High Oil Retention Research Articles

Oil spill sorption using carbonized pith bagasse: trial for practical application

In the present work, an attempt was made to provide an efficient, easily deployable method of cleaning up oil spills and recovering of the oil. Carbonized pith bagasse, a relatively abundant and inexpensive material is currently being investigated as an adsorbent to remove contaminants “oil” from water. Fibers extracted from bagasse and carbonized at 300 °C were found to have a high performance for sorption and recovery of light, heavy oils and even the viscous ones. The physical properties of pith bagasse were investigated using scanning electronic microscope to show the inner and the outer surface and the cross section area of the pith bagasse and thermo gravimetric analyzer to investigate the degradation profile of the pith bagasse. The carbonized pith bagasse was packed into a polypropylene bag and its sorption behavior was studied. A comparison was made between the prepared pad and the commercial sorbents show that the pad containing carbonized pith bagasse has higher sorption capacity in comparison to the commercial sorbents. The pad exhibited high oil retention ability and a high selectivity for the oils over the water. The pad showed a possibility of reuse for eight times. The sorption capacity of the pads containing carbonized pith bagasse was found to increase with increasing the time of sorption till it reaches the maximum value at the time of sorption equal to 60 min.

Evaluation of kapok ( Ceiba pentandra (L.) Gaertn.) as a natural hollow hydrophobic–oleophilic fibrous sorbent for oil spill cleanup

Oil sorption capacity and hydrophobic–oleophilic characteristics of an agricultural product, kapok ( Ceiba pentandra), was thoroughly examined. The kapok fiber has a hollow structure with large lumen. Its performance was compared with that of a polypropylene (PP), a widely used commercial oil sorbent for oil spill cleanup. The oils investigated were diesel, hydraulic oil (AWS46), and engine oil (HD40). Reusability of the kapok after application to various oils was also evaluated. Both loose (at its natural state) and densely packed kapok assemblies were examined. Sorption capacities of the packed kapok assemblies were very much dependent on their packing densities. At 0.02 g cm −3, its oil sorption capacities were 36, 43 and 45 g g −1 for diesel, ASW46 and HD40, respectively. The values decreased to 7.9, 8.1 and 8.6 g g −1 at 0.09 g cm −3. Its sorption capacities for the three oils were significantly higher than those of PP. When the oil-saturated kapok assemblies were allowed to drain, they exhibited high oil retention ability, with less than 8% of the absorbed diesel and HD40, and 12% of the absorbed AWS46 lost even after 1 h of dripping. When applied on oil-over-water baths, the kapok exhibited high selectivity for the oils over the water; almost all oils spilled could be removed with the kapok, leaving an invisible oil slick on water. After the 4th cycle of reuse, the reused kapok assembly only lost 30% of its virgin sorption capacity if packed at 0.02 g cm −3, and the loss in sorption capacity was much less at higher packing densities. The hydrophobic–oleophilic characteristics of the kapok fiber could be attributed to its waxy surface, while its large lumen contributed to its excellent oil absorbency and retention capacity.

Solvent recovery from soybean oil/hexane miscella by polymeric membranes

In this work, solvent recovery from soybean oil/hexane miscellas (1:3, w/w) was studied. Flat sheet polymeric membranes, polysulfone and polysulfone/polyamide based, used in reverse osmosis, nanofiltration and ultrafiltration, were tested. The effects of pressure (13–27 bar) and temperature (21–49 °C) on permeate flux, oil retention and separation of free fatty acids (FFA) were evaluated by a 2 2 complete factorial design, with three central points and four axial points. Increased pressure resulted in a higher permeate flux though the retention of oil and free fatty acids by the membranes has decreased. However, higher temperatures showed positive effects on the permeate flux, retention of oil and free fatty acids permeation. The highest oil retention (67.12%) was observed for low pressure (15 bar) and high temperature (45 °C).

Characterization of spray-dried tuna oil emulsified in two-layered interfacial membranes prepared using electrostatic layer-by-layer deposition

Tuna oil-in-water emulsions containing droplets stabilized by lecithin–chitosan membranes were produced using an electrostatic layer-by-layer deposition process. Corn syrup solids were added to the emulsions and then the emulsions were spray-dried, which produced a powder consisting of spheroid microcapsules (diameter = 5–30 μm) containing tuna oil droplets (diameter <1 μm) embedded within a carbohydrate wall matrix. The powders had relatively low moisture contents (<3%), high oil retention levels (>85%) and rapid water dispersibility (<1 min). The structure of the microcapsules was unaffected by drying temperature from 165 to 195 °C. We have demonstrated that a novel interfacial engineering technology, based on production of multilayer membranes around oil droplets, is effective for producing spray-dried encapsulated tuna oil. The powdered tuna oil produced by this method has good physicochemical properties and dispersibility, which may lead to its more widespread utilization as a food additive.

ADSORPTION EFFICIENCY OF SELECTED ADSORBENTS IN SESAME OIL MISCELLAS

In a sesame oil miscella (40% and 60%) system the adsorption efficiency for free fatty acids (QFFA.) and carotenoids (Qc) provided by pine wood carbon (also known as vegetable carbon), two commercial synthetic silica adsorbents, and rice hull ash were compared at different adsorbent dosages (1.0, 2.5 and 5.0%). At all the adsorbent dosages investigated the pine wood carbon achieved a higher QFFA than synthetic silicas and rice hull (P < 0.05). This effect was more evident as the carbon concentration decreased (P < 0.05). However, in the case of carotenoids none of the adsorbents exhibited a significant advantage in Qc (P < 0.50) at any of the adsorbents dosages utilized. Rice hull ash had the highest oil retention, while silicas exhibited an oil retention profile with lower values than that obtained with pine wood carbon (P < 0.10). The results suggest that pine wood carbon might have the same capability as silicas when used with sequential addition of clay in sesame oil miscella refining, with the advantage of higher adsorption efficiency than silicas for free fatty acid adsorption.

Laboratory trials on bleaching palm oil with selected acid-activated Nigerian clays

The optimum conditions for acid activation of some selected Nigerian clays were determined. The bleaching potential of the activated clays on crude palm oil relative to a commercial Fuller's earth (Fulmont 700C) were assessed. Bleaching activity was highest when 1 part of clay of particle size < 180 μm was mixed with 3 parts of 1·4–2·7 m HCl or 0·5–1·0 m H 2SO 4, refluxed for 2–6 h, dried to between 5–15% moisture content, milled and sifted to obtain a particle size of <90 μm. Clays from Ewekoro and Shagamu in southern Nigeria, when properly activated using the wet slurry method, compared favorably with the commercial Fuller's earth in bleaching activity. The Nigerian clays, however, showed lower apparent bulk densities and, consequently, a corresponding higher oil retention.

Preparation of high apparent bulk density clays by fluidized activation

AbstractFluidizing a free‐flowing mixture of clay and concentrated sulfuric acid in a medium of hot air at 150 C yields an active product of high apparent bulk density (ABD) and consequent low oil retention unlike the conventional “wet” method of activation which yields a fluffy clay with high oil retention. Comparative data on bleaching capacity, ABD and oil retention of the products obtained by both methods are given.