Search results for "renewable"
showing 10 items of 2395 documents
Nano-magnetic potassium impregnated ceria as catalyst for the biodiesel production
2019
Abstract The main objective of this work comprises the investigation of biodiesel production from rapeseed oil using potassium impregnated Fe3O4-CeO2 nanocatalyst. The various concentration of potassium impregnated Fe3O4-CeO2 was screened for catalytic conversion of rapeseed oil to triglyceride methyl ester. The 25 wt % potassium impregnated Fe3O4-CeO2 nanocatalyst showed best biodiesel production. Nanocatalyst was characterized by FTIR, XRD, SEM, TEM, BET and Hammett indicator for basicity test. The characterization of biodiesel was performed with GC-MS, 1H and 13C NMR. Moreover, the optimum reaction parameters such as catalyst amount (wt %), oil to methanol ratio, reaction time and reacti…
Modeling solid waste decomposition.
2004
The hydrolysis rate coefficients of sorted municipal waste were evaluated from the biochemical methane potential tests using non-linear regression. A distributed mathematical model of anaerobic digestion of rich (food) and lean (non-food) solid wastes with greatly different rates of polymer hydrolysis/acidogenesis was developed to describe the balance between the rates of hydrolysis/acidogenesis and methanogenesis. The model was calibrated using previously published experimental data [Biores. Technol. 52 (1995) 245] obtained upon various initial food waste loadings. Simulations of one- and two-stage digestion systems were carried out. The results showed that initial spatial separation of fo…
Complete genome sequence of the strain Defluviitoga tunisiensis L3, isolated from a thermophilic, production-scale biogas plant.
2015
An anaerobic, thermophilic bacterium belonging to the phylum Thermotogae was isolated from a rural, thermophilic biogas plant (54 degrees C) producing methane-rich biogas from maize silage, barley, cattle and pig manure. Here we report the first complete genome sequence of the Defluviitoga tunisiensis strain L3, an isolate from the family Thermotogaceae. The strain L3 encodes several genes predicted to be involved in utilization of a large diversity of complex carbohydrates including cellobiose and xylan for the production of acetate, hydrogen (H-2) and carbon dioxide (CO2). The genome sequence of D. tunisiensis L3 provides the basis for biotechnological exploitation of genetic determinants…
Effect of biomass features on oxygen transfer in conventional activated sludge and membrane bioreactor systems
2019
Abstract The aim of the present study was to compare the oxygen transfer efficiency in a conventional activated sludge and a membrane bioreactor system. The oxygen transfer was evaluated by means of the oxygen transfer coefficient and α-factor calculation, under different total suspended solids concentration, extracellular polymeric substances, sludge apparent viscosity and size of the flocs. The oxygen transfer coefficient and α-factor showed an exponential decreasing trend with total suspended solid, with a stronger oxygen transfer coefficient dependence in the conventional activated sludge compared to the membrane bioreactor. It was noted that the oxygen transfer coefficient in the conve…
Values of broad band turbidity coefficients in a mediterranean coastal site
1999
Abstract The Angstrom turbidity coefficient, the Linke turbidity factor, and the Unsworth–Monteith coefficient have been determined and analysed based on measurements of normal direct irradiance and global horizontal irradiance taken in Valencia, Spain, between January 1990 and December 1996. The data, which were acquired automatically and continuously, have been filtered to select only those values corresponding to clear sky conditions. To determine the Angstrom turbidity coefficient the method proposed by Louche et al. has been used whilst the expression for δCDA proposed by Kasten was used to obtain the Linke turbidity coefficient. The Angstrom turbidity coefficient showed a minimum in w…
Dissolution and hydrolysis of fibre sludge using hydroxyalkylimidazolium hydrogensulphate ionic liquids
2014
Abstract The dissolution and hydrolysis of wet fibre sludge in ionic liquids (ILs) with different reaction conditions are performed in this study. Novel types of hydroxyalkylimidazolium hydrogensulphate ILs, [glymim]HSO 4 , [hemim]HSO 4 and [hpmim]HSO 4 , are especially designed and aimed to combine the dissolution and hydrolysis of wet fibre sludge in a one-step pretreatment. The results were obtained based on the analysis of total reducing sugars (TRS) with the DNS method. The dissolution and hydrolysis of fresh wild horse chestnut fruit ( Aesculus hippocastanum ) with the same ILs were also carried out as a comparison reference. Since fibre sludge is cellulose based and horse chestnut fr…
New Challenges for Sustainable Organizations in Light of Agenda 2030 for Sustainability
2021
Sustainability is one of humanity’s most daunting issues at present. Increasing popula- tion, escalation of anthropogenic activities, industrialization, modern agricultural practices that pollute water, air, and soil around the world, and ever-increasing greenhouse gas emissions mean that sustainability is now in doubt [1]. In response to these critical concerns, the world has come up with several initiatives including Agenda 2030. Agenda 2030 is a commitment to eradicate poverty and achieve sustainable development worldwide, ensuring that no one is left behind by 2030. Its adoption was a landmark achievement, providing a shared vision towards sustainable development for all. Its 17 Sustain…
Beyond Biodegradability of Poly(lactic acid): Physical and Chemical Stability in Humid Environments
2017
International audience; Poly(lactic acid) (PLA) is the most traded biodegradable and biobased material. It is largely used as ecofriendly substitute of conventional plastics. Nevertheless, one of the main limiting factors is its water sensitivity. PLA reacts with water and is hydrolyzed during time, which determines its performance. Limited information related to the hydrolysis mechanism driven by water in vapor state is available in scientific literature. Literature is mainly focused on the effects of water in liquid state. This lack of information is of significant importance, since PLA interacts with water in both phases. This work was aimed to give a full depiction of the chemical and p…
Le filiere del sistema agricolo per l'energia e l'efficienza energetica
2011
Increasing the use of renewable energies and Energy Efficiency offer significant opportunities for Italy to reduce fossil energy, greenhouse gas emissions and secure its energy supply. This report presents a brief analysis of the most important supply chains of the Agriculture system. Greatest attention is paid to the significant role that agriculture and its supply chains are likely to play in terms of bioenergy production and energy saving. Special attention is devoted to new agricultural activities like those associated with the reduction of vegetable food waste, the agrotourism, the urban agriculture, the plastic coverings and the greenhouses, the plant protection and the fertilizers. D…
Energy-saving potential of ground source multiple chillers in simple and hybrid configurations for Mediterranean climates
2022
Air conditioning accounts for a large share of energy usage in residential and tertiary sectors. Renewable energy technologies offer promising solutions to reduce the environmental impacts of meeting buildings’ energy loads. The possibility of using the soil as a thermal reservoir for heating and cooling systems has gained growing attention in the last decade due to its high potential for energy saving. In this paper, the benefits achievable using ground source chillers for air conditioning in an office building located in Southern Italy are discussed. A multiple chillers system coupled with a borehole heat exchanger is investigated and compared to conventional air-cooled and water-cooled s…