scholarly journals ASSESSMENT OF ANTIOXIDANT ACTION OF CURCUMIN DURING STORAGE OF COMMERCIAL BIODIESEL PRODUCED FROM SOYBEAN OIL AND BEEF TALLOW

2019 ◽  
Vol 16 (31) ◽  
pp. 491-502
Author(s):  
Mikaelly Nayara SANTOS ◽  
Eliane Ferreira DE SOUZA ◽  
Antonio Rogério FIORUCCI ◽  
Margarete Soares DA SILVA

Biodiesel has emerged as an alternative source to fossil fuels. In Brazil, to assign a good quality to biodiesel, regarding oxidation stability, it is necessary that the biodiesel shows a minimum of 8 h of induction period (IP), determined at a temperature of 110 ºC by the Rancimat method, in accordance with Resolution No. 45/2014 of ANP. As, in most cases, the biodiesel produced does not meet the established standards of oxidation stability, it is necessary to add antioxidants, which slow down the oxidative process. Thus, this paper proposes a study on the action of curcumin, a natural antioxidant, on commercial biodiesel produced from blending 80% soybean oil and 20% beef tallow. In this study, samples were stored for 180 days at 43 ºC, according to ASTM D4625 recommendations. It was possible to observe that curcumin ensured greater oxidation stability to biodiesel and lower acid number values during the period of storage. Kinetic studies showed that samples with the addition of curcumin showed the highest value of activation energy for the oxidative degradation process, demonstrating that adding this natural antioxidant makes biodiesel more resistant to oxidation.

2018 ◽  
Vol 40 ◽  
pp. 61
Author(s):  
Eliane Ferreira de Souza ◽  
Talita Cuenca Pina Moreira Ramos ◽  
Mikaelly Nayara Santos ◽  
Juliana Rodrigues Ferraz ◽  
Margarete Soares da Silva ◽  
...  

The objetive of this study was to evaluate the eugenol antioxidant efficiency on the oxidation stability of commercial biodiesel synthesized from soybean oil (SB) and wast fring oil (ORB) by determining induction period (IP) and acid number (AN) during storage at 10 °C or in accelerated oxidation test at 85 °C. For the oxidation stability evaluation, the Rancimat method (EN 14112) and AN (ASTM D664) analyses were used. The initial studies showed that the antioxidants eugenol and TBHQ when added separately increased IP values for the two types of biodiesel analyzed. During the storage at 10 °C, the IP was reduced for all samples. However, the lowest reduction percentages were for samples containing eugenol (-2.07 and -11.30% for SB and ORB, respectively). In relation to AN, the samples with the antioxidant eugenol led a greater decrease of this index, with the 10000 mg kg-1 concentration being the most efficient in the conservation of biodiesel. In the accelerated oxidation test in oven at 85 °C, pure BS presented higher susceptibility to degradation than the sample containing 10000 mg kg-1 of eugenol. In both storage studies, the eugenol natural antioxidant efficiency in the control of oxidative degradation of biodiesel becomes evident. 


2018 ◽  
Vol 68 (12) ◽  
pp. 2771-2775
Author(s):  
Mihaela Gabriela Dumitru ◽  
Delia Nica Badea ◽  
Dragos Tutunea

Across the world the fossil fuels are depleting and countries are forced to find an alternative source to reduce green house gases and replace petroleum fuels. Depending of the raw material sources, vegetable oils, animal fats or algae, biodiesel offers a solution for a clean-burning diesel fuel. Watermelon (Citrullus lanatus L.) seed were collected and the oil was extracted. The oil was transformed into fatty acid methyl esters through a transesterification process and blended in various proportions with diesel fuel. The physico-chemical properties of fuels were determined. Results obtained showed that the biodiesel has a density (0.870 g/cm3), kinematic viscosity 40�C (3.1 mm2/s), flash point (128�C), saponification index (150 mgKOH/g), iodine index (108 mgI2/100g), peroxide index (3.7 mEqO2/Kg) and oxidation stability (6 hours) in the range of UE specifications. The engine tests were conducted on a Deutz F4L912 diesel engine, 51 kW, 4-stroke, air cooled, direct injection diesel engine. From the test performed was observed that the CO and HC emissions were reduced due to high content of oxygen in biodiesel blends.


