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Fitri, Ernarisa
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Agriculture, Biological Sciences & Forestry Astronomy Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Mechanical Engineering

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Synthesis of Kaolinite Nanotubes as Heterogeneous Catalysts for Transesterification Reaction of Waste Cooking Oil into Biodiesel Muhammad Rizki; Fitri, Ernarisa; Syukri Arief; Rahadian Zainul; Syukri
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 25 No. 04 (2024): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/eksakta/vol25-iss04/545

Abstract

Kaolinite, a naturally abundant clay mineral, possesses a significant surface area and catalytic properties. To enhance its catalytic efficiency, modification into kaolinite nanotubes is necessary, as this transformation increases surface area and porosity. The synthesis of kaolinite nanotubes was achieved through a solvothermal method, incorporating multiple intercalation and rolling processes influenced by ultrasonic waves, subsequently utilizing these nanotubes as heterogeneous catalysts. The resulting kaolinite nanotube catalysts exhibited well-defined nanotube morphology and were applied in the transesterification of waste cooking oil, with variations in methanol-to-oil ratios. The optimal biodiesel yield achieved was 49.84%, obtained after a 3-hour reaction period using a 3% w catalyst at 60 °C, with a methanol-oil ratio of 3:1. This research highlights the potential of kaolinite nanotubes as effective catalysts in biodiesel production.
Utilization of Dry Cocoa Pod Husks as an Antioxidant-Rich Herbal Drink Fitri, Ernarisa; Effendi, Effendi; Azra, Azmi
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 22 No. 2 (2021): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (596.871 KB) | DOI: 10.24036/eksakta/vol22-iss2/262

Abstract

Cocoa (Theobroma cacao L) production in Indonesian has increased every year, therefore more cocoa pod husks are produced. Currently, the use of cocoa pod husks is still very limited, even most farmers only dump the pods and turn them into plantation waste which will later become new problems in the plantation environment, such as causing bad smell and spreading diseases to healthy cocoa. Even if there is use of cocoa pods, at this point it is only used for animal feed and compost. In fact, cacao pod husks contain flavonoids and phenolic compounds which have high levels of antioxidant activity which are very beneficial fot the health. Based on the results of the sample analysis test using the FTIR and XRF instrument, there are functional groups that contain antioxidants and based on the XRF test, the pods of cocoa also contain several minerals, including 60,69% potassium and 24,56 calcium. Antioxidants can prevent the activity of free radicals which are the main causes of degenerative diseases. Therefore, cacao pod husks are very useful for making herbal drinks by drying and pounding them into a homogeneous powder product.
Kaolinite Nanotubes as Support Catalysts of Sulfuric Acid (H2SO4) for Transesterification Reaction of Waste Cooking Oil into Methyl Ester for Biodiesel Fitri, Ernarisa; Rahadian Zainul; Syukri
EKSAKTA: Berkala Ilmiah Bidang MIPA Vol. 26 No. 02 (2025): Eksakta : Berkala Ilmiah Bidang MIPA (E-ISSN : 2549-7464)
Publisher : Faculty of Mathematics and Natural Sciences (FMIPA), Universitas Negeri Padang, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24036/eksakta/vol26-iss02/577

Abstract

This study aims to improve the catalytic performance of kaolinite by converting it into kaolinite nanotubes and utilizing it as a support for sulfuric acid catalysts. Analysis using XRD and TEM revealed that the kaolinite crystal phase remained stable after being modified with sulfuric acid, while kaolinite nanotubes underwent little structural change. In addition, characterization via FTIR and XRF confirmed the presence of sulfate ions in kaolinite nanotubes and kaolinite after combination with sulfuric acid. Catalytic test on transesterification of used cooking oil under uniform conditions (catalyst 3% w/v, oil to methanol ratio 1:6, temperature 90 °C, and stirring speed 700 rpm) showed that sulfuric acid supported by kaolinite nanotubes gave the best performance, producing methyl ester of 65.01%. These findings indicate that converting kaolinite into nanotubes significantly improves its performance as a catalyst support. Practically, this increase in catalytic activity contributes to the efficiency of used cooking oil-based biodiesel production, which can reduce dependence on virgin vegetable oil raw materials and support waste oil recycling efforts. In addition, the use of cheap and easily available kaolinite-based catalysts can reduce the cost of biodiesel production, making it more competitive as an environmentally friendly fuel.
Co-Authors Azra, Azmi Effendi Effendi Muhammad Rizki Rahadian Zainul Syukri Syukri Arief