Renewable Resource

A renewable natural resource, vanillin, is used to synthesize polybenzoxazine with the expected desirable benzoxazine properties as well as a high char yield of 55.3%. The synthesized monomer provides an unused aldehyde group from vanillin. The aldehyde can be further reacted with other materials to enhance properties. As a model, the unused aldehyde is reacted with amine terminated poly(ethylene oxide) to form a surfactant which retains 1,3-benzoxazine's reactivity. The chemical structure of the synthesized monomers, surfactant and polymers are characterized by Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance spectroscopy (1 H NMR). Thermal properties are also characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Miniemulsions with stability up to 2 weeks are created with the newly synthesized surfactant and polystyrene. Dynamic light scattering (DLS) indicates 627 nm as the average diameter of the emulsion droplets.

Hydrogen (H 2 ) is one of renewable energy sources known for its non-polluting and environmentally friendly nature, as its end combustion product is water (H 2 O). The biological production of H 2 is a less energy intensive alternative where processes can be operated at ambient temperature and pressure. Dark fermentation by bacterial biomass is one of multitude of approaches to produce hydrogen which is known as the cleanest renewable energy and is thus receiving increasing attention worldwide. The present study briefly reviews the biohydrogen production process with special attention on the effects of several environmental and operational factors towards the process. Factors such as organic loading rate, hydraulic retention time, temperature, and pH studied in published reports were compared and their influences are discussed in this work. This review highlights the variations in examined operating ranges for the factors as well as their reported optimum values. Divergent values observed for the environmental/operational factors merit further exploration in this field.

Copolymers of tributyl citrate (TBC) and hexamethylenediamine (HMDA) were synthesized with a solvent-free condensation method with molar ratios of TBC to HMDA varying from 2:1 to 1:2. The reaction led to poly(succinimide-co-citramide) copolymers which were characterized by infrared and Raman spectroscopies, X-ray diffraction, and thermal analyses. Hydrolysis of the copolymers resulted in water soluble polycitramides with number averaged molecular weights ranging from 1.16 Â 10 4 to 5.00 Â 10 3 as determined by gel permeation chromatography. 1 H, 13 C, and 13 C-1 H-heteronuclear single quantum coherence NMR spectroscopy has confirmed that the hydrolyzed polycitra-mides with COOH side chains and amide backbones are structurally similar to biodegradable poly(aspartic acid) (PASP). Interestingly, the polycitramides showed Ca 2þ and Pb 2þ ion chelating capabilities higher than PASP, citric acid-sorbitol copolymers, or conventional resins. Thus, the polycitramides offer promise as a totally new class of metal sequesters and renewable substitutes for PASP and poly(acrylic acid). V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 000: 000-000, 2012

Le triple résultat : Concilier des objectifs écologiques, économiques et sociaux en présence de quotas individuels et transférables Résumé Cet article analyse le fonctionnement d'un système de management d'une ressource renouvelable fondé sur des quotas individuels et transférables en présence d'agents hétérogènes sur leurs coûts et leurs coefficients de capture. Dans un modèle bioéconomique dynamique, nous déterminons sous quelles conditions, le décideur d'une pêcherie peut satisfaire durablement des objectifs de conservation de la ressource, d'efficience économique et de maintien de l'activité de pêche. Nous montrons que la viabilité des stratégies de capture totale autorisée dépend du degré d'hétérogénéité des exploitants de la ressource, du niveau initial et de la dynamique du stock. En particulier, pour un montant de stock initial, nous calculons l'effort maximum possible pour un groupe donné d'exploitants et nous calculons le nombre maximum d'exploitant actifs possible pour un niveau d'effort garanti. Nous illustrons nos résultats à la pêcherie de la langoustine dans le Golfe de Gascogne. Abstract This paper deals with the sustainable management of a renewable resource based on individual and transferable quotas (ITQs) when agents differ in terms of harvesting costs or catching capabilities. In a dynamic bio-economic model, we determine the feasibility conditions under which a fishery manager can achieve sustainability objectives which simultaneously account for stock renewal, economic efficiency and maintenance of fishing activity for the agents along time. We show that the viability of quota management strategies based on fixing Total Allowable Catch (TAC) limits depends on the degree of heterogeneity of users in the fishery, the current status and the dynamics of the stock. In particular for a given stock, we compute the maximin effort for a given set of agents and we derive the maximal number of active agents for a given guaranteed effort. An application to the nephrops fishery in the Bay of Biscay illustrates the results.

