Compositional Analysis and Advanced Distillation Curve for Mixed Alcohols Produced via Syngas on a K-CoMoSx Catalyst

Published

April 19, 2013

Author(s)

Jesse E. Hensley, Tara Lovestead, Earl Christensen, Abhijit Dutta, Thomas J. Bruno, Robert McCormick

Abstract

The distillation behavior of mixed alcohols was studied using the Advanced Distillation Curve (ADC) methodology. Crude mixed oxygenates were generated from syngas over a potassium promoted cobalt molybdenum sulfide catalyst and assayed for major and minor products. Then, boiling curves were generated for these samples and composition channel data was collected. Methanol, aldehydes, and dimethyl sulfide were the first to vaporize from the mixture and C4+ alcohols remained within the last 20% of distilled volume. Other species, including ethanol, propanols, esters, and organic sulfur species distilled over a range of boiling temperatures. ADCs suggest the presence of one or more azeotropes in distillate, consistent with a large number of known binary azeotropes between components found in the crude. A comparison of fractional distillation of the mixed alcohols showed directional agreement between experiment and simulation with Aspen Plus. Enthalpies of combustion were calculated for multiple distilled fractions and ranged from 890 kJ mol-1 in the first drop of distillate to 1150 kJ mol-1 in the first drop collected after distilling 80% of the original liquid volume. This energy density is low compared to 91 octane gasoline at 3700 and 4940 kJ mol-1 in the first drop and at 80%, respectively. In sum this study provides useful insights into mixed alcohols products derived from a sulfided catalyst, including considerations for process recycle, product constituents and their blending, and the applicability of distillation information from process simulators.

Citation

Energy and Fuels

Volume

27

Pub Type

Journals

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DOI Link

Keywords

advanced distillation curve (ADC), mixed alcohols, biofuels

Citation

Hensley, J. , Lovestead, T. , Christensen, E. , Dutta, A. , Bruno, T. and McCormick, R. (2013), Compositional Analysis and Advanced Distillation Curve for Mixed Alcohols Produced via Syngas on a K-CoMoSx Catalyst, Energy and Fuels, [online], https://doi.org/10.1021/ef400252x (Accessed December 12, 2024)