The thermal cracking of soybean/canola oils and their methyl esters Yan Luo a , Irshad Ahmed b , Alena Kubátová c , Jana Šťávová c , Ted Aulich d , S.M. Sadrameli e , W.S. Seames f, ⁎ a Union Oil Products, Des Plaines, Illinois, USA b Koch Refining, St. Paul, MN, USA c Chemistry Department, University of North Dakota, Grand Forks, ND, USA d Energy and Environmental Research Center, University of North Dakota, Grand Forks, ND, USA e Tarbiat Modares University, Tehran, Iran f Chemical Engineering Department, University of North Dakota, USA abstract article info Article history: Received 30 September 2009 Received in revised form 31 December 2009 Accepted 1 January 2010 Keywords: Vegetable oils Thermal cracking Biojet fuel Optimization Triacyl glycerides (TGs) are naturally occurring oils produced by a significant variety of crops, microorganisms (bacteria and algae), and animals (certain fats). The diversity and prevalence of the sources of these compounds suggest that they may serve as an attractive alternative to crude oil as the feedstock for the production of transportation fuels and certain industrial chemicals — organic compounds with carbon chain lengths in the range of C 7 to C 15 . In the present study a series of batch thermal cracking reactions was performed using soybean oil and canola oil under reaction conditions leading towards attractive yields of potentially valuable (as fuels and/or chemicals) shorter chain products. An attractive yield of alkanes and fatty acids (from oil cracking) or esters (from biodiesel) was obtained. From a parametric study reaction temperature, followed by residence time, was found to have the most significant effect. Significantly, cracking under increased pressures in a hydrogen atmosphere did not improve the yields of desirable species. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Triacyl glycerides (also known as triacylglycerols; TGs) are naturally occurring oils produced by a number of crops, microorgan- isms (bacteria and algae), and animals (certain fats). The diversity and prevalence of the sources of these compounds suggest that they may serve as an attractive alternative to crude oil as the feedstock for the production of compounds utilized in transportation fuels and certain industrial chemicals. In fact, TGs are currently used in the process that produces most of the biodiesel products commercially available via transesterification with an alcohol, most commonly methanol to produce methyl esters [1,2]. A number of research groups are exploring technologies to produce renewable transportation fuels (e.g. diesel, jet fuel). In general, these fall into the following categories: • Hydrotreated crop oils [2–5]. In these processes, the crop oil is reacted for decarboxylation and hydrotreated using an external hydrogen source. Crop oils or animal fats are processed alone or co- processed with petroleum diesel. These processes use a catalyst to decarboxylate the fatty acids. The resulting alkanes and alkenes may then be subjected to high temperature and high pressure to cleave the long carbon chains into smaller carbon chain length compounds. In addition, some approaches employ an isomerization catalyst to produce branched chain alkanes to supplement the cleavage step or to replace it. The principal drawbacks to these methods are the need for an external source of hydrogen and the lack of valuable by- products to increase commercial feasibility. Some fuel applications also require blending with an external source of aromatics to make an on-specification product. • Fischer–Tropsch [6–8]. Cellulosic biomass is converted using a gasification process (typically the Fischer–Tropsch reaction set) producing a hydrocarbon mixture. A kerosene fraction can be purified out of many versions of this process. To date none of the processes achieve a high degree of conversion efficiency into middle distillate transportation fuels. • Rapid pyrolysis [9–11]. Cellulosic biomass or other carbon-contain- ing feedstocks are subjected to a very high temperature oxidation process at very short residence times to partially gasify the feedstock. A kerosene fraction can be purified out of the resulting hydrocarbon mixture. To date none of the processes achieve a high degree of conversion efficiency into middle distillate transportation fuels. • Transesterification [1,2,12,13]. This process involves the catalyzed reaction of triacyl glycerides with an alcohol to produce biodiesel. The limitations of biodiesels are their high freeze point, low energy density, and reduced oxidative stability compared to their petro- leum derived analogs. Fuel Processing Technology 91 (2010) 613–617 ⁎ Corresponding author. Tel.: +1 701 777 2958. E-mail address: WayneSeames@mail.und.nodak.edu (W.S. Seames). 0378-3820/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.fuproc.2010.01.007 Contents lists available at ScienceDirect Fuel Processing Technology journal homepage: www.elsevier.com/locate/fuproc