DesaLink:solar powered desalination of brackish groundwater giving high output and high recovery

Desalination of groundwater is essential in many arid areas that are far from both seawater and fresh water resources. The ideal groundwater desalination system should operate using a sustainable energy source and provide high water output per land area and cost. To avoid discharging voluminous brine, it should also provide high recovery. To achieve these aims, we have designed DesaLink, a novel approach to linking the solar Rankine cycle to reverse osmosis (RO). To achieve high recovery without the need for multiple RO stages, DesaLink adopts a batch mode of operation. It is suited to use with a variety of solar thermal collectors including linear Fresnel reflectors (LFR). For example, using a LFR occupying 1,000m of land and providing steam at 200°C and 15.5 bar, DesaLink is predicted to provide 350m of fresh water per day at a recovery ratio of 0.7, when fed with brackish groundwater containing 5,000ppm of sodium chloride. Here, we report preliminary experiments to assess the feasibility of the concept. We study the effects of longitudinal dispersion, concentration polarisation and describe a pilot experiment to demonstrate the batch process using a materials testing machine. In addition, we demonstrate a prototype of DesaLink running from compressed air to simulate steam.

Decision support for lifecycle planning and risk management of small-scale biomass combined heat and power (bCHP) projects in the UK

Biomass is projected to account for approximately half of the new energy production required to achieve the 2020 primary energy target in the UK. Combined heat and power (CHP) bioenergy systems are not only a highly efficient method of energy conversion, at smaller-scales a significant proportion of the heat produced can be effectively utilised for hot water, space heating or industrial heating purposes. However, there are many barriers to project development and this has greatly inhibited deployment in the UK. Project viability is highly subjective to changes in policy, regulation, the finance market and the low cost incumbent; a high carbon centralised energy system. Unidentified or unmitigated barriers occurring during the project lifecycle may not only negatively impact on the project but could ultimately lead to project failure. The research develops a decision support system (DSS) for small-scale (500 kWe to 10 MWe) biomass combustion CHP project development and risk management in the early stages of a potential project’s lifecycle. By supporting developers in the early stages of project development with financial, scheduling and risk management analysis, the research aims to reduce the barriers identified and streamline decision-making. A fuzzy methodology is also applied throughout the developed DSS to support developers in handling the uncertain or approximate information often held at the early stages of the project lifecycle. The DSS is applied to a case study of a recently failed (2011) small-scale biomass CHP project to demonstrate its applicability and benefits. The application highlights that the proposed development within the case study was not viable. Moreover, further analysis of the possible barriers with the DSS confirmed that some possible modifications to be project could have improved this, such as a possible change of feedstock to a waste or residue, addressing the unnecessary land lease cost or by increasing heat utilisation onsite. This analysis is further supported by a practitioner evaluation survey that confirms the research contribution and objectives are achieved.

Molecular and biochemical characterization of postharvest senescence in broccoli

Postharvest senescence in broccoli (Brassica oleracea L. var Italica) florets results in phenotypic changes similar to those seen in developmental leaf senescence. To compare these two processes in more detail, we investigated molecular and biochemical changes in broccoli florets stored at two different temperatures after harvest. We found that storage at cooler temperatures delayed the symptoms of senescence at both the biochemical and gene expression levels. Changes in key biochemical components (lipids, protein, and chlorophyll) and in gene expression patterns occurred in the harvested tissue well before any visible signs of senescence were detected. Using previously identified senescence-enhanced genes and also newly isolated, differentially expressed genes, we found that the majority of these showed a similar enhancement of expression in postharvest broccoli as in developmental leaf senescence. At the biochemical level, a rapid loss of membrane fatty acids was detected after harvest, when stored at room temperature. However, there was no corresponding increase in levels of lipid peroxidation products. This, together with an increased expression of protective antioxidant genes, indicated that, in the initial stages of postharvest senescence, an orderly dismantling of the cellular constituents occurs, using the available lipid as an energy source. Postharvest changes in broccoli florets, therefore, show many similarities to the processes of developmental leaf senescence.

