Utilization of Triglycerides and Related Feedstocks for Production of Clean Hydrocarbon Fuels and Petrochemicals: A Review

Abstract

Catalytic deoxygenation of triglycerides and related feedstocks for production of biofuels is reviewed in this paper. Green diesel, triglyceride-based hydrocarbons in diesel boiling range, is an attractive alternative to biodiesel-a product of transesterification of vegetable oils, particularly due to its superior fuel properties and full compatibility with current diesel fuels. Two basic approaches to production of green diesel-(i) hydrodeoxygenation of triglycerides and related compounds over metal sulfide catalysts and (ii) deoxygenation over supported noble metal catalysts are thoroughly discussed from the point of view of reaction conditions, catalyst composition and reaction pathways and products. Furthermore, catalytic cracking of triglycerides and related feedstocks over microporous and mesoporous catalysts is reviewed as well. It constitutes an interesting alternative to deoxygenation using hydrotreating and noble metal catalysts as it does not consume hydrogen. It provides a wide spectrum of products reaching from olefins to green gasoline and diesel.

A real support effect on the hydrodeoxygenation of methyl oleate by sulfided NiMo catalysts

“…On the other hand, second-and third-generation biofuels derive from non-edible biomass such as woody biomass and waste streams and algae. Whilst more sustainable, the associated conversion technologies are typically less mature than first-generation biofuels manufacture [4] and involve biochemical and thermochemical processes such as pyrolysis, gasification, supercritical fluid extraction, and direct liquefaction [5,6].…”

“…FAMEs are unstable on storage and may also cause problems when used in combustion engines. This limits the amount of biodiesel that can be blended in diesel fuel [4,7]. Another drawback is that transesterification leads to the co-production of significant amounts of glycerol as low-value byproduct [4].…”

“…This limits the amount of biodiesel that can be blended in diesel fuel [4,7]. Another drawback is that transesterification leads to the co-production of significant amounts of glycerol as low-value byproduct [4]. An alternative approach involves the direct hydrodeoxygenation (HDO) of triglycerides into hydrocarbons.…”

“…A third approach avoids the use of hydrogen and uses precious metals such as Pt and Pd to remove oxygen from triglycerides [9,10]. Compared with biodiesel, green diesel is compatible with existing combustion engines and has better fuel properties because of its higher cetane number, higher energy density and very low sulfur content [4,7]. It is also possible to obtain lighter hydrocarbons for the jet or gasoline fuel pool by using catalysts with strong acid sites.…”

“…These catalysts consist of Co-and Nipromoted MoS 2 supported on γ-alumina. HDO of vegetable oil feedstock using supported NiMo sulfides has been studied in the past [4,9,23,8,[24][25][26][27][28][29][30][31][32]. Usually, model compounds have been employed in this context [25][26][27][28]33,34].…”