Solvent Extraction Of Oil Research Articles

Mathematical modeling of vegetable oil–solvent extraction in a multistage horizontal extractor

A new mathematical model of vegetable oil extraction in an industrial De Smet type extractor is proposed. Solvent extraction from a mobile bed of oilseed material was modeled considering different availability of oil in pellets, countercurrent cross-flow of the porous solid and the miscella, diffusion in the entire extraction field, mass transfer between pellets and miscella, miscella transport between the percolation sections, loading and drainage zones, and transient operational regime of the extractor. The mathematical model was solved numerically to predict oil concentration in miscella and pellets through the percolation sections and at the outlets. Model predictions were compared with experimental industrial data for sunflower oil extraction with hexane. Differentiation in two oil categories in terms of availability and extraction kinetics allows to represent the extraction phenomena in a better way than considering a single process. Consideration of dispersion fluxes improves the results without increasing the computing time. Saturation is reached in the stages near to loading zone when low miscella velocity is used.

03/02152 An investigation on solvent extraction of oil from Egyptian oil-shale: Ebrahiem, E. I. Alexandria Engineering Journal, 2002, 41, (3), 572–986

Soapstock and deodorizer distillates are the major by-products from vegetable oil refining. They have little commercial value and are sold at a fraction of the oil cost. However, their characterization reveals the presence of numerous types of compounds, which could be extremely valuable if extracted at low cost. The literature in this area is discontinuous and warrants the effort to produce a comprehensive review. The aim of this review is to combine and condense the body of research performed on these materials, as well as to suggest the best routes for characterization and extraction. Utilization of the components is also discussed.

CHARACTERIZATION OF PREPARATION PARAMETERS FOR IMPROVED SCREW PRESSING OF CRAMBE SEED

Screw pressing of niche oilseeds such as crambe may be a viable alternative to solvent extraction of oil. Cookingbefore pressing is known to improve oil recovery. Use of welldefined cooking conditions of time and temperature wasexpected to aid characterization of the relationship between cooking and press performance, and to reduce soluble seedprotein according to a fundamental kinetic model. A pressure cooker modified to permit both steam injection and vacuumpermitted the cooking of crambe seed at welldefined conditions of 90C to 120C for 5 to 20 min. Oil recovery increasedwith increasing cooking temperature and time to a maximum of 75.9% at 100C and 12 min, versus 70.9% for uncooked seed,and a low of 70.6% at 120C and 20 min. Oil recovery and press rate were nonlinear functions of cooking temperature andtime. A cooking index based on soluble protein decreased according to a modified thermal processing model with D0 and zvalues of 3.3 min and 28C, respectively. The index was also useful for identifying optimally cooked seed. Oil recoveryincreased with decreasing seed moisture content to a high of 82.5% recovery at 3.5% m.c. The approach described here maybe extended to the tuning of other screw presses for crambe and other oilseeds.

97/00232 Method and apparatus for the solvent extraction of oil from bitumen containing tar sand

97/00232 Method and apparatus for the solvent extraction of oil from bitumen containing tar sand

5534136 Method and apparatus for the solvent extraction of oil from bitumen containing tar sand: Rosenbloom William, Westport, CT, United States

To assess non-destructive above-ground biomass measurements in comparison to destructive measurements in willow (Salix sp.) coppice plantations, individual plant weights of twelve 4-year old willow clones (Salix viminalis L., S. dasyclados Wimm.) were estimated by constructing allometric relationships between stem diameter and shoot dry weight. The plants were also measured with a destructive method, i.e. harvest, weighing, and determination of wood dry matter content. The allometric relationships between shoot dry weight and stem diameter at 55, 85 and 105cm from the shoot base, were compared. Mean differences between the destructively and non-destructively measured plant weights were small and only significant for two of the clones. For nine of the clones, the non-destructive assessments deviated less than 3% from destructively measured weights. The maximum deviation was a 7% underestimation of the mean plant weight. However, the resulting differences between methods increased with increasing plant weight for six of the clones. For most clones, the best fit of the model relating shoot dry weight and stem diameter was found at 105cm above shoot base (r2-adj⩾0.987) but high model fits also were found at 55cm(r2-adj⩾0.973) and 85cm(r2-adj⩾0.961) above shoot base. Plant survival was determined to obtain production assessments per unit area. Standing woody biomass after 4 years ranged from 24.6 to 38.1t dry matter ha−1 and plant survival from 71% to 98%. We conclude that non-destructive methods are reliable for a range of clones in commercial practice, while improvement is needed for purposes in which detection of small growth differences is crucial.

