Increased research efforts have recently been accelerated to develop liquid transportation fuels from bio-oil produced by fast pyrolysis. However, these bio-oils contain high levels of oxygenated compounds that require removal to produce viable transportation fuels. A variety of upgrading technologies have been proposed, of which catalytic hydroprocessing of the raw bio-oil has appears to have the best potential due to the fact that no fractionation of the bio-oil is required prior to treatment. The objective of this research was to apply two-stage catalytic hydroprocessing to bio-oil with heterogeneous catalysts to produce hydrocarbon fuels. To achieve this objective seven catalysts were initially compared in first-stage hydrotreating reactions. The result of the comparison of the seven hydrotreating catalysts showed that the MSU-1 catalyst had the significantly highest yield at 38 wt%, had the highest H/C ratio, and reduced oxygen adequately. The MSU-1 catalyst had an energy efficiency of 80%, reduced acid value by 45% and water content by 78%. Higher heating value was doubled by the hydrotreating process of raw bio-oil. Three catalysts were compared as second-stage hydrocracking catalysts. All liquid organic products produced by the catalytic reactions were compared with regard to yield and chemical and physical qualities. Results from these experiments showed that the MSU-2 catalyst had the significantly highest yield at 68 wt%; oxygen value was significantly lower than for the compared catalysts at zero percent. MSU-2 also produced the lowest amount of char at 3.5 wt%. Additionally, MSU-2 produced a high volume of methane gas as a byproduct, with a high value for utilization for production of process heat. A study of reaction time optimization found that best results from application of MSU-2 were for the shortest reaction time of 1 h. This short reaction time is important to reduce hydroprocessing costs. Simulated distillation of hydrocarbon mix results in distribution of these by fuel weights with gasoline comprising 37%, jet fuel 27%, diesel 25% and heavy fuel oil 11%.The energy efficiency of the hydrocracking of first-stage stabilized bio-oil with MSU-2 catalyst was 93.61%.
| Identifer | oai:union.ndltd.org:MSSTATE/oai:scholarsjunction.msstate.edu:td-4651 |
| Date | 10 December 2010 |
| Creators | Gajjela, Sanjeev Kumar |
| Publisher | Scholars Junction |
| Source Sets | Mississippi State University |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Theses and Dissertations |
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