Amount Of FFA Research Articles

Quality and composition of lipids used in biodiesel production and methods of transesterification: A review

This study presents a brief overview of the composition and properties of various oils used in biodiesel production and the alkali, acidic and enzymatic transesterification reactions used in production. Nowadays, vegetable and microalgae oils are mostly used in biodiesel production. Recently, however, animal fats, processed oils, industrial oils and yeast and bacterial oils have also gained importance. Although all fats and oils are roughly similar, their saturated fatty acids (SFA), polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), free fatty acids (FFA), cholesterol or glycerol contents may be different and affect the production and efficiency of the biodiesel. Triglycerides are the most significant lipids in biodiesel production. Triglycerides in vegetable oils dominantly contain C18:1ω9 and C18:2ω6 fatty acids. Whereas, triglycerides in animal fats mostly include C16:0 and C18:1ω9 fatty acids. Microalgae are rich in long-chain fatty acids such as C20 and C22. Also, fatty acids such as C14:0, C16:1ω7, C18:0, C20:0, C22:0, C24:0, C22:1ω9, C18:3ω6, C20:4ω6 and C20:5ω6 are present in oils and fats. However, their proportions change from feedstock to feedstock. Rendered animal-originated fats include larger quantities of FFA than waste vegetable oils and, as known, excessive amounts of FFA generate soap in reactions with the alkaline catalyst, reducing biodiesel efficiency. For this reason, generally vegetable and microalgal oils containing a large number of triglycerides and less FFA are preferred for biodiesel production. Bacteria can synthesize branched fatty acids. It has been reported that biodiesel produced from branched fatty acids has advantages according to biodiesel produced from other lipids. Consequently, the use of correct and reliable lipids in biodiesel production is very important for the quality of fuel.

Assessment of the Transesterification Stage of Biodiesel Production I: Application of a Plackett–Burman Design to Select the Process Variables

Although the independent effects of the predictors of the yield in transesterification are well documented, there are still gaps in our current understanding of how specific process variables cumulatively influence the yield of biodiesel. In this study, a two-level Plackett–Burman experimental design was used to assess the set of active process variables that most decisively influence the yield of biodiesel in transesterification. The results of the model in which the parameters were entered at once show in decreasing order, the magnitude of the effect of the process variables on the yield was as follows: amount of FFA > weight of catatlyst > rate of stirring > duration of reaction > temperature > methanol for the ranges of values that were studied. In the sequential/nested ordinary least squares regression model, the order of importance of the predictors was almost maintained however the coefficients varied somewhat. This indicates that the level and the order of entry of variables within each level makes a fundamental difference to the results. The methanol-oil ratio had no influence on biofuel yield within the range of values studied. Overall, the adjusted model in which most of the variables had been taken into consideration explained approximately 94 % of the total variance in the data.

PENGARUH KONSENTRASI Li YANG DI-DOPING KE DALAM KATALIS CaO TERHADAP REAKSI TRANSESTERIFIKASI MINYAK SAWIT

The development of biodiesel which is derived from Crude Palm Oil (CPO) shows a risingtrend forpetroleum-based energy reserves are running low.Oil palm is the largestplantation commodity in Indonesia, so, it has high potential as raw material of biodiesel.Transesterification is a reaction of producingbiodiesel (methyl ester). Nevertheless, CPO is easy to be degraded byhydrolysis, so, it couldincrease the amount of Free Fatty Acid (FFA) content which hampers transesterification process. As a consequence, there is formation of soaps as side product. Tomaximize the production of biodiesel which is derived frompalm oil that contains of large amount of FFA (low grade CPO) one of the waysis by applying catalyst through doped-process. This research is held togive information about the effect of Li+ion concentration (inLiNO3 form) which is doped to calcium oxide (CaO) to palm oil transesterification with the large amount ofFFA to produce methyl ester, attemperature of 120oC,the ratio of methanol:CPO = 12:1 (mol/mol), catalyst amount 2,5% (w/w) CPO, for 3,5 hours and usespressured reactor. The variable of research is Liconcentration that isdoped to CaO with concentration: 0%, 1% and 4% (w/w) CaO. The parameter test is methyl ester content that is derived from the result of transesterification with GasChromatography (GC) analysis. The research shows that Li+ion that is doped to CaO catalyst could increase the reaction of methyl ester production which is derived from low grade CPO with FFA>3,5 %, in which the finest of Liconcentration that is doped to CaO is 1%, with result of 90,88% methyl ester.

The Influence of Molar Ratio of Methanol to PFAD and Esterification Reaction Time towards Biodiesel Characteristics Palm Fatty Acids Distillate Produced

PFAD is potential enough to be developed as a biodiesel feedstock because it is cheap and always available. But the FFA in PFAD is so high, so esterification process is necessary to lower levels of the FFA. High levels of FFA PFAD and a solid form at room temperature need necessary studies to determine the needs of methanol as a reactant and reaction time esterification for high yield and characteristics of biodiesel. Esterification of PFAD were carried out to study the effect of : molar ratios of methanol to PFAD of 6 : 1 – 10 : 1 and reaction time of 60 – 120 min. The optimum condition for esterification process was molar ratio of methanol to PFAD at 10 : 1 with 2 wt% of H2SO4 at 60˚C and 60 min. The amount of FFA was reduced from 97,17 wt% to less then 10 wt %, at the end of esterification process. The characteristic of biodiesel produced were 9.36 mg KOH/gr acid value, 5.01% FFA, 244 mg KOH/g saponification, 47.94 mg I/gr iodine value, 890 kg/m3 density, and negative result for determination water and sediment content.

