High‐temperature pre‐conditioning of rapeseed: A polyphenol‐enriched oil and the effect of refining

In this work, a pretreatment process for rapeseeds, which involves the use of high‐temperature steam, is presented. This method, besides accomplishing the beneficial effects of the conventional industrial thermal treatment, leads to an enrichment of some important minor compounds (polyphenols and phosphatides) in the resulting oil. Rapeseeds were pretreated at different operative conditions. Then, the seeds were pressed and the press‐cake was solvent extracted. The obtained oils were then refined by both chemical and physical refining techniques, and the influence of each refining step on the content of minor compounds was evaluated. The results show that the amounts of polyphenols and phospholipids present in the oil coming from pretreated seeds increase and that their concentrations depend on the conditioning time. The polyphenols present in the oil correspond mostly to 2,6‐dimethoxy‐4‐vinylphenol (vinylsyringol). The content of polyphenols was only slightly reduced during degumming. Neutralization resulted in a complete removal of these minor compounds. For the physical refining process, the type and amount of bleaching clay used had a significant influence on the content of polyphenols. After deodorization, oil samples with a considerable amount of polyphenols were obtained. These samples show a higher oxidative stability than chemically refined oils.     

Jatropha curcas,a promising crop for the generation of biodiesel and value‐added coproducts

The review highlights the specific features of the Jatropha curcas plant and its potential for the production of biofuel, protein concentrates as livestock feed and value‐added products that could enhance the economic viability of Jatropha seed oil‐based biodiesel production. The roles of the plant in carbon capture, enhancing socio‐economic conditions, food production in the tropical regions, and influencing micro‐climate, vegetation and soil quality are discussed. The paper also gives a comparative account of the toxic and non‐toxic genotypes of J. curcas from the point of view of their physical and chemical properties and their potential for biodiesel and livestock feed production. Future areas of research are also presented.     

Synthesis,effectiveness, and working mechanism of humic acid‐{sodium 2‐acrylamido‐2‐methylpropane sulfonate‐co‐N,N‐dimethyl acrylamide‐co‐acrylic acid} graft copolymer as high‐temperature fluid loss additive in oil well cementing

Monomers of 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS®), N,N–dimethyl acrylamide (NNDMA) and acrylic acid (AA) were grafted on humic acid as backbone by aqueous free radical copolymerization in such a manner that a graft copolymer possessing lateral terpolymer chains was obtained. Molar ratios between AMPS®, NNDMA, and AA were found to be 1 : 1.54 : 0.02 and the ratio between backbone and graft chain was 20 : 80 wt %. The synthesized fluid loss additive (FLA) was characterized by size exclusion chromatography (SEC), charge titration, and Brookfield viscometry. Thermogravimetric and SEC analysis revealed stretched backbone worm architecture for the polymer whereby humic acid constitutes the backbone decorated with lateral graft chains. Grafting was confirmed by SEC data (R_g) and by ineffectiveness of a blend of AMPS®‐NNDMA‐AA copolymer with humic acid. Their performance as high temperature FLA was studied at 150°C by measuring static filtration properties of oil well cement slurries containing 35% bwoc of silica fume and 1.2% bwoc AMPS®‐co‐itaconic acid retarder. At this temperature, 1.0% bwoc graft copolymer achieves API fluid loss value of 40 mL, thus confirming high effectiveness. The graft copolymer viscosifies cement slurries less than other common synthetic FLAs. The working mechanism of the graft copolymer was found to rely on adsorption onto surface of hydrating cement, as was evidenced by adsorption and zeta potential measurements. Adsorption is hardly affected by temperature and results in constriction of the filter cake pores. The study provides insight into performance of cement additives under the harsh conditions of high temperature and high pressure. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Kinetics of hydroxide‐catalyzed methanolysis of crude sunflower oil for the production of fuel‐grade methyl esters

