Biodiesel Production from Waste Frying Oils by Potassium Methoxide Supported on Activated Carbon Catalysts from Lignocellulosic Biomass

Various carbon-rich solid catalysts are evaluated for the synthesis of biodiesel from waste frying oil. The study results showed that the use of activated carbon made of corn stalk could increase the biodiesel yield by 7%. The heterogeneous carbon-based catalysts made of lignocellulosic residues could successfully improve the quality of biodiesel properties. The results obtained revealed that the biodiesel properties, including relative density (852–900 kg·m−3) and kinematic viscosity (2.4–3.9 mm2·s−1), are in compliance with the standard limits of ASTM and the European Biodiesel Standard, suggesting that the biodiesel produced would be decent as a diesel fuel that potentially can minimize the serious damage of engine parts, and prolong the engine life.

Optimization of In-situ Transesterification Process for Biodiesel Production from High Free Fatty Acid Feedstock by Semi-continuous Column Reactor

An in-situ transesterification (in-situ TE) process can reduce the multiple steps of biodiesel production by merging vegetable oil extraction and biodiesel synthesis into a single step. However, high free fatty acid, generally found in waste feedstock, dramatically reduce both yield and quality of biodiesel. In this work the new concept of a semi-continuous column reactor was introduced to mitigate the negative effect of high free fatty acid found in spent coffee grounds (SCGs). The potassium methoxide solution, as reactive solvent, was pumped through the series of column reactors. At the beginning of process free fatty acid in SCGs was promptly extracted in form of soap as a pretreatment fraction. Then, the residual mono-, di- and triglyceride in SCGs matrix were covert to fatty acid methyl ester (FAME) biodiesel and simultaneously extracted. A liquid fraction analysis was conducted to distinguish the pretreatment fraction from biodiesel. A central composited rotatable design was applied to determine optimal process conditions of potassium methoxide concentration and solid retention time at 30°C. Under the optimal conditions, up to 88% FAME yield was observed. The residual triglyceride in defatted SCGs was less than 1.5%mass. Compared to batch reactor type, the semi-continuous column reactor used only half of the required methanol for in-situ TE by recirculating the reagent in the series of reactors. This could dramatically reduce the energy usage and environmental impact of FAME production from high free fatty acid feedstock via in-situ TE.

Continuous Methyl Ester Production Process from Refined Palm Oil Using 3D-Printed Static Mixers

The objective of this research was to study the methyl ester purity and pressure drop when the reactants flowed through the 3D-printed continuous static mixer reactor. The various types of 3D-printed mixing elements: KSM, LSM, SMX-3, SMX-4, SMX-5, SMV-3, SMV-4, and SMV-5 were inserted into the tube to blend the refined palm oil (RPO) and potassium methoxide (CH3KO) during the transesterification process. Therefore, the comparison of various types and plug flow (PF) reactors in continuous methyl ester production was carried out to assessed the purity of methyl ester with the condition was 23.81 vol.% methanol and 11.8 wt.% KOH at 50°C temperature. The results showed that the pressure drop had increased when a flow rate of water was increased. The pressure drop in the continuous reactor increased to 29.9% of SMV-5, 19.9% of SMV-4, 12.0% of SMV-3, 7.0% of SMX-5, 7.0% of SMX-4, 7.0% of SMX-3, 3.6% of LSM and 0.9% of KSM when compared with the empty tube cases. According to biodiesel production, the purity of methyl ester decreased by 93.63% of SMV-5, 92.49% of SMV-4, 91.63% of SMV-3, 51.68% of SMX-5, 47.47% of LSM, 46.17% of SMX-4, 45.31% of SMX-3, 42.36% of KSM, and 12.28% of PF, respectively, when compared to the highest purities achieved with PF reactor. Thus, a 662% improvement in ester purity was obtained by using the SMV-5 reactor instead of the PF reactor within 360 mm.

Potassium methoxide/disilane-mediated formylation of aryl iodides with DMF at room temperature

A formylation of aryl iodides at room temperature using a weaker base KOMe instead of BuLi was developed.

Potassium Alkoxide/Disilane-Mediated Dehalogenative Deuteration

Deuterated compounds are of great importance in chemistry and pharmaceuticals. Reductive dehalogenation is one of the most useful methods to incorporate deuterium into molecules. This article briefly discusses the historical development of dehalogenative deuteration reactions that involve transition-metal catalysis, radical halogen abstraction, alkali-metal reductive deuteration, and the recently developed potassium methoxide/hexamethyldisilane-mediated dehalogenation of aryl halides.