Distillation Research Articles

Heat Integrated Distillation System Design

Distillation is the largest single energy consumer in the chemical process industries. However, distillation does not consume energy but degrades the heat input to the reboiler that is subsequently rejected in the condenser. The most effective way to reduce the energy consumption of distillation is by effective heat integration. However, the distillation design and operation must be considered simultaneously with its heat integration. For single distillation columns it is straightforward to identify appropriate heat integration opportunities. For complex distillation systems, the most appropriate combination of distillation system design and operation and heat integration are far from straightforward. The whole separation system together with its heat integration and utility system must be considered simultaneously. This presentation will explain new approaches to be design of heat integrated distillation systems. Examples will be developed from crude oil distillation and from low-temperature separation in chemicals production. Copyright ? 2010, AIDIC Servizi S.r.l.

Dynamic Behavior of an Internally Heat-integrated Distillation Column (HIDIC)

This paper reports the analysis of the energy saving for design of an internally heat integrated distillation column (HIDiC) conducted in the second-phase of Japanese national research project for energy conservation in multicomponent petroleum distillation. The practical commercial scale distillation column separating cyclopentane from a multicomponent mixture consisting of mainly C5 hydrocarbons was selected as a target of the application of HIDiC technology. By choosing the compression ratio, the number of the theoretical stages, and the heat transfer rate as design and operating variables, temperature, pressure, flow rates, and composition profiles were computed as well as the reboiler heat duty of the HIDiC by Pro/II. The energy consumption of the HIDiC was compared with that of the practical conventional distillation column operated at the minimal reflux ratio. It was confirmed that at least 25 % of energy saving can be achieved by means of the HIDiC system. A pilot plant of the HIDiC was designed based on the results obtained in this study. It was constructed and has been in operation since 2005. The pilot HIDiC shows more than 50 % of energy savings compared to the conventional distillation column, validating the analysis of this study.

Selection of membrane contactors used in a membrane distillation based micro-separator

In this paper the separation performance of a membrane distillation based microseparator has been investigated. Particularly the influence of the membrane properties (surface chemistry, material and characteristics) on the distillate quality has been studied. The experimental results showed that the surface chemistry of the membrane with respect to its free surface energy constitutes the main limiting factor for the separation. Indeed, independently of their material and characteristics, the tested oleophobic membranes present lower free surface energy than hydrophobic membranes. Consequently they are more appropriate as non selective liquid-gas contactors for the separation of aqueous mixtures with low to high methanol concentration. Furthermore, it is shown that the impact of membrane characteristics (porosity, thickness, pore size) on the distillate quality (separation factor) is almost negligible since the resistance to mass transfer is concentrated in both feed and gas channels for the investigated microseparator design. That suggests that the separation factor may be further enhanced by decreasing the feed/gas channel height in the micro-separator.

A new design methodology for heat integrated distillation column based on self-heat recuperation

In this paper, a novel design methodology based on self-heat recuperation for heat integrated distillation column (HIDiC) is proposed. In HIDiC, the condensation heat is recovered and exchanged with the vaporization heat in the column for energy saving. By following self-heat recuperation technology, the energy input and output of HIDiC are analyzed and the process heat circulates through the process by using pressure change, leading to further energy saving. The simulation result demonstrates that the energy consumption for HIDiC based on the proposed design methodology by using self-heat recuperation is drastically decreased as compared with benchmark processes which use external heat sources.

Selective Isolation of Component Myristicine from Ligustium sinense oliv by Second-Sphere Coordination Inclusion Crystallization

The first ligand of [CoCl4 ]2 - and the second ligand of protonated N,N,N',N'-tetra-p-methyl- benzyl-ethylenediamine were used to construct a second-sphere coordination complex as the host framework. Myristicine was selectively isolated from the volatile oil of Ligustium sinense oliv by the inclusion crystalline method as the guest molecules. IR,NMR,X-ray diffraction were used to determine the structure of the inclusion complex,and the host-guest molar ratio in the complex was found to be 2∶ 1. The myristicine was isolated from the inclusion complex via Kugelrohr vacuum distillation technique and was characterized by IR, NMR and GC. According to the result of GC,the content of myristicine in the volatile oil of Ligustium sinense oliv is 60. 4% ,and the purity of isolated myristicine reaches 100% .

