Fatty acid methyl esters (biodiesel)

Advantages: high cetane number (CN) – renewable source domestic production Disadvantages: high cloud point and pour point, low thermal and chemical stability, heat content 9-13 % lower than conventional diesel.

Reason: Presence of oxygen

Possible solution: CATALYTIC DEOXYGENATION

Desirable operating conditions: Mild temperature and pressure Low hydrogen consumption

 

Vapor phase

Reaction with methyl octanoate as model compound to screen catalysts and understand reaction mechanisms

Liquid phase

Reaction with real FAME feedstock, methyl stearate, to produce normal diesel substances

 

 

 

 

 

 

Vapor phase

Reaction condition:
P: 15 to 500 psig; T: 300 to 400 oC; Flow of He or H2; Catalysts: Supported Pt, Pd, Pt-Sn catalysts

Liquid phase

The production of long chain hydrocarbons C17 from real fatty acid methyl ester feedstock was achieved with Parr reactor

The reaction condition is mild: P< 100psig, T < 350oC High C17 hydrocarbon selectivities were obtained with different tested catalysts, even under low H2 consumption condition

 

Vapor phase

Deoxygenated products: C7 and C8 hydrocarbons with high selectivity (>80%)

Liquid phase

Conclusions

Combination of vapor phase and liquid phase reactions enables us to screen effectiveness of different supported noble metal catalysts and produce high selectivities of diesel-range hydrocarbons from real FAME feedstock

Operating conditions are milder compared with hydrotreating option. Hydrogen consumption is optimized