Methyl esters from crude sunflower oil were produced via methanolysis reaction using sodium hydroxide catalyst. Methanolysis was carried out at different agitation speeds (200–600 rpm), temperatures (25–60 °C), catalyst loadings (0.25–1.00% by weight of oil), and methanol:oil mole ratios (6:1–20:1). Mass‐transfer limitation was effectively minimized at agitation speeds of 400–600 rpm with no apparent lag period. Lowering the temperature resulted in a fall in the rate of reaction prolonging the reaction time necessary to achieve maximum production of methyl ester. Using 0.50% hydroxide catalyst was found to be adequate, resulting in 97–98% conversion without compromising recovery due to soap formation. Increasing the methanol:oil mole ratio beyond the usual amount of 6:1 tended to speed up the initial rate of methanolysis and was found to lower the bonded glycerol content, especially the amount of diglyceride in the sample. Kinetic rate constants were derived from experimental results using second‐order rate expressions, and values of activation energy for glyceride methanolysis have been established. Copyright © 2007 Society of Chemical Industry     

Medium optimization for lipid production through co‐fermentation of glucose and xylose by the oleaginous yeast Lipomyces starkeyi

Co‐fermentation of lignocellulose‐based carbohydrates is a potential solution to improve the economics of microbial lipid production. In the present paper, experiments were performed to optimize the media composition for lipid production by the oleaginous yeast Lipomyces starkeyi AS 2.1560 through co‐fermentation of glucose and xylose (2 : 1 wt/wt). Statistical screening of nine media variables was performed by a Plackett–Burman design. Three factors, namely mixed sugar, yeast extract and FeSO₄, were found as significant components influencing cellular lipid accumulation. Further optimization was carried out using a Box–Behnken factorial design to study the effects of these three variables on lipid production. A mathematical model with the R² value at 96.66% was developed to show the effect of each medium composition and their interactions on the lipid production. The model estimated that a maximal lipid content of 61.0 wt‐% could be obtained when the concentrations of mixed sugar, yeast extract and FeSO₄ were at 73.3 g/L (glucose 48.9 g/L, xylose 24.4 g/L), 7.9 g/L and 4.0 mg/L, respectively. The predicted value was in good accordance with the experimental data of 61.5%. Compared with the initial media, the optimized media gave 1.59‐fold and 2.03‐fold increases for lipid content and lipid productivity, respectively.     

Refining of Roundup Ready® soya bean oil: Effect on the fatty acid,phytosterol and tocopherol profiles

In this study, genetically modified (GM) soya bean seeds with the event known as Roundup Ready® were used for the production of soya bean oil and their fatty acid, phytosterol and tocopherol composition was characterised. Since these compounds can be partially lost during refining, this study also aimed at evaluating the compositional changes along the GM soya bean oil extraction and refining processes carried out industrially. During the refining process of crude soya bean oil, neutralisation was responsible for the major losses on phytosterols (15%). The greatest reduction of tocopherols was also caused by the neutralisation step (20%), while the deodorisation step caused minor losses (9%). Along the refining process, the decreases of total phytosterols and total tocopherols were 20 and 30%, respectively, which are lower than the losses reported in other studies, reflecting the industrial improvements in preserving beneficial health compounds in the refined oil. The results showed that the refined GM soya bean oil presented higher contents of phytosterols (313 mg/100 g) and tocopherols (931 mg/kg) comparing to other reports.     

Kinetics and mechanism of the KOH — catalyzed methanolysis of rapeseed oil for biodiesel production

The reaction of rapeseed oil with methanol catalyzed by KOH is described by a model consisting of two sequences of consecutive competitive reactions. The first sequence expresses the methanolysis of rapeseed oil to methyl esters (biodiesel) whereas the second sequence describes the always present side reaction‐saponification of glycerides and methyl esters by KOH. The proposed chemical model is described (after rational simplifications) by a system of differential kinetic equations which are solved numerically by two independent computing methods. The thus obtained theoretical kinetic and equilibrium results are compared numerically and/or graphically with the experimental parameters. The latter were obtained by the determination of the relevant components in the actual reaction mixture by analytical methods. According to the experimental results, the proposed reaction scheme is fulfilled with the probability of ca. 78%. The optimal average rate constants and equilibrium constants of individual reaction steps of the discussed scheme are introduced. The limitations of the proposed reaction model are discussed.     