Inhibitory Effects of Plant Extracts on the Growth of Five Pathogenic Bacteria

The objective of this study was to investigate the antimicrobial activities of essential oils (EO) and spice extracts of the plants popularly used in Thai cuisines, namely galangal (Alpinia galanga (Linn.) Stuntz.), finger root (Boesenbergia pandurata Roxb.), lemongrass (Cymbopogon citrates) and torch ginger (Etlingera elatior). The plant extracts were prepared using steam distillation, supercritical fluid extraction (SFE) and conventional Soxhlet extraction techniques. Results demonstrated that galangal extracted by SFE and Soxhlet extraction techniques showed stronger antimicrobial activity against Staphylococcus aureus and Listeria monocytogenes than those of finger root, lemongrass and torch ginger, respectively. Escherichia coli and Salmonella typhimurium, as well as Gram-positive pathogenic bacteria, such as S. aureus and L. monocytogenes, were sensitive to lemongrass EO.

Dienophile compounds as inhibitors of resin formation in fuels

Summary Dienophyl compounds are effective inhibitors of resin formation in petroleum distillates containing diene hydrocarbons. These dienophyls reduce 3 times and more the proportion of resin-forming products of oxidation, but do not affect in practice the induction period of oxidation of the fuel.

Optimal design of a system of distillation columns

Systems of distillation columns for separation of multicomponent mixtures are highly metaland energyintensive. Therefore, in optimal design of dis� tillation units, the optimality criterion is generally economic criteria, including investment and operating costs. The investment cost is proportional to the metal and content of the plant and depends on the number of separation stages and the reflux ratios (reflux flows) in distillation columns. The cost of a column increases with an increase in the number of separation stages (trays) and, hence, in the column height. An increase in the reflux ratio initially leads to reduction in the col� umn cost because the number of trays decreases. How� ever, further enhancement of internal liquid and vapor flows in the column causes an increase in the column diameter, which increases the column cost. The oper� ating cost is constituted by the costs of arrangement of vapor flows in columns and heating and cooling of intermediate and end flows. The operating cost increases with an increase in the reflux ratio. Conse� quently, from the energy standpoint, distillation should be performed at minimum reflux. At the same time, at minimum reflux, the number of separation stages is maximal. Hence, the main problem of opti� mal design of distillation units is to find a tradeoff between the investment (lumpsum) cost of installa� tion and the operating cost of operation (1-3). The issue of optimal design of distillation columns was considered in a large number of works. This issue can be split into at least two problems. The first prob� lem is to find the optimal sequence of distillation col� umns that ensures the minimal cost of separation. The second problem is to optimize a distillation plant of a given topology that minimizes the total (investment and operating) costs. In this work, we propose a new approach to solving the second problem. The optimal design problem is posed as follows. Given are the parameters (flow rate, composition, temperature, pressure) of multicomponent feed sup� plied for separation, the topology (sequence of distil� lation columns) of the separation plant to be designed, and requirements for quality of end products. It is nec� essary to design a system of distillation columns, namely, to determine the number of trays in each col� umn, feed points, and column operation modes at which the reduced cost criterion (sum of operating and investment costs) takes the minimal value and the requirements for quality of end products are met. Let us consider a distillation plant as a single chem� ical engineering system consisting of N distillation columns the optimal design of which is proposed to be performed using a global approach. In this case, the design problem reduces to discretecontinuous opti� mization of the entire system simultaneously, in which discrete variables are the numbers of trays of the exhausting and rectifying sections of each column and continuous variables are operating parameters.

