Continuous refining of crude cottonseed miscella

A simple, easily controlled process for continuous caustic refining of crude cottonseed miscella in a two-stage system is described. The effect of crude oil quality, oil: hexane ratios, temp, mixing conditions and chemical treatment are noted. The chemical reactions in the process are followed microscopically. The process yields a refined oil of less than: 1.0 bleach oil color, 0.03% free fatty acid and 15 ppm soap, and with 30~40% oil savings over Official Cup Loss. The by-product soap may be used advantageously in the meal from the extractor unit. Presented at the AOCS Meeting in Minneapolis, 1963.     

Current practices in continuous cottonseed miscella refining

Miscella refining of crude cottonseed oil has become a generally accepted commercial process for the past 20 years. The simple and efficient continuous process for removal of undesirable impurities is described, having changed little in its basic form since discovery 40 years ago. The individual unit processes, control systems, process flow charts, chemical reactions and oil-to-hexane ratios used in miscella refining are described. The several advantages to miscella refining vs conventional oil refining are noted.     

A comparative study of batch and continuous refining of cottonseed oil in the Sudan

This study is concerned with a comparison of some technical aspects regarding batch vs continuous refining (centrifugal alkali refining) of crude cottonseed oil. Implication of processing modes of operation were examined in light of their effect on the following performance criteria: (a) percentage of refining loss as a function of the initial crude-oil free fatty acid (FFA) content: (b) refined oil color as a function of initial crude-oil FFA: (c) caustic soda consumption as a function of initial crude-oil FFA: (d) bleachability characteristics of refined oil. The study shows, in quantitative terms, that continuous refining of cottonseed oil is more efficient in each of these performance criteria, particularly the percentage of refining loss.     

Plant scale comparisons of various refining methods for cottonseed oil

Three different refining processes were commercially compared by processing 15,148 metric tons of cottonseed with free fatty acid content varying between 7.1% and 8.9%. All of the seed was prepressed and solvent extracted in the Sanbra plant at Bauru, Brazil. The Ranchers Miscella refining process operating on seed averaging 8.8% F.F.A. yielded more oil of lighter color per ton of seed processed than either of the other processes compared, even though the average F.F.A. of the seed processed during the Ranchers Miscella Refining test averaged 1.7% higher than the seed used in the Sanbra process and 1.1% higher than the average F.F.A. for the seed used in the Low Loss Refining test. In another comparison, screw pressed oil, Modified Soda Ash refined was compared to Ranchers Miscella refining with seed containing about 0.5% F.F.A. The results showed 42% lower refining loss and a color of 3.5 Red Lovibond units less for Ranchers Miscella refined oil than for Modified Soda Ash refined oil. The average cost of converting crude cottonseed oil to prime bleachable summer yellow oil by the miscella refining process described is 20.8￠ per hundred weight of oil (not including refining loss). These costs include the prorated cost of control laboratory, plant labor and supervision, fuel, power, chemicals, depreciation, taxes and insurance.     

Alternative hydrocarbon solvents for cottonseed extraction: Plant trials

Hexane has been used for decades to extract oil from cottonseed and is still the solvent of choice for the edible-oil industry. Due to increased regulations as a result of the 1990 Clean Air Act and potential health risks, the edible-oil extraction industry urgently needs an alternate hydrocarbon solvent to replace hexane. Based on laboratory-scale extraction tests, two hydrocarbon solvents, heptane and isohexane, were recommended as potential replacements for hexane. A cottonseed processing mill with a 270 MT/day (300 tons/day) capacity agreed to test both solvents with their expander-solvent process. Extraction efficiencies of isohexane and heptane, judged by extraction time and residual oil in meal, refined and bleached color of miscella refined oil, and solvent loss, were comparable to that of hexane. However, fewer problems were encountered with the lower-boiling isohexane than with the higher-boiling heptane. With isohexane, the daily throughput increased more than 20%, and natural gas consumption decreased more than 40% as compared to hexane.     

