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The use of biomass as a renewable energy source is currently a reality, mainly due to the role it can play in replacing fossil energy sources. Within this possibility, coal substitution in the production of electric energy presents itself as a strong alternative with high potential, mostly due to the possibility of contributing to the decarbonization of energy production while, at the same time, contributing to the circularization of energy generation processes. This can be achieved through the use of biomass waste forms, which have undergone a process of improving their properties, such as torrefaction. However, for this to be viable, it is necessary that the biomass has a set of characteristics similar to those of coal, such that its use may occur in previously installed systems. In particular, with respect to grindability, which is associated with one of the core equipment technologies of coal-fired power plants—the coal mill. The objective of the present study is to determine the potential of certain residues with agroforestry origins as a replacement for coal in power generation by using empirical methods. Selected materials—namely, almond shells, kiwifruit pruning, vine pruning, olive pomace, pine woodchips, and eucalyptus woodchips—are characterized in this regard. The materials were characterized in the laboratory and submitted to a torrefaction process at 300 °C. Then, the Statistical Grindability Index and the Hardgrove Grindability Index were determined, using empirical methods derived from coal analysis. The results obtained indicate the good potential of the studied biomasses for use in large-scale torrefaction processes and as replacements for coal in the generation of electrical energy. However, further tests are still needed, particularly relating to the definition of the ideal parameters of the torrefaction process, in order to optimize the grindability of the materials.

Agroforestry waste stores a considerable amount of energy that can be used. Portugal has great potential to produce bioenergy. The waste generated during agricultural production and forestry operation processes can be used for energy generation, and it can be used either in the form in which it is collected, or it can be processed using thermochemical conversion technologies, such as torrefaction. This work aimed to characterize the properties of a set of residues from agroforestry activities, namely rice husk, almond husk, kiwi pruning, vine pruning, olive pomace, and pine woodchips. To characterize the different materials, both as-collected and after being subjected to a torrefaction process at 300 °C, thermogravimetric analyses were carried out to determine the moisture content, ash content, fixed carbon content, and the content of volatile substances; elementary analyses were performed to determine the levels of carbon, nitrogen, hydrogen, and oxygen, and the high and low heating values were determined. With these assumptions, it was observed that each form of residual biomass had different characteristics, which are important to know when adapting to conversion technology, and they also had different degrees of efficiency, that is, the amount of energy generated and potentially used when analyzing all factors.

Background: This study investigates the vital significance of logistical cost optimization within the residual woody biomass supply chain, aiming to boost both sustainability and the efficient utilization of this resource. There is an emphasis on how adept cost management can determine the economic feasibility of exploiting residual biomass. Methods: The research delves into crucial areas including collection, transportation, storage, and processing of biomass, highlighting their respective roles in the total cost. The influence of factors such as seasonality and biomass quality variations on the supply chain's cost and efficiency is explored. To provide an in-depth analysis of these factors, mathematical models are presented that allow for the examination of a variety of scenarios and optimization strategies. Techniques such as linear programming, genetic algorithms, and tabu search are contextualized within these models. Results: The study provides in-sights into individual cost contributions of different logistical operations. It also reveals how seasonality and biomass quality variations directly affect the cost and efficacy of the supply chain. Conclusions: Proficient logistical cost management is crucial for the successful exploitation of residual biomass. The findings have substantial implications for managing the residual biomass supply chain, paving the way for a transition to a low-carbon economy.

Waste management is a current and transversal problem in all production areas, including agriculture. Within this economic activity, wine production generates a large amount of waste, namely, that resulting from the winemaking activity itself, such as pomace and grape stalks, and waste resulting from the management of the vineyards, with operations such as vine pruning. The management of vine pruning residuals has traditionally been conducted by burning leftovers on-site, without any use for the energy produced. This research analyzed the potential for the valorization of residual biomass resulting from vine pruning by creating a business model based on value chains of local scale. For this analysis, several samples of residues resulting from the “Loureiro” vine variety planted in Ponte de Lima (northern Portugal) were collected and characterized. The objective of the small-scale business model created, in addition, to solving the environmental problems related to the disposal of waste from agricultural activities, a value chain can be established, contributing to increasing the income of the farmers while introducing a circular bioeconomy and sustainable rural development practices.

