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Ibrahim Ahmad Ibadurrohman

Bio: Ibrahim Ahmad Ibadurrohman is an academic researcher from University of Brawijaya. The author has contributed to research in topics: Combustion & Chemistry. The author has an hindex of 1, co-authored 3 publications receiving 1 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the role of unsaturation degree in single-molecule droplet combustion from three fatty acid methyl ester compounds was observed under normal gravity at ambient temperature and atmospheric pressure.
Abstract: Biodiesel is composed of various types of methyl ester compounds with different concentrations. The role of unsaturation degree was observed through single-molecule droplet combustion from three fatty acid methyl ester compounds. This research was conducted under normal gravity at ambient temperature and atmospheric pressure. Analysis of droplet combustion characteristics was observed along the heating, evaporation, ignition, and combustion stages. The cis configuration and allyl groups in unsaturated molecules related to different unsaturation degrees affect the droplet combustion process. Allyl and bis-allyl groups play an important role in accelerating hydrogen atom abstraction due to the weaker bond dissociation energy of the C H bond adjacent to the carbon double bond. The lower energy gap in unsaturated molecules is prone to electron excitation. Increasing the unsaturation degree resulted in shorter ignition delay and burning duration but higher droplet temperature, burning rate constant, specific power output, and flame dimensions. Soot particles formed above the flame tip on the unsaturated molecules gave a higher flame dimension. A high concentration of linoleic methyl ester in biodiesel fuel is recommended due to of high power output. However, the soot formation at a higher level of unsaturation degree should be considered.

6 citations

Journal ArticleDOI
01 Feb 2021
TL;DR: In this article, a single fatty acid methyl ester from various saturated fatty acids was analyzed to analyze the effects of carbon chain length on the droplet combustion during evaporation and combustion stages in ambient temperature and atmospheric pressure.
Abstract: Biodiesel which produces from vegetable oil consists of various fatty acids as fatty acid methyl ester constituent. Each fatty acid has a specific combustion characteristic due to the difference in physicochemical characteristics. This study was done with a single fatty acid methyl ester from various saturated fatty acids to analyze the effects of carbon chain length on the droplet combustion during the evaporation and combustion stages in ambient temperature and atmospheric pressure. Results show that the ignition delay time increase with the longer carbon chain due to the higher viscosity and boiling point. The higher oxygen content in the fatty acid methyl ester molecule promotes the faster combustion, gives a higher burning rate, and cause the flame dimension shorter. Furthermore, oxygen content results in higher radiation caused a brighter flame. The high droplet temperature occurs in the long carbon chain due to the higher of combustible matter gives an increase to the heating value. Low radiation heat loss in a long carbon chain which indicates by the flameless bright also causes the droplet temperature higher. The higher droplet temperature gives the lower gas density which causes the flame dimension higher due to the natural convection.

1 citations

Journal ArticleDOI
15 Dec 2019
TL;DR: In this article, the effect of the geometry and blockage ratio of the flame connector on the combustion characteristics of wood pellets on a wood pellet stove was investigated, which included flame visualization, flame temperature, specific fuel consumption, and corrected-specific fuel consumption.
Abstract: This research was intended to investigate the effect of the geometry and blockage ratio of the flame connector on the combustion characteristics of wood pellets on a wood pellet stove. Combustion characteristics observed in this research included flame visualization, flame temperature, specific fuel consumption, and corrected-specific fuel consumption. Two types of geometry were used as a flame connector, i.e. disk and cone; for each geometry, the blockage ratio was varied at 0,6, 0,7, and 0,8. The blockage ratio was varied by change the number of the circular hole on the flame connector. Combustion in wood pellet stove without flame connector was then used as a comparison. The flame visualization test was applied to find out the color and dimensions of the flame, which was then used to determine the temperature on this flame. The water boiling test method version 4.2.3 was used to determine specific fuel consumption and corrected specific fuel consumption. The combustion chamber of the wood pellet stove has a dimension of 15 cm diameter and 20 cm height. Wood pellet supply used intermittent - continuous feeding system with a mass flow rate of 16 gram/minute. Flame visualization shows that stove with cone flame connector has a larger flame dimension and flame dimension decreases with the increasing of blockage ratio. The highest flame temperature occurred near the outlet of the combustion chamber, the same conditions were observed in all variations experiment. The application of flame connector involves greater specific fuel consumption due to longer boiling time. However, a correction factor by considering the amount of evaporated water results from corrected specific fuel consumption of wood pellet stove with cone flame connector which is smaller compared to the other type of wood pellet stove.
Journal ArticleDOI
01 Feb 2023-Fuel
TL;DR: In this article , different combustion mechanisms and their interactions with ethanol between laurate and oleate as the base fuel were investigated under normal gravity at room temperature and atmospheric pressure.