Comparative study of the extraction and measurement of cottonseed free fatty acids

Crude oil was extracted from cottonseed by three different methods to study the influence of extraction technique on the free fatty acid (FFA) concentration. Extraction procedures that recovered more oil had higher levels of FFA. In addition, the highest concentration of FFA was found in oil recovered by Soxhlet reextraction of a meal initially defatted by a room-temperature extraction process. The FFA concentrations of oils recovered by Soxhlet extraction were highly correlated with the FFA concentration of oils recovered by the other extraction methods studied (R ²>0.96). Titration of oil and gas chromatography of silylated oil were compared as methods to determine FFA concentration. The methods compared well (R ²=0.998) with the titration method, giving ∼5% higher values for FFA than the chromatography method. Half of this difference appeared to be due to the oleic acid approximation used in the titration approach. The other half of the difference is likely due to the detection of other acidic components in crude oil.     

Color stability of glandless cottonseed oil

The color stability of oil extracted from glandless cottonseed contaminated with various levels of glanded cottonseed was studied. The rate of darkening in bleached color of cottonseed oil during storage was proportional to the original glanded cottonseed or gossypol content in the oil and to time and temperature of storage. Glandless cottonseed with 0–10% glanded seed contamination, as might be expected in commercial production of glandless cotton, yielded oil with equivalent or better color when conventionally refined and bleached after 30 days storage at 25 to 40 C than miscella refined oil from glanded cottonseed. This indicates that new oil mills for extracting glandless cottonseed need not invest in miscella-refining units in order to produce high quality oil.     

Effects of Crude Rice Bran Oil Components on Alkali-Refining Loss

The effects of minor components in crude rice bran oil (RBO) including free fatty acids (FFA), rice bran wax (RBW), γ-oryzanol, and long-chain fatty alcohols (LCFA), on alkali refining losses were determined. Refined palm oil (PO), soybean oil (SBO) and sunflower oil (SFO) were used as oil models to which minor component present in RBO were added. Refining losses of all model oils were linearly related to the amount of FFA incorporated. At 6.8% FFA, the refining losses of all the model oils were between 13.16 and 13.42%. When <1.0% of LCFA, RBW and γ-oryzanol were added to the model oils (with 6.8% FFA), the refining losses were approximately the same, however, with higher amounts of LCFA greatly increased refining losses. At 3% LCFA, the refining losses of all the model oils were as high as 69.43–78.75%, whereas the losses of oils containing 3% RBW and γ-oryzanol were 33.46–45.01% and 17.82–20.45%, respectively.     

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.     

Effect of different methods of disintegration of cottonseed on some properties of the crude oil with special reference to high moisture seed

Summary Both the expeller and hydraulic types of mills are used for crushing high moisture seed in the northeastern section of North Carolina. The quality of crude oil from the hydraulic mill is decidedly better than crude oil from the expeller mill, when the seed are comparable and as the moisture content of the seed increases the difference in quality of crude oil from the two types of mill is progressively greater in favor of the hydraulic mill. The disintegration of cottonseed meats in the food chopper, used for the free fatty acid determination in cottonseed, and the expeller mill have a very similar effect on the color of the oil. Apparently the effect of expelling also causes an increase in free fatty acids and refining loss, especially when working high moisture seed. A Paper Presented at the 26th Annual Meeting of the American Oil Chemists’ Society at Memphis, Tenn, May 23–24, 1935     

无毒聚丙烯酰胺快速提炼毛棉籽油(英文)

The traditional method to refine crude cottonseed oil is time-consuming and expensive. This study evaluates the effectiveness of coagulation–flocculation–sedimentation process using quaternary polyamine-based polymers in refining crude cottonseed oil. Flocculated by four commercial polyamine-based cationic polymers (SL2700, SL3000, SL4500 and SL5000) with varied molecular weight (MW) and charge density (CD) and followed by co-agulation with sodium hydroxide, crude cottonseed oil can be effectively purified. Free fatty acids, gossypol, pig-ments and trace elements are all effectively and sufficiently removed by the four polymers in a MW-and CD-dependent manner. Our results suggest that the use of polyamine-based cationic polymers may offer an effective and feasible alternative to the traditional method for crude cottonseed oil refining.     

