Pyrolysis using microwave absorbents as reaction bed: An improved approach to transform used frying oil into biofuel product with desirable properties

Abstract

cracking capacity to pyrolyze the used oil, thus showing favorable features that could lead to 34 short process time and less energy usage. This resulted in a production of a high yield of a 35 biofuel product (up to 73 wt%) in a process taking less than 35 min. The biofuel showed a 36 composition dominated by light C 5-C 20 aliphatic hydrocarbons with low amounts of oxygenated 37 compounds (≤ 11%). In particular, the oil product obtained from activated carbon bed showed a 38 low nitrogen content and was free of carboxylic acid and sulphur. The absence of carboxylic 39 acids with low amounts of oxygenated compounds could reduce the formation of oxygenated by-40 2 products that could generate undesirable acidic tar or potentially hazardous sludge in the biofuel 41 during storage. Combined with the detection of a high calorific value (46 MJ/kg) nearly 42 comparable to diesel fuel, the biofuel shows great promise to be upgraded for use as a 'cleaner' 43 fuel source with potentially reduced oxygenated by-products plus low or zero emissions of NO x 44 and SO x during the use of the fuel in combustion process. This study also revealed that the use of 45 activated carbon bed results in the highest energy recovery (88-90%) from the used frying oil. 46 Our results demonstrated that the use of a microwave-heated reaction bed of activated carbon 47 shows great potential as an improved and sustainable pyrolysis approach that is energy-efficient 48 and timesaving for the recycling of used frying oil into a biofuel product with desirable 49 properties. This pyrolysis approach provides an alternative to transesterification that avoids the 50 use of solvents and catalysts, and thus could be developed further as a promising route to recycle 51 various types of waste and biomass materials.

Self‐purging microwave pyrolysis: an innovative approach to convert oil palm shell into carbon‐rich biochar for methylene blue adsorption

“…Figure shows the temperature profiles recorded during microwave pyrolysis of the OPS over a range of feedstock amounts loaded at a constant microwave power of 900 W. The use of a microwave absorber as reaction bed to achieve the desired pyrolysis temperature has been well reported in the literature. Interestingly, this research achieved pyrolysis temperatures up to 760 °C when higher amounts of OPS (both 300 and 400 g) were loaded without the use of microwave absorber as reaction bed.…”

“…Hence, a porcelain reactor was tested in this study in order to investigate its suitability for use as a pyrolysis reactor. Figure 2 shows the temperature profiles recorded during microwave pyrolysis of the OPS over a range of feedstock amounts loaded at a constant microwave power of 900 W. The use of a microwave absorber as reaction bed to achieve the desired pyrolysis temperature 45,46 has been well reported in the literature. loaded.…”

Microwave-assisted pyrolysis with chemical activation, an innovative method to convert orange peel into activated carbon with improved properties as dye adsorbent

“…This could generate micro-plasma spots throughout the material being heated (Menéndez et al, 2007) and promote certain chemical reactions in a way that is not possible in conventional processing by selectively heating the reactants and initiating extensive pyrolysis cracking at a significantly lower process temperature (Lam et al, 2015). Other advantages shown by microwave-assisted pyrolysis compared with conventional electricheated pyrolysis techniques include better process control in terms of quick start-up and shutdown, a more uniform heat distribution, increased production speeds and decreased production costs (Kundu et al, 2015a;Lam et al, 2017;Menéndez et al, 2004). It is thus thought that the application of microwave-assisted pyrolysis in the production of AC could show favorable features that could lead to an energy-efficient heating process, savings in process time, and improved yield of desirable products.…”

A Non-Probabilistic Solution for Uncertainty and Sensitivity Analysis on Techno-Economic Assessments of Biodiesel Production with Interval Uncertainties

“…Being a valuable renewable energy resource, biodiesel is friendly to the natural environment and human health, compared to the traditional fossil fuels [10][11][12][13][14][15]. Various feedstocks-derived biodiesel production have been reported, for example, palm oil [16], waste cooking oil [17][18][19], vegetable oils [20,21], soybean oil [22][23][24][25], Jatropha curcas L. [26], algae [27,28], microalgae [28][29][30], Oleaginous yeast [31,32], lignocellulosic biomass [33], used frying oil [34], waste cottonseed oil with heterogeneous catalyst [35,36], Annona squamosa L. seed oil with heterogeneous catalyst [36,37], Butanol and pentanol [38], etc., and recent advances in biofeedstocks and biofuels have also been reviewed in [39].…”