PDVSA-Bitor revamps Orimulsion formula to boost environmental cost benefits

Orimulsion400 is a new generation of the Orimulsion formula. This new generation is a more environmentally friendly, cost-effective energy source. This article describes the product's evolution as well as test results from diverse power plants.

Protection schemes for meshed VSC-HVDC transmission systems for large-scale offshore wind farms

This chapter discusses network protection of high-voltage direct current (HVDC) transmission systems for large-scale offshore wind farms where the HVDC system utilizes voltage-source converters. The multi-terminal HVDC network topology and protection allocation and configuration are discussed with DC circuit breaker and protection relay configurations studied for different fault conditions. A detailed protection scheme is designed with a solution that does not require relay communication. Advanced understanding of protection system design and operation is necessary for reliable and safe operation of the meshed HVDC system under fault conditions. Meshed-HVDC systems are important as they will be used to interconnect large-scale offshore wind generation projects. Offshore wind generation is growing rapidly and offers a means of securing energy supply and addressing emissions targets whilst minimising community impacts. There are ambitious plans concerning such projects in Europe and in the Asia-Pacific region which will all require a reliable yet economic system to generate, collect, and transmit electrical power from renewable resources. Collective offshore wind farms are efficient and have potential as a significant low-carbon energy source. However, this requires a reliable collection and transmission system. Offshore wind power generation is a relatively new area and lacks systematic analysis of faults and associated operational experience to enhance further development. Appropriate fault protection schemes are required and this chapter highlights the process of developing and assessing such schemes. The chapter illustrates the basic meshed topology, identifies the need for distance evaluation, and appropriate cable models, then details the design and operation of the protection scheme with simulation results used to illustrate operation. © Springer Science+Business Media Singapore 2014.

Impact of electric vehicles on GB electricity demand and associated benefits for system control

This paper investigates the impact that electric vehicle uptake will have on the national electricity demand of Great Britain. Data from the National Travel Survey, and the Coventry and Birmingham Low Emissions Demonstration (CABLED) are used to model an electrical demand profile in a future scenario of significant electric vehicle market penetration. These two methods allow comparison of how conventional cars are currently used, and the resulting electrical demand with simple substitution of energy source, with data showing how electric vehicles are actually being used at present. The report finds that electric vehicles are unlikely to significantly impact electricity demand in GB. The paper also aims to determine whether electric vehicles have the potential to provide ancillary services to the grid operator, and if so, the capacity for such services that would be available. Demand side management, frequency response and Short term Operating Reserve (STOR) are the services considered. The report finds that electric cars are unlikely to provide enough moveable demand peak shedding to be worthwhile. However, it is found that controlling vehicle charging would provide sufficient power control to viably act as frequency response for dispatch by the transmission system operator. This paper concludes that electric vehicles have technical potential to aid management of the transmission network without adding a significant demand burden. © 2013 IEEE.

Geochemical variation among small eruptive centers in the central SVZ of the Andes: An evaluation of subduction, mantle and crustal influences

Subduction zone magmatism is an important and extensively studied topic in igneous geochemistry. Recent studies focus on from where arc magmas are generated, how subduction components (fluids or melts) are fluxed into the source of the magmas, and whether or how the subduction components affect partial melting processes beneath volcanic arcs at convergent boundaries. ^ At 39.5°S in the Central Southern Volcanic Zone of the Andes, Volcano Villarrica is surrounded by a suite of Small Eruptive Centers (SEC). The SECs are located mostly to the east and northeast of the stratovolcano and aligned along the Liquine-Ofqui Fault Zone, the major fracture system in this area. Former studies observed the geochemical patterns of the SECs differ distinctively from those of V. Villarrica and suggested there may be a relationship between the compositions of the volcanic units and their edifice sizes. This work is a comprehensive geochemical study on the SECs near V. Villarrica, using a variety of geochemical tracers and tools including major, trace and REE elements, Li-Be-B elements, Sr-Nd-Pb isotopes and short-lived isotopes such as U-series and 10Be. In this work, systematic differences between the elemental and isotopic compositions of the SECs and those of V. Villarrica are revealed and more importantly, modeled in terms of magmatic processes occurring at continental arc margins. Detailed modeling calculations in this work reconstruct chemical compositions of the primary magmas, source compositions, compositions and percentages of different subduction endmembers mixed into the source, degrees of partial melting and different time scales of the SECs and V. Villarrica, respectively. Geochemical characteristics and possible origins of the two special SECs—andesitic Llizan, with crustal signatures, and Rucapillan, to the northwest toward the trench, are also discussed in this work. ^