Miscella refining

Miscella refining can be practiced as a batch process or, preferably, as a continuous process with oil concentrations through the range of 30–70% by wt of oil. Miscella refining is preferably practiced at the oilseed solvent extraction plant for the economic reason of single solvent recovery system. Three immediate benefits are lower refining loss, lighter colored refined oil, and elimination of water washing. Various types of chemical conditioning, mechanical conditioning, and combinations of both are discussed for miscella refining certain oils. Blends of compatible crude oils can be advantageously miscella refined and, if desired, winterized or hydrogenated to produce oils with unique properties.     

An aqueous ethanol extraction process for cottonseed oil

A bench-top process for the extraction of cottonseed flakes with aqueous ethanol has been developed. The process consists of cottonseed meat flaking, drying and extraction with boiling, aqueous ethanol (95% by volume) at atmospheric pressure. The resulting miscella is chilled, producing free oil, emulsified oil and mucilaginous gum. The heterogeneous solution is processed through a phase separator where free and emulsified oil and gum are separated from oil-lean miscella. The oil and gum phases are treated with caustic soda and centrifuged to produce semirefined oil containing about 4% volatiles. The miscella phase, containing about 3.3% lipid-like material and 1% petroleum ether insolubles, is reheated and recycled to the extractor. After the marc is pressed foots are added, and it is desolventized to produce a meal having a residual oil content less than 1%. Although not yet otpimized, the process shows potential for scaleup to pilot plant processing and adaptability to current oil mill solvent operations. Presented at the AOCS annual meeting, Chicago, May 1983.     

Biodiesel Production from Mustard Emulsion by a Combined Destabilization/Adsorption Process

Tetrahydrofuran, added to the oil‐in‐water emulsions formed by the aqueous processing of yellow mustard flour, produced oil/water/THF miscellas containing 1–2 % water. The high water content prevented the direct conversion of the system to fatty acid methyl esters (FAME) through a single‐phase base‐catalyzed transmethylation process. Dehydration of these miscellas by adsorption on 4A molecular sieves at room temperature using either batch or continuous fixed‐bed systems successfully reduced the water content to the quality standards needed for biodiesel feedstock (0.3 %). Equilibrium adsorption studies for the uptake of water from oil/THF/water miscella phases at room temperature allowed quantitative comparison of the water adsorption capacity based on the oil and THF concentrations of the miscellas. Batch contact was used to investigate the dominant parameters affecting the uptake of water including miscella composition, adsorbent dose and contact time. The adsorption of the water was strongly dependent on adsorbent dose and miscella oil concentrations. The regeneration of molecular sieves by heating under nitrogen at reduced pressure for 6 h at 275 °C resulted in incomplete desorption of miscella components. The adsorption breakthrough curves in terms of flow rates, initial water and oil miscella concentrations were determined. The dehydrated miscella phases were reacted with methanol in a single‐phase base‐catalyzed transmethylation process with high yields (99.3 wt%) to FAME. The resulting FAME met the ASTM international standard in terms of total glycerol content and acid number.     

Aerobic Liquor Washing Improves the Quality of Crude Palm Oil by Reducing Free Fatty Acids and Chloride Contents

The presence of free fatty acids (FFA) and chloride contents in crude palm oil is not desirable because they have an impact on oil quality and food safety. This work presents a method to reduce these compounds by washing the crude palm oil (CPO) with treated aerobic liquor (AL). The effects of process parameters on the reduction of FFA and chloride in CPO and the resultant 3-monochloropropane-1,2 diol ester (3-MCPDE) formed after refining are investigated. The results show that the AL dosage, initial FFA content, mixing speed, and duration have significant influence on the reduction of FFA in the CPO. Meanwhile, the chloride content is reduced by approximately 50% regardless of the AL dosage used. Consequently, the 3-MCPDE content in the oil after refining is up to 53% lower than that of the refined oil produced from the untreated CPO. Furthermore, an oil recovery above 97% can be achieved after the AL-washing step. The implementation strategy of this method in the palm oil mills has also been proposed. In conclusion, an effective and sustainable method for in situ improvements of the quality and food safety of palm oil has been developed without the need for additional water or chemical. Practical Applications: Treated aerobic liquor can be used to wash the CPO in palm oil mill for in situ reductions of FFA and chloride contents in CPO to improve the oxidative stability of CPO. The lower content of chlorides in CPO could mitigate the formation of 3-MCPDE during refining, thus improving the food safety of palm oil. This method can readily be implemented by the industry and it is sustainable because it does not require the use of additional process water or chemical.     