Adsorption behavior and effectiveness of poly(N,N‐dimethylacrylamide‐co‐Ca 2‐acrylamido‐2‐methylpropanesulfonate) as cement fluid loss additive in the presence of acetone‐formaldehyde‐sulfite dispersant

A copolymer of N,N‐dimethylacrylamide and Calcium 2‐acrylamido‐2‐methylpropanesulfonate was synthesized by free‐radical copolymerization. Its performance as anionic fluid loss additive (FLA) was studied by measuring static filtration properties of oil well cement slurries at 27°C and 70 bar pressure, respectively. It was found that cement filter cake permeability and API fluid loss decrease with increasing FLA dosage. Filtrate analysis revealed a linear correlation between fluid loss and the amount of FLA adsorbed on the cement surface. FLA adsorption on cement was determined by total organic carbon (TOC) analysis in cement filtrate and confirmed by ζ‐potential measurement. According to environmental scanning electron microscopy (ESEM) investigations, FLA does not alter the filter cake structure. In the presence of an anionic acetone–formaldehyde–sulfite (AFS) polycondensate dispersant, fluid loss control from FLA decreased and cement filter cake permeability increased because AFS reduces the amount of FLA adsorbed. In comparison to FLA, AFS shows stronger adsorption on the cement surface and succeeds in the competition with FLA. The different adsorption behavior of the two polymers is the reason for limited compatibility of this admixture com bination. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4341–4347, 2006     

Effect of α‐, γ‐, and δ‐tocopherol on the distribution of volatile secondary oxidation products in fish oil

The relative ability of α‐, γ‐ and δ‐tocopherol (TOH) to influence the distribution of volatile secondary oxidation products in fish oil was studied, with particular emphasis on oxidation products expected to be important for adverse flavour formation. Purified fish oil samples with 100 ppm or 1000 ppm of the different tocopherols were analysed by dynamic headspace analysis of the volatiles formed after 2, 5 and 8 d of storage at 30 �C. The tocopherol type and concentration affected not only the overall formation of volatile secondary oxidation products, but also the composition of this group of oxidation products. Principal component analysis of the data obtained suggested that high tocopherol hydrogen‐donating power, i.e. a high tocopherol concentration or the use of αTOH as opposed to γTOH or δTOH, directs the formation of hydrocarbons, unsaturated carbonyl compounds of relatively high molecular weight, as well as the formation of cis, trans isomers of unsaturated aldehydes. Although an active inhibitor of overall volatile formation, αTOH at a high concentration thus appears to direct the formation of the more flavour‐potent aldehydes, such as those linking the carbonyl group with ethylenic conjugated unsaturation.     

Synthesis,characterization, and working mechanism of a synthetic high temperature (200°C) fluid loss polymer for oil well cementing containing allyloxy‐2‐hydroxy propane sulfonic (AHPS) acid monomer

A polymer comprising of 2‐acrylamido‐2‐methyl propane sulfonic acid, N, N‐dimethyl acrylamide, allyloxy‐2‐hydroxy propane sulfonic acid (AHPS), acrylic acid, and N, N‐methylene bisacrylamide was synthesized by aqueous free radical copolymerization and tested as high temperature performing fluid loss additive (FLA) in oil well cement. Successful incorporation of AHPS was confirmed and characteristic properties of the copolymer were determined using size exclusion chromatography. The FLA showed excellent water retention in cement at 200°C/70 bar. At this temperature, polymer structure changed from branched to linear and hydrodynamic size decreased by ～50%, thus indicating potential fragmentation, while performance remained unaffected by these alterations. The FLA copolymer does not viscosify cement slurries which is advantageous in high temperature well cementing. The working mechanism of the AHPS‐based copolymer was found to rely on reduction of filtercake permeability which is caused by a voluminous coprecipitate of the FLA with tartaric acid retarder, mediated by Ca²⁺ ions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis,characterization, reactivity ratios by nuclear magnetic resonance spectroscopy,and application of (2,5‐Dichlorophenyl acrylate‐co‐glycidyl methacrylate) polymers as adhesives for the leather industry

