398 research outputs found

    A site selection model to identify optimal locations for microalgae biofuel production facilities in sicily (Italy)

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    The lack of sustainability and negative environmental impacts of using fossil fuel resources for energy production and their consequent increase in prices during last decades have led to an increasing interest in the development of renewable biofuels. Among possible biomass fuel sources, microalgae represent one of the most promising solutions. The present work is based on the implementation of a model that facilitates identification of optimal geographic locations for large-scale open ponds for microalgae cultivation for biofuels production. The combination of a biomass production model with specific site location parameters such as irradiance, geographical constraints, land use, topography, temperatures and CO2 for biofuels plants were identified in Sicily (Italy). A simulation of CO2 saved by using the theoretical biofuel produced in place of traditional fuel was implemented. Results indicate that the territory of Sicily offers a good prospective for these technologies and the results identify ideal locations for locating biomass fuel production facilities. Moreover, the research provides a robust method that can be tailored to the specific requirements and data availability of other territories. © Research India Publications

    The Challenge of Bioenergies: An Overview

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    Phycoremediation of municipal wastewater by microalgae to produce biofuel

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    Municipal wastewater (WW), if not properly remediated, poses a threat to the environment and human health by carrying significant loads of nutrients and pathogens. These contaminants pollute rivers, lakes and natural reservoirs where they cause eutrophication and pathogen-mediated diseases. However, the high nutrient content of WW makes it an ideal environment for remediation with microalgae that require high nutrient concentrations for growth and are not susceptible to toxins and pathogens. Given that an appropriate algal strain is used for remediation, the incurred biomass can be refined for the production of biofuel. Four microalgal species (Chlamydomonas reinhardtii, Chlorella sp., Parachlorella kessleri-I and Nannochloropsis gaditana) were screened for efficient phycoremediation of municipal WW and potential use for biodiesel production. Among the four strains tested, P. kessleri-I showed the highest growth rate and biomass production in 100% WW. It efficiently removed all major nutrients with a removal rate of up to 98% for phosphate after ten days of growth in 100% municipal WW collected from Delhi. The growth of P. kessleri-I in WW resulted in a 50% increase of biomass and a 115% increase of lipid content in comparison to growth in control media. The FAME and fuel properties of lipids isolated from cells grown in WW complied with international standards. The present study provides evidence that the green alga P. kessleri-I effectively remediates municipal WW and can be used to produce biodiesel

    A perspective on algal biogas

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    Algae are suggested as a biomass source with significant growth rates, which may be cultivated in the ocean (seaweed) or on marginal land (microalgae). Biogas is suggested as a beneficial route to sustainable energy; however the scientific literature on algal biogas is relatively sparse. This report comprises a review of the literature and provides a state of the art in algal biogas and is aimed at an audience of academics and energy policy makers. It was produced by IEA Bioenergy Task 37 which addresses the challenges related to the economic and environmental sustainability of biogas production and utilisation.JRC.F.8-Sustainable Transpor

    A techno-economic assessment of nutrient recovery from wastewater using microalgae: scenario in India collected from published literature

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    The true potential of the microalgae-based wastewater treatment (MWT) process is determined based on whether the process will provide a positive energy output and whether it is economically viable. The objectives of this study are dynamic modelling of microalgae growth based on initial wastewater concentration, temperature, solar radiation and a techno-economic assessment for an MWT scheme for application in a hot, dry climate. Through reference to relevant literature data on MWT in the Indian subcontinent, a selection of appropriate microalgal species Chlorella and Scenedesmus was made. The dynamic model developed was successfully calibrated and validated using independent experimental data collected from the published literature. Cost of production of bio-crude from microalgae grown in a hybrid photobioreactor and pond system in kitchen wastewater of Indian Institute of Technology, Hyderabad was calculated. A break-even selling price (BESP) of US0.549/kgwasobtainedforthemicroalgaebiomass.Thecostofproductionof1LbiocrudewasUS0.549/kg was obtained for the microalgae biomass. The cost of production of 1 L bio-crude was US0.96 (Rs 69-74), which is comparable with crude oil cost. The model developed can be used by practising engineers to predict biomass growth and nutrient removal, thereby achieving a break-even point for cost efficiency