2018 ◽  
Vol 69 (6) ◽  
pp. 1378-1385
Author(s):  
Mihaela Gabriela Dumitru

The increase of energy demand associated with stringent worldwide emission legislation and the depletion of fossil resources has led to the use of biodiesel and biodiesel blends from various feedstocks. One of the main problems with biodiesel is the susceptibility to oxidation and degradability due to the environmental factors. The oxidation process is complex affecting the fuel quality resulting in choking of injector and formation of deposits in fuel system. Antioxidants are used to limit the oxidative degradation. The present paper review some attempts to use natural and synthetic antioxidants form different papers available in the public domain. Two types of biodiesel from oils of Citrullus lanatus and Vitis vinifera were obtained by base catalyzed transesterification. Peroxide value, iodine value, acid value and induction period were determined monthly to observe the degradation process for biodiesel samples. The biodiesel from Citrullus lanatus 90% and oil of Vitis vinifera 10% exhibits presented the best oxidation stability over a period of 12 months. A single cylinder diesel engine setup was used to determine the performance and gas emissions for biodiesel samples. The results show that biodiesel can be used without engine modification with results comparable with diesel fuel.


Paliva ◽  
2020 ◽  
pp. 93-97
Author(s):  
Karolína Jaklová ◽  
Aleš Vráblík

The current trend of reducing greenhouse gas emissions and carbon footprint as well as legislation requirements means an increase in the effort to replace fossil fuels by using renewable sources. One of the possibilities is usage of methyl esters (FAME or UCOME) as a bio-component in diesel fuel. Now the maximum FAME content in diesel is 7 vol% (according to the standard EN590 – B7). Increasing the proportion of FAME means a deterioration in oxidation stability. FAME is produced by the transesterification of the triglycerides present in vegetable oils. A major disadvantage of biodiesel (FAME) is ability to be slowly oxidised by air oxygen. Oxidation products may impair fuel properties, quality and engine performance. This is the reason why the oxidation stability of diesel and biodiesel is an important quality parameter. It could be detected using several methods, for example: Rancimat, PetroOxy or thermal techniques. The Rancimat method is intended for biodiesel and for diesel with a minimum 2 vol% content of FAME as mentioned in the standards EN 590 and EN 14214. The disadvantage is the time required for this method (more than 8 h for biodiesel and 20 h for diesel). The PetroOxy is shorter and its results can be converted to Rancimat stability. The set of 75 samples (40 samples of B7 and 35 samples of FAME) was measured using both mentioned methods. Three values of oxidation stability were determined for all of the analysed samples. In the first laboratory, oxidation stability of the samples was measured using both methods. In the second laboratory, oxidation stability was measured using only the PetroOxy. The PetroOxy results from both laboratories were compared with a high correlation value (R2 = 0,954). In the next step, outliers were removed from dataset. Experimental results of the Rancimat method were correlated with recalculated values of PetroOxy method from both laboratories. Correlation equation provided by the manufacturer of PetroOxy was used for recalculation of PetroOxy results to Rancimat results at first. Measured results were then compared with recalculated results. The largest difference in results was found in the B7 samples. Because of these differences the correlation equation between PetroOxy and Rancimat was optimized. Two different equation were made (for each laboratory). The recalculated oxidation stability results were compared with the primary results from Rancimat. The newly correlated values showed a higher degree of agreement with the experimental data than when the results were recalculated using the correlation equation provided by manufacturer. These optimized correlation equation have proven to be more suitable for industrial laboratories.