2,5‐ Dichlorophenyl acrylate (DPA)‐co‐glycidyl methacrylate (GMA) polymers having five different compositions were synthesized in 1,4‐dioxane using benzoyl peroxide as a free‐radical initiator at 70 ± 0.5°C. Using ¹H‐NMR spectroscopy, the composition of the two monomers in the copolymers was calculated by comparing the integral values of the aromatic and aliphatic proton peaks. The reactivity ratios were calculated by Fineman–Ross (r₁ = 0.31 and r₂ = 1.08), Kelen–Tudos (r₁ = 0.40 and r₂ = 1.15), and extended Kelen–Tudos (r₁ = 0.39 and r₂ = 1.16) methods. The nonlinear error‐in‐variables model was used to compare the reactivity ratios. The copolymers were characterized by ¹H and proton decoupled ¹³C‐NMR spectroscopes. Gel permeation chromatography was performed for estimating the M_w and M_n and M_w/M_n of the poly(DPA) and copolymers (DPA‐co‐GMA: 09 : 91 and 50 : 50). Thermal stability of the homo‐ and copolymers was estimated using TGA [poly(DPA) > DPA‐co‐GMA (50 : 50) > DPA‐co‐GMA (09:91)], while DSC was utilized for determining the glass transition temperature. T_g increased with increased DPA content in the copolymer. The 50 : 50 mol % copolymer was chosen for curing with diethanolamine in chloroform. The cured resins were tested for the adhesive properties on leather at different temperatures (50, 90, 100, and 110°C). The resin cured at 50 °C exhibited a maximum peel strength of 1.6 N/mm, revealing a good adhesive behavior. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1167–1174, 2006     

Grafting of poly[styrene‐co‐N‐(4‐vinylbenzyl)‐N,N‐diethylamine] polymer film onto the surface of silica microspheres and their application as an effective sorbent for lead ions

Amino containing polymer of poly[styrene‐co‐N‐(4‐vinylbenzyl)‐N,N‐diethylamine] (PS‐co‐PVEA) was successfully grafted onto the surface of silica microspheres via the seed dispersion polymerization of styrene and N‐(4‐vinylbenzyl)‐N,N‐diethylamine in the presence of divinylbenzene employing the 3‐(methacryloxy)propyltrimethoxysilane activated silica microspheres as the seed. The polymerization led to thin chelating polymer films (30 nm) coated silica microspheres (silica@polymer) as determined by transmission electron microscopy. The synthesized silica@polymer composites were used as sorbents for lead ions (Pb²⁺). The adsorption properties, such as the pH effect, the adsorption kinetic, adsorption isotherm as well as the reuse of the silica@polymer sorbent were evaluated. The results demonstrated that the optimized adsorption condition was under neutral and the silica@polymer sorbent was efficient since it showed higher adsorption amounts (8.0 mg/g) and shorter adsorption equilibrium time (8 h) than that of the PS‐co‐PVEA microspheres and the pristine silica microspheres. Moreover, the silica@polymer sorbent was reusable even after four cycles of adsorption. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 39973.     

Development of a vision‐based online soft sensor for oil sands flotation using support vector regression and its application in the dynamic monitoring of bitumen extraction

Extraction from oil sands is a crucial step in the industrial recovery of bitumen. It is challenging to obtain online measurements of process outputs such as bitumen grade and recovery. Online measurements are a prerequisite for innovating better process control solutions for process efficiency and cost reduction. We have developed a soft sensor to provide online measurements of bitumen grade and recovery in a flotation‐based oil sand extraction process. Continuous froth images were captured using a VisioFroth camera system on a batch flotation unit. A support vector regression (SVR) model with a Gaussian kernel was constructed to develop a soft sensor for bitumen grade and recovery using froth image features as the inputs. The model was trained and validated for batch flotation of different grades of oil sands ore at industry‐relevant process conditions. A Dean‐Stark analyzer was used to obtain offline grade and recovery measurements that were used to calibrate the soft sensor. Mean squared errors (MSE) of 62 and 74 were achieved for grade (%) and recovery (%), respectively, and this was obtained using 5‐fold cross validation. The developed soft sensor model has been applied successfully in the real‐time dynamic monitoring of flotation grade and recovery for different grades of ore and operating conditions.