Modeling solvent extraction of vegetable oil in a packed bed

AbstractA one‐dimensional model was developed for solvent extraction of oil from a packed bed of oil‐bearing vegetable materials. The equilibrium relationship between the residual oil content of marc and oil concentration of stagnant miscella in pores of the bed material was generated through experiments with rice bran and hexane. The nondimensional parameters recognized from the model describing extraction were initial Reynolds number (Rei), initial Schmidt number (Sci), bed void fraction (εb), particle porosity (εp), ratio of bed diameter to particle diameter (Dt/dp), ratio of bed depth to bed diameter (L/Dt), ratio of particle surface area to bed cross‐section (apAL/A=apL), and recycle of solvent and equilibrium distribution coefficient (EDC). For reducing the time required to extract to the same residual oil content of marc, higher values of Rei, εb, and apL were beneficial, whereas higher values of Sci, εp, Dt/dp, L/Dt, and EDC were detrimental.

Physical characteristics of mustard oil solvent miscella

AbstractDuring commercial solvent extraction of oil from an oil‐seed, it is necessary to determine oil content in the miscella, drawn intermittently from the extractor, to obtain an overall extraction rate. We measured optical density, specific gravity, refractive index and viscosity of miscella of different known oil concentrations. These four characteristics were measured by calculating deviations from the actual values. The deviations were maximum for optical density, intermediate for specific gravity and viscosity, and small for refractive index, suggesting the latter to be an appropriate rapid method of determining miscella oil content.

Solvent extraction of oil from soybean flour II— pilot plant and two‐solvent extractions

The process of grinding soybeans to a fine flour and extracting the flour with hexane was studied on a pilot plant scale. The crude oil from the pilot plant study had 15 ppm phosphorus and was suitable for physical refining after a light acid pretreatment and bleaching. The refined oil showed a Lovibond color of 1.4 yellow and 0.3 red. The pilot plant study also showed that grinding of the soybeans and the separation of solid from miscella were the most difficult steps in solvent extraction with fine flour.A laboratory study on separation of miscella from meal by aqueous ethanol reduced the hold‐up volume, but it did not remove all the miscella. A test with betacarotene showed that only the miscella outside the flour particles was displaced.Aqueous ethanol solutions used as a second solvent extracted additional nontriglyceride materials (primarily phospholipids) from the meal. Also, the free fatty acid content of the oil was increased with aqueous ethanol solution wash. The quality of the extracted crude oil was lowered by using a second solvent, but it had the advantage of needing only one centrifugation to separate miscella from meal.

Solvent extraction of oil from soybean flour I— extraction rate, a countercurrent extraction system, and oil quality

Measurements of rates of oil extraction from either fine flour or soybean flakes in a column showed that oil extraction from flour was dependent on the volume of solvent, but oil extraction from flakes depended on time of contact rather than volume of solvent. We interpreted the data to mean that oil was being washed out of the fine flour with little diffusion involved, whereas in flakes, the limit on rate was diffusion of the solvent into and out of the tissue.Fine full fat flour worked well in a batchwise countercurrent extraction system with mixing and centrifugal separation. Because the oil dissolved immediately and reached equilibrium rapidly, the actual material balance was close to calculated values. However, due to the large hold‐up volume, the separation of miscella from the meal required several mixing and separation stages. The oil resulting from this countercurrent extraction system had a superior quality with 37 ppm phosphorus, 0.08% free fatty acids, and a light color.

