2 and 30.08% CO). Increasing the power load to 10 kW resulted in a 13.35% and 13.76% reduction in H2 and CO molar concentrations, respectively. ASPEN Plus coupled with an external FORTRAN subroutine was used to kinetically simulate the experimental system. Compared to the equilibrium and modified equilibrium models available in the literature, kinetic simulation results showed perfect agreement with the experimental results; it gave syngas composition with ideal accuracy and acceptable mean absolute percentage errors of 8.91 and 1.98 for H2 and CO, respectively.
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•Pomegranate wood proved to be a suitable biomass for the gasification process.•H2 and CO concentrations decreased with increasing power load from 7 to 10 kW.•A kinetic model was developed using ASPEN Plus and an external FORTRAN subroutine.•The model predicted syngas composition with H2 and CO errors of 8.91 and 1.98%.
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•Agro-industrial residues are excellent pyrolysis feedstocks.•TG-DTA is a promising technique to study the thermal decomposition of residues.•Coats-Redfern is successfully applied to ...slow pyrolysis using five reaction mechanisms.•The ascending order of the activation energy: corncob > rice husk > wood chips > wheat straw > bagasse.
Agro-industrial residue is widely considered as a rich source of energy, with varying characteristics depending on the geographical region or origin from where it is collected. Rice husk, bagasse, corncob, wheat straw and wood chips do not find many applications in Pakistan. As they are available in large quantities and at lower cost, therefore it makes them a favorable candidate for bioenergy. In this study, five agro-industrial residues, of Pakistani origin, were thermally degraded in the absence of air and at a constant heating rate of 5 °C min−1. Kinetics of the pyrolysis process was performed using Coats-Redfern method at five reaction mechanisms. Corncob was found to degrade at lower temperature with fastest rate as compared to all the other wastes. The kinetic parameters obtained from Coats-Redfern method were used to evaluate the thermodynamic behavior of these wastes and afterwards a comparison was drawn. Based on the ascending order of the activation energy, the residues can be classified in terms of preference as corncob > rice husk > wood chips > wheat straw > bagasse.
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•Coal and biomass samples have been experimentally characterized by TGA and DSC.•Combustion and oxy-combustion behaviours are assessed and kinetically analysed.•Kinetic analysis is ...based on both FWO and KAS methods and results are compared.•Oxy-combustion can improve the burning rate of fuels, shortening the burning time.•Both FWO and KAS are reliable for combustion, but only for coal for oxy-combustion.
This paper reports on the results of air-blown combustion and oxy-combustion kinetic characterization (comparing two different isoconversional methods: Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose) of different kinds of coal (from Italy, South Africa and Hungary) and biomass (pine and eucalyptus chips) by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) together with the assessment of different characteristic combustion parameters. It can be observed that the burning rate of fuels can be improved by the oxy-combustion process, shortening the burning time (a mean reduction of the burnout time of 14% and 22% can be observed for coal and biomass samples, respectively). Moreover, biomass shows better ignition performance than coal and enhances combustibility indexes (S and Hf), especially in oxy-combustion conditions. For example, the S index, which reflects combustion properties, increases by an order of magnitude for biomass combustion and oxy-combustion with respect to coal values, thus indicating a higher combustion activity for biomass; an opposite trend can be observed for the Hf index, which describes the rate and intensity of the process and is lower for biomass than for coal, thus indicating better performance for wood chips combustion. Kinetic analysis shows that the activation energy Ea varies with conversion values, reflecting the kinetic complexity in both the processes. Moreover, with the same range of heating rates (10 ≤ β ≤ 50 °C/min) and for the overall range of conversion (0.1 ≤ α ≤ 0.9), both of the models used fit the experimental data in combustion regime, whereas the increase of the oxygen concentration makes the results reliable for coal samples and more sensitive to weight loss for biomass samples.
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