Nowadays biodiesel, as an alternative fuel, is attracting increasing attention. Microalgae appear as a solution for this crucial problem. As renewable energy resource, microalgae capable of meeting the global demand for transport fuels. Like plants, microalgae use sunlight, carbon dioxide and several nutrients to produce oils but they do so more efficient than crop plants. Oil productivity of microalgae greatly exceeds the oil productivity of the best producing oil crops. Due to their high biomass productivity, rapid lipid accumulation, and ability to survive in saline water, microalgae have been identified as promising feedstocks for industrial-scale production of carbon-neutral biodiesel. This paper reviews the reasons for choosing microalgae as renewable energy resources and the process of biodiesel production, including growth rate and productivity.

The potential of durian (Durio zibethinus Murr.) peel as feedstock for the production of fermentable sugars was evaluated. Durian peel biomass from two cultivars, monthong (Durio zibethinus Murr. cv. Monthong) and chanee (Durio zibethinus Murr. cv. Chanee), were pretreated with different concentrations (70%, 75%, 80%, and 85%) of phosphoric acid (H 3 PO 4) at a moderate temperature of 60 • C for 60 min. The H 3 PO 4-pretreated durian peel biomass was then subjected to enzymatic hydrolysis. Significantly higher glucan (44.74 ± 0.21%) content was observed in the monthong peel compared to the chanee peel (42.06 ± 0.28%). Phosphoric acid pretreatment caused the significant solubilization of the xylan and acid soluble lignin (ASL) contents. This enhanced the enzymatic hydrolysis process causing a significant increase in the hydrolysis efficiency and glucose concentration. The highest hydrolysis efficiency and glucose concentration were obtained after 72 h from the 75% H 3 PO 4-pretreated peel biomass for both the monthong (90.33 ± 0.42% and 9.55 ± 0.11 g/L, respectively) and chanee (90.06 ± 0.40% and 8.56 ± 0.13 g/L, respectively) peels. Biomass to glucose recovery for monthong and chanee were improved by approximately 7-and 6-fold, respectively. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis showed destruction of the peel biomass structure and changes in the cellulose crystallinity index (CrIs).

This paper proposed an improved incremental conductance method to track the Maximum Power Point (MPP) for PV Panel under fast changing solar irradiation. When there is increment in solar irradiation level, the conventional incremental conductance method is confused and responses incorrectly. The proposed method response correctly and there is no steady state oscillation compared to the conventional method. Matlab simulation is carried out for both the improved and conventional incremental conductance method under fast changing solar irradiation level. The simulation results showed the system able to track the MPP faster than the conventional method. © Published under licence by IOP Publishing Ltd.

iopscience.iop.org/1755-1315/16/1/012017

A lack of understanding of the quantitative rhamnolipid production regulation in bioreactor cultivations of Pseudomonas aeruginosa and the absence of respective comparative studies are important reasons for achieving insufficient productivities for an economic production of these biosurfactants. The Pseudomonas strains DSM 7108 and DSM 2874 are described to be good rhamnolipid overproducers. The strain PAO1 on the other hand is the best analyzed type strain for genetic regulation mechanisms in the species P. aeruginosa. These three strains were cultivated in a 30-L bioreactor with a medium containing nitrate and sunflower oil as sole C-source at 30 and 37°C. The achieved maximum rhamnolipid concentrations varied from 7 to 38 g/ L, the volumetric productivities from 0.16 to 0.43 g/(L•h), and the cellular yield from 0.67 to 3.15 g/g, with PAO1 showing the highest results for all of these variables. The molar di-to mono-rhamnolipid ratio changed during the cultivations; it was strain dependent but not significantly influenced by the temperature. This study explicitly shows that the specific rhamnolipid synthesis rate per cell follows secondary metabolite-like courses coinciding with the transition to the stationary phase of typical logistic growth behavior. However, the rhamnolipid synthesis was already induced before N-limitation occurred.

