142 research outputs found

    Increased charcoal yield & production of lighter oils from the slow pyrolysis of biomass

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    In an effort to reduce CO2 emissions from solid fuels, a considerable amount of research is going into how improve the manufacturing processes and product properties of the products from pyrolysis. One aspect that is often overlooked is the production of charcoal for cooking and soil remediation, which is an inefficient conversion process. There is considerable interest into using additives to increase charcoal yields, and based on the observation from fast pyrolysis work that certain catalyst tar cracking pathways can deposit considerable amounts of coke on the surface of the catalyst, there is a potential application to slow pyrolysis processes producing charcoal. Alumino-silicate catalysts have been shown to have a relatively high tendency to do this. This work hypothesises that this catalysation can be applied to slow pyrolysis, with low cost alumino-silicate minerals, specially bentonite clay, which has been added to pine pyrolysis in concentrations up to 60% wt (against input biomass) at temperatures 300–700 °C. This study has shown that the use of bentonite clay minerals can be beneficial to the process, as there is an increase in the charcoal yield from biomass, whilst the proximate analysis of the charcoal shows little change from levels expected from biomass only pyrolysis. The conversion of oil to charcoal was more effective at high temperatures due to higher levels of oil cracking. At 700 °C with 60% clay loading, charcoal yield increased 16%wt (dry ash free basis) was seen, while at the same time 19% extra gas was produced at the expense of 35% of the oil from raw pine pyrolysis. This indicates fuel properties of the charcoal are predictable, and changes in yield considerable. At the same time, the abundance of lower molecular weight oils is increased (relative to 4-methyl phenol). It is though that pyrolysis oil reacts with the clay, causing the heavier tars to disproportionate into charcoal and gas

    Long term impacts of transitions in charcoal production systems in tropical biomes

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    Mitigation of greenhouse gas emissions through transitions to biomass-based renewable energy may result in higher land needs, affecting ecosystem services and livelihoods. Charcoal is a biomass-based renewable energy that provides energy for hundreds of millions of households worldwide and generates income for 40 million people. However, it currently causes up to 7% of the global deforestation rate. In the absence of affordable alternative fuels, it is necessary to identify conditions that foster sustainable charcoal production. In this study, we (a) develop a stylized model that simulates feedbacks between forest biomass and charcoal production, and (b) use the model to examine the effects of interventions that foster sustainable charcoal systems through transitions to communal management or private systems, increases in carbonization efficiency and charcoal demand reductions. Our model simulations suggest that at low demand, a transition is unnecessary. At intermediate to high demands, interventions that increase carbonization efficiency and/or reduce demand should be combined with transitions to communal management (at intermediate forest biomass levels) or private systems (at low forest biomass levels) to ensure long-term sustainability of charcoal systems and avoid collapse within 100 years. These results highlight multiple pathways for sustainable charcoal production systems tailored to meet supply and demand. All pathways are feasible across tropical biomes and could foster the simultaneous continuation of forests and charcoal production in the near future

    Transdisciplinary studies in socio-ecosystems: Theoretical considerations and its application in Latin American contexts