An exergy based engineering and economic analysis of sustainable building

To achieve the goal of sustainable development, the building energy system was evaluated from both the first and second law of thermodynamics point of view. The relationship between exergy destruction and sustainable development were discussed at first, followed by the description of the resource abundance model, the life cycle analysis model and the economic investment effectiveness model. By combining the forgoing models, a new sustainable index was proposed. Several green building case studies in U.S. and China were presented. The influences of building function, geographic location, climate pattern, the regional energy structure, and the technology improvement potential of renewable energy in the future were discussed. The building’s envelope, HVAC system, on-site renewable energy system life cycle analysis from energy, exergy, environmental and economic perspective were compared. It was found that climate pattern had a dramatic influence on the life cycle investment effectiveness of the building envelope. The building HVAC system energy performance was much better than its exergy performance. To further increase the exergy efficiency, renewable energy rather than fossil fuel should be used as the primary energy. A building life cycle cost and exergy consumption regression model was set up. The optimal building insulation level could be affected by either cost minimization or exergy consumption minimization approach. The exergy approach would cause better insulation than cost approach. The influence of energy price on the system selection strategy was discussed. Two photovoltaics (PV) systems—stand alone and grid tied system were compared by the life cycle assessment method. The superiority of the latter one was quite obvious. The analysis also showed that during its life span PV technology was less attractive economically because the electricity price in U.S. and China did not fully reflect the environmental burden associated with it. However if future energy price surges and PV system cost reductions were considered, the technology could be very promising for sustainable buildings in the future.

Local biomass control on the composition and reactivity of particulate organic matter in aquatic environments

Freshwater ecosystems have been recognized as important components of the global carbon cycle, and the flux of organic matter (OM) from freshwater to marine environments can significantly affect estuarine and coastal productivity. The focus of this study was the assessment of carbon dynamics in two aquatic environments, namely the Florida Everglades and small prairie streams in Kansas, with the aim of characterizing the biogeochemistry of OM. In the Everglades, particulate OM (POM) is mostly found as a layer of flocculent material (floc). While floc is believed to be the main energy source driving trophic dynamics in this oligotrophic wetland, not much is known about its biogeochemistry. The objective of this study was to determine the origin/sources of OM in floc using biomarkers and pigment-based chemotaxonomy to assess specific biomass contributions to this material, on a spatial (freshwater marshes vs. mangrove fringe) and seasonal (wet vs. dry) scales. It was found that floc OM is derived from the local vegetation (mainly algal components and macrophyte litter) and its composition is controlled by seasonal drivers of hydrology and local biomass productivity. Photo-reactivity experiments showed that light exposure on floc resulted in photo-dissolution of POC with the generation of significant amounts of both dissolved OM (DOM) and nutrients (N & P), potentially influencing nutrient dynamics in this ecosystem. The bio-reactivity experiments determined as the amount and rate of CO2 evolution during incubation were found to vary on seasonal and spatial scales and were highly influenced by phosphorus limitation. Not much is known on OM dynamics in small headwater streams. The objective of this study was to determine carbon dynamics in sediments from intermittent prairie streams, characterized by different vegetation cover for their watershed (C4 grasses) vs. riparian zone (C3 plants). In this study sedimentary OM was characterized using a biomarker and compound specific carbon stable isotope approach. It was found that the biomarker composition of these sediments is dominated by higher plant inputs from the riparian zone, although inputs from adjacent prairie grasses were also apparent. Conflicting to some extent with the River Continuum Concept, sediments of the upper reaches contained more degraded OM, while the lower reaches were enriched in fresh material deriving from higher plants and plankton sources as a result of hydrological regimes and particle sorting.

