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This study aimed to assess the economic and engineering feasibility of a large-scale biodiesel manufacturing operation from edible oil waste. The edible oil model used for economic analysis in this study is palm oil waste. Several economic parameters (i.e., gross profit margin (GPM), payback period (PBP), break-even point (BEP), cumulative net present value (CNPV), profitability index (PI)), and internal rate return (IRR) were examined to inform the potential production of biodiesel from edible oil waste in ideal condition. To confirm the feasibility of a manufacturing project, the project is estimated from ideal to worst-case conditions in production activities such as analysis of changing raw material, labor, tax, utility, and selling price costs. Based on an engineering perspective, the result indicated that biodiesel production from edible and non-edible oil is feasible. From an economic perspective, economic analysis shows that biodiesel production from edible oil waste is promising because the economic parameters as analyzed show positive results. Our findings are expected to provide an industrial-scale picture of economic evaluation and layout, particularly in the production of biodiesel, which is commonly used as a renewable energy source for fuel in trucks, trains, ships, and barges.

In the sustainability paradigm, the concept of converting waste into valuable products is one of the problem solvers. The goal of this study was to investigate the adsorption mechanism of carbon-based adsorbent particles from papaya seed waste with various sizes (i.e. 500, 1000, and 2000 microns) that can be used as alternative adsorbents in pollutant removal in aqueous solution. In the experiment, papaya seeds were carbonized at 400°C for 4 hours and ground to produce carbon-based particles, which were then used as adsorbent. The adsorption characteristics of curcumin (as a dye model) by carbon adsorbents were evaluated in a batch reactor. The results showed that adsorption occurred via monolayer (for small adsorbents) and multilayer (for large adsorbents). Concerns on the size of the adsorbent have been found, playing a role in the enhancement of adsorption capacity due to its offering the existence of a larger surface area. In addition, small adsorbents have attractive electrostatic adsorbent-adsorbate interaction, giving benefits in the adsorption process, while large adsorbents have issues in the repulsive electrostatic interaction. In conclusion, effective carbon-based adsorbents can be designed and produced from papaya stem wastes, providing alternative ways to remove pollutants from aqueous solutions, thereby achieving the primary objective of the sustainable development goals (SDGs), Moroccan Journal of Chemistry, Vol. 11, No 2 (2023): In progress

This study aims to design a continuous stirred tank reactor (CSTR) type reactor used in the production of zinc oxide (ZnO) nanoparticles. Mass balance calculations were carried out in this study as a benchmark to find out whether the reactor was working properly by knowing the flow of incoming raw materials and the products produced by the reactor. Furthermore, the design of the reactor and the design of the stirrer used in the reactor is calculated manually using Microsoft Excel. Based on the calculation results of the reactor design, the reactor volume is 8224.359 liters, with a vessel diameter of 73.298 in, a cylinder height of 166.090 in and a cylinder thickness of 73.444 in. The top cover of the reactor measures 12.387 inches with a thickness of 0.072 inches while the bottom cover measures 21.185 inches with a thickness of 0.083 inches. So that the overall height of the reactor is 37.552 in. The reactor is equipped with 1 stirrer with an impeller diameter of 36.722 in, impeller height from the bottom of the tank is 24.433 in, impeller width is 7.344 in and impeller length is 9.180 in. Turbulent stirring flow conditions with a standard motor power for the stirrer is 6.849 HP. It is hoped that this design will serve as a reference for building more economical, more efficient and highly demanding reactors., Maghrebian Journal of Pure and Applied Science, Vol. 8, No 2 (2022): In progress

This study was conducted to analyze scientific trends about mercury-related applications in artisanal and small-scale gold mining (ASGM) through a bibliometric study on the Google Scholar database using VOSviewer. To support the analysis, this study was also completed with a literature review of ASGM. Based on the results of data using the keywords of "mercury", "gold mining", "particle technology", and "adsorption" using Publish or Perish from 2018 to 2022, 988 articles were detected and selected from Google Scholar. The results of searching data for the last 5 years showed that publications on related keywords increased in 2020 to 239 publications and decreased in 2021 and 2022 to 210 and 121, respectively. To support the analysis, three visualization forms in the data mapping analysis were completed: network visualization, overlay visualization, and density visualization. The results of this study are expected to assist researchers in recognizing global research trends regarding the proposed keywords that can be used as a reference in conducting further research, Moroccan Journal of Chemistry, Vol. 11, No 1 (2023)

One of the metal nanoparticles that is widely used is silver nanoparticles (AgNPs) because of their potential applications in various scientific fields. Silver is a material that is abundant in nature, attractive, and inexpenive. This paper aims to conduct a literature review from 12 papers on the synthesis of AgNPs from 2007 to 2020. Based on several articles, there are 3 methods for synthesizing AgNPs: physics, chemistry, and biology. Physical methods use laser ablation and arc-discharge, chemical methods use gamma irradiation and chemical reduction, and biological methods use bacteria, plants, and fungi. The best method is biosynthesis because it is facile, safe, cost-effective, and environmentally friendly. AgNPs produced from biosynthesis using plants is better than using bacteria and fungi because it produces pure and small particle of AgNPs., Maghrebian Journal of Pure and Applied Science, Vol 6, No 2 (2020)

Utilization of electric vehicles (EVs) for grid ancillary services, especially for frequency regulation, in Denmark is analysed. Denmark has two different electricity grids: DK1 (Western Denmark) and DK2 (Eastern Denmark). However, although both of the grids are coordinated by the same transmission service operator (TSO, which is Energinet.dk), they have different characteristics related to the capacity, supply composition, and grid connections. The capacity of DK2 network is significantly smaller than DK1, although the share of renewable energy in DK1 is higher. However, as DK1 is connected to very large European grid, DK1 seems to be more stable than DK2. Related to frequency regulation, especially the primary regulation, DK2 provides symmetrical regulation for both up and down regulations, while DK1 adopted an independent price for each of up and down regulations. From revenue comparison of services conducted by passenger EVs, frequency regulation in DK2 brings higher revenue than one conducted in DK1. However, as the frequency and fluctuation of both up and down services are higher in DK2, faster battery degradation of EVs in DK2 feared to occur.