Significance of the structural properties of CaO catalyst in the production of biodiesel: An effect on the reduction of greenhouse gases emission

Abstract

The influence of the physicochemical properties of a series of CaO catalysts activated at different temperatures on the biodiesel production was investigated. These catalysts show dissimilar yields in the transesterification of triglycerides with methanol. We have found significant relationships between structural properties (the type of the pore system, the typical CaO crystal phase and the sizes of crystallites (up to 25 nm), the minimal weight percentage of CaO phase, the total surface basicity and potential existence of two types of basic active sites) of CaO prepared and activated by means of thermal treatment at highest temperature and catalytic efficiency. Benefits of this catalyst are short contact time, standard operating temperature and atmospheric conditions, relatively low molar ratios and small catalyst loading. These all together resulted in a very high biodiesel yield of high purity. The properties of different biodiesel (obtained with the use of the prepared CaO catalyst) blends with different diesel and biodiesel ratios indicate that the higher the fraction of biodiesel fuel the better the achieved fuel properties according to the EU standards. A significant reduction of CO 2 and CO emissions and only a negligible NO x increase occurred when blends with an increased biodiesel portion was used. The use of biodiesel derived blends, and the eventual complete replacement of fossil fuels with biodiesel as a renewable, alternative fuel for diesel engines, would greatly contribute to the reduction of greenhouse gas emissions.

Active Heterogeneous CaO Catalyst Synthesis fromAnadara granosa(Kerang) Seashells for Jatropha Biodiesel Production

“…It's evident that Ca-O group absorptions were strongly attributed over wavenumbers <600cm -1 , along with medium bands at 1427cm -1 and 876cm -1 , as well as weak bands at 3740cm -1 , 3850cm -1 and 978cm -1 A Sharp absorption peak at 1427 cm -1 corresponds a carbonyl group due to their asymmetrical stretching vibration [23]. The carbonyl and hydroxyl group traces were exist in the IR spectrograph due to absorption of carbon dioxide and moisture on to the calcined CaO samples from the atmosphere [10].…”

The effect of economic variables on a bio‐refinery for biodiesel production using calcium oxide catalyst

“…Lower emission of pollutants and GHGs is attributed to the existence of more free oxygen than is the case with conventional diesel. More free oxygen leads to complete combustion and reduced emissions . Moreover, biodiesel has better lubricity than fossil diesel.…”

“…Ljupkovic et al . investigated the significance of the structural properties of a CaO catalyst in the production of biodiesel and discovered that the catalyst has benefits such as short contact time (up to 2 h), standard operating temperature (64 °C) and atmospheric pressure, a relatively low molar ratio (6:1), and small catalyst loading (1 wt.%). This study revealed that all the above factors could result in attaining a very high biodiesel yield with a high level of purity (> 95%) .…”

“… investigated the significance of the structural properties of a CaO catalyst in the production of biodiesel and discovered that the catalyst has benefits such as short contact time (up to 2 h), standard operating temperature (64 °C) and atmospheric pressure, a relatively low molar ratio (6:1), and small catalyst loading (1 wt.%). This study revealed that all the above factors could result in attaining a very high biodiesel yield with a high level of purity (> 95%) . In another study, by Avhad et al ., it was reported that the optimum reaction conditions to obtain the maximum conversion within 2 h, for ethanolysis of avocado oil using glycerol enriched CaO catalyst, is 75 °C reaction temperature, 9:1 molar ratio of ethanol to oil, and 7% catalyst amount with respect to weight of the oil.…”

Production of Karanja Methyl Ester from Crude Karanja Oil Using Meretrix Lyrata Synthesised Active CaO Catalyst

“…There are several types of catalysts used for biodiesel production via transesterification reaction such as homogenous catalyst, heterogeneous catalyst and certain enzymes [11][12][13]. Usually KOH or NaOH are frequently being used as base homogenous catalyst, since the rate of reaction is relatively fast [14][15][16]. Unfortunately, the use of homogenous catalyst causes a high volume of wastewater discharged during the purification or washing process of biodiesel production in order to remove the residual catalyst present.…”