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Cold Rolling Lubrication
Published in William L. Roberts, Cold Rolling of Steel, 2017
The peroxide content of oils is measured by the peroxide value or number which is the milliequivalents of constituents per kilogram of sample that will oxidize potassium iodide. This value is determined as follows.∿ The oil sample is dissolved in carbon tetrachloride and brought into contact with aqueous potassium iodide solution. The peroxides present are reduced by the potassium iodide and an equivalent amount of iodine is liberated, this being quantitatively determined by titration with sodium thiosulphate solution.
Biodiesel from First-Generation Feedstock
Published in Bhaskar Singh, Ramesh Oraon, Advanced Nanocatalysts for Biodiesel Production, 2023
Madhu Agarwal, Pushpendra Kushwaha, Karishma Maheshwari
The peroxide value is a measurement of the concentration of peroxide in biodiesel that can be used to track oxidation over time. Although PV is not included in the biodiesel fuel specification, it is worth exploring as it has an indirect effect on other qualities such as cetane number and so on (Kumar, 2017). The standard technique for determining peroxide values for traditional diesel fuel is ASTM D3703-13 (Syafiuddin et al., 2020).
Optimization of reaction variables of ultrasound-assisted transesterification of Abelmoscus esculentus seed oil into biodiesel
Published in Biofuels, 2021
Aminu Bayawa Muhammad, Lubabatu Mu’azu Jodi, Lawal Gusau Hassan, Lawal Abubakar, Abdullahi Muhammad Sokoto
The properties of the oil (Table 2) are comparable to AOCS standard values. The oil is quite dense (0.89 ± 0.07g/cm3) and viscous (48.04 ± 0.01 cSt). This makes it necessary to process it in order to reduce the viscosity, thereby improving fuel flow characteristics [35] for application in diesel engines. The free fatty acid content of the oil (4.96 ± 0.26 mg KOH/g) is high, and thus it is predisposed to soap formation during homogeneous base-catalyzed transesterification. Consequently, for the homogeneous base-catalyzed transesterification, the oil has to be esterified to reduce the free acid to the acceptable level of 1.0 mg KOH/g [40]. The saponification value (128.13 ± 0.04 mg KOH/g) of the oil is lower than that of most other vegetable oils [41]. The low peroxide value of the oil is an indication of its good oxidation stability [42]. The iodine value is moderate and similar to those of cottonseed oil and corn oil [41].
Effects of different drying methods on the extraction rate and qualities of oils from demucilaged flaxseed
Published in Drying Technology, 2018
Zhenshan Zhang, Yulan Liu, Liming Che
Peroxide value measures the content of primary oxidation products in oil. It is desirable to have a low peroxide value, because a lower peroxide value means that the oil is less oxidized. As shown in Fig. 5b, the oxidation degree of oil extracted from native flaxseed was low as the peroxide value was lower than the maximum limit (10 meq/kg oil) of peroxide value of edible oils.[30] A remarkable increase in peroxide value was found in the oils extracted from dried flaxseed. The oil from FDS had the highest peroxide value (21.63 meq/kg), followed by MDS (13.67 meq/kg) and ODS (9.18 meq/kg).
Large scale strategy for the extraction of oil from sesame seed: scalable approach
Published in Indian Chemical Engineer, 2023
Jayeshkumar S. Mevada, Yogeshsing N. Rajput, Shaziya Chowdhary, Shirley Kokane, Faith Dias, Ranjeet B. Doke, Ravindra D. Kulkarni, Amit P. Pratap, Aniruddha B. Pandit
Comparative analysis of all the physicochemical properties of commercial sesame seed oil with the oil extracted by Soxhlet, without pretreatment, pretreatment with ultrasound method is shown in Table 2. The Acid value (4.01 ± 0.2 mg KOH g−1) and peroxide value (40.5 ± 05 m Eq kg−1) of the oil extracted by using the conventional Soxhlet method was high as compared to the oil recovered by using ultrasound-assisted extraction with pretreatment (Acid value; 0.55 ± 0.02 mg KOH g−1) and peroxide value (0.4 ± 0.01 m Eq kg−1). This is because the prolonged heating time (6-8 h) and high temperature for the extraction used in the Soxhlet method are responsible for the higher acid and peroxide value, and it does not comply with the international standard for oils as the unsaturated fatty acids are present in the sesame seed oil, the chances of oxidation is high [45]. High peroxide values indicate that the oil has been damaged by free radicals, which will increase the formation of aldehydes and ketones that lead the oil to smell musty and rancid [46, 47]. As per international standards, the oil's Acid value (free fatty acids) is not recommended to be more than 0.6 mg KOH g−1 because of the health hazards, and it also increases the chances of rancidity of oil. The peroxide value for refined and virgin oil should be less than 15 mEq kg−1, as the international food standard agency recommends. The highest peroxide value also increases the chance of rancidity, which has a side effect on the human body. The iodine value indicates the unsaturation content of the oil, and according to the international standard, the Iodine value should be in the range of 104-120 mg I2 g−1. The iodine value of oil extracted by the Soxhlet method, ultrasound-assisted extraction, and combined ultrasound with pretreatment are 94.3 ± 0.4 mg I2 g−1, 102.5 ± 0.5 mg I2 g−1, and 104.8 ± 0.5 mg I2 g−1 respectively. The oil extracted by the Soxhlet method has a high acid value, peroxide value, and low amount of iodine value indicating the oil quality of the oil recovered by using the Soxhlet method is not meeting the specification, while the analysis of oil recovered by using ultrasound method is meeting specifications approved by CODEX IFS. The quality of the oil recovered by using the acoustic method with and without pretreatment meets all the international standards as compared to the quality of the oil recovered by using Soxhlet method based on analysis.