Comparison of the performance of different homogeneous alkali catalysts during transesterification of waste and virgin oils and evaluation of biodiesel quality
TL;DR: In this paper, the authors evaluated the performance of the catalysts for different raw materials and the final product quality according to European biodiesel standard EN 14214 and found that the use of virgin oils resulted in higher yields as compared to waste frying oils.
About: This article is published in Fuel.The article was published on 2008-12-01. It has received 299 citations till now. The article focuses on the topics: Biodiesel production & EN 14214.
Citations
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TL;DR: In this article, the main factors affecting the yield of biodiesel, i.e. alcohol quantity, reaction time, reaction temperature and catalyst concentration, are discussed, as well as new new processes for biodiesel production.
2,207 citations
TL;DR: In this paper, the authors reviewed the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
Abstract: The world is confronted with the twin crises of fossil fuel depletion and environmental degradation. The indiscriminate extraction and consumption of fossil fuels have led to a reduction in petroleum reserves. Petroleum based fuels are obtained from limited reserves. These finite reserves are highly concentrated in certain region of the world. Therefore, those countries not having these resources are facing a foreign exchange crisis, mainly due to the import of crude petroleum oil. Hence it is necessary to look for alternative fuels, which can be produced from materials available within the country. Although vegetative oils can be fuel for diesel engines, but their high viscosities, low volatilities and poor cold flow properties have led to the investigation of its various derivatives. Among the different possible sources, fatty acid methyl esters, known as Biodiesel fuel derived from triglycerides (vegetable oil and animal fates) by transesterification with methanol, present the promising alternative substitute to diesel fuels and have received the most attention now a day. The main advantages of using Biodiesel are its renewability, better quality exhaust gas emission, its biodegradability and the organic carbon present in it is photosynthetic in origin. It does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the green house effect. This paper reviews the source of production and characterization of vegetable oils and their methyl ester as the substitute of the petroleum fuel and future possibilities of Biodiesel production.
1,250 citations
TL;DR: The conversion of vegetable oils into biodiesel is an effective way to overcome all the problems associated with the vegetable oils, such as high fuel viscosity, high ignition delay and longer combustion duration and hence low particulate emissions as discussed by the authors.
782 citations
TL;DR: This review covers the process by which biodiesel is prepared, the types of catalysts that may be used for the production of biodiesel, the influence of free fatty acids on biodiesel production, the use of different monohydric alcohols in the preparation of biod diesel, the effects of blending biodiesel with other fuels on fuel properties, alternative uses for biod Diesel, and value-added uses of glycerol.
Abstract: Biodiesel, defined as the mono-alkyl esters of vegetable oils or animal fats, is an environmentally attractive alternative to conventional petroleum diesel fuel (petrodiesel). Produced by transesterification with a monohydric alcohol, usually methanol, biodiesel has many important technical advantages over petrodiesel, such as inherent lubricity, low toxicity, derivation from a renewable and domestic feedstock, superior flash point and biodegradability, negligible sulfur content, and lower exhaust emissions. Important disadvantages of biodiesel include high feedstock cost, inferior storage and oxidative stability, lower volumetric energy content, inferior low-temperature operability, and in some cases, higher NO
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exhaust emissions. This review covers the process by which biodiesel is prepared, the types of catalysts that may be used for the production of biodiesel, the influence of free fatty acids on biodiesel production, the use of different monohydric alcohols in the preparation of biodiesel, the influence of biodiesel composition on fuel properties, the influence of blending biodiesel with other fuels on fuel properties, alternative uses for biodiesel, and value-added uses of glycerol, a co-product of biodiesel production. A particular emphasis is placed on alternative feedstocks for biodiesel production. Lastly, future challenges and outlook for biodiesel are discussed.
766 citations
TL;DR: In this paper, the effect of novel processes such as membrane reactor, reactive distillation column, reactive absorption, ultrasonic and microwave irradiation significantly influenced the final conversion, yield and in particular, the quality of product.
630 citations
References
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TL;DR: In this article, the transesterification reaction is aected by molar ratio of glycerides to alcohol, catalysts, reaction temperature, reaction time and free fatty acids and water content of oils or fats.
