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Separation Strategies (separation + strategy)
Selected AbstractsDesign and integration of eco-industrial parks for managing water resourcesENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 2 2009Eva M. Lovelady Abstract This work is aimed at developing an optimization-based approach to the design and integration of eco-industrial parks (EIPs). Focus is given to the management of water among multiple processes in a common EIP facility. Recycle, reuse, and separation using interception devices are considered as possible strategies for managing wastewater. A source-interception-sink structural representation is used to embed potential configurations of interest. The representation accounts for the possibilities of direct recycle, material (waste) exchange, mixing and segregation of different streams, separation and treatment in interception units, and allocation to process users (sinks). Then, the EIP design problem is formulated as an optimization program whose objective is to minimize cost of the EIP while determining optimal recycle and separation strategies. A case study is solved to illustrate the applicability of the devised approach. © 2009 American Institute of Chemical Engineers Environ Prog, 2009 [source] Analysis and control of heteroazeotropic batch distillationAICHE JOURNAL, Issue 4 2005S. Skouras Abstract The separation of close-boiling and azeotropic mixtures by heterogeneous azeotropic distillation is addressed in batch columns. Both a common rectifier and a multivessel batch column are considered. Theoretical and graphical analyses of the process are presented for both column configurations and different separation strategies are presented. A simple control scheme is proposed for the practical operation of the columns, the implementation of different separation strategies and the realization of the final results. Dynamic simulations for mixtures classified under Serafimov's topological classes 2.0-2b and 3.1-2 verify the theoretical findings. The results show that heteroazeotropic batch distillation exhibits substantial flexibility. The column profile can be totally restored during the process and lie in regions different from those of the initial feed. The still path can cross distillation boundaries and the still product does not have to be the stable node of the feed region. Such results cannot be obtained by homogeneous azeotropic batch distillation. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source] Capillary electrochromatographic chiral separations with potential for pharmaceutical analysisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 8 2005Debby Mangelings Abstract The use of capillary electrochromatography as a chiral separation technique for pharmaceutical applications is reviewed. Publications of the past 10 years that provide a potential practical application in pharmaceutical analysis are considered. Method development or validation, separation strategies, and potential routine analysis by the methods/applications cited are the main subjects on which we focused our attention. The indirect chiral separation method was only used once in CEC mode. In the direct chiral separations, the use of chiral stationary phases was obviously preferred over the use of chiral mobile phases with non-chiral stationary phases. Amongst the chiral stationary phases, those based on macrocyclic antibiotics and polysaccharide selectors were the most frequently used. Monolithic stationary phases also have several applications, but not so extended as those with packed capillary electrochromatography. The considered papers not only describe the applicability of the technique for relatively large sets of chiral analytes, they also showed that various types of stationary phases can be produced in-house in a simple manner. However, to survive as a mature separation technique, considerable time and effort are still needed to solve some disadvantages currently characterizing capillary electrochromatography. [source] Recovery and separation of cell lysate proteins using hydrogels guided by aqueous two-phase extraction principlesBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2002Christopher S. Putka Abstract The addition of poly(ethylene glycol) and salts to clarified cell lysates of Thiosphaera pantotropha increases sorption of microbial proteins into dextran hydrogels, consistent with the thermodynamics of aqueous two-phase extraction. Addition of 12 wt% PEG-10,000 to the lysate increased total sorption of protein by the dextran gel from 5.2 mg/g dextran to 37 mg/g; addition of either 0.1 M potassium iodide or tetrabutylammonium fluoride along with PEG to the lysate increased protein sorption to more than 63 mg/g, a 12-fold increase. SDS-PAGE demonstrated that the type of salt added controls which proteins are absorbed by the gel. Previously demonstrated only with model solutions, these results suggest another approach to recovery and separation strategies for proteins produced by fermentation. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 80: 139,143, 2002. [source] Net primary productivity mapped for Canada at 1-km resolutionGLOBAL ECOLOGY, Issue 2 2002J Liu Abstract Aim To map net primary productivity (NPP) over the Canadian landmass at 1-km resolution. Location Canada. Methods A simulation model, the Boreal Ecosystem Productivity Simulator (BEPS), has been developed. The model uses a sunlit and shaded leaf separation strategy and a daily integration scheme in order to implement an instantaneous leaf-level photosynthesis model over large areas. Two key driving variables, leaf area index (every 10 days) and land cover type (annual), are derived from satellite measurements of the Advanced Very High Resolution Radiometer (AVHRR). Other spatially explicit input data are also prepared, including daily meteorological data (radiation, precipitation, temperature, and humidity), available soil water holding capacity (AWC) and forest biomass. The model outputs are compared with ground plot data to ensure that no significant systematic biases are created. Results The simulation results show that Canada's annual net primary production was 1.22 Gt C year,1 in 1994, 78% attributed to forests, mainly the boreal forest, without considering the contribution of the understorey. The NPP averaged over the entire landmass was ~140 g C m,2 year,1 in 1994. Geographically, NPP varied greatly among ecozones and provinces/territories. The seasonality of NPP is characterized by strong summer photosynthesis capacities and a short growing season in northern ecosystems. Conclusions This study is the first attempt to simulate Canada-wide NPP with a process-based model at 1-km resolution and using a daily step. The statistics of NPP are therefore expected to be more accurate than previous analyses at coarser spatial or temporal resolutions. The use of remote sensing data makes such simulations possible. BEPS is capable of integrating the effects of climate, vegetation, and soil on plant growth at a regional scale. BEPS and its parameterization scheme and products can be a basis for future studies of the carbon cycle in mid-high latitude ecosystems. [source] | |||||||||||||