Carbon or charcoal can be made from biomass or cellulose-containing materials such as coconut shells or candlenut shells using a thermal process. One of the thermal process is pyrolysis, which in this process, the material is converted to carbon. The results of pyrolysis are in the form of three types of products namely solids (charcoal / carbon), gas (fuel gas) and liquid (bio-oil). Other products are gases such as carbon dioxide (CO2), methane (CH4) and some gases that have small contents. In general, the pyrolysis process takes place at temperatures above 300 ° C within 4-7 hours. Carbonized carbon or pyrolysis does not have a large adsorption capacity because the pore structure does not develop, so it is need activation process. One way to activate carbon is chemical activation. There is a need to know the best material for activating carbon through chemical process. This article aims to discuss the advantages and disadvantages of various types of chemical activation and to determine the promising chemical for activation. From various methods of chemical activation, the activator that promises to make activated carbon is Phosphoric Acid (H3PO4) because it can produce activated carbon which has a maximum micropore at operating conditions <450oC with a weight percent ratio between activator and sample around 29 - 52%.
Used cooking oil is widely considered waste because it can damage the environment and cause health problems. Meanwhile, used cooking oil can be used as a substitute raw material for Crude Palm Oil (CPO) in Indonesia's national biodiesel program.Indonesia has a remarkable ability to use used cooking oil as a raw material for making biodiesel. If the 1.2 million kiloliters of biodiesel made from CPO raw materials are exchanged with used cooking oil raw materials, it can save approximately Rp.4.2 trillion. There are various process technologies in making biodiesel, including microemulsion, pyrolysis, and transesterification. Transesterification is a process in which triglycerides and methanol are reacted to create biodiesel and glycerol as a by-product. Transesterification using a homogeneous catalyst has advantages such as lower cost, relatively short processing time, and higher yield of biodiesel products.Transesterification using a homogeneous catalyst has the disadvantage of a more complex separation. This literature study aims to explain the method for biodiesel production and becomes a reference in terms of process selection in biodiesel manufacturing plants, especially from used cooking oil as raw material.
The development of heterogeneous catalysts for biodiesel production became a hot topic among scientists because of its many advantages including easy separation and catalyst reusability. In this study, multi-walled carbon nanotubes supported zinc oxide (MWCNTsZ) as a solid acid catalyst had been successfully prepared via the stober-like process. There are several % loading of ZnO variations ranging from 10 – 35 % of catalyst weight. These catalysts were characterized by x-ray diffraction (XRD), BET surface area analysis, and scanning electron microscope with energy-dispersive x-ray spectroscopy (SEM-EDX) analysis. Transesterification of kesambi (Schleichera oleosa) oil also had been done to test the activity of the solid catalyst. The potential of this catalyst is shown from its large surface area with the maximum surface area until 409 m2/gram. However, the quantity of dispersed zinc oxide (ZnO) on multi-walled carbon nanotubes (MWCNTs) via that modified Stober preparation is quite small lower than 5% weight. This phenomenon is resulting in a low yield of biodiesel after 3 h of transesterification reaction. The highest yield of biodiesel is obtained with 20% weight of loading ZnO variable producing 13.82% yield of methyl ester.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.