Fluid Catalytic Cracking of Biomass-Derived Oils and Their Blends with Petroleum Feedstocks: A Review

Abstract

To reduce the carbon footprint and greenhouse gas (GHG) emissions associated with heavy crude oil/bitumen upgrading and refining in the production of clean transportation fuels, researchers are targeting the production of fuels from renewable energy resources. These resources are mainly biomass-derived oils, which include oils produced by biomass pyrolysis (bio-oil), edible and inedible vegetable oils, and animal fats. Over the past 2 decades, research has focused on the evaluation of biomass-derived oil processing using conventional fluid catalytic cracking (FCC), a technology responsible for producing the majority of gasoline in a petroleum refinery. The present review summarizes research associated with the FCC of various biomass-derived oil feedstocks as well as studies related to the co-processing of these oils with conventional petroleum feedstocks. The objective of this review is to present a comprehensive perspective of the effects of renewable oil processing on existing FCC technology, operation, catalysts, and product quality and quantity.

Review of Heterogeneous Catalysts for Catalytically Upgrading Vegetable Oils into Hydrocarbon Biofuels

“…The densities of vegetable oil ranged between 0.84 g/mL and 0.97 g/Ml. This was lower than that of bio-oil (1.05-1.25 g/mL) [8]. The higher heating value of vegetable oils was high (between 37.1 MJ/kg and 40.6 MJ/kg) when compared to that of bio-oil (16)(17)(18)(19) MJ/kg) [8].…”

“…Usually, the vegetable oil does not dissolve in water because the vegetable oil molecules are non-polar while the water molecules are polar. The water content of vegetable oil was much lower than that of bio-oil (15-30 wt %) [8]. These vegetable oils have an acid number since some of the triglycerides present in the vegetable oils are decomposed to free fatty acids.…”

“…The viscosity of vegetable oil is high due to its long carbon chain and large molecules with oxygen atoms. The viscosity of bio-oils was also high, ranging from 40 cP to 100 cP [8]. The densities of vegetable oil ranged between 0.84 g/mL and 0.97 g/Ml.…”

“…Vegetable oil is extracted from vegetable oilseeds such as canola and camelina seeds [6]. The upgrading of bio-oil into hydrocarbon biofuel has faced many challenges including the bio-oil's high oxygen content, low heating value, and being corrosive to common metals, acidic, and thermally/chemically unstable [7,8]. Because of its high energy and low oxygen content, vegetable oil is easier to be converted into liquid biofuel than the bio-oil derived from cellulosic biomass [9].…”

Impact of Chain Length of Saturated Fatty Acids during Their Heterogeneously Catalyzed Deoxygenation

“…However, the unsaturation in the chain and oxygen content lead to instability that affects the chemical properties and leads to corrosion of wetted materials like polymer gaskets. Thus, various attempts were carried out in the recent years on hydroprocessing and up-grade of biomass derived oils aiming at using such feedstock as blending component for fuels [4] [5].…”