With the increasing stringency on sulfur content in petrodiesel, there is a growing
tendency of broader usage of ultra low sulfur diesel (ULSD) with sulfur content of 15
ppm. Refineries around the world should develop cost-effective and sustainable
strategies to meet these requirements. The primary objective of this work is to analyze
alternatives for producing ULSD. In addition to the conventional approach of revamping
existing hydrotreating facilities, the option of blending petrodiesel with biodiesel is
investigated. Blending petrodiesel with biodiesel is a potentially attractive option
because it is naturally low in sulfur, enhances the lubricity of petrodiesel, and is a
sustainable energy resource.
In order to investigate alternatives for producing ULSD, several research tasks were
undertaken in this work. Firstly, base-case designs of petrodiesel and biodiesel
production processes were developed using computer-aided tools ASPEN Plus. The
simulations were adjusted until the technical criteria and specifications of petrodiesel
and biodiesel production were met. Next, process integration techniques were employed
to optimize the synthesized processes. Heat integration for petrodiesel and biodiesel was
carried out using algebraic, graphical and optimization methods to maximize the
integrated heat exchange and minimize the heating and cooling utilities. Additionally,
mass integration was applied to conserve material resources. Cost estimation was carried
out for both processes. The capital investments were obtained from ASPEN ICARUS
Process Evaluator, while operating costs were calculated based on the updated chemical
market prices. The total operating costs before and after process integration were calculated and compared. Next, blending optimization was performed for three blending
options with the optimum blend for each option identified. Economic comparison (total
annualized cost, breakeven analysis, return on investment, and payback period) of the
three options indicated that the blending of ULSD with chemical additives was the most
profitable. However, the subsequent life-cycle greenhouse gas (GHG) emission and
safety comparisons demonstrated that the blending of ULSD with biodiesel was
superior.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2908 |
| Date | 15 May 2009 |
| Creators | Wang, Ting |
| Contributors | El-Halwagi, Mahmoud M. |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | electronic, application/pdf, born digital |
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