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    Debido a limitaciones para abordar la complejidad de la relación sociedad-naturaleza, los esfuerzos para solucionar los problemas ambientales han sido en general infructuosos. Aquí proponemos que el enfoque holístico de “socio-ecosistema” por parte de la academia, podría contribuir a disminuir estas limitaciones desde la adopción de cuatro cambios: i) ontológico, que presenta el concepto de “socio-ecosistemas”; ii) epistemológico, que propone a la transdisciplina como la forma de entenderlos, iii) metodológico, que sugiere intervenir en ellos de forma participativa y adaptativa y, iv) cambios institucionales que facilitarían la adopción de esta propuesta. Este planteamiento se complementa con la descripción de una experiencia transdiciplinaria en la cuenca del río San Juan Zitácuaro, México, en el contexto de un curso internacional de manejo de socio-ecosistemas.Given the difficulties to approach the complex relationship bettween society and nature, efforts to solve environmental problems have generally been unsuccessful. Here we suggest that a hollistic “socio-ecosystem” approach by the sciencies could help diminish these difficulties by embracing four kinds of changes: i) ontological, which introduces the concept of “socio-ecosystem”; ii) epistemological, which proposes transdiscipline as the way to understand them, iii) metholodogical, which suggests that in intervention in them must be participatory and adaptive, iv) institutional changes that would facilitate the adoption of this approach. This is then followed by a description of a transdisciplinary work experience in the Zitácuaro river basin, in Mexico, in the context of an international course on socio-ecosystem management.Fil: Ortega Uribe, Tamara. Universidad de Chile; ChileFil: Mastrangelo, Matias Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Villarroel Torrez, Daniel. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piaz, Agustín Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Humanidades. Centro de Estudios de Historia de la Ciencia y de la Técnica ; ArgentinaFil: Vallejos, María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Saenz Ceja, Jesús Eduardo. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; MéxicoFil: Gallego, Federico. Universidad de la República. Facultad de Ciencias; UruguayFil: Franquesa Soler, Monserrat. Instituto de Ecología; MéxicoFil: Calzada Peña, Leonardo. Universidad Nacional Autónoma de México; MéxicoFil: Espinosa Mellado, Noelia. Universidad de la Armada; MéxicoFil: Fiestas Flores, Jerico. Instituto de Estudios Peruanos; PerúFil: Gill Mairhofer, Luis R.. Ministerio de la Defensa Pública; ParaguayFil: González Espino, Zarahí. Instituto Superior de Tecnologías y Ciencias Aplicadas. Facultad de Medio Ambiente. Departamento de Meteorología; CubaFil: Luna Salguero, Betsabé Montserrat. Sociedad de Historia Natural Niparajá; MéxicoFil: Martinez Peralta, Claudia María. Comisión de Ecología y Desarrollo Sustentable del Estado de Sonora. Dirección General de Conservación; MéxicoFil: Ochoa, Olivia. Universidad Nacional Autónoma de México; MéxicoFil: Pérez Volkow,Lucía. No especifica;Fil: Sala, Juan Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Sánchez Rose, Isabelle. Universidad Central de Venezuela; VenezuelaFil: Weeks, Madeline. University of Cambridge; Reino UnidoFil: Ávila García, Daniela. Universidad Nacional Autónoma de México; MéxicoFil: García Reyes, Isabel Bueno. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; MéxicoFil: Carmona, Alejandra. Universidad Austral de Chile. Instituto de Economía Agraria; ChileFil: Castro Videla, Fernando Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan; ArgentinaFil: Ferrer Gonzalez, César Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Frank Buss, María Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Pampa. Facultad de Agronomía; ArgentinaFil: López Carapia, Gabriela. Universidad Nacional Autónoma de México; MéxicoFil: Núñez Cruz, Martha. Universidad Nacional Autónoma de México; MéxicoFil: Taboada Hermoza, Rossi. Universidad Nacional Mayor de San Marcos; PerúFil: Benet, Daniel. Alternare A. C.; MéxicoFil: Venegas, Ysmael. Alternare A. C.; MéxicoFil: Balvanera, Patricia. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; MéxicoFil: Mwampamba, Tuyeni H.. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; MéxicoFil: Lazos Chavero, Elena. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; MéxicoFil: Noellemeyer, Elke Johanna. Universidad Nacional de La Pampa. Facultad de Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Maass, Manuel. Universidad Nacional Autónoma de México. Centro de Investigaciones en Ecosistemas; Méxic

    Incorporating Ecohydrological Processes Into an Analysis of Charcoal-Livestock Production Systems in the Tropics: An Alternative Interpretation of the Water-Energy-Food Nexus

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    In the tropics, livestock grazing usually occurs simultaneously with charcoal production, yet empirical understanding of the combined activities remains poor, especially in terms of their effects on hydrological functions. Given predicted growth in both charcoal and beef production in Sub-Sahara Africa, South East Asia, and Central and South America, understanding the potential effects of maintaining this dual production system on local and landscape level hydrological dynamics is paramount for ensuring long-term ecosystem sustainability. Based on a synthesis of existing literature, we propose a theoretical and conceptual framework for analyzing the interlinks between charcoal, livestock, and hydrological processes where they co-exist. As a silo approach, we first analyze the isolated effects of charcoal production and livestock on hydrological processes before exploring their combined effects (systemic approach). Given the scarcity of studies that explicitly address the influence of traditional small-scale charcoal production on hydrological processes, we base our findings on existing knowledge about deforestation, forest fire and grazing impacts on hydrology. We find that exclusion of the effects of companion activities and omission of information on the intensity of biomass harvesting (i.e., pruning branches, selective harvest, clear cutting, uprooting tree stumps) can lead to over-attributing changes in hydrological processes to charcoal, thus exaggerating the effects on ecosystems which might lead to inappropriate interventions. We also find that, in the case of livestock keeping, impacts on hydrological processes are highly dependent on grazing intensity, with low intensity grazing possibly having negligible or even positive effects on forest regrowth and thereby restoration of hydrological processes. Thus, the charcoal-livestock-water nexus may have a wide range of outcomes for hydrological processes from negligible to highly profound effects, depending on key decisions in management and practice. To test these findings, however, field studies are needed that explicitly treat the combined effects of different biomass harvesting practices and grazing intensities on hydrological processes across different scales. Albeit conceptual at this stage, we believe that our approach is a necessary first step in the process of diagnosing potential shortcomings of past approaches for studying charcoal production systems and developing new understanding of this three-way nexus