Polymers based on renewable resources are promising candidates for replacing common organic polymers, and thus, for reducing oil consumption. In this contribution we report the microwave-assisted synthesis of block and statistical copolymers from 2-ethyl-2-oxazoline and 2-"soy alkyl"-2-oxazoline via a cationic ringopening polymerization mechanism. The synthesized copolymers were characterized by gel permeation chromatography and 1 H-NMR spec-troscopy. The micellization of these amphiphilic copolymers was investigated by dynamic light scattering and atomic force microscopy to examine the effect of hydrophobic block length and monomer distribution on the resulting micellar characteristics.

The main goal of this paper is the overview of the scope and dynamics of biomass production as a renewable energy source for substitution of coal in the production of electrical energy in the Kolubara coal basin. In order to successfully realize this goal, it was necessary to develop a dynamic model of the process of coal production, overburden dumping and re-cultivation of dumping sites by biomass planting. The results obtained by simulation of the dynamic model of biomass production in Kolubara mine basin until year 2045 show that 6870 hectares of overburden waste dumps will be re-cultivated by biomass plantations. Biomass production modeling point out the significant benefits of biomass production by planting the willow Salix viminalis cultivated for energy purposes. Under these conditions, a 0.6 % participation of biomass at the end of the period of intensive coal production, year 2037, is achieved. With the decrease of coal production to 15 million tons per year, this percentage steeply rises to 1.4 % in 2045. This amount of equivalent tons of coal from biomass can be used for coal substitution in the production of electrical energy.

Wood is a unique and renewable resource material that has been an important substance since time immemorial of human civilization because of its easy availability unique aesthetic look and useful properties 1. It can be reaped sustainably at a constant rate without depleting the existing resource pool. Because of the influence of increasing human activities on the environment, awareness of the society on the environment is rapidly increasing, thus environmental considerations have given due attention to effect a change in the way of utilization of materials for various purposes. Thus, chemical industries are seeking to manufacture products with minimal environmental impact. Scientists have been working to improve the utilization of raw material, reduce production inefficiencies and develop more sustainable industrial practices. The widespread occurrence, stability, hardness, lightness, elasticity and as perspective potential renewable material make wood an important raw material sources 2. Natural look and versatility make wood a class of material for various purposes of applications. It has wide range of applications to make items like paper, pulp, construction of materials and as resource material for energy generation 3. Wood is a natural polymeric composite consisting of cellulose, hemicelluloses and phenolic polymers of lignin. The cellulose is a polymer of D-glucopyranose units linked together by β(1→4) glycosidic bonds. Hemicelluloses are heteropolysaccharides having a lower degree of polymerization (DP) than cellulose of about 100-300. Cellulose is more ordered than hemicellulose, although some hemicellulose can form crystalline units. Water present in atmospheric moisture can easily form hydrogen bonding with the free hydroxyl groups in cellulose resulting in shrinking and swelling of wood depending upon its moisture content. Lignins have the least water sorption tendency and are amorphous, highly complex, mainly aromatic, polymers of phenylpropane units 4. Lignin is associated with hemicelluloses through covalent bond forming lignin-carbohydrate complexes but there is no evidence of their association with cellulose. Thus, the hydroxyl groups present in the cell wall of wood are the most abundant reactive and vulnerable chemical site 3. Mechanical anisotropy arises in wood due to its highly heterogeneous structure. Among the numerous applications, the utilization of wood in particular for flooring and hard wearing wood surfaces preferably need an improvement of strength and elasticity in the direction normal to the grain. Hence strength in lateral direction is most desirable. The success of trees as

A PV-Wind hybrid system has been developed at the energy Laboratory of the Autonomous university of Yucatan in order to evaluate the performance of this kind of generators in the tropical conditions of the North of the Yucatan Peninsula. The systems comprise a PV array, a wind generator, a battery bank and a set of electric regulators, converters and an inverter. The voltage and the electric current of the main components of the system have been studied monthly along with their corresponding diurnal cycles. This paper presents an outline of the PV-Wind hybrid energy generator and its main characteristics which will allow to evaluate strategies to improve the performance of independent energy generation systems from renewable resources in the study region.