Grinding and Detoxification of Canola Using a Szego Mill-Hydrocyclone Combination

A process yielding a finely ground, low-glucosinolate canola meal using a semi-pilot-scale Szego mill combined with a hydrocyclone was investigated. A methanol solution (CH3OH) containing 10% (w/v) ammonia (NH3) and 5% (v/v) water was used as the medium for grinding. Compared with grinding with the Szego mill alone, the combined Szego mill-hydrocyclone unit produced a more uniform finely ground meal. The glucosinolate content of the meal was decreased to less than 1.8μM/g dry meal, and the polyphenol content was reduced by as much as 88%. The polar filtrate (obtained from the ground slurry), after being mixed with fresh methanol-ammonia solvent at a ratio (v/v) 2.6:1, was used in further grinding of fresh seed. The presence of methanol in the meal, prior to the solvent extraction of oil with hexane, enhanced the oil recovery.

Solvent extraction of oil and chlorogenic acid from green coffee. Part II: Kinetic data

Solid-liquid extraction kinetic data for green coffee oil and chlorogenic acid were obtained using respectively hexane and methanol-water as solvents. The influence of the various extraction variables, i.e. the green coffee particle diameter, the mass ratio of ground coffee to solvent and the temperature, was studied. The mass transport is entirely controlled by the internal resistance of the solid. The kinetic results for the chlorogenic acid were interpreted by the diffusional model (Fick's second law) with apparent diffusivity values independent of concentration and slightly influenced by the temperature (E a ≈ 9·74 kJ/mol). For the coffee oil extraction kinetics, the same model can be used only for long times (t > 30 min). The experimental values for short times (t < 10 min) are much longer than those predicted by the model; this could be due to leaching phenomena.

Solvent extraction of oil and chlorogenic acid from green coffee part I: Equilibrium data

Solid-liquid equilibrium data for green coffee oil and chlorogenic acid as a function of mass ratio of ground coffee to solvent and temperature were obtained using hexane and methanol as solvents. Equilibrium yield and concentration were correlated with these operating variables. Distribution curves and solubility diagrams were established for the two systems.

Comparison of solvent extraction characteristics of rice bran pretreated by hot air drying, steam cooking and extrusion

AbstractRice bran was pretreated by hot air drying, steam cooking and extrusion before solvent extraction of oil. The extractions were conducted in a glass column percolator (i.d. 120 mm), packed to a depth of 90 cm and using n‐hexane at 60 C and gravity feed. Fines (defined as&lt;0.5 mm) in raw bran were significantly reduced by steam cooking and extrusion treatments. Extruded rice bran (ERB) was pelletized and had a bulk density 1.5 times higher than the other products. Regardless of the weight of bran loaded in the percolator, extraction time to reach 1% residual oil was decreased in the order of 116, 67 and 10 min for hot air‐dried rice bran (HARB), steam‐cooked rice bran (SRB) and ERB, respectively. This was due to increases in the percolation rate of SRB by 2 times and by 9 times for ERB compared to HARB. The solvent/bran ratio for extraction to 1% residual oil was decreased by nearly half, from 3.18 for HARB and 3.12 for SRB to 1.77 for ERB.

Electrophoretic mobility of solvent extraction oil drops: Effects of mixed extractants and metal ions

The electrophoretic mobility of hexane droplets dispersed in aqueous solution has been investigated in the presence of mixed extractant systems consisting of anti-5,8-diethyl-7-hydroxy-6-dodecanone oxime (the active extractant in LIX63) + dinonylnaphthalenesulfonic acid (HDNNS), di(2-ethylhexyl)phosphoric acid (HDEHP) + HDNNS, and tricaprylylmethylammonium chloride (Aliquat 336) + HDNNS. LIX63 was found to lower the electrophoretic mobility of HDNNS-hexane droplets, an additive effect in electrophoretic mobility was seen in HDEHP + HDNNS systems, while the presence of Aliquat 336 in HDNNS solution reversed the interfacial charge from negative to positive. The effects of aqueous metal ions, Ni(II), Co(II) and Fe(III), on the electrophoretic mobility of LIX63-, HDNNS- and LIX63 + HDNNS-containing hexane droplets were also investigated. It was found that the effects of these metal ions are strongly pH-dependent. Charge reversals (CRs) were generally observed in the pH range 9–11 for Ni(II)- and Co(II)-containing systems, and in a wider pH range (3–11) for Fe(III). The first CR is attributed to a partial coating of the oil drops by metal hydroxide precipitates, while the second CR reflects the behavior of a completed surface layer of metal hydroxide precipitate.