Refining and Bleaching of Peanut Miscella

The effects of type of crude miscella, oil content in miscella, concentrations of caustic soda solutions, method of mixing and temperature on the refining of high f. f. a. dark coloured peanut miscellas were investigated. Very effective removal of free fatty acids and decolorisation of the peanut miscellas were achieved by treating at 45-60% oil content with 16°-20° Bé caustic soda solution at room temperature (ca. 32 ± 1° C). Good bleaching of refined miscella samples also at room temperature with commercial acid treated earth and active charcoal was possible. Refined oils had 0.02-0.06% f. f. a. with 94-99% colour removed. Successful commercial possibilities are indicated.     

Extraction of lipids from cottonseed tissue: IV. Use of hexane-acetic acid

Hexane and mixtures of hexane and 2–25% acetic acid (v/v) were used to prepare oil and protein from glanded cottonseed by solvent extraction. As the amount of acetic acid in the solvent increased, the amounts of total lipid, phospholipid, neutral oil, and gossypol in each miscella increased, but the amount of free fatty acids did not change significantly. However, the solubility of protein in 0.02N NaOH decreased as the amount of acetic acid in the solvent used to prepare each meal increased. Other aspects of using acidified hexane are described. A preliminary report was presented at the AOCS Meeting in New Orleans, April 1973. ARS, USDA.     

Steam (physical) refining deodorizer for malaysian palm oil

The production of Malaysian palm oil is expected to increase 20% per year for the next 5 yr. Already planted are more than a million acres which will start to produce in the next few years. Recent plantings of new strains will produce 2400 to 3000 lb of palm oil per acre. Palmex Industries, Penang, Malaysia started in operation in August, 1975, a physical refining system to produce a deodorized palm oil with 0.03% free fatty acid (FFA) from crude palm oil containing 5.0% FFA. Production records confirm the feasibility of physical refining crude palm oil in Malaysia, ex-porting the oil to the United States, and producing a quality product with a minimum of additional pro-cessing.     

Gossypol content and refining losses on crude cottonseed oil

Summary 1. Gossypol has been found to be almost universally present in hot pressed crude cottonseed oils from all of the important cotton growing sections in the United States. 2. The average amount found in crude oils from 62 scattered mills was 0.05 per cent. The highest percentage found in a hot pressed oil was 0.210. Only 7 out of 124 oils failed to show the presence of gossypol. 3. Since gossypol content was not found to be proportional to deviation from average refining loss, it was concluded that at least a portion of the gossypol occurs in the oil in the bound state, associated with protein fragments.     

Effect of Selected Polyhydric Alcohols on Refining Oil Loss in the Neutralization Step

Alkaline neutralization is a classical method for removal of free fatty acids (FFA) in crude oil. It is generally accompanied by neutral oil loss. Thus, reduction of refining losses associated with alkaline neutralization is very desirable. Refined, bleached and deodorized (RBD) palm oils with different FFA contents were used as oil models in this study. FFA in the oil models were neutralized with sodium hydroxide in polyhydric alcohols as neutralization media. Glycerol, propylene glycol and ethylene glycol in water were effective neutralization media. FFA in the oil models were totally removed in one step of neutralization, while percentages of refining losses were different. The losses were increased in the order of water > propylene glycol > ethylene glycol > glycerol used as neutralization media. Also, a higher concentration of polyhydric alcohol in the neutralizing media significantly reduced the percentage of refining loss (p < 0.05). Glycerol (90% in water) was the most effective neutralization media (p < 0.05). When neutralization was carried out on crude palm oil (containing 7.53% FFA), refining loss was reduced from 36.1% (in water) to 20.0% (in 90% glycerol in water).