4,902 citations
"Comparison of the performance of di..." refers background in this paper
...The ones known to greatly influence the reaction are: temperature, methanol/oil molar ratio, mixing rate, catalyst type and amount of catalyst [9,10]....
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TL;DR: In this paper, various methods of preparation of biodiesel with different combination of oil and catalysts have been described and technical tools and processes for monitoring the transesterification reactions like TLC, GC, HPLC, GPC, 1H NMR and NIR have also been summarized.
Abstract: Biodiesel is gaining more and more importance as an attractive fuel due to the depleting fossil fuel resources. Chemically biodiesel is monoalkyl esters of long chain fatty acids derived from renewable feed stock like vegetable oils and animal fats. It is produced by transesterification in which, oil or fat is reacted with a monohydric alcohol in presence of a catalyst. The process of transesterification is affected by the mode of reaction condition, molar ratio of alcohol to oil, type of alcohol, type and amount of catalysts, reaction time and temperature and purity of reactants. In the present paper various methods of preparation of biodiesel with different combination of oil and catalysts have been described. The technical tools and processes for monitoring the transesterification reactions like TLC, GC, HPLC, GPC, 1H NMR and NIR have also been summarized. In addition, fuel properties and specifications provided by different countries are discussed.
3,232 citations
"Comparison of the performance of di..." refers background in this paper
...The ones known to greatly influence the reaction are: temperature, methanol/oil molar ratio, mixing rate, catalyst type and amount of catalyst [9,10]....
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...High viscosities lead to negative impacts on fuel injector performance [9] leading to carbon deposition on the injectors [18]....
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...The flash point of biodiesel is higher than the conventional fuel which makes it safer [9]....
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TL;DR: Biodiesel is an alternative diesel fuel that is produced from vegetable oils and animal fats, which consists of the monoalkyl esters formed by a catalyzed reaction of the triglycerides in the oil or fat with a simple monohydric alcohol.
2,164 citations
"Comparison of the performance of di..." refers background in this paper
...Its production from renewable resources, such as vegetable oils and animal fats, makes it biodegradable and non-toxic; also, it contributes to the reduction of CO2 emissions, because it comprises a closed carbon cycle [1,2]....
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TL;DR: In this paper, the authors showed that the conversion to methyl, ethyl and butyl esters from cottonseed, peanut, soybean and sunflower oils can be done in 1 hr with an alkaline catalyst.
Abstract: Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of 60 C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters was essentially complete in 1 hr. At moderate temperatures (32 C), vegetable oils were 99% transesterified in ca. 4 hr with an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils.
1,990 citations
"Comparison of the performance of di..." refers background in this paper
...It is necessary to also consider that even when using the same vegetable oil, different behaviour might be found regarding production processes due to different refinement processes adopted [11], reason why it is essential to know and understand feedstock composition....
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TL;DR: The main advantages of using biodiesel are its renewability, better-quality exhaust gas emissions, its biodegradability and given that all the organic carbon present is photosynthetic in origin, it does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the greenhouse effect as mentioned in this paper.
Abstract: Efforts are under way in many countries, including India, to search for suitable alternative diesel fuels that are environment friendly. The need to search for these fuels arises mainly from the standpoint of preserving the global environment and the concern about long-term supplies of conventional hydrocarbon-based diesel fuels. Among the different possible sources, diesel fuels derived from triglycerides (vegetable oils/animal fats) present a promising alternative to substitute diesel fuels. Although triglycerides can fuel diesel engines, their high viscosities, low volatilities and poor cold flow properties have led to the investigation of various derivatives. Fatty acid methyl esters, known as biodiesel, derived from triglycerides by transesterification with methanol have received the most attention. The main advantages of using biodiesel are its renewability, better-quality exhaust gas emissions, its biodegradability and given that all the organic carbon present is photosynthetic in origin, it does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the greenhouse effect.
1,733 citations
"Comparison of the performance of di..." refers background in this paper
...It is a measure to assess corrosivity, generally indicating the presence of sulphur compounds in the fuel [32]....
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...Low flash points will also indicate the presence of methanol and therefore it is a very important parameter to be determined considering handling, storage and safety of the fuel [18,32]....
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...Viscosity is important for transport purposes, namely to guarantee good conditions for oil flow into pipelines [32], as well as to predict cold weather behaviour [1]....
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