2015 ◽  
Vol 44 (5) ◽  
pp. 36-40
Author(s):  
KE Van der Walt ◽  
OB Einkamerer ◽  
HJ Van der Merwe ◽  
A Hugo ◽  
SC Slippers ◽  
...  

The effect on production performance of a synthetic or natural antioxidant and lipid saturation in the finishing diets of lambs was investigated. The four dietary treatments consisted of the same basal diet (187 g CP, 355 g NDF, and 71 g EE per kg DM), differing only in regard to the supplemental lipid source (30 g/kg of either saturated beef tallow or unsaturated soybean oil) and type of antioxidant (125 g/ton of either a synthetic or natural antioxidant) included, in a 2 x 2 factorial design experiment. Eighty-four S.A. Mutton Merino lambs (27.64 ± 1.72 kg) were randomly allocated to the four dietary treatments (n = 21 lambs per treatment) and subdivided into 7 replicates per treatment (n = 3 lambs per replicate). After a dietary adaptation period of 8 days, all lambs received the respective experimental diets for the remaining period (41 days). The average daily DM feed intake, weight gain and feed efficiency was calculated accordingly. No significant differences in DMI, ADG and the efficiency with which ingested feed were utilized (FCR), were recorded for the treatments. However, the addition of unsaturated soybean oil to the diet significantly increased the efficiency with which the ME of the diet was utilized. In contrast with the natural antioxidant, the inclusion of unsaturated soybean oil in the diet containing a synthetic antioxidant, resulted in a significant lower MEI by the lambs – indicating that a lipid x antioxidant interaction occurred. Results of the present study seem to indicate that dietary lipid saturation in the finishing diets of lambs had no influence on their growth performance. However, a more efficient utilisation of ME in the finishing diet containing unsaturated soybean oil, compared to the saturated beef tallow, did occur.Keywords: Fatty acid, flavonoid, metabolizable energy, oil, production, sheep, soybean, tallow


2019 ◽  
Vol 9 (3) ◽  
pp. 3963-3968

Given the importance and role of edible fats in human health and their sensitivity against oxidative degradation the one hand, and the adverse effect of synthetic antioxidants on consumers health while increasing their awareness on the other hand, this study aimed to improve the effectiveness of the natural antioxidant ascorbyl palmitate, its stability and control release by nanoencapsulation of ascorbyl palmitate using \nanolipososmes, and further its comparison with tert-butylhydroquinone and butylated hydroxy toluene as synthetic antioxidants in soybean oil. Results of this study showed that utilization of 200 ppm tert-butylhydroquinone, 600 ppm ascorbyl palmitate and 250 ppm butylated hydroxy toluene in nanoliposome form had the greatest oxidative stability in soybean oil respectively. These results indicated that the use of nanoliposomes encapsulated antioxidants improve the antioxidant efficacy and that ascorbyl palmitate perform as efficiently as butylated hydroxy toluene, making it suitable to be used as a natural antioxidant. The antioxidant encapsulation in nanoliposomes is a practical approach for expedient protection of these compounds in food systems, while at the same time increasing their performance and stability in food applications.


2021 ◽  
Vol 50 (4-5) ◽  
pp. 433-444
Author(s):  
Olusola Joshua Olujobi ◽  
Temilola Olusola-Olujobi

Fossil fuels have been the mainstream of energy supply and a major source of foreign exchange earnings for the Federal Government of Nigeria, in spite of being an unrenewable and unsustainable source of energy. Nigeria is yet to tap into the full benefits after privatising its power sector, including the new global evolution in the energy sector and the resulting increasing demand for renewable energy sources, which some consider to be cheaper and more environmentally friendly than fossil fuels and their allied products. Energy security is a challenge to socio-economic development in Nigeria, due to the country’s over-dependency on fossil fuels. In terms of their impact and the potentials to preserve energy sources for longevity and sustainability, however, fossil fuels will come to be seen as an out-dated alternative in the power sector as the energy industry evolves. The implications for Nigeria’s oil sector will not be limited to dwindling crude oil prices. The concerns include poor energy utilisation in Nigeria and the need to promote energy efficiency and sustainability. They have led to the formulation of new energy policies around the world to serve as a vehicle for translating solutions into reality. This study has adopted a library-based legal research method with a comparative approach. The study reveals that it is the lack of a coherent legal framework with incentives for using renewable energy that is largely seen as the key issue causing slow uptake of renewable energy as an alternative source of energy in Nigeria. As well as the need for a coherent legal framework on energy and incentives for using renewable energy sources, the study advocates stringent enforcement of existing energy regulatory policies.


