(471c) Optimal Design of Integrated Upgrading Plant and Utility System for the Oil Sands Industry

Profitability in the oil sands industry historically has been quite unstable and it is significantly affected by the fluctuating crude oil price. Specially, the margin between bitumen production costs and the synthetic crude oil market price is insignificant these days. However, despite the unstable market and low profitability, oil sands production is predicted to be tripled by the year 2020, when taking into account existing projects, projects under development, and announced investments. Hence, it is imperative to reduce the operating costs for both existing and developing upgrading plants to allow for a more sustainable industry with a larger profit margin.

Limited number of works studied the optimization of oil sands upgrading and utility system. Ordorica-Garcia et al. [1] provided a model for the estimation of the energy requirements associated with producing crude oil products from oil sands according to the current commercially used production schemes. In their later work, Ordorica-Garcia et al. [2] presented a model for optimizing energy production for oil sands operations to reach the minimum of the total annual cost of energy consumptions in the oil sands industry. The model determined the optimal combinations of power and hydrogen plants to meet the given energy demands. Betancourt-Torcat et al. [3] incorporated the two previous studies into a more complex model simultaneously searching for the optimal set of oil production schemes and the corresponding energy infrastructures that meet the total production demands. The proposed superstructure involves multiple extraction and upgrading technologies and it is useful for production costs estimation, evaluating future production schemes and energy demand scenarios, and identifying the key parameters that affect the oil sands industry. In a more recent work [4], an energy optimization model for the oil sands upgrading operations was presented to reach the minimum downstream operating costs at the upgrading part in the oil sands industry, and the proposed superstructure of this work only focused on upgrading plants.

In this work, optimal design of integrated upgrading plants and utility systems in the oil sands industry is investigated. For the upgrading plant part, several state-of-the-art applicable upgrading schemes are considered, which include atmospheric and vacuum distillation, LC-fining, delayed coking and hydrotreatment. For the utility system part, a detailed superstructure model is proposed in this work. Compared to previous works [1-4] where the utility systems were just taken account as energy producers and very rough approximations were used for their operational and economic features, this work considers detailed features including process capacity, heating rate, capital cost, and operation and maintenance cost. A more complex polygeneration superstructure is developed in this study for the utility systems which can produce power, hydrogen and steam of varying quality. It includes gasifier (to produce syngas from coke or residue withdrawing from the upgrading plants), syngas cleaning, air separation unit, gas turbine, heat recovery steam generator, gas-fired boiler, and steam turbine. Results of various case studies demonstrate that the proposed work can efficiently address the optimal design of the integrated upgrading plant and utility system, which can lead to significant cost reduction of the oil sands industry operations.

References:

[1] G. Ordorica-Garcia, E. Croiset, P. Douglas, A. Elkamel, and M. Gupta, "Modeling the Energy Demands and Greenhouse Gas Emissions of the Canadian Oil Sands Industry," Energy & Fuels, vol. 21, pp. 2098-2111, 2007.

[2] G. Ordorica-Garcia, A. Elkamel, P. L. Douglas, E. Croiset, and M. Gupta, "Energy optimization model with CO2-emission constraints for the Canadian oil sands industry," Energy and Fuels, vol. 22, pp. 2660-2670, 2008.

[3] A. Betancourt-Torcat, G. Gutierrez, A. Elkamel, and L. Ricardez-Sandoval, "Integrated Energy Optimization Model for Oil Sands Operations," Industrial & Engineering Chemistry Research, vol. 50, pp. 12641-12663, 2011.

[4] J. Charry-Sanchez, A. Betancourt-Torcat, and L. Ricardez-Sandoval, "An optimization energy model for the upgrading processes of Canadian unconventional oil," Energy, vol. 68, pp. 629-643, 2014.