Helmi Maryam, Hemmati Alireza, Tahvildari Kambiz
Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran.
School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology, Tehran, Iran.
J Environ Health Sci Eng. 2022 Jan 23;20(1):187-204. doi: 10.1007/s40201-021-00766-y. eCollection 2022 Jun.
In recent years, fossil fuels are the main energy supply in both transportation and industry. Their increasing consumption has been causing global warming and acid raining. One of the alternative fuels that is considered today is biodiesel, which is clean and eco-friendly. The main method for biodiesel production is transesterification reaction of triglyceride oil with methanol in the presence of a suitable catalyst.
In this research, biodiesel was produced from oil in the presence of KOH/Clinoptilolite catalyst. The impregnation, hydrothermal, and incipient wetness methods were used for loading KOH on the Clinoptilolite support to produce biodiesel via electrolysis method. The characteristics of the KOH/Clinoptilolite catalyst were examined through scanning electron microscopy (SEM), energy dispersive X-ray Spectroscopy (EDX), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) analyses. The effects of key parameters including catalyst amount, methanol to oil molar ration, reaction time, reaction temperature, co-solvent type and its proportion, electrolysis voltage, catalyst reusability, and KOH concentration were examined on the biodiesel yield.
The results of elemental analysis confirmed that KOH was well loaded on Clinoptilolite support. The highest yield of biodiesel was obtained 79% in the presence of 10 wt% catalyst, alcohol to oil ratio of 9:1, acetone concentration of 10 wt%, temperature of 60 °C, and voltage of 10 V. The results of GC-MS, FTIR and H-NMR analyses illustrated that biodiesel as a product was produced with good quality.
Based on the obtained results, in all three methods of catalyst synthesis KOH was loaded on Clinoptilolite support but at the end of the transesterification reaction only the catalyst synthesis via incipient wetness method could be reused three times under optimum reaction conditions. The produced biodiesel had high quality, whose physical and chemical properties had good agreement with ASTM, EN 14214, IS 15607 standards. Since the oil is an appropriate feedstock source for biodiesel production, it is suggested to use oil and KOH/Clinoptilolite catalyst to produce biodiesel on industrial scale.
近年来，化石燃料是交通运输和工业领域的主要能源供应。其消费量的不断增加导致了全球变暖和酸雨。目前被认为的替代燃料之一是生物柴油，它清洁且环保。生物柴油生产的主要方法是在合适催化剂存在的情况下，甘油三酯油与甲醇发生酯交换反应。
在本研究中，在KOH/斜发沸石催化剂存在的情况下，由油生产生物柴油。采用浸渍法、水热法和初湿含浸法将KOH负载在斜发沸石载体上，通过电解法生产生物柴油。通过扫描电子显微镜（SEM）、能量色散X射线光谱（EDX）、X射线衍射（XRD）和布鲁诺尔-埃米特-泰勒（BET）分析来研究KOH/斜发沸石催化剂的特性。考察了催化剂用量、甲醇与油的摩尔比、反应时间、反应温度、共溶剂类型及其比例、电解电压、催化剂可重复使用性和KOH浓度等关键参数对生物柴油产率的影响。
元素分析结果证实KOH已良好负载在斜发沸石载体上。在10 wt%催化剂、醇油比为9:1、丙酮浓度为10 wt%、温度为60°C和电压为10 V的条件下，生物柴油的最高产率达到79%。气相色谱-质谱联用（GC-MS）、傅里叶变换红外光谱（FTIR）和氢核磁共振（H-NMR）分析结果表明，作为产物的生物柴油质量良好。
基于所得结果，在所有三种催化剂合成方法中，KOH都负载在了斜发沸石载体上，但在酯交换反应结束时，只有通过初湿含浸法合成的催化剂在最佳反应条件下可重复使用三次。所生产的生物柴油质量高，其物理和化学性质与美国材料与试验协会（ASTM）、欧洲标准EN 14214、印度标准IS 15607标准高度一致。由于该油是生物柴油生产的合适原料来源，建议在工业规模上使用该油和KOH/斜发沸石催化剂来生产生物柴油。
