The widely used separation process of liquid-liquid extraction is performed in a variety of contactors. The interfacial area in these conventional contactors is often poorly defined, because of the complex hydrodynamics involved, and the intensity of mass transfer is limited by the constraints imposed by the underlying buoyancy or gravitational effects being exploited. Similar shortcomings are apparent in most of the laboratory equipment presently used for investigating extraction and biphasic reactions. In the present work, a new contactor concept, liquid-liquid slug flow in a capillary, is presented as an alternative to conventional equipment. Experiments were performed to investigate the effect of operating conditions on mass-transfer coefficients for different nonreacting systems. In addition, a flow splitter was developed for downstream separation of two liquid phases. The combination of this flow splitter with the capillary provides miniature mixer-settler modules, which can be networked in a wide variety of configurations. Finally, the results obtained were compared with the literature data, and it was determined that such a microextractor-reactor offers superior performance and greater efficiency, in comparison to conventional equipment for liquid-liquid extraction. The results also show that such equipment can be exploited to enhance mass-transfer-and heat-transfer-limited liquidphase reactions.
Carbon dioxide can be used in various ways as a cheap C1 source. However, the utilization of CO2 requires energy or energy-rich reagents, which leads to further emissions, and therefore, diminishes the CO2-saving potential. Therefore, life cycle assessment (LCA) is required for each process that uses CO2 to provide valid data for CO2 savings. Carbon dioxide can be incorporated into epoxidized fatty acid esters to provide the corresponding carbonates. A robust catalytic process was developed based on simple halide salts in combination with a phase-transfer catalyst. The CO2-saving potential was determined by comparing the carbonates as a plasticizer with an established phthalate-based plasticizer. Although CO2 savings of up to 80 % were achieved, most of the savings arose from indirect effects and not from CO2 utilization. Furthermore, other categories have been analyzed in the LCA. The use of biobased material has a variety of impacts on categories such as eutrophication and marine toxicity. Therefore, the benefits of biobased materials have to be evaluated carefully for each case. Finally, interesting properties as plasticizers were obtained with the carbonates. The volatility and water extraction could be improved relative to the epoxidized system.
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