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Second generational biofuels offer the possibility of using biomass residues such as agricultural or industrial wastes for use in internal combustion engines. However, biochemical and thermochemical conversions to liquid or gaseous fuels require elaborate and expensive pre-treatment facilities. Decreasing the complexity, size and cost of these facilities can alleviate sourcing constraints, increasing implementation in a wide range of applications. Remaining in its original solid form, biomass powder is a simplified biofuel requiring only drying and milling which is technically and economically feasible at a wide range of scale. By exploiting its explosive character, we can operate a standard diesel engine directly on powder for energy generation. The demand for a low-tech biofuel along with advances in milling techniques motivates the idea of using biomass powder in an engine. In this paper we provide experimental proof by operating a diesel engine on fumigated Wheat Straw and Pine Bark dust each for 35 minutes. Emissions, operational performance and combustion data show that biomass powders from agricultural residues should be considered for use as an adaptable technology for existing engine installations. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 618-621

Oxidative pyrolysis of pine wood particles was analysed thermo-gravimetrically. The effects of the concentration of oxygen in the surrounding gas and of particle size were investigated. Three different oxygen concentrations (0%, 10% and 20% v/v) and three different sized cylindrical pine wood samples (4 mm, 8 mm and 12 mm in diameter and 15 mm long) were tested. Two types of Macro-TG apparatuses were used; the first was non isothermal and was used at a heating rate of 20 degrees C/min, and the second was isothermal used at two temperatures, 400 degrees C and 600 degrees C. In the low heating rate non isothermal apparatus, results showed that oxygen had a strong influence on pyrolysis behaviour, but particle size did not. In the high heating rate isothermal apparatus, particle size had a significant influence on conversion: transfer phenomena limit oxidative pyrolysis.

Tropical reforestation (TR) has been highlighted as an important intervention for climate change mitigation because of its carbon storage potential. TR can also play other frequently overlooked, but significant, roles in helping society and ecosystems adapt to climate variability and change. For example, reforestation can ameliorate climate‐associated impacts of altered hydrological cycles in watersheds, protect coastal areas from increased storms, and provide habitat to reduce the probability of species' extinctions under a changing climate. Consequently, reforestation should be managed with both adaptation and mitigation objectives in mind, so as to maximize synergies among these diverse roles, and to avoid trade‐offs in which the achievement of one goal is detrimental to another. Management of increased forest cover must also incorporate measures for reducing the direct and indirect impacts of changing climate on reforestation itself. Here we advocate a focus on “climate‐smart reforestation,” defined as reforesting for climate change mitigation and adaptation, while ensuring that the direct and indirect impacts of climate change on reforestation are anticipated and minimized.

Tropical forests harbor the greatest terrestrial biodiversity and provide various ecosystem services. The increase of human activities on these forests, among which logging, makes the conservation of biodiversity and associated services strongly dependent on the sustainability of these activities. However the indicators commonly used to assess the impact of forest exploitation, namely species richness and biomass, provide a limited understanding of their sustainability. Here, we assessed the sustainability of common forest exploitation in the Guiana Shield studying the recovery of two ecosystem services i.e. carbon storage and wood stock, and an ecosystem function i.e. seed dispersal by animals. Specifically, we compared total and commercial biomass, as well as functional composition in seed size of animal-dispersed species in replicated forest plots before and 27 years after exploitation. Species richness is also studied to allow comparison. While species richness was not affected by forest exploitation, total and commercial biomass as well as seed size of animal-dispersed species decreased 27 years after exploitation, similarly to forests affected by hunting. These results show that ecosystem services and function likely did not recover even at the lowest intensity of forest exploitation studied, questioning the sustainability of the most common rotation-cycle duration applied in the tropics.

When biomass is thermally treated, the enrichment of carbon in the remaining “green coal” is correlated with the temperature and duration. Other properties related to the energetic properties of the torrefied biomass are closely related to chemical modifications and correlated to the material mass loss occurring during the thermal degradation. The possibility of using near infrared spectrometry has been investigated to predict the mass loss of Pinus sylvestris wood torrefied at temperatures ranging from 220°C to 300°C with durations varying from 1 minute to 10 hours. A first mass loss prediction model (NIR‐260) associated with the mean torrefaction temperature of 260°C was developed, and appeared suitable only for this temperature due to specific chemical reactions rate. A second model (NIRS‐All), using all available data was constructed and showed an accurate mass loss prediction, for both low (220°C) and high temperatures (300°C). The main differences between NIRS‐260 and NIRS‐All models are mainly attributed to the thermal modification of hemicelluloses and cellulose fractions occurred during the wood torrefaction. The results showed near infrared spectrometry combined with multivariate calibration modeling have potential utility in an industrial context as a standardized continuous method to figure out the mass loss of biomass during torrefaction by a rapid characterization. Novelty Statement The novelty concerns the use of the Near Infrared Spectrometry (NIRS) combined with multivariate calibration modeling as a standardized method for determining the mass loss biomass during torrefaction by a rapid and nondestructive characterization. A model was constructed and showed an accurate mass loss prediction, for both low (220°C) and high temperatures (300°C). Near infrared spectrometry have potential utility in an industrial context as a standardized continuous method.

AbstractMost tropical forests outside protected areas have been or will be selectively logged so it is essential to maximize the conservation values of partially harvested areas. Here we examine the extent to which these forests sustain timber production, retain species, and conserve carbon stocks. We then describe some improvements in tropical forestry and how their implementation can be promoted. A simple meta‐analysis based on >100 publications revealed substantial variability but that: timber yields decline by about 46% after the first harvest but are subsequently sustained at that level; 76% of carbon is retained in once‐logged forests; and, 85–100% of species of mammals, birds, invertebrates, and plants remain after logging. Timber stocks will not regain primary‐forest levels within current harvest cycles, but yields increase if collateral damage is reduced and silvicultural treatments are applied. Given that selectively logged forests retain substantial biodiversity, carbon, and timber stocks, this “middle way” between deforestation and total protection deserves more attention from researchers, conservation organizations, and policy‐makers. Improvements in forest management are now likely if synergies are enhanced among initiatives to retain forest carbon stocks (REDD+), assure the legality of forest products, certify responsible management, and devolve control over forests to empowered local communities.