    Technologies for Climate Change Mitigation - Agriculture Sector

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    This guidebook describes crop and livestock management technologies and practices that contribute to climate change mitigation while improving crop productivity, reducing reliance on synthetic fertilizers, and lowering water consumption. It is co-authored by internationally recognised experts in the areas of crops, livestock, emissions, and economics, and we are grateful for their efforts in producing this cross disciplinary work.This publication is part of a technical guidebook series produced by the UNEP Risø Centre on Energy, Climate and Sustainable Development (URC) as part of the Technology Needs Assessment (TNA) project(http://tech-action.org) that is assisting developing countries in identifying and analysing the priority technology needs for mitigating and adapting to climate change. The TNA process involves differentstakeholders in a consultative process, enabling all stakeholders to understand their technology needs in a cohesive manner, and prepare Technology Action Plans (TAPs) accordingly.The TNA project is funded by the Global Environment Facility (GEF) and is being implemented by UNEP and the URC in 36 developing countries

    Energy balance and techno-economic assessment of algal biofuel production systems

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    There has been considerable discussion in recent years about the potential of micro-algae for the production of sustainable and renewable biofuels. Unfortunately the scientific studies are accompanied by a multitude of semi-technical and commercial literature in which the claims made are difficult to substantiate or validate on the basis of theoretical considerations.To determine whether biofuel from micro-algae is a viable source of renewable energy three questions must be answered:a. How much energy can be produced by the micro-algae?b. How much energy is used in the production of micro-algae?c. Is more energy produced than used?A simple approach has been developed that allows calculation of maximum theoretical dry algal biomass and oil yields which can be used to counter some of the extreme yield values suggested in the 'grey' literature. No ready made platform was found that was capable of producing an energy balance model for micro-algal biofuel. A mechanistic energy balance model was successfully developed for the production of biogas from the anaerobic digestion of micro-algal biomass from raceways. Preliminary calculations had suggested this was the most promising approach. The energy balance model was used to consider the energetic viability of a number of production scenarios, and to identify the most critical parameters affecting net energy production. These were:a. Favourable climatic conditions. The production of micro-algal biofuel in UK would be energetically challenging at best.b. Achievement of ‘reasonable yields’ equivalent to ~3 % photosynthetic efficiency (25 g m-2 day-1)c. Low or no cost and embodied energy sources of CO2 and nutrients from flue gas and wastewaterd. Mesophilic rather than thermophilic digestione. Adequate conversion of the organic carbon to biogas (? 60 %)f. A low dose and low embodied energy organic flocculant that is readily digested, or micro-algal communities that settle readilyg. Additional concentration after flocculation or sedimentationh. Exploitation of the heat produced from parasitic combustion of micro-algal biogas in CHP unitsi. Minimisation of pumping of dilute micro-algal suspensionIt was concluded that the production of only biodiesel from micro-algae is not economically or energetically viable using current commercial technology, however, the production of micro-algal biogas is energetically viable, but is dependent on the exploitation of the heat generated by the combustion of biogas in combined heat and power units to show a positive balance.Two novel concepts are briefly examined and proposed for further research:a. The co-production of Dunaliella in open pan salt pans.b. A 'Horizontal biorefinery' where micro-algae species and useful products vary with salt concentration driven by solar evaporation.<br/

    Restoring Pre-Industrial CO\u3csub\u3e2\u3c/sub\u3e Levels While Achieving Sustainable Development Goals

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    © 2020 by the authors. Unless humanity achieves United Nations Sustainable Development Goals (SDGs) by 2030 and restores the relatively stable climate of pre-industrial CO2 levels (as early as 2140), species extinctions, starvation, drought/floods, and violence will exacerbate mass migrations. This paper presents conceptual designs and techno-economic analyses to calculate sustainable limits for growing high-protein seafood and macroalgae-for-biofuel. We review the availability of wet solid waste and outline the mass balance of carbon and plant nutrients passing through a hydrothermal liquefaction process. The paper reviews the availability of dry solid waste and dry biomass for bioenergy with CO2 capture and storage (BECCS) while generating Allam Cycle electricity. Sufficient wet-waste biomass supports quickly building hydrothermal liquefaction facilities. Macroalgae-for-biofuel technology can be developed and straightforwardly implemented on SDG-achieving high protein seafood infrastructure. The analyses indicate a potential for (1) 0.5 billion tonnes/yr of seafood; (2) 20 million barrels/day of biofuel from solid waste; (3) more biocrude oil from macroalgae than current fossil oil; and (4) sequestration of 28 to 38 billion tonnes/yr of bio-CO2. Carbon dioxide removal (CDR) costs are between 25–33% of those for BECCS with pre-2019 technology or the projected cost of air-capture CDR
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