Variation in oxygen isotope fractionation during cellulose synthesis: intramolecular and biosynthetic effects

The oxygen isotopic composition of plant cellulose is commonly used for the interpretations of climate, ecophysiology and dendrochronology in both modern and palaeoenvironments. Further applications of this analytical tool depends on our in-depth knowledge of the isotopic fractionations associated with the biochemical pathways leading to cellulose. Here, we test two important assumptions regarding isotopic effects resulting from the location of oxygen in the carbohydrate moiety and the biosynthetic pathway towards cellulose synthesis. We show that the oxygen isotopic fractionation of the oxygen attached to carbon 2 of the glucose moieties differs from the average fractionation of the oxygens attached to carbons 3–6 from cellulose by at least 9%, for cellulose synthesized within seedlings of two different species (Triticum aestivum L. and Ricinus communis L.). The fractionation for a given oxygen in cellulose synthesized by the Triticum seedlings, which have starch as their primary carbon source, is different than the corresponding fractionation in Ricinus seedlings, within which lipids are the primary carbon source. This observation shows that the biosynthetic pathway towards cellulose affects oxygen isotope partitioning, a fact heretofore undemonstrated. Our findings may explain the species-dependent variability in the overall oxygen isotope fractionation during cellulose synthesis, and may provide much-needed insight for palaeoclimate reconstruction using fossil cellulose.

An Exergy Based Engineering and Economic Analysis of Sustainable Building

To achieve the goal of sustainable development, the building energy system was evaluated from both the first and second law of thermodynamics point of view. The relationship between exergy destruction and sustainable development were discussed at first, followed by the description of the resource abundance model, the life cycle analysis model and the economic investment effectiveness model. By combining the forgoing models, a new sustainable index was proposed. Several green building case studies in U.S. and China were presented. The influences of building function, geographic location, climate pattern, the regional energy structure, and the technology improvement potential of renewable energy in the future were discussed. The building’s envelope, HVAC system, on-site renewable energy system life cycle analysis from energy, exergy, environmental and economic perspective were compared. It was found that climate pattern had a dramatic influence on the life cycle investment effectiveness of the building envelope. The building HVAC system energy performance was much better than its exergy performance. To further increase the exergy efficiency, renewable energy rather than fossil fuel should be used as the primary energy. A building life cycle cost and exergy consumption regression model was set up. The optimal building insulation level could be affected by either cost minimization or exergy consumption minimization approach. The exergy approach would cause better insulation than cost approach. The influence of energy price on the system selection strategy was discussed. Two photovoltaics (PV) systems – stand alone and grid tied system were compared by the life cycle assessment method. The superiority of the latter one was quite obvious. The analysis also showed that during its life span PV technology was less attractive economically because the electricity price in U.S. and China did not fully reflect the environmental burden associated with it. However if future energy price surges and PV system cost reductions were considered, the technology could be very promising for sustainable buildings in the future.

Estudo de um secador híbrido (solar-elétrico) para desidratação de frutas

The growing need for food is something that worries the world, which has a population that is growing at a geometric progression while their resources grows at an arithmetic progression. To alleviate this problem there are some proposals, including increased food production or reduce waste thereof. Many studies have been conducted in the world in order to reduce food waste that can reach 40% of production, depending on the region. For this purpose techniques are used to retard degradation of foods, including drying. This paper presents a design of a hybrid fruit dryer that uses solar energy and electric energy with automation of the process. To accomplish drying tests were chosen Typical fruits with good acceptability as processed fruits. During the experiments were measured temperature values at different points. Were also measured humidity values, solar radiation and mass. A data acquisition system was built using a Arduino for obtaining temperatures. The data were sent to a program named Secador de Frutas, done in this work, to plot the same. The volume of the drying chamber was 423 liters and despite the unusual size test using mirrors to increase the incidence of direct radiation, showed that the drier is competitive when compared with other solar dryers produced in Hydraulic Machines and Solar Energy Laboratory (LMHES ) UFRN. The drier has been built at a cost of 3 to 5 times smaller than industrial dryers that operate with the same load of fruit. And the energy cost to produce dried fruits was more feasible compared with such dryers that use LPG as an energy source. However, the drying time was longer.

