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Biodiesel from Second-Generation Feedstock:
Published in Bhaskar Singh, Ramesh Oraon, Advanced Nanocatalysts for Biodiesel Production, 2023
Amjad Ali, Km Abida, Himmat Singh
Homogeneous acid (e.g., H2SO4 and HCl) catalysts, on the other hand, could be used for BD production from high-FFA-containing second-generation feedstock as they can catalyse the simultaneous esterification of fatty acid and transesterification of triglycerides, as shown in Figure 3.3.46 Thus, such catalysts could be useful for the generation of BD from second-generation feedstock with a high FFA content. However, these catalysts are less effective as the rate of acid-catalysed transesterification is ~ 4000 times slower than the alkali-catalysed ones.39 For this reason, acid catalysts usually required a relatively high temperature (100–120 °C), a high alcohol/oil molar ratio, and a longer reaction duration for completion of the reaction. The presence of water, which is usually found in second-generation feedstock and a by-product of the esterification reaction, was also found to reduce the activity of the acid catalysts to a significant extent. Moreover, acid catalysts are highly corrosive and hence, acid-resistant, complicated, and costly reactors are required to perform the reaction. The acid catalysts, after the reaction, must be neutralized by suitable alkali (e.g., CaO) and the resulting formed salt must be separated from the reaction mixture.
Reactive Adsorption
Published in Carlos Ariel Cardona Alzate, Mariana Ortiz Sanchez, Yury Pisarenko, Reactive Separation for Process Intensification and Sustainability, 2019
Carlos Ariel Cardona Alzate, Mariana Ortiz Sanchez, Yury Pisarenko
As it was discussed before, in the literature, there are a number of studies focusing on the application of RAd. A case that draws attention is the catalytic dehydration of sugars to furans, especially the synthesis of 5-hydroxymethylfurfural (HMF) [26]. HMF is considered primarily as a platform compound in the design of biorefineries according to IEA Bioenergy [27] for the production of levulinic acid or 2,5-furandicarboxylic acid, among others. HMF is synthesized from the sugars obtained from the lignocellulosic matrix of a natural source in the raw material. One of the advantages in the production of HMF is the great variety of sugars from which it can be obtained. Thus, HMF can be obtained from glucose, xylose, or fructose. This reaction is carried out under acidic conditions, and hence, acid catalysts are used. A recent study reported a 28.2% yield of HMF in a continuous compact bed reactor using a cation exchange resin (with sulfonic acid groups) [28].
Bioenergy From Activated Sludge and Wastewater
Published in Veera Gnaneswar Gude, Green chemistry for Sustainable Biofuel Production, 2018
Andro Mondala, Rafael Hernandez, Todd French, Emmanuel Revellame, Dhan Lord Fortela, Marta Amirsadeghi
In situ transesterification processes for biodiesel production from sewage sludge typically employ acids instead of bases as catalyst to prevent soap formation due to the expected high FFA content of sewage sludges. However, the use of acid catalysts can be disadvantageous in commercial applications due to issues such as equipment corrosion, high methanol consumption, and biodiesel washing [114]. Sangaletti-Gerhard and co-workers [184] used a commercially available lipase Novozyme 435 from the Candida antartica B yeast as an alternative catalyst for biodiesel production from sewage sludge via in situ transesterification. Although biodiesel yields using this biocatalyst were comparable with the acid-catalyzed processes, the enzymatic process was deemed uneconomical due to the high cost of lipase enzymes.
Plant design of biodiesel production from waste cooking oil in Malaysia
Published in Biofuels, 2023
Angnes Ngieng Tze Tiong, Zuhair Khan, Valerie Chin, Osama Abdul Wahid, Regina Mbeu Wachira, Shannon Michaela Kung, Ashvin Viknesh Mahenthiran
The commonly utilized catalysts are sulfuric acid (acid catalyst), sodium hydroxide (alkali catalyst), lipase (enzyme catalyst), and sodium hydroxide in acetone (co-solvent catalyst). The lipase-catalyzed process appears to be the best among all the catalyzed processes as transesterification via lipases generates a smaller amount of waste, and it has a conversion rate of 95%. Unfortunately, this type of process has only been conducted in a lab-scale arrangement as the cost of enzyme catalyst makes it economically unfeasible at an industrial scale [43]. The co-solvent process seems to have a lower temperature requirement and results in the same yield. Nonetheless, the additional acetone solvent increases the production cost. Besides, the acetone solvent would mix with the product biodiesel, and its removal needs extra costs. The co-solvent process is also mainly being tested on a laboratory scale [44, 45].
Catalytic cracking of off grade crude palm oil to biogasoline using Co-Mo/α-Fe2O3 catalyst
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2023
Aman Santoso, Asri Mulyaningsih, Sumari Sumari, Rini Retnosari, Adilah Aliyatulmuna, Indah Nur Pramesti, Muhammad Roy Asrori
Heterogeneous catalytic cracking of vegetable oil is being developed in recent years, because of low temperature and pressure that compared to vegetable oil cracking without a catalyst (thermal cracking) (Qiu et al. 2022). The catalysts commonly used such as bifunctional catalysts, which are a combination of acid catalysts such as zeolite, Al2O3, SiO2, etc., and transition metals such as Co, Mo, Ni, Cr, Zr, and Pt (Hanaoka et al. 2015; Regali, Boutonnet, and Järås 2013). Examples of the catalyst were Co-Mo/γ-Al2O3, NiMo/γ-Al2O3, NiMo/γ-Al2O3-SiO2. As catalyst in cracking, metal oxides were confirmed which have relatively better catalytic activity in vegetable oil cracking in the product range of gasoline, kerosene and diesel fuel fractions (Thangadurai and Tye 2021).
Production of biodiesel from high free fatty acid feedstock using heterogeneous acid catalyst derived from palm-fruit-bunch
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Himanshu Choksi, Sivakumar Pandian, Sakthi Saravanan Arumugamurthi, Periyasamy Sivanandi, Anirbid Sircar, Vijaya Kumar Booramurthy
The yield of oil from C. inophyllum seeds by means of mechanical expeller was 58 wt%. The FFA content of the oil was 18% which makes it unfit for alkali-catalyzed transesterification reaction process. Therefore, acid catalysts were used to facilitate both esterification and transesterification reaction. This oil was categorized under semi-drying oil with an iodine value of 92.01 g I2 100 g-1, the viscosity of 62.18 mm2 s−1 (at 40°C) and saponification value of 189.16 mg KOH per g of oil (Deepalakshmi et al. 2015). Table 1 shows the fatty acid distribution of C. inophyllum oil. It consists of six different fatty acids with 31.55 wt% of saturates and 68.45 wt% of unsaturates. The biodiesel produced from this oil has better cold flow properties and will emit less NOx (Pali and Kumar 2016). The calculated AMW of the oil was 871.87 g mol−1 which indicates the presence of longer fatty acid carbon chains with more unsaturation (Demirbas and Karslioglu 2007). Moreover, the AMW was also used to calculate the methanol to oil molar ratio during optimization of biodiesel.