Sanette Marx

n-Butanol derived from biochemical and chemical routes: A review

Traditionally, bio-butanol is produced with the ABE (Acetone Butanol Ethanol) process using Clostridium species to ferment sugars from biomass. However, the route is associated with some disadvantages such as low butanol yield and by-product formation (acetone and ethanol). On the other hand, butanol can be directly produced from ethanol through aldol condensation over metal oxides/ hydroxyapatite catalysts. This paper suggests that the chemical conversion route is more preferable than the ABE process, because the reaction proceeds more quickly compared to the fermentation route and fewer steps are required to get to the product.

Cassava as Feedstock for Ethanol Production: A Global Perspective

Abstract In this chapter, cassava as an energy crop for bioethanol production is discussed in terms of its carbon and water footprints and eutrophication potential. Production processes from starch and cassava waste are discussed and new developments highlighted. Production potential and risks of cassava-based ethanol production in China, Thailand, and Vietnam is assessed in terms of government policies and future planned activities.

Biofuel production from spent coffee grounds via lipase catalysis

ABSTRACT Lipases namely Mucor miehei, Pseudomonas cepacia, Rhizopus delemar, Geotrichum candidum, Candida rugosa, Porcine pancreas-II, Pseudomonas fluorescence, and Candida antarctica lipase-B (Novozyme-435) were employed for biodiesel synthesis from spent coffee oil. Around 96% oil-to-biodiesel conversion was obtained using Novozyme-435 as a catalyst at 1:5 oil-to-methanol molar ratio and 40ºC. Total spent coffee grounds generated at the North-West University, Potchefstroom Campus (NWU PC) was estimated which could be used to produce 162 L of biodiesel. A waste valorization strategy was devised for converting organic wastes produced at the NWU PC to bioenergy.

Biodiesel production from butter factory effluent

The increase in energy demand coupled with the depletion of fossil fuels has increased the need for renewable and sustainable energy sources. Butter waste effluent was identified as a possible feedstock for biodiesel. The effects of the temperature, alcohol to oil molar ratio, catalyst concentration and the reaction time were investigated to determine the optimal reaction conditions of the transesterification reaction. The optimal reaction conditions according to the results were 50°C, 6:1 alcohol to oil molar ratio, 1.0 to 1.2 wt% catalyst loads and a reaction time of 60 to 90 min. Different methods of purification were investigated in an attempt to decrease waste of a biodiesel plant, including the dry washing agents, Magnesol ® D-SOL TM and Purolite ® PD-206. The Magnesol ® D-SOL TM was found to be the optimum method for lowering the water content and the acid value of the fuel. The biodiesel was tested according to the SANS 1935:2011 standard and did not meet the requirements of the standard with regard to flash point, sulphur content, carbon residue, oxidation stability, free glycerol, total glycerol and cold filter plugging point. In order for the biodiesel to be suitable for commercial use, it should be blended with mineral diesel.

Experimental and reaction kinetic investigation of 1-octene metathesis reaction with Hoveyda-Grubbs first generation precatalyst

Abstract In this work, we report the catalytic performance of the first generation Hoveyda-Grubbs precatalyst for the metathesis reaction of 1-octene. The reaction temperature (30 to 100°C) and catalyst load (1-octene/Ru molar ratio 5,000 to 10,000) were varied and quantities such as product distribution, activity and selectivity were evaluated. Reaction temperature showed a significant effect and turn over numbers as high as 4458 were observed for this system. Two competing mechanisms were observed for temperatures above 60°C, namely metathesis and isomerisation. The experimental product-time distribution data for the complex parallel reaction system was fairly accurately described by three elementary pseudo-first order reaction rates. The effects of temperature (Arrhenius Equation) and catalyst load were incorporated in the observed rate constant. The observed activation energies were around 10 kcal/mol.