The diet and influence of the spionid polychaete Marenzelleria on benthic communities in coastal Newfoundland

Spionid polychaetes within the genus Marenzelleria are common inhabitants of organically enriched sediments in the Northern hemisphere. The species M. viridis has unique ventilation behaviors that create dynamic, fluctuating oxygen conditions in sediments, enhancing sulfate reduction. These behaviours may have negative effects on other macrofauna and positive effects on sulfur bacteria. A Marenzelleria species recently sampled in Newfoundland is here identified as M. viridis, and its abundance correlates little with abiotic factors and macrofaunal community composition at examined sites. Various types of surrounding sediments (oxic and suboxic as well as M. viridis burrow linings) contained surprisingly similar total prokaryotic, sulfate reducing and sulfur oxidizing bacteria numbers. The high abundance of sedimentary prokaryotes, combined with the stable isotopic composition of M. viridis tissues and lack of obvious symbionts, suggest that, thanks to its ventilation behaviour, this species may “farm” sulfur bacteria in sediments and use them as a primary food source.

Investigação da rota biohidrometalúrgica com Acidithiobacillus ferrooxidans/thiooxidans para recuperação do cobalto de baterias de íons lítio descartadas

The recycling of metals from secondary sources can be advantageous. Among the metals of interest, we have cobalt, a metal used for various purposes. As regards the secondary sources of cobalt, the lithium-ion batteries can be considered, since they contain cobalt oxide in their composition (LiCoO2). This way, the objective of this work was to use the microorganism strains (Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans) to bioleach the LiCoO2 extracted from discarded lithium ion batteries with emphasis on the recovery of cobalt for synthesis of new materials of interest. The lineage growth occurred in T&K medium and the growth investigation was made by observing the media, by platelet growth and microscope analysis. Then, the inoculum was standardized on 5 x 106 cells mL-1 and used in bioleaching tests. The bioleaching was investigated: the microorganism nature: separate strains and A. ferrooxidans and A. thiooxidans consortium, bioleaching time (0 to 40 days), inoculum proportion (5 to 50% v/v), energy source (iron and sulfur) and residue concentration (1063 to 8500 mg L-1 of cobalt). The cobalt concentration in the media was found by atomic absorption spectrometry and the medium pH was monitored during the bioleaching. The results show that the amount of bioleached cobalt increases with time and the iron concentration. The bioleaching with A. thiooxidans was not influenced by the addition of sulfur. The use of the two lineages together did not improve the bioleaching rates. Among the lineages, the A. thiooxidans presented better results and was able to bioleach cobalt amounts above 50% in most of the experiments. A. thiooxidans presented lower bioleaching rates, with a maximum of 50% after 24 days of experiment. After reprocessing by bioleaching, the cobalt in solution was used for synthesis of new materials: such as LiCoO2 cathode and as adsorbent pesticide double lamellar hydroxide (HDL Co-Al-Cl) by the Pechini and co-precipitation methods. The reprocessed LiCoO2 presented a unique stoichiometric phase relative to the HT-LiCoO2 structure similar to the JCPDS 44-0145, presenting electrochemical activity when tested as a cathode material. The double lamellar hydroxide Co-Al-Cl was tested as pesticide adsorbent, being possible to adsorb around 100% of the pesticide. The bioleaching was efficient in the recovery of cobalt present in lithium-ion batteries and microorganisms presented high tolerance to the residue, being able to bioleach even at higher LiCoO2 concentrations. The cobalt bioleaching medium did not impair the synthesis phases and the obtained materials presented structure and activity similar to the sintered materials from the reagents containing cobalt.

Zinc regeneration in rechargeable zinc-air fuel cells:a review

Zinc-air fuel cells (ZAFCs) present a promising energy source with a competing potential with the lithium-ion battery and even with proton-exchange membrane fuel cells (PEMFCs) for applications in next generation electrified transport and energy storage. The regeneration of zinc is essential for developing the next-generation, i.e., electrochemically rechargeable ZAFCs. This review aims to provide a comprehensive view on both theoretical and industrial platforms already built hitherto, with focus on electrode materials, electrode and electrolyte additives, solution chemistry, zinc deposition reaction mechanisms and kinetics, and electrochemical zinc regeneration systems. The related technological challenges and their possible solutions are described and discussed. A summary of important R&D patents published within the recent 10 years is also presented.