• Energy Research
• Restricted close
• FR close
• SN close
• Agritrop close

Five caesalpinioid legumes, Afzelia africana, Afzelia bella, Anthonotha macrophylla, Cryptosepalum tetraphylum and Paramacrolobium coeruleum, and one Euphorbiaceae species, Uapaca somon, with a considerable range in seed sizes, exhibited different responses to inoculation by four species of ectomycorrhizal (ECM) fungi, Scleroderma dictyosporum, S. verrucosum, Pisolithus sp. and one thelephoroid sp. in greenhouse conditions. Thelephoroid sp. efficiently colonized seedlings of all of the five caesalpinioid legumes except U. somon, but provided no more growth benefit than the other fungi. Thelephoroid sp. and S. dictyosporum colonized seedlings of U. somon poorly, but stimulated plant growth more than the other fungi. The relative mycorrhizal dependency (RMD) values of the caesalpinioid legumes were never higher than 50%, whilst U. somon had RMD values ranging from 84.6 to 88.6%, irrespective of the fungal species. The RMD values were negatively related to seed mass for all plant species. Potassium concentrations in leaves were more closely related than phosphorus to the stimulation of seedling biomass production by the ECM fungi. Our data support the hypothesis that African caesalpinioid legumes and euphorbe tree species with smaller seeds show higher RMD values than those with the larger seeds.

The current paper presents a study combining experimentation and modelling of char gasification in a continuous fixed bed reactor. The char bed gasification was characterised using the Continuous Fixed Bed Reactor (CFiBR) at CIRAD (Montpellier, France). This reactor replicates the gasification zone apart from the rest of the zones present at fixed bed gasification processes. It is instrumented specifically to allow the measurement of thermal and chemical profiles all the way along the bed. Indeed, measurements for temperature, pressure, gas composition and char conversion rate are performed every 10 cm along the bed. A model of the gasification of wood char in a continuous fixed bed reactor is being developed using COMSOL software. It couples heat and mass transfer phenomena with heterogeneous and homogenous chemical reactions taking place inside the bed. Proceedings of the 18th European Biomass Conference and Exhibition, 3-7 May 2010, Lyon, France, pp. 567-573

The liquid fuels production from biomass is one of the most efficient ways to energetic conversion, beyond the energy concentration, there are still economic and operational advantages due to transport and storage conditions. So, fast pyrolysis is the purpose of several researches all over the world for the production of bio-oils that can enrich the energetic supply. However, bio-oil has heterogeneous properties due to the biomass characteristics and to the operational conditions of the pyrolysis process. The present review aims to evaluate the state of art of the bio-oil production, their properties and their principal energetic ways of utilization. (Résumé d'auteur)

Abstract In this study, favorable conditions to achieve good combustion of cottonseed oil and its blends with diesel fuel in a direct injection diesel engine have been highlighted. This has been performed by analyzing fuel droplet size distribution and determining engine specific fuel consumption and thermal efficiency, combustion parameters (ignition delay, rate of heat release) and emissions (carbon monoxide (CO), nitrogen oxides (NOx) and carbon dioxide (CO2)). Results show that thermal efficiency and CO2 are almost similar for all tested fuels while the specific fuel consumption and CO emissions increase and NOx emissions decrease with increasing percentage of cottonseed oil in blends. Cylinder pressures are very close and rates of heat release are slightly different for cottonseed oil and diesel fuel. Results on droplet size analysis show that to obtain an adequate droplet size distribution, the percentage of cottonseed oil in diesel fuel should be limited to 40% by volume. Results on engine performance show that engine loads must be above 50%. These results are valid for diesel engines of conventional design, using low-pressure injection systems; they do not apply to modern high injection pressure engines.

