Production of jet and diesel fuel range alkanes from waste hemicellulose-derived aqueous solutions

Abstract

In this paper we report a novel four-step process for the production of jet and diesel fuel range alkanes from hemicellulose extracts derived from northeastern hardwood trees. The extract is representative of a byproduct that could be produced by wood-processing industries such as biomass boilers or pulp mills in the northeastern U.S. The hemicellulose extract tested in this study contained mainly xylose oligomers (21.2 g/l xylose after the acid hydrolysis) as well as 0.31 g/l glucose, 0.91 g/l arabinose, 0.2 g/l lactic acid, 2.39 g/l acetic acid, 0.31 g/l formic acid, and other minor products. The first step in this process is an acid-catalyzed biphasic dehydration to produce furfural in yields up to 87%. The furfural is extracted from the aqueous solution into a tetrahydrofuran (THF) phase which is then fed into an aldol condensation step. The furfural-acetone-furfural (F-Ac-F) dimer is produced in this step by reaction of furfural with acetone in yields up to 96% for the F-Ac-F dimer. The F-Ac-F dimer is then subject to a low-temperature hydrogenation to form the hydrogenated dimer (H-FAF) at 110-130 • C and 800 psig with a 5 wt% Ru/C catalyst. Finally the H-FAF undergoes hydrodeoxygenation to make jet and diesel fuel range alkanes, primarily C 13 and C 12 , in yields up to 91%. The theoretical yield for this process is 0.61 kg of alkane per kg of dry xylose derived from the hemicellulose extract. Experimentally we were able to obtain 76% of the theoretical yield for the overall process. We estimate that jet and diesel fuel range alkanes can be produced from between $2.06/gal to $4.39/gal depending on the feed xylose concentration, the size of the biorefinery, and the overall yield. Sensitivity analysis shows that the prices of raw materials, the organic-to-aqueous mass ratio in the biphasic dehydration, and the feed xylose concentration in the hemicellulose extract significantly affect the product cost.

Synthesis of Furfural from Xylose by Heterogeneous and Reusable Nafion Catalysts

“…In addition to using biphasic solvent systems, most notably water and tetrahydrofuran, [3] processes such as Suprayield [15] aim to produce high yields of furfural by rapidly removing furfural vapor away from xylose as it is being formed by adiabatic distillation. Presently, only orthophosphoric acid is used as the catalyst in the Suprayield process due to corrosion problems associated with other mineral acids.…”

“…Other major drawbacks to mineral acids include: the occurrence of extensive side reactions from long reaction times that reduce furfural yield; neutralization of the spent acid; and technological challenges in the development, use, and maintenance of equipment exposed to the corrosive liquids. As part of a four-step process for the formation of jetand diesel-fuel-range alkanes, Xing et al [3] reported the synthesis of furfural from HCl-catalyzed biphasic dehydration of hemicellulose extracts at 87 % yield. However, they acknowledge that the high cost of producing such alkanes could be reduced by using solid acids in place of HCl.…”

Utilization of biodiesel-derived glycerol or xylose for increased growth and lipid production by indigenous microalgae

“…One suggested strategy is the chemical transformation of this waste into valuable products such as furfural and carboxylic acids (Xing et al 2011 (Xing et al 2010). However, these processes are highly dependent on the purity of the waste stream and face several challenges before being scaled up.…”

Supported iron nanoparticles for the hydrodeoxygenation of microalgal oil to green diesel

“…[1,2] In this context, microalgae are considered as one of the most promising renewable energy resources owing to their short harvest cycle, small cultivation area, high lipid content (up to 80% of their dry weight) and minimum greenhouse gas emission. [3,4] The major components of microalgal oil are free fatty acids (FFAs) and triglycerides.…”