2008 ◽  
Vol 3 (4) ◽  
pp. 155892500800300 ◽  
Author(s):  
Walter R. Hall ◽  
Warren F. Knoff

The strength retention after exposure to elevated temperature in air of continuous filament and staple spun PPTA sewing thread and the precursor yarns was determined. For both types, the process of converting the greige yarn to thread reduced the amount of strength retained after thermal exposure. The continuous filament products retained more strength than the staple products. The data was fitted to a kinetic rate model in which two strength loss processes occurred. The first process occurred within about the first 5 minutes of thermal exposure and is hypothesized to be hydrolytic degradation. The estimated secondary degradation process activation energy suggests this to be thermo-oxidative degradation. Optical microscopy of filaments indicates a higher level of kink banding and other damage in continuous filament versus staple products and in finished thread versus the precursor yarns. The kink bands and damage are believed to be caused by the staple manufacturing process and the downstream processing of precursor yarn to finished sewing thread. The kink bands and damage are hypothesized to be responsible for the differences in strength retention.


2012 ◽  
pp. 33-51
Author(s):  
AKM Iftekharul Islam

A significant geopolitical consequence of the demise of the Soviet Union1 in the international arena is the rise of intense political and commercial competition for control of the vast energy resources of the newly independent and vulnerable states of the Caucasus and Central Asia. These energy resources and, in particular, the oil and natural gas deposits have now become the apple of discord in Central Asia introducing a new chapter in the Great Game of control over Eurasia (Hill 1997: 200). The region has great energy potential and is strategically important. The United States has varied and at times competing interests in Central Asia. In the past few years, real and present dangers to the U.S. national security especially Islamist terrorism and threats to the energy supply, have affected the U.S. policy in Central Asia. The region, which includes the five post-Soviet states of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan, as well as Afghanistan and the Caspian basin, plays an important part in the U.S. global strategy in view of its proximity to Russia, China, India, Pakistan, Iran, and other key regional actors. No less important are its ethno-religious composition and vast deposits of oil, gas, coal, and uranium. Literally, the U.S. interests in Central Asia can be summarized in three simple words: security, energy, and democracy. Moreover, a key U.S. national security concern is the diversification of energy sources and the Caspian region is a significant alternative source of fossil fuels. In this article a critical analysis will be attempted on the U.S. policy and role in central Asia. DOI: http://dx.doi.org/10.3329/afj.v4i0.12931 The Arts Faculty Journal Vol.4 July 2010-June 2011 pp.33-51


Author(s):  
Ghazanfar Abbas ◽  
Rizwan Raza ◽  
Muhammad Ashraf Chaudhry ◽  
Bin Zhu

The entire world’s challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid Oxide Fuel Cells (SOFCs) are believed to be the best alternative source which converts chemical energy into electricity without combustion. Nanostructured study is required to develop highly ionic conductive electrolyte for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M = Na and K) electrolyte was prepared by co-precipitation method in this study. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology was characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). The particle size was calculated in the range of 10–20nm by Scherrer’s formula and compared with SEM and TEM results. The ionic conductivity was measured by using AC Electrochemical Impedance Spectroscopy (EIS) method. The activation energy was also evaluated. The performance of the cell was measured 0.567W/cm2 at temperature 550°C with hydrogen as a fuel.


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