Selection of highly ethanol productive yeast

Seventy five isolates of Saccharomyces cerevisiae were identified, they were isolated from different local sources which included decayed fruits and vegetables, vinegar, fermented pasta, baker yeast and an alcohol factory. Identification of isolates was carried out by cultural microscopical and biochemical tests. Ethanol sensitivity of the isolates showed that the minimal inhibitory concentration of the isolate (Sy18) was 16% and Lethal concentration was 17%. The isolate (Sy18) was most efficient as ethanol producer 9.36% (v/w). The ideal conditions to produce ethanol from Date syrup by yeast isolate, were evaluated, various temperatures, pH, Brix, incubation period and different levels of (NH4)2HP04. Maximum ethanol produced was 10.32% (v/v). Experimental production of ethanol using continuous methodology with immobilized cells of Saccharomyces cerevisiae showed that this method is superior by producing 5.83 g/L/h in comparison with 1.95 g/l/h produced by batch culture method

Aqueous extract of Salvia officinalis and Ruta graveolens: Potential source of reactive nitrogen species

There are scarce evidences about the effects of herbs on nitrogen species that induced nitrosative stress. We here investigated the effect of simple water distilled extract of dry leaves salvia officinalis (sage) and Ruta graveolens (Rue) on the nitric oxide (NO) – peroxynitrite (ONOO-) cycle biochemistry in vitro experiments. Aqueous extract of sage or rue (1%) were prepared by simple distillation and scanned by UV-visible spectrophotometer. Their effects were studied on the synthesized ONOO- as well as their ability to generate ONOO. It is ability to donate NO or to scavange released NO by sodium nitroprusside (10 mM) also investigated. UV-visible scan of sage extract revealed the presence of peaks at λ195 and 348.5 while that of rue extract at λ 200, λ242, λ291.5. Both extracts not generate ONOO- radical in form of nitrophenols. Rue extract increased the yield of prepared ONOO- by more than five times. Rue extract donated NO and improved the release NO from sodium nitroprusside while sage extract only improved the release of NO released by sodium nitroprusside. We conclude that simple distilled - aqueous extract of rue and sage extracts improved nitric oxide bioavailability that may be helpful in coronary artery disease with nitrate tolerance. Key words: Nitric oxide, Peroxynitrite, Ruta graveolens, Salvia officinalis

Phytochemical constituents of some selected medicinal plants

Tannins, saponins, phlobatannins, flavonoids, anthraquinones, terpenoids, steroids, alkaloids, carbohydrates and glycosides distribution in four medicinal plants belonging to different families were investigated and compared. The medicinal plants investigated are Carica papaya, Ocimum gratissimum, Adenia cissampeloides and Cymbopogan citratus. All the plants were found to contain tannins, flavonoids, terpenoids, steroids and carbohydrates while anthraquinones were absent in all. Alkaloids were absent in both O. gratissimum and C. citratus. Glycosides were absent in only C. papaya, saponins were absent in only O. gratissimum while phlobatannins were absent in only C. citratus. The extraction of oils was carried out by solvent extraction and steam distillation methods and the percentage yield of extracts by each method determined. Solvent extraction method gave percentage yield of 7.40, 6.30, 6.75 and 5.63% for C. papaya, O. gratissimum, A. cissampeloides and C. citratus respectively. For steam distillation, C. papaya, O. gratissimum, A. cissampeloides and C. citratus gave percentage yield of 5.60, 5.80, 5.44 and 3.82% respectively. The significance of the plants in traditional medicine and the importance of the distribution of these chemical constituents were discussed with respect to the role of these plants in ethnomedicine in Nigeria. Key words: Ethnomedicine; medicinal plants; natural products; phytochemicals.

Ethanol Production from Banana Fruit and its Lignocellulosic Residues: Exergy and Renewability Analysis

Tropical countries such as Brazil and Colombia have the possibility of using their lands for growing vegetable products to produce biofuels such as biodiesel and ethanol. The objective of this work is to apply exergy analysis to evaluate the renewability of anhydrous ethanol production from surplus banana fruit production and its residual biomass. The study takes into account all production stages: growing, feedstock transport, hydrolysis, fermentation, distillation, and dehydration. It also considers the cogeneration plant and residues treatment. Four production routes were analyzed according to the biomass used as feedstock: banana pulp, banana fruit, hanging cluster or banana skin. Based on the exergy concept, performance indicators are proposed and calculated. In order to quantify the renewability of the ethanol production processes, a new indicator called “Renewability Performance Indicator” is defined and applied to the four ethanol production routes studied. The results show that when amilaceous material is used, better results than lignocellulosic material are obtained and four production processes studied must be classified as non-renewable. This paper is an updated version of a paper published in the ECOS'08 proceedings.

