Activated carbon supported molybdenum and tungsten carbides for hydrotreatment of fatty acids into green diesel

Abstract

The activated carbon supported Mo2C and W2C were synthesized successfully for hydrotreatment of fatty acids to produce diesel-like hydrocarbons. The carburization temperature, carburization gas as well as metal loading amount were studied. High carburization temperature was feasible for W2C/AC, but not for Mo2C/AC because it resulted in agglomeration of molybdenum compound and destruction of catalyst. Under hydrotreatment condition (360 °C, H2 3.0 MPa, 3.0 h) the conversion achieved 96.01% over Mo2C/AC prepared at 700 °C and 54.88% over W2C/AC prepared at 900 °C respectively. During carburization both flowing nitrogen and hydrogen were proper for formation of W2C/AC, while only flowing hydrogen was appropriate for Mo2C/AC. The hydrotreatment parameters (reaction temperature and reaction time) were also investigated. The high reaction temperature and long reaction time facilitated the conversion of fatty acids, meanwhile the high reaction temperature simultaneously improved the cracking degree of products.