Search results for "Distillation"
showing 10 items of 184 documents
Divided Wall Column Modeling and Simulation in an Open-Source Environment
2020
The divided wall column (DWC) can achieve sharp separations of three or more components in a single shell, substituting conventional sequences of two or more binary distillation columns, with lower expenses. Despite these advantages, DWC models are not available in commercial chemical process simulators. To simulate DWC, users must employ instances of conventional column model and couple them in different configurations. In this paper, a DWC model was developed in EMSO (Environment for Modeling, Simulation and Optimization). DWC model was then used for simulating the separation of an equimolar mixture of three hydrocarbons. Results show that, depending on the number of trays, DWC presented …
Recovery of aliphatic low-molecular-mass carboxylic acids from hardwood kraft black liquor
2015
Abstract During alkaline pulping of wood, substantial amounts of carbohydrates-derived aliphatic carboxylic acids (formic and acetic acids together with various hydroxy acids) are formed and dissolved into the cooking liquor (“black liquor”). These acids with low heating values are considered to be potential feedstocks for the chemical industry but, due to many factors, their straightforward recovery as free acids from black liquor (pH 13–14) is difficult. In this paper, we outlined the partial recovery of volatile formic and acetic acids from the acidified birch ( Betula pendula ) kraft black liquor (pH approximately 2.5) by distillation, and the partial recovery of significant low-molecul…
Chemical characterization of Anthemis parlatoreana fresh and dried aerial parts by GC and LC chromatographic techniques and evaluation of the antioxi…
2022
Anthemis parlatoreana was collected in the north west coast of Sicily. Fresh and dried aerial parts were subjected to distillation procedure for the extraction and isolation of essential oils. In both fresh and dried samples, the most abundant chemical classes were ketones and esters, represented to a greater extent by β-thujone and β-artemisia acetate, respectively. In dried vegetable material, a high content of α-pinene and δ3-carene was also registered. Aqueous, methanol and ethyl acetate extracts of aerial parts were also investigated in terms of polyphenolic content and antioxidant potential. All the extracts tested showed a quite different quali-quantitative profile and in terms of ch…
Composition and antibacterial activity of the essential oil ofAnisochilus carnosus (Linn. ?l.) Benth., a Tamil plant acclimatized in Sicily
2003
The essential oil from aerial parts of Anisochilus carnosus (Linn. fil.) Benth. (Lamiaceae) was obtained by hydrodistillation. The oil content was 0.13% (v/w), on a fresh weight basis. The oil composition was analysed by GC and GC–MS and 28 compounds were identified, accounting for 94.3% of the oil. Carvacrol (27.9%), camphor (14.1%) and α-cis-bergamotene (10.2%) were the most abundant components. The oil is active against Gram-positive and Gram-negative bacteria. Copyright © 2003 John Wiley & Sons, Ltd.
Variations in the Chemical Composition of the Essential Oil of Lavandula angustifolia Mill., Moldoveanca 4 Romanian Variety
2020
International audience; In this research, the variations in the chemical composition of the Lavandula angustifolia Mill. essential oil, the Romanian variety Moldoveanca 4, obtained from the same culture, in the same harvesting and extraction conditions, during the years 2016-2018, representing the years 2-4 of culture. Lavandula angustifolia Mill. flowers were supplied from an ecological-crops from N-E Romania and the essential oils were obtained by hydro distillation of freshly harvested flowers. To determine the chemical composition, the essential oil was semi-quantitatively analysed by using gas chromatography coupled with mass spectrometry (GC-MS). In all the samples, 30 organic compoun…
Modeling and Design of Membrane Integrated Processes for HCl and Metals Recovery from Pickling Solutions
2018
Hydrochloric acid pickling is a common practice in steel manufacturing industry. During the process, acid is consumed to dissolve surface oxides and metals are accumulated in the solution. This fact leads to a process efficiency decrease. Continuous regeneration of pickling solutions enhances process rate and performance, but also minimises the highly expensive and environmentally risky wastewater disposal. The recovery of valuable substances (e.g. acid and metals) can be accomplished by coupling diffusion dialysis (DD) and membrane distillation (MD) technologies. In the present work, a steady state process simulator for the integrated process has been developed. The aim is to analyze and p…
Water Fluxes in Polymeric Membranes for Desalination via Membrane Distillation
2010
Membrane distillation is an emerging technique for seawater desalination. Hydrophobic polymeric membranes are used to separate the solute‐free water vapour from the hot solution. Vapour fluxes of commercial polymeric membranes were measured in various conditions, i.e. natural and forced convection and vacuum. Vapour fluxes were also predicted with models and compared with experimentals. Higher fluxes were recorded in vacuum conditions.
Essential Oils
2016
Abstract Essential oils are aromatic, volatile liquids obtained from plant material through steam distillation and named after the plant from which they are derived. Essential oils can be defined as either products or mixtures of fragrant substances or as mixtures of fragrant and odorless substances. These fragrant substances are chemically pure compounds that are volatile under normal conditions. Essential oils vary greatly, sometimes due to genetic causes, but also because of climate, rainfall, or geographic origin. They are composed principally of lipophilic and highly volatile secondary plant metabolites, principally mono- and sesquiterpenes, but other types of compounds such as allyl a…
Chemical composition and antimicrobial activity of the essential oil from aerial parts of Micromeria fruticulosa (Bertol.) Grande (Lamiaceae) growing…
2007
The essential oil of aerial parts of Micromeria fruticulosa (Lamiaceae) growing wild in Southern Italy was obtained by hydrodistillation and analysed by GC and GC–MS. Sixty-one compounds, representing 91.3% of the oil, were identified. The major components were γ-terpinene (14.5%), β-caryophyllene (12.6%), p-cymene (8.9%), α-pinene (8.2%) and β-bisabolene (7.2%). The essential oil showed action mainly against Gram-positive bacteria. Copyright © 2007 John Wiley & Sons, Ltd.
Extraction Methods of Essential Oils From Herbs and Spices
2017
International audience; This chapter describes both conventional and non‐conventional extraction methods of essential oils (EOs) from herbs and spices. Although hydrodistillation, steam distillation and solvent extraction are the most applied methods, several non‐conventional technologies have been evaluated, especially in respect to EO recovery, and a great potential has been attributed to these non‐conventional methods. For instance, ultrasound, microwave, supercritical fluid, pulsed electric fields, ohmic‐heating and microwave (MW) extraction techniques applied alone or combined with other techniques are potent tools to obtain EOs in a 'green' way from natural resources such as aromatic …