Chemical composition and antimicrobial activity of the essential oil from Rosa rugosa Thunb.

The rose essential oil was extracted using simultaneous steam distillation,and the chemical composition was analyzed by GC-MS,which identified a total of 14 chemical components and the total content was 95.25%.Citronellol is the main component of the essential oil,the relative content was 90.37%.Antimicrobial activity showed that rose essential oil possessed different excent antimicrobial activity to seven kinds of bacteria except for Aspergillus niger,in which,the MIC values of rose essential oil against Staphylococcus epidermidis,Staphylococcus aureus and Escherichia coli were all 0.063% v/v,the MIC values of rose essential oil against Bacillus subtilis,Proteus vulgaris and Candida albicans were all 0.125% v/v,however,the antibacterial activity of the essential oil against Pseudomonas aeruginosa was relatively weak,MIC was 0.500% v/v.The results of inhibition diameters also showed that inhibition diameters of rose essential oil against six strains were higher than 8.5mm except for A.niger and P.aeruginosa.The bactericidal dynamic studies of rose essential oil against three-sensitive strains including S.aureus(gram-positive bacteria),E.coli(gram-negative bacteria) and C.albicans(fungi) were investigated,which provides a theoretical basis for the application of rose essential oil.

Influence of light and gibberellin on the germination velocity of coffee seeds (Coffea arabica L.)

There are various factors that interfere with seed germination. In this research the effect of light, gibberellins and paclobutrazol in coffee seed germination were evaluated. Seeds of coffee (Coffea arabica L.) from cultivar Rubi harvested at the developmental stage known as cherry were dried until 12% of water content. The first trial was performed in factorial design (2x2), the condtions being two (light and dark), presence and absence of gibberellins. The substrate was imbibed with 20 ml of GA3 (100 mM) and the control treatment with distillated water. The second trial was performed in factorial design (4x2x3), with four concentrations of paclobutrazol (0; 0,1;1,0; and 10 mM), two conditions (light and dark) and three storage conditions (0, 4 and 8 months). The substrate was imbibed with 20 mL of paclobutrazol and the control treatment with distillated water. Both trials were performed in four replications of fifty seeds. Seed sowing was performed in gerbox tray with two blotting papers and one germitest paper. The dark condition was created by wrapping the gerbox with an aluminum foil. The germiantion velocity rate, germination at thirty days and the time to 50% root protrusion were evaluated. The gibberellin treatment in seed coffee decreases the germination velocity rate and percentage of germination. The gibberellin inhibitor decreases the gemination velocity rate but it did not reduce the effect of light. High values of germination velocity rate were observed in dark.

Auto-adaptive interval selection algorithm for quantum key distribution

Key reconciliation plays an important role in quantum key distribution, as well as shared bit string distillation. To distill efficiently the final key a so-called Winnow protocol has been proposed...

Isolation of Molds for Reducing the Color of Vinase

Vinase or ethanol slop is blackish brown liquid, which is not friendly to the environment. Therefore, it is necessary the possibility to reduce the color biologically. The study was started by isolating molds from the vinase of Jatiroto Alcohol factory and the isolated molds was tested to study the capability of their color reduction. The results showed that there were 4 kinds of molds in the vinase i.e. : Rhizopus sp., Penicillium A, Penicillium B, and Aspergillus. Amongst these molds, Penicillium A and Penicillium B had the best potency in reducing the slop color. Around 54 % of its absorbency value at 420 nm could be reduced by the molds.

Chemical constituents and antimicrobial activity of essential oil and extracts of heartwood of Aquilaria crassna obtained from water distillation and supercritical fluid carbon dioxide extraction.