The production of pulsed E.H.T. voltages for electrostatic coalescence

The use of an electric field, applied between immersed electrodes, is known to promote the separation of water-in-oil type dispersions or emulsions. Recent work has established that pulsed unidirectional voltages applied to electrodes insulated from the liquids is an efficient means of promoting phase disengagement particularly for dispersions with a high conducting phase content. The range of applications is thus extended to include chemical engineering operations such as solvent extraction and crude oil dehydration. It has been shown that the rate of coalescence is not only a function of pulse amplitude but also its shape, mark space ratio and frequency; all of these parameters having physical optimum values. There is, at present, no commercially available package capable of generating a pulsed EHT output of any form in the required frequency range (0.1 – 50 Hz). This paper therefore describes an existing arrangement for laboratory use and a more compact solid state version. The implementation of monitoring and external control facilities is also briefly mentioned.

Cottonseed oil

AbstractResearch on the effects of genetics and growing location on cottonseed has shown that oil and fatty acid composition could be improved if geneticists and agronomists would strive for improved seed quality as vigorously as they do for improved fiber quality. Breeding of glandless or gossypol‐free cottonseed was a genetic breakthrough. Glandless varieties are now available that produce yields having the quality of fiber and seed equivalent to those of glanded cultivars. Oil, food‐grade lecithin and meal byproducts are readily processed from glandless cottonseeds because of the absence of gossypol. Major research programs on cottonseed processing include: (a) testing alternative screw‐press and extrusion operations for efficient direct solvent oil extraction; (b) developing alternative solvent extraction systems with ethanol, isopropanol and supercritical fluids; (c) using gas chromatographic/mass spectrophotometric techniques to characterize enzymatic and nonenzymatic mechanisms that produce secondary oxidation off‐flavor products; and (d) controlling hexane losses in solvent extraction systems.

The technical developments of the oil solvent extraction industry in China

AbstractThe development of the oil solvent extraction industry in China is described. The first continuous oil solvent extraction plant (modeled on a Rotocel extractor) was built in 1955. Since then, other types of extractors have been installed and processes such as the desolventizing of extracted meal, the evaporation of miscella and the recovery of solvent vapor have been adopted. This essay documents improvements in technology and machinery and discusses future developments in the industry.

Soybean preparation

Abstract and SummaryTechniques and equipment for a typical soybean preparation plant prior to solvent oil extraction are described. The bean flow is described from incoming beans, to the inlet, to the extractor.

Continuous process monitor for selective solvent extraction of oils with furfural

Continuous process monitor for selective solvent extraction of oils with furfural

Bleaching off‐colored cottonseed oils with activated alumina: A preliminary cost study

AbstractThe majority of off‐colored cottonseed oils can be bleached to a prime color with 4% by weight or less of activated alumina in a single operation. Increasing the amount of alumina beyond 4% makes it possible to bleach the most difficult‐to‐bleach off‐colored cottonseed oils. Although additional research is required to establish the process and optimize conditions, results of a preliminary cost study indicate that this method should be competitive on a large scale with rerefining followed by conventional earth bleaching.A flow sheet is given. Investment and operating costs are reported for bleaching for six months annually in plants having daily capacities of 100,000, 500,000, and 1,000,000 lb of cottonseed oil, prime and/or off‐colored, in batches of 6,000, 30,000, and 60,000 lb, respectively.It is estimated that alumina bleaching of off‐colored oil, with solvent extraction of oil from spent alumina, would cost as little as 0.4Ţ/lb in the largest plant, 0.5Ţ/lb in the medium plant, and 1.2Ţ/lb in the small plant. These costs are calculated on the basis of the use of 4% alumina by weight of oil for off‐colored oil during one‐fourth of the season, in combination with 1%, 2%, or 4% of alumina for prime oil during three‐fourths of the season.Costs could be lowered by reducing oil losses and losses of alumina in regeneration, increasing filtration rates, and lowering alumina price as a result of additional research on its preparation. Lowered cost would make the method more attractive forprime oils as well.