Frying quality and oxidative stability of two unconventional oils

AbstractThe behavior of crude Sclerocarya birrea kernel oil (SCO) and Sorghum bug (Agonoscelis pubescens) oil (SBO) during deep‐frying of par‐fried potatoes was studied with regard to chemical, physical, and sensory parameters, such as content of FFA, tocopherols, polar compounds, oligomer TG, volatile compounds, oxidative stability, and total oxidation (TOTOX) value. Palm olein was used for comparison. Whereas potatoes fried in SCO that had been used for 24 h of deep‐frying at 175°C were still suitable for human consumption, potatoes prepared in SBO that had been used for 6 to 12 h were not, considering the sensory evaluation. In looking at the chemical and physical parameters, SBO exceeded the limits, after no later than 18 h of use, for the amount of polar compounds, oligomer TG, and FFA recommended by the German Society of Fat Sciences (DGF) as criteria for the rejection of used frying oils. In contrast to SBO, SCO oil did not exceed the limits for the content of polar compounds and oligomer TG during the frying experiment. Only the amount of FFA was exceeded; this was because the amount of FFA at the beginning of the experiment was higher than for refined oils. The results showed that both oils were suitable for deep‐frying of potatoes, but remarkable differences in the time during which both oils produced palatable products were found.

Metabolities of dietary triacylglycerol and diacylglycerol during the digestion process in rats

The present study investigated the metabolic fate of dietary TAG and DAG and also their digestion products in the stomach and small intestine. A diet containing 10% TAG or DAG oil, enriched in 1,3-DAG, was fed to Wistar rats ad libitum for 9 d. After 18 h of fasting, each diet was re-fed ad libitum for 1 h. The weights of the contents of the stomach and small intestine were measured, and the acylglycerol and FFA levels were analyzed by GC at 0, 1, and 4 h after the 1-h re-feeding. The amounts of re-fed diet ingested and the gastric and small intestinal content were not different between the two diet groups. In the TAG diet group, the main products were TAG and DAG, especially 1(3),2-DAG. In addition, 1,3-DAG and 1(3)-MAG were present in the stomach, and the 1,3-DAG levels increased over time after the re-feeding period. In the DAG diet group, the main products in the stomach were DAG, MAG, FFA, and TAG. There were significantly greater amounts of 1,3-DAG, 1(3)-MAG, and FFA in the DAG diet group in the stomach compared with the TAG diet group. The amount of FFA in the stomach relative to the amount of ingested TAG plus DAG in the DAG diet group was higher than that in the TAG diet group. Acylglycerol and FFA levels were considerably lower in the small intestine than in the stomach. These results indicate that, in the stomach, where acyl migration might occur, the digestion products were already different between TAG and DAG oil ingestion, and that DAG might be more readily digested by lingual lipase compared with TAG. Furthermore, almost all of the dietary lipid was absorbed, irrespective of the structure of the acylglycerol present in the small intestine.

FREE FATTY ACID TURNOVER AND THE AVAILABILITY OF SUBSTRATES AS A LIMITING FACTOR IN PROLONGED EXERCISE

A continual hydrolysis and release of FFA from the triglycerides stores of adipose tissue occurs during prolonged moderately severe exercise. The uptake and oxidation of plasma FFA by the working skeletal muscles represents a major source of energy during such exercise. During light and moderately intense prolonged exercise, lipolysis and the release of FFA from the adipose tissue exceeds uptake by peripheral tissue and the net result is an increase in plasma FFA levels. FFA uptake appears to be related to plasma concentrations and uses no membrane transport system. As work intensity increases the release of FFA from adipose tissue declines and the relative contribution of the plasma FFA to the work metabolism declines until at high work rates there is an almost complete reliance on the intramuscular glycogen reserves. At work loads above about 65% of the individual's aerobic capacity the limiting factor for prolonged exercise appears to be the glycogen stores of the working muscle. When these stores are depleted the work either must stop or its intensity be reduced. Trained individuals have a greater capacity to oxidize fats at high work loads than do untrained subjects. This, however, is not matched by an increased capacity for lipolysis. Why intramuscular glycogen stores are required for prolonged relatively severe exercise when the amount of FFA and glucose that perfuses the skeletal muscles under such conditions is theoretically capable of supporting the exercise metabolism is unknown.

A cell culture assay to evaluate the toxicity of arlacel A.

SummaryAn assay using the L-929 mouse fibroblast cell culture line was described to evaluate the toxicity of Arlacel A. The toxic lots of AA produced a characteristic cytotoxic effect consisting of intracytoplasmic refractile bodies. The results obtained by the cell culture and mouse assays were similar for 18 of 19 lots tested; one lot was moderately toxic by the cell culture assay only. A correlation was seen between the amount of FFA and the toxicity of AA. The cell culture assay provides a sensitive and reproducible assay to evaluate AA toxicity.We thank Dr. B. S. Berlin for his critical review of the manuscript, the Cell Biology Section (DBS) for providing the cells used in these studies, and acknowledge the excellent assistance of Mr. Donald Riggs, Mrs. Norma Duffin, Mrs. Marion Grabowski, Mr. Ethan Summers, and Mrs. Hazel Young.

Relationship of Hepatic Uptake of Free Fatty Acids to Plasma Concentration.

SummaryBehavior of liver to changes in portal concentration of FFA was studied. Rapid infusion of serum containing large amounts of FFA into portal veins of dogs caused increased hepatic uptakes of this metabolite. Uptake of FFA was a function of portal concentration. Liver cells behave in a passive manner to fluctuations in serum FFA concentration, and local hepatic mechanisms are responsible for changing degree of FFA uptake.