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TL;DR: In this article, a novel potassium tin oxide (KSO) catalyst was synthesized via polymer precursor auto combustion method, which showed the best physicochemical properties when it was calcined at 800°C.

9 citations

Journal ArticleDOI
TL;DR: A calcium-loaded activated carbon catalyst was prepared through pyrolysis of peach shell followed by chemical activation with KOH and then calcium loading through the wet impregnation method as mentioned in this paper .
Abstract: In recent years, the scope for replacing fossil fuels has been appealing to the world, owing to limited conventional fuels, crude oil price volatility, and greenhouse gas emission concerns. In this regard, this article demonstrates the preparation of a novel solid base catalyst for the transesterification of waste cooking oil. A calcium-loaded activated carbon catalyst was prepared through pyrolysis of peach shell followed by chemical activation with KOH and then calcium loading through the wet impregnation method. The prepared catalyst showed the best performance with 20% calcium loading and 650 °C of calcination temperature. The catalyst’s physicochemical, structural, and textural properties were examined using XRD, FTIR, SEM, EDX, and BET analysis. The catalyst showed a maximum yield of 96% at optimized conditions, i.e., 65 °C temperature, oil to methanol ratio 1:8, 5 wt% catalyst concentration, and a 160 min reaction time. Additionally, it illustrated high recyclability up to 10 cycles with negligible leaching of Ca+2 ions. The high activity of the catalyst was due to the presence of calcium ions on the activated carbon support. Physio–chemical properties and GC-MS analysis of prepared biodiesel determined that all attributes were within the biodiesel standard tolerances set by ASTM D6751 and EN 14214. Therefore, all the innovations mentioned above concluded that catalyst generated from peach shell biochar is a promising candidate for biodiesel production, ultimately resulting in solid and liquid waste management.

6 citations

Journal ArticleDOI
TL;DR: In this article , a review of the latest scientific progress and the accomplishments of interesterification technology as an alternative to conventional transesterification reaction is presented, where the merits and limitations of various types of catalytic techniques as well as non-catalytic supercritical supercritical glycerol-free processes have been elucidated with a comprehensive comparison.
Abstract: This review appraises the latest scientific progress and the accomplishments of interesterification technology as an alternative to conventional transesterification reaction. The merits and limitations of various types of catalytic techniques as well as non-catalytic supercritical glycerol-free processes have been elucidated with a comprehensive comparison. Contrary to the cheap price of glycerol, the higher-revenue by-products, triacetin and glycerol carbonate, will boost the gross profit margin of biodiesel production. The influences of reaction parameters such as reactant ratio, catalyst loading, reaction time, temperature, and co-solvent addition are also addressed. According to the latest research, the alkali-catalyzed and non-catalytic supercritical interesterifications are preferable due to higher yield. Methyl acetate, ethyl acetate and dimethyl carbonate do not inhibit lipase activity, unlike typical alcohols. Acidic catalysis may be the way forward to resolve the extreme operating conditions of non-catalytic supercritical interesterification, high cost of enzymes and manage waste feedstocks with high free fatty acid and water contents under moderate conditions. Currently, the majority of interesterification reactions were undertaken on laboratory size, whereas just a handful was evaluated on a pilot scale. A continuous research in interesterification technology is necessary by conducting a thorough investigation of the feasibility of state-of-the-art technology to engage a wide array of feedstocks. Future study should also concentrate on microbes and agricultural waste as a sustainable route for energy recovery from renewable feedstocks.