In this paper, a commonly owned resource (an environmental or social asset) and a private good are substitutes in consumption. The households can buy the private good on the market, while the resource is available for free. The resource is renewable, but its ability to regenerate declines with the level of aggregate production: each single firm producing the private good has only a negligible impact on the resource, but the impact caused by the entire population of firms is considerable. In the face of a decrease in the stock of the resource, households are induced to increase their participation in market activities in order to raise their income and buy more private goods. Hence, each household contributes to a further increase in aggregate production, thus causing additional damage to the resource's ability to regenerate and feeding the growth process. Given the presence of negative externalities, multiple equilibrium paths are possible. In this situation, social conventions may guide individuals to coordinate expectations and behavior toward a particular steady state: one can speculate that the dominance of cultural values favorable to a lifestyle based on a mix of high consumption and hard work leads the economy to converge on a Pareto-inferior steady-state. #

Policies for managing a renewable resource in the presence of a backstop substitute are analysed. Conditions for renewable and backstop resources to be "relevant" are discussed. The extinction issue, the role of myopic decision rules and the optimality of singular arc policies are reexamined with non-autonomous prices.

This paper analyses the economics of grid-connected photovoltaic systems. With the 2003 costs of photovoltaic systems, under prevailing capital market conditions, with a system lifetime of 30 years, and under the best climatic conditions, it appears that the cost of production of grid-connected electricity could be of 0.28 US $/kWh. Similar values hold for other regions (US locations under medium climatic conditions, European locations, Switzerland and Japan with, in these countries, low costs of capital). If the lifetime of the system goes up, due to future technological improvements, to a very large value such as 50 years, these costs can be lowered by a significant amount, leading to estimates of of 0.24 US $/kWh. Competitiveness of grid-connected photovoltaic electricity, while it still cannot be taken for granted, is a possibility, especially if major technological advances further lowers the costs of photocells and increases their lifetimes.

Soft PVC was obtained by using a new plasticizer, based on cardanol, a renewable resource characterized by chemical and physical properties very close to those of diethylhexyl phthalate (DEHP). Cardanol acetate (CA) was obtained by solvent free esterification of cardanol, and used as secondary plasticizer, by partial substitution of DEHP in soft PVC formulations. Ageing tests were performed in order to study the stability of properties of the soft PVC formulations related to plasticizer diffusion. Tensile properties and hardness changes were used to monitor the macroscopic effects of plasticizer diffusion. Soft PVC obtained by partial substitution of DEHP by CA showed a significant modification of mechanical properties related to a higher plasticizer evaporation during ageing tests. Migration tests confirmed that CA is characterized by a higher diffusivity in soft PVC compared to DEHP.

A PV-Wind hybrid system has been developed at the energy Laboratory of the Autonomous university of Yucatan in order to evaluate the performance of this kind of generators in the tropical conditions of the North of the Yucatan Peninsula. The systems comprise a PV array, a wind generator, a battery bank and a set of electric regulators, converters and an inverter. The voltage and the electric current of the main components of the system have been studied monthly along with their corresponding diurnal cycles. This paper presents an outline of the PV-Wind hybrid energy generator and its main characteristics which will allow to evaluate strategies to improve the performance of independent energy generation systems from renewable resources in the study region.

Novel self-assembled nano/microstructured conducting PANICN was prepared by in situ intercalative emulsion polymerization of aniline in aqueous dispersion of clay using bifunctional amphiphilic dopant, 3-pentadecyl phenol-4-sulphonic acid (PDPSA) derivable from renewable resource. X-ray diffraction and scanning electron microscopy (SEM) studies revealed the formation of monolayer of protonated PANI intercalated nanoclays with template polymerized self-assembled micro/nanostructured protonated PANI. Nano/micro structured PANIs were formed by the supra molecular self-assembling of the inter-chain hydrogen bonding, inter-plane phenyl stacking and electrostatic layer by layer self-assembling (ELBS) between polarized alkyl chains present dopant anions and were manifested using fourier transform infra red spectroscopy and differential scanning calorimetry. On the basis of the results, structure-directing effect of 'anilinium salt micelle' was schematically illustrated in this article.