Agarwood (Aquilaria crassna) is a high value economic plant.Agarwood oil is widely used among variouscountries as perfumes and ingredient inmedical recipes. In this study, the extraction of driedAgarwood powderbywater distillation (WD), supercritical fluid carbon dioxide extraction (SFE) and SFEwith ethanol as cosolvent(SFE+co) gave 0.2%oil, 0.06%and 0.014%extracts, respectively. The types of chemical constituents of oil andextracts from these 3 extraction methods were quite similar. The major chemical constituents ofWD oil, SFEand SFE+co extracts were g-selinene (13.66%), selina-4,11-dien-14-al (14.25%) and selina-4,11-dien-14-al(13.39%), respectively. The WD oil, SFE and SFE+co extracts had antimicrobial activities against S. auruesand C. albicans, but were not sensitive to E. coli at maximum concentration of the study, 2mg/mL. KeyWords: Agarwood; Aquilaria crassna; Distillation; Supercritical fluid carbon dioxide

Parametric study of pressure increase across a compressor in ethanol-water vapour recompression distillation column

Heat pumping has been used in reducing energy consumption in distillation columns. However, the effects of some parameters have not been taken into consideration in the determination of energy consumption in such systems. The consideration of these parameters may give more insight into the performance of such systems. The purpose of this study was to develop a thermodynamic simulation model for comparing two distillation systems: one operating with pressure increase across the compressor and the other with negligible pressure increase over the compressor. An ethanol-water conventional distillation column with direct vapour recompression was used as a case study. The study shows that when the pressure across the compressor increases, the compressor power input, compressor displacement rate, compressor heat load rate and total energy consumption increased while the coefficient of performance and compressor volumetric efficiency decreased. The significance of this work is the provision of information for the determination of energy effectiveness as well as appropriate capacity of the auxiliary equipment for ethanol separation which is becoming a more competitive fuel. Key words: Compressor, distillation column, energy, pressure drop, vapour recompression.

Application of PLE for the determination of essential oil components from Thymus vulgaris L.

Essential plants, due to their long presence in human history, their status in culinary arts, their use in medicine and perfume manufacture, belong to frequently examined stock materials in scientific and industrial laboratories. Because of a large number of freshly cut, dried or frozen plant samples requiring the determination of essential oil amount and composition, a fast, safe, simple, efficient and highly automatic sample preparation method is needed. Five sample preparation methods (steam distillation, extraction in the Soxhlet apparatus, supercritical fluid extraction, solid phase microextraction and pressurized liquid extraction) used for the isolation of aroma-active components from Thymus vulgaris L. are compared in the paper. The methods are mainly discussed with regard to the recovery of components which typically exist in essential oil isolated by steam distillation. According to the obtained data, PLE is the most efficient sample preparation method in determining the essential oil from the thyme herb. Although co-extraction of non-volatile ingredients is the main drawback of this method, it is characterized by the highest yield of essential oil components and the shortest extraction time required. Moreover, the relative peak amounts of essential components revealed by PLE are comparable with those obtained by steam distillation, which is recognized as standard sample preparation method for the analysis of essential oils in aromatic plants.

Pozzolanic activity and filler effect of sugar cane bagasse ash in Portland cement and lime mortars

Sugar cane bagasse ash (SCBA) is generated as a combustion by-product from boilers of sugar and alcohol factories. Composed mainly of silica, this by-product can be used as a mineral admixture in mortar and concrete. Several studies have shown that the use of SCBA as partial Portland cement replacement can improve some properties of cementitious materials. However, it is not yet clear if these improvements are associated to physical or chemical effects. This work investigates the pozzolanic and filler effects of a residual SCBA in mortars. Initially, the influence of particle size of SCBA on the packing density, pozzolanic activity of SCBA and compressive strength of mortars was analyzed. In addition, the behavior of SCBA was compared to that of an insoluble material of the same packing density. The results indicate that SCBA may be classified as a pozzolanic material, but that its activity depends significantly on its particle size and fineness.