Ende natural zeolite as a catalyst in the biodiesel production from nyamplung oil

International Journal of Basic and Applied Science 12 (2) (2023) 53-61 Published by: IOCSCIENCE International Journal of Basic and Applied Science Journal homepage: www.ijobas.pelnus.ac.id Ende natural zeolite as a catalyst in the biodiesel production from nyamplung oil Gregorio Antonny Bani1, and Mario Donald Bani2 1Faculty 2Department of Science and Agriculture, Aryasatya Deo Muri University, Indonesia of Biotechnology, School of Life Sciences, Indonesia International Institute for Life Sciences, Indonesia Article Info ABSTRACT Article history: Fuel use as a primary energy source is increasing daily, and the reserves of these natural resources are diminishing quickly. Different studies have been performed to see the potential use of the seeds of the Nyamplung plant (Chalophyllum inophyllum L.) as biodiesel. To produce biodiesel from Nyamplung oil, a catalyst, such as zeolite, is often required to speed up the reaction, save energy use, and increase the quantity and quality of the biodiesel. There is a high variation in terms of natural zeolite’s catalytic activity, depending on the location where the zeolite was formed in the past. The objectives of this study were to characterize and understand the Ende natural zeolite, before and after activation, and to see the catalytic activity of the HCl-activated zeolite in the production of biodiesel from Nyamplung oil. When zeolite was used as a catalyst, optimum effects on the esterification were observed at 700 rpm stirring speed with a reaction time of 15 minutes. These conditions optimally converted 100% of Nyemplung oil into biodiesel. Received Jul 27, 2023 Revised Aug 10, 2023 Accepted Sep 23, 2023 Keywords: Esterification; HCl activation; Nyamplung biodiesel; Sustainable energy; Zeolite catalyst. This is an open access article under the CC BY-NC license. Corresponding Author: Gregorio Antonny Bani, Faculty of Science and Agriculture, Aryasatya Deo Muri University, Jl. Perintis Kemerdekaan 1, No.09. Kota Kupang, NTT, 85111, Indonesia Email: 1. INTRODUCTION An increase in the number of human activities requires fuel as the main energy source on a daily basis [1]. However, oil reserves as the main raw material are also depleting very quickly [2]. Different alternatives for energy sources have also been developed lately, such as nuclear and solar energy, but these alternatives often pose high production costs [3, 4]. Biodiesel production has also got its share of attention as an alternative energy source [5]. There have been different research on biodiesel commodities, and one of them is to produce it from the seeds of the Nyamplung/Tamanu plant (Chalophyllum inophyllum L.), which often grows in coastal and lowland areas [6]. Indonesia, as an archipelagic country, has its advantage due to its vast coastal region overgrown by Nyamplung plants [7]. The production of biodiesel from the seeds of the Nyamplung plant is considered more economical due to the large number of seeds that can be produced by one tree [8]. In addition, Nyamplung is not consumed, so its utilization can be focused only on biodiesel production [9]. Another advantage of Nyamplung is its relatively fast and fruitful growth throughout the year. It has a high adaptability to tropical climates and does not require any special treatment for its growth Journal homepage: www.ijobas.pelnus.ac.id 54 p-ISSN 2301-8038 e-ISSN 2776-3013 [9]. Ecologically, Nyamplung is also a type of mangrove that protects coastal areas from abrasion [10], adding up the value of planting this tree in the Indonesian coastal region. Biodiesel from Nyamplung seed oil is made through an esterification or transesterification process [11]. This process requires catalysts to speed up the reaction, save energy, and increase the quantity and quality of the biodiesel yield [12]. The widely used catalyst is often a homogenous catalyst which has a similar phase to the product, making it hard to separate them after the reaction completes [13]. Because of that, the use of heterogeneous catalysts, including zeolite minerals, can be an option [14]. As a mineral, zeolite consists of a silica-alumina component. Its synthetic form, zeolite socony mobile-5 (ZSM-5), has been proven to be one of the best catalysts out there [15]. However, the use of synthetic zeolite comes with a great price that increases the overall production cost, opening up the possibility of employing natural zeolite as a cheaply abundant alternative to ZSM-5 [16]. Indonesia has abundant natural zeolite reserves, including in Ende Regency, East Nusa Tenggara Province [17]. However, a natural zeolite often comes in non-uniform pore sizes filled with different impurities that reduce its catalytic activity and chemical stability under thermal conditions [18]. Therefore, natural zeolite must be activated and modified first before it can be used as a catalyst in biodiesel production [19]. Among all the many variations in the activation procedures, the best results were shown by the natural zeolite activated and modified with hydrochloric acid (HCl) treatment only when compared to the one that was modified with a combination of HCl and metal impregnation [20]. For example, in the esterification of vegetable oil, the most effective percentage of zeolite as a catalyst was shown to be 3% of the total reactant used [21]. The activation of Wonosari natural zeolite with 6 N solution of HCl converted 100% of the feedstock into biodiesel at 60 °C [22]. With the same treatment, natural Bayah zeolite (originated from Sukabumi, West Java) that mostly consists of mordenite crystal could convert up to 70% of glycerol at 60 °C [23]. Despite its potency, the properties of natural zeolite vary greatly from one region to another. This is largely due to the environmental factors where the zeolite was formed in the past [24]. The variation in the properties of the natural zeolite provides an opportunity to explore the characteristics of the mineral from different regions in Indonesia, allowing a better understanding of their utilization as a catalyst in different chemical reactions [25]. By doing this, we expect to have a better understanding of the characteristics of the cheaply available natural zeolite from the seashore of Ende District in Flores, East Nusa Tenggara, which has never been researched before. This knowledge will be very useful in the future to develop an alternative to the expensive synthetic zeolite by using what nature has already provided for us. Because of that, the objectives of this study were to characterize and understand the Ende natural zeolite, before and after activation. The catalytic activity of Ende zeolite in biodiesel production from Nyamplung oil through esterification reaction, especially after its activation with hydrochloric acid (HCl), was the highlight of this research. This study mainly focused on the effects of adding an activated natural zeolite as a catalyst towards the stirring speed and the prod (...truncated)