Short rotation woody coppice (SRWC) cultivations of species like poplar, eucalyptus, or willow are promising options for biomass production, insofar that high biomass productivities, averaging 12–14 Mg ha−1 year−1 are possible, with heating values varying from 16 to 19 MJ kg−1, along with environmental positive effects such as increases in soil fertility or carbon sequestration. SRWC cultivations can last by about 20 years or more, corresponding to 4 to 7 cycles coppice rotation periods of 2 to 5 years, and subjected to intensive management regimes with requirements of herbicides, fertilizers, or irrigation lower than food crops. SRWC cultivations can be installed in marginal lands and, due to positive effects on soil, contribute to upgrade of site quality, including posterior installation of food crops. Overall, these cultivations are considered carbon neutral, with reductions of greenhouse gases of 90% to 99%, comparatively with emissions from coal fired power stations. The biomass production of SRWC cultivations is dependent on factors such management regime, harvesting practices, weed competition, or plant density and rotation time. Biomass from SRWC cultivations along with biomass conversion units shows a decisive potential for contributing to boost economies of rural areas. In this context, this chapter intends to make an integrated evaluation of the cultivation techniques in the field, from the nursery to farm gate, with some focus on topics such as biomass production modeling or genotypic stability along with fuel aptitude of biofuels from SRWC, with a significant focus on information obtained by research carried out by the authors.

Background: With the increasing societal focus on sustainability and the critical need for innovative energy solutions, this research emphasizes the undervalued biomass originating from waste products of agroforestry activities. The traditional practice of disposing of these waste products through open-air burning has led to environmental challenges and a tragic loss of their inherent energy potential. Methods: This study adopts a multifaceted approach, integrating literature reviews, expert interviews from both the academic and professional sectors, and surveys. The central focus is on understanding supply chain inefficiencies and communication gaps that contribute to waste and addressing them through the Lean philosophy, renowned for its waste reduction benefits. Results: Our research culminated in the development of a unique information management model based on a web application. Additionally, the study provides a theoretical groundwork for an application that backs the proposed model. Conclusions: The presented strategy and web-based model offer promising avenues for managing waste products from agroforestry activities more sustainably and efficiently. This approach not only addresses the environmental issues arising from waste disposal but also taps into the significant energy potential these waste products hold.

The production of residual biomass, such as vine pruning, presents environmental problems since its elimination is usually carried out through the uncontrolled burning of the remaining materials and with the emission of greenhouse gases without any counterpart. The use of these residues to produce biochar presents several advantages. In addition to the more common energy recovery, other conversion ways allowing new uses, such as soil amendment and carbon sequestration, can be analyzed as options as well. In the present study, vine pruning biomasses are characterized to evaluate the behavior of the different constituents. Then, the different possible applications are discussed. It is concluded that materials resulting from the pruning of vineyards have excellent characteristics for energy recovery, with an increment of more than 50% in the heating value and almost 60% in the carbon content when carbonized. This recovery procedure contributes to creating new value chains for residual materials to promote sustainable practices in the wine sector.

The sugarcane industry has assumed an increasingly important role at a global level, with countries such as Brazil and India dominating the field. However, this causes environmental problems, since the industry produces large amounts of waste, such as sugarcane bagasse. This by-product, which is energetically partially recovered in sugar mills and in the pulp and paper industry, can make a significant contribution to the general use of biomass energy, if the usual disadvantages associated with products with low density and a high moisture content are overcome. From this perspective, thermochemical conversion technologies, especially torrefaction, are assumed to be capable of improving the fuel properties of this material, making it more appealing for potential export and use in far-off destinations. In this work, sugarcane samples were acquired, and the process of obtaining bagasse was simulated. Subsequently, the bagasse was dried and heat-treated at 200 and 300 °C to simulate the over-drying and torrefaction process. Afterward, product characterization was performed, including thermogravimetric analysis, elemental analysis, calorimetry, and energy densification. The results showed significant improvements in the energy content, from 18.17 to 33.36 MJ·kg−1 from dried bagasse to torrefied bagasse at 300 °C, showing that despite high mass loss, there is potential for a future value added chain for this waste form, since the increment in energy density could enhance its transportation and use in locations far off the production site.