Cotton cropping in Pakistan uses substantial quantities of resources and adversely affects the environment with pollutants from the inputs, particularly pesticides. A question remains regarding to what extent the reduction of such environmental impact is possible without compromising the farmers' income. This paper investigates the environmental, technical, and economic performances of selected irrigated cotton-cropping systems in Punjab to quantify the sustainability of cotton farming and reveal options for improvement. Using mostly primary data, our study quantifies the technical, cost, and environmental efficiencies of different farm sizes. A set of indicators has been computed to reflect these three domains of efficiency using the data envelopment analysis technique. The results indicate that farmers are broadly environmentally inefficient; which primarily results from poor technical inefficiency. Based on an improved input mix, the average potential environmental impact reduction for small, medium, and large farms is 9, 13, and 11 %, respectively, without compromising the economic return. Moreover, the differences in technical, cost, and environmental efficiencies between small and medium and small and large farm sizes were statistically significant. The second-stage regression analysis identifies that the entire farm size significantly affects the efficiencies, whereas exposure to extension and training has positive effects, and the sowing methods significantly affect the technical and environmental efficiencies. Paradoxically, the formal education level is determined to affect the efficiencies negatively. This paper discusses policy interventions that can improve the technical efficiency to ultimately increase the environmental efficiency and reduce the farmers' operating costs.

Metal-blending of biomass prior to pyrolysis is investigated in this work as a tool to modify biochar physico-chemical properties and its behavior as adsorbent. Six different compounds were used for metal-blending: AlCl3, Cu(OH)2, FeSO4, KCl, MgCl2 and Mg(OH)2. Pyrolysis experiments were performed at 400 and 700 °C and the characterization of biochar properties included: elemental composition, thermal stability, surface area and pore size distribution, Zeta potential, redox potential, chemical structure (with nuclear magnetic resonance) and adsorption behavior of arsenate, phosphate and nitrate. Metalblending strongly affected biochars' surface charge and redox potential. Moreover, it increased biochars' microporosity (per mass of organic carbon). For most biochars, mesoporosity was also increased. The adsorption behavior was enhanced for all metal-blended biochars, although with significant differences across species: Mg(OH)2-blended biochar produced at 400 °C showed the highest phosphate adsorption capacity (Langmuir Qmax approx. 250 mg g-1), while AlCl3-blended biochar produced also at 400 °C showed the highest arsenate adsorption (Langmuir Qmax approx. 14 mg g-1). Significant differences were present, even for the same biochar, with respect to the investigated oxyanions. This indicates that biochar properties need to be optimized for each application, but also that this optimization can be achieved with tools such as metal-blending. These results constitute a significant contribution towards the production of designer biochars.

The study assesses the implications of the bioethanol policy mandate in Thailand of producing 9 M litre ethanol per day by 2021 on water use and water deprivation. The results reveal that water footprint (WF) of bioethanol varies between 1396 and 3105 L water/L ethanol. Cassava ethanol has the highest WF followed by molasses and sugarcane ethanol, respectively. However, in terms of fresh water (especially irrigation water) consumption, molasses ethanol is highest with 699-1220 L/L ethanol. To satisfy the government plan of bioethanol production in 2021, around 1625 million m(3) of irrigation water/year will be additionally required, accounting for about 3% of the current active water storage of Thailand. Two important watersheds in the northeastern region of Thailand are found to be potentially facing serious water stress if water resources are not properly managed. Measures to reduce water footprint of bioethanol are recommended.

Geopolitical tensions in some oil producing regions and the uncertainties surrounding the future availability of fossil fuels, as well as the urgent necessity to mitigate negative impacts on climate through reduced CO2 emissions, have created a strong interest for biofuels. Among potential crops for the production of biofuels, sorghum is an interesting C4 plant, able to combine production of food and fuel as well as a variety of other products. However, new ideotypes of sorghum need to be defined in order to optimise efficiency with respect to the following three potential use options of sorghum: (1) production of ethanol through second generation processes, (2) production of first generation ethanol combined with the use of bagasse for co-generation, and (3) production of first generation ethanol combined with the production of grain and the use of bagasse as fodder. This paper presents results elaborated in the framework of the project SWEETFUEL, supported by the European Commission, on the successful combination of traits of new sorghum ideotypes suitable for the three abovementioned use options. Proceedings of the 19th European Biomass Conference and Exhibition, 6-10 June 2011, Berlin, Germany, pp. 782-786