    The pitfalls of plural valuation

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    This paper critically examines the current political context in which valuation studies of nature are undertaken. It challenges the belief that somehow, more and technically better valuation will drive the societal change toward more just and sustainable futures. Instead, we argue that current and proposed valuation practices risk to continue to overrepresent the values of those who hold power and dominate the valuation space, and to perpetuate the discrimination of the views and values of nondominant stakeholders. In tackling this politically sensitive issue, we define a political typology of valuations, making explicit the roles of power and discrimination. This is done to provide valuation professionals and other actors with a simple framework to determine if valuation actions and activities are constructive, inclusive, resolve injustices and enable systemic change, or rather entrench the status quo or aggravate existing injustices. The objective is to buttress actors in their decisions to support, accept, improve, oppose, or reject such valuations

    Five steps towards transformative valuation of nature

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    The Values Assessment (VA) of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services shows that while a wide range of valuation methods exist to include nature\u27s values in diverse decision-making contexts, uptake of these methods remains limited. Building on the VA, this paper reviews five critical steps in the evaluation of project or policy proposals that can improve the inclusion of nature’s values in decisions. Furthermore, improving valuation practice requires guidelines that utilise quality criteria for valuation of nature and ensure a balance between them. This paper proposes three such quality criteria: relevance, robustness and resource efficiency. The paper argues that the five steps and three Rs can generate a practical checklist to support commissioning, evaluation and performance of more plural valuations. Such guidelines can provide the next steps needed to improve uptake of nature valuation in decision-making

    Five steps towards transformative valuation of nature

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    The Values Assessment (VA) of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services shows that while a wide range of valuation methods exist to include nature's values in diverse decision-making contexts, uptake of these methods remains limited. Building on the VA, this paper reviews five critical steps in the evaluation of project or policy proposals that can improve the inclusion of nature's values in decisions. Furthermore, improving valuation practice requires guidelines that utilise quality criteria for valuation of nature and ensure a balance between them. This paper proposes three such quality criteria: relevance, robustness and resource efficiency. The paper argues that the five steps and three Rs can generate a practical checklist to support commissioning, evaluation and performance of more plural valuations. Such guidelines can provide the next steps needed to improve uptake of nature valuation in decision-making

    Whose values count? A review of the nature valuation studies with a focus on justice

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    The Values Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services shows that multiple valuation methods and approaches exist to assess diverse value types. The evidence is based on the largest review of academic valuation studies on nature to date, developed for the Values Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). We evaluate studies according to environmental justice criteria. The results suggest that although diverse value types and indicators are assessed across studies, few individual studies are plural, and studies fail to provide evidence on distributive justice and score low on procedural justice indicators. We provide a set of recommendations for incorporating issues of justice in the design of valuation studies

    Whose values count? A review of the nature valuation studies with a focus on justice

    Get PDF
    The Values Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services shows that multiple valuation methods and approaches exist to assess diverse value types. The evidence is based on the largest review of academic valuation studies on nature to date, developed for the Values Assessment of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). We evaluate studies according to environmental justice criteria. The results suggest that although diverse value types and indicators are assessed across studies, few individual studies are plural, and studies fail to provide evidence on distributive justice and score low on procedural justice indicators. We provide a set of recommendations for incorporating issues of justice in the design of valuation studies

    Modelling carbon stock and carbon sequestration ecosystem services for policy design: a comprehensive approach using a dynamic vegetation model.

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    Ecosystem service (ES) models can only inform policy design adequately if they incorporate ecological processes. We used the Lund-Potsdam-Jena managed Land (LPJmL) model, to address following questions for Mexico, Bolivia and Brazilian Amazon: (i) How different are C stocks and C sequestration quantifications under standard (when soil and litter C and heterotrophic respiration are not considered) and comprehensive (including all C stock and heterotrophic respiration) approach? and (ii) How does the valuation of C stock and C sequestration differ in national payments for ES and global C funds or markets when comparing both approach? We found that up to 65% of C stocks have not been taken into account by neglecting to include C stored in soil and litter, resulting in gross underpayments (up to 500 times lower). Since emissions from heterotrophic respiration of organic material offset a large proportion of C gained through growth of living matter, we found that markets and decision-makers are inadvertently overestimating up to 100 times C sequestrated. New approaches for modelling C services relevant ecological process-based can help accounting for C in soil, litter and heterotrophic respiration and become important for the operationalization of agreements on climate change mitigation following the COP21 in 2015
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