193 research outputs found

    Industrial Separation Processes:Fundamentals

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    Separation processes on an industrial scale account for well over half of the capital and operating costs in the chemical industry. Knowledge of these processes is key for every student of chemical or process engineering. This book is ideally suited to university teaching, thanks to its wealth of exercises and solutions. The second edition boasts an even greater number of applied examples and case studies as well as references for further reading. - An authoritative introduction to industrial separation technology. - Contains exercises at the end of each subject as well as solutions. - Now with extended and updated examples and case studies

    Equilibrium studies on butane-1,4-diamine extraction with 4-nonylphenol

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    BACKGROUND: The extraction of butane-1,4-diamine (BDA) from aqueous solutions with undiluted 4-nonylphenol (4NP) has been studied at three temperatures (298 K, 310 K and 323 K) in a batch system. A reactive extraction model based on mass action law was applied to describe the experimental data. RESULTS: The model developed describes the distribution of BDA between the 4NP phase and the aqueous phase, and the average stoichiometry of the complexation due to interactions between the two amine groups of BDA and 4NP, as well as the complexation constant were fitted to experimental data with good accuracy for each of the three temperatures, the largest error at the confidence limit of the estimated parameters being 6%. Using a Van't Hoff plot, the thermodynamic parameters of the equilibrium constant were determined and used to estimate that in a single stage with only S/F = 0.5, over 99% of the BDA can be extracted from a 1.146 wt% aqueous solution. High distribution ratios at low BDA concentrations hampered the effective recovery by back-extraction in a single stage, therefore multistage processing was considered and short-cut calculations revealed a maximum concentration factor of 3.6. CONCLUSION: Good agreement between single stage equilibrium data and the model was obtained and the model developed was used in short-cut calculation of a coupled multistage forward and back-extraction process showing a maximum concentration factor of only 3.6, therefore an alternative, more effective recovery strategy, e.g. through anti-solvent addition is suggested

    Mass Transfer in Extractive Distillation when Using Ionic Liquids as Solvents

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    Mass transfer efficiency study in extractive distillation with ionic liquids for the mixtures water-ethanol and toluene-methylcyclohexane has been carried out in this work. Ionic liquids for the separation of these mixtures overcome the performance of the common volatile organic solvents. However, these also showed higher viscosities. A rated-based analysis was performed in order to quantify the effect of the solvent viscosity and relative volatility on mass transfer efficiency. In addition to this, an experimental analysis of the mass transfer efficiency was carried out experimentally in an extractive distillation pilot plant. The results indicated that, high liquid viscosities of ionic liquids should not affect the mass transfer efficiency negatively if the produced relative volatilities are sufficiently higher than those produced by organic solvents. However, when the ionic liquid showed very high viscosities or this solvent was present in large concentrations inside the column, the mass transfer efficiency decreases no matter how high the relative volatility is

    Reconciling biodiversity and carbon stock conservation in an Afrotropical forest landscape

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    Protecting aboveground carbon stocks in tropical forests is essential for mitigating global climate change and is assumed to simultaneously conserve biodiversity. Although the relationship between tree diversity and carbon stocks is generally positive, the relationship remains unclear for consumers or decomposers. We assessed this relationship for multiple trophic levels across the tree of life (10 organismal groups, 3 kingdoms) in lowland rainforests of the Congo Basin. Comparisons across regrowth and old-growth forests evinced the expected positive relationship for trees, but not for other organismal groups. Moreover, differences in species composition between forests increased with difference in carbon stock. These variable associations across the tree of life contradict the implicit assumption that maximum co-benefits to biodiversity are associated with conservation of forests with the highest carbon storage. Initiatives targeting climate change mitigation and biodiversity conservation should include both old-growth and regenerating forests to optimally benefit biodiversity and carbon storage

    A Genetic Deconstruction of Neurocognitive Traits in Schizophrenia and Bipolar Disorder

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    Background: Impairments in cognitive functions are common in patients suffering from psychiatric disorders, such as schizophrenia and bipolar disorder. Cognitive traits have been proposed as useful for understanding the biological and genetic mechanisms implicated in cognitive function in healthy individuals and in the dysfunction observed in psychiatric disorders. Methods: Sets of genes associated with a range of cognitive functions often impaired in schizophrenia and bipolar disorder were generated from a genome-wide association study (GWAS) on a sample comprising 670 healthy Norwegian adults who were phenotyped for a broad battery of cognitive tests. These gene sets were then tested for enrichment of association in GWASs of schizophrenia and bipolar disorder. The GWAS data was derived from three independent single-centre schizophrenia samples, three independent single-centre bipolar disorder samples, and the multi-centre schizophrenia and bipolar disorder samples from the Psychiatric Genomics Consortium. Results: The strongest enrichments were observed for visuospatial attention and verbal abilities sets in bipolar disorder. Delayed verbal memory was also enriched in one sample of bipolar disorder. For schizophrenia, the strongest evidence of enrichment was observed for the sets of genes associated with performance in a colour-word interference test and for sets associated with memory learning slope. Conclusions: Our results are consistent with the increasing evidence that cognitive functions share genetic factors with schizophrenia and bipolar disorder. Our data provides evidence that genetic studies using polygenic and pleiotropic models can be used to link specific cognitive functions with psychiatric disorders

    Low relapse risk in poor risk AML after conditioning with 10-day decitabine, fludarabine and 2 Gray TBI prior to allogeneic hematopoietic cell transplantation.

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    Patients with poor risk acute myeloid leukemia (AML) have a dismal outcome. We hypothesized that combining decitabine with a standard non-myeloablative (NMA) conditioning regimen prior to allogeneic hematopoietic cell transplantation (allo HCT), might decrease the relapse incidence. We conducted a multicenter prospective phase II study (NCT02252107) with 10-day decitabine (20 mg/m(2)/day) integrated in a standard non-myeloablative conditioning regimen (3 days fludarabine 30 mg/m(2) with 2 Gray total body irradiation (TBI)). Patients with AML ≥ 18 years in 1st (in)complete remission (CR/CRi) with a poor or very poor risk profile, as defined by the HOVON-132 protocol, were eligible. Results: Forty-six patients (median age 60; range 23-74) were included. Median follow up time was 44 months (range 31-65 months). The cumulative 1-year incidence of relapse and NRM were respectively 23% and 11%. Incidence of grade III-IV acute graft-vs-host-disease (GVHD) and severe chronic GVHD were 13% and 20%, respectively. One-year OS was 70%. Application of ELN 2017 risk classification to the study cohort revealed a cumulative one-year relapse rate of respectively 31% and 13% for the adverse and intermediate risk patients. To conclude, the 10-day DEC/FLU/TBI conditioning regimen prior to allo HCT in poor risk AML patients is effective and feasible
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