Vera G. Mata

Adsorption of carbon dioxide at high temperature—a review

In this review, the adsorption of carbon dioxide on adsorbent materials at high temperature is examined critically. Adsorbent materials including carbon-based adsorbents, metal oxide sorbents, zeolites and hydrotalcite-like compounds (HTlcs) for carbon dioxide at high temperature are discussed. Research areas, which may make a significant impact in future are put forward.

Adsorption of Carbon Dioxide on Chemically Modified High Surface Area Carbon-Based Adsorbents at High Temperature

The adsorption capacity of carbon dioxide on high surface area carbon-based adsorbents before and after chemical modification at 28°C and 300°C have been studied. The high adsorption capacity adsorbents for carbon dioxide at high temperature have been developed by introducing MgO and S–CaO–MgO on carbon-based adsorbents. Their adsorption capacities for carbon dioxide were 0.28 and 0.22 m mol/g at 300°C, 1 Bar, respectively.

Separation of ternary mixtures by pseudo-simulated moving bed chromatography

Modeling and simulation are presented of the separation of a ternary mixture by pseudo-simulated moving bed chromatography, according to the JO process of Japan Organo Co. The process cycle is divided into two steps. In step 1, feed and eluent streams are introduced into the system, equivalent to a series of preparative chromatographic columns, and the intermediate component is produced. In step 2, similar to a simulated moving bed (SMB), there is no feed and the less adsorbed species is collected in the raffinate while the more retained species is collected in the extract; this step is described by an equivalent TMB model. A parametric study is presented in order to analyze the sensitivity of the model to variations on the duration of step 1 and step 2 and on the intraparticle mass transfer coefficient.

Characterization of the Portuguese-Grown Cistus ladanifer Essential Oil

Abstract The chemical composition of the cistus oil from Portuguese-grown rockrose (Cistus ladanifer) was determined using GC and GC/MS. A comparison was also made in terms of the geographical source and use of either dry or fresh plant material. The cistus oil herein obtained was richer in amber-like compounds and had a low content of monoterpenes when compared to the usual values found in the literature. Moreover, it presented a relatively high content of ambrox (amber odor), which usually is only reported in labdanum oil. The major constituents were three sesquiterpene alcohols: viridiflorol (13.6–17.4%), globulol (3.1–5.0%) and an unknown sesquiterpene alcohol (2.7–6.0%), as well as the diterpene alcohol 15-nor-labdan-8-ol (1.7–5.2%). Three samples of commercially available cistus oil were also analyzed and compared.

Characterization and evaluation of commercial fragrance microcapsules for textile application

In this paper, some commercial microcapsule samples, containing different fragrances used for textile application purposes, were characterized and evaluated. Microcapsule samples were evaluated in terms of particle size, morphology, shell material composition, and fragrance intensity. The effectiveness of the textile impregnation and its durability were assessed. The selection of samples used in each study was made in order to the specific goals of characterization and evaluation of microcapsules. Lemon_Bayer, Lemon_Focor, Lemon_Horquim, Strawberry_Horquim, and Jasmine_Focor samples were used to study the morphology and particle size distribution, and it was observed that microcapsules have a spherical shape with size between 2 and 6 m. The chemical composition of Lavender_Horquim, Mints_Horquim, Eucaliptus_Focor, and Apple_Focor samples was checked/ confirmed and was based on melamine copolymers including melamine-formaldehyde ones. Lemon_Horquim microcapsules were impregnated on textile substrates, and it was observed that a loss of 46% of limonene occurred after one domestic wash and a loss of 97% occurred after 20 domestic washes.

Characterization of Portuguese-Grown Geranium Oil (Pelargonium sp.)

Abstract The chemical composition of the Portuguese-grown geranium essential oil (Pelargonium hybrid) cultivated in northern Portugal, which also grows wild, was examined. It was found that the geranium oil herein obtained had characteristics intermediate between Bourbon and China types, with good olfactory quality and presenting characteristics different from those previously studied. The essential oils of fresh/dried and green/yellow geranium leaves were compared. Solvent extraction methods were also employed and the composition of the respective absolutes was determined and compared with the essential oil. It was concluded that using air-dried plant and yellow leaves improved the quality of geranium oil. Moreover, the absolute obtained from a diethyl ether extract had the best organoleptic properties of the extracts studied.

MEASUREMENTS OF EFFECTIVE DIFFUSIVITY IN LARGE-PORE PERMEABLE PELLETS WITH VARIOUS GEOMETRIES USING THE CHROMATOGRAPHIC METHOD

Abstract Mathematical models for solid cylinder and hollow cylinder pellets, where intraparticle convection was considered, have been established and solutions in the Laplace domain have been obtained. Consequently, the equivalence between the hollow cylinder and the slab characteristic dimensions was presented for the first-order-reaction/diffusion/convection problem. A modified chromatographic method has been developed to measure the intraparticle diffusivity in solid cylinder pellets. The axial dispersion of the column packed with the hollow cylinder pellets was measured and a correlation for the Peclet number versus Reynolds number has been obtained. Intraparticle convection has been measured with large pore sphere pellets which present a “foam structure” by using the conventional chromatographic method. Intraparticle Peclet numbers and the permeability of this pellet were determined.

Design of Perfumes

In this chapter, the Perfumery Ternary Diagram methodology is presented as a tool for the prediction and mapping of the odor character of ternary to quaternary mixtures of fragrance ingredients. To present this methodology, the effect of different base notes in simple fragrance mixtures of the type (top note+middle note+base note and/or+solvent) will be studied to illustrate the potential of this tool. In this study, the selected base notes were three ingredients commonly used in perfumery: vanillin, tonalide, and galaxolide. Moreover, as a proof of concept the PTD® predictive tool is experimentally validated using headspace gas chromatography techniques.

Classification of Perfumes–Perfumery Radar

The qualitative classification of fragrances by words or descriptors is a difficult task, and so its prediction (using any kind of theoretical model) is even more complex. If the former is addressed by experts in perfumery, the latter is mostly considered as utopian, at least in forthcoming years. That is why F&F companies have been doing this job on the basis of sensorial analysis performed by their experienced perfumers, who use multiple (and sometimes complex) odor descriptors to map the olfactory space. However, because the universe is not governed by laws that approach to ideality but instead foresee the increasing of entropy, the way we perceive odor quality varies from person to person and so remains difficult to explain. Consequently, there are significant differences between the classifications obtained from different F&F companies. As a result, once again, human empiric knowledge and expertise rules this job. Altogether, these facts make it virtually impossible to believe in a classification of fragrances with universal acceptance.

Performance of Perfumes

In this chapter, we will address fragrance performance, a very relevant topic for the design of novel and improved fragranced products. Fragrance performance is often assessed by experimental sensory evaluation using panelists, not so by predictive models. Consequently, it introduces human interpersonal variability and increases the time needed for such evaluations. It is no surprise that it would be a tremendous breakthrough to have theoretical models capable of doing so, in seconds.