Alternatives for petroleum-based products are much needed now due to the depletion of resources and the negative impact of its usage. Amongst the many renewable alternatives of cellulose-based products, nitrocellulose is the oldest and longest thriving derivatives in the world, obtaining a long line of utilization such as biodegradable plastics and film, wood coatings, nail lacquer, automotive paints, and leather finishes. The inexhaustible selection of raw materials for nitrocellulose production are easily obtainable from the copious lignocellulose materials, primarily from cotton and wood pulp. In this study, the Acacia mangium, which is a timber species that heavily populates the plantation of Sabah, in pulp form are used to produce nitrocellulose. The objectives of this research was to determine the physical and chemical attributes of the nitrocellulose from two different sizes of A. mangium particles (75 and 150 μm), such as its degree of substitution, nitrogen content, rate of efficiency and weight percentage gained. The production method of nitrocellulose includes the nitration process of the A. mangium pulp with nitric and sulphuric acid, followed by repeated stabilizing procedures using hot water, and finally the extraction process. Among the different sizes, the 75 μm sample showed a lower degree of substitution and nitrogen content compared to the other, but however showed higher rate of efficiency and weight percentage gained. This is due to the higher surface area per volume for the 75 μm samples but which contradicts in DS value due its higher affinity towards absorbing other materials more than the nitrate itself. This was further proven by the infrared and EDX spectra, where the 75 μm sized sample was absorbing more elements but at a lower concentration than the other. This goes to show that samples with a higher surface area per volume does not guarantee a better substitution of nitrate in nitrocellulose production due to the non-specific preference of cellulose absorption.

Background. Peatlands are becoming more vulnerable to smouldering fires, driven by climate change and human activities. Aims. This work explores the persistent burning, propagation, and emission of the deep peat fire. Methods. Laboratory experiments are conducted with a 1-m deep peat column, and smouldering fires are initiated at different depths. Key results. We found localised burning and multi-directional smouldering fire spread in deep peat layers. The smouldering temperature first decreases with depths up to −40 cm (from around 550 to 350°C) and then remains at about 300°C in the deeper layers. High moisture content can slow down in-depth fire propagation and reduce the burning duration. Conclusions. Peat fire can burn in deep layers for weeks, and its combustion is incomplete with small mass loss, because of a limited oxygen supply and low smouldering temperature. Measuring the carbon monoxide concentration near the surface can detect underground fire and monitor its intensity. Implications. This work helps reveal the underlying mechanism of the in-depth smouldering wildfires in peatland and supports future larger-scale peat fire experiments in the field.

Information on calorific value is very important factor in fuel evaluation. The objective of the study was to investigate the calorific values of the leaves of five (5) selected trees species of dipterocarp in Piah Forest Reserve, Perak, Malaysia. The species are Hopea sp., Shorea parvifolia, Shorea leprosula, Shorea macroptera and Dipterocarpus sp. The calorific values were determined using the Adiabatic Bomb Calorimeter. The difference of calorific value between the five species were also examined. It was found that, the mean calorific value for the dipterocarp species were within the range of 4041.28 Cal g-1 to 4820.78 Cal g-1. The leaves of the Shorea macroptera contain higher calorific value compared to other four species. The findings will be useful in the preparation of forest fire management plan, and also in the development of bioenergy project of wood-based biomass from forest species.

Peatlands are important terrestrial carbon pools. Due to climate change and human activities, peatlands are more prone to large-scale fires than ever before, especially deep underground fires. However, most current smouldering researches focus on small-scale smouldering behaviour in relatively shallow layers, which poses a research gap. This work explores in-depth (up to 60 cm) smouldering behaviour, such as persistence, propagation and emission. Experimental results demonstrate that underground smouldering fires can sustain in deep soil layers for more than a week without any additional oxygen supply. Because of the competition of oxygen supply and heat losses, a critical depth of 55 cm for smouldering propagation was obtained, below which smouldering cannot self-sustained propagate. This work will help better connect lab-scale experiments with real underground smouldering peat fires and understand smouldering dynamics in deep soil layers.