Continuous low pressure decarboxylation of fatty acids to fuel-range hydrocarbons with in situ hydrogen production. (15th January 2018)

• Record Type: Journal Article
• Authors: Hossain, Md. Zakir; Chowdhury, Muhammad B.I.; Jhawar, Anil Kumar; Xu, William Z.; Charpentier, Paul A.
• Is Part Of: Fuel. Volume 212(2018)
• Page Start: 470
• Page End: 478
• Publication Date: 2018-01-15
• Subjects: Decarboxylation -- Subcritical water -- Continuous flow reactor -- Activated carbon -- Heptadecane -- In situ hydrogen; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2017.09.092
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: Low pressure continuous decarboxylation of oleic acid to fuel range liquid hydrocarbons. Liquid hydrocarbon mainly contains heptadecane with 89.3% selectivity. Liquid hydrocarbons have similar density and HHV's as commercial fuels. Abstract: Fatty acids are considered as a renewable feedstock for the production of high value products such as fuel-range hydrocarbons. Decarboxylation can produce high quality fuels from fatty acids, although either high pressure or additional hydrogen is required. This study investigated a low pressure (<500 psi) continuous decarboxylation process examining oleic acid in a continuous fixed bed reactor using activated carbon, which gave surprisingly high quality fuel-like hydrocarbons with no external hydrogen. The results showed that activated carbon performed as a catalyst for both decarboxylation and in situ hydrogen production. The reaction parameters for maximum degree of decarboxylation (91%) was found to be 400 °C, 2 h and water-to-oleic acid ratio of 4:1. To determine the degree of decarboxylation and reaction mechanism, the formed liquid products were examined by ATR-FTIR, Raman and GC-FID analysis, respectively. The liquid product was found to consist of mainly saturated hydrocarbons containing heptadecane (89.3% selectivity) as the major compound. The liquid product was found to have a similar density and higher heating value (HHV) to commercial diesel and jet fuel. The mechanism for decarboxylation reaction along with in situ hydrogen formation was proposed in this study.