(180e) Computer-Aided Modeling for Tailor-Made Design of Surrogate Fuels

Modern society needs various chemical products for its survival. Nowadays, more than 70,000 chemical products are used in our society [1]. These widely used chemical products include fuels for transport and energy; materials for the manufacture of cars, planes, housing and electronics; medicines for healthcare; foods for nutrition; fertilizers for agriculture; plastics for storage; paints for printing; and detergents for cleaning; etc. [2] Among all these products, fuels such as gasoline are one of the most widely used chemicals, and continue to play a significant role in meeting the energy demand. Alternatively, surrogate fuels are developed with their ingredients and additives from renewable sources. A surrogate fuel is one that comprises of a small and diverse number of compounds that mimic certain target characteristics of the original fuel [3]. Currently, many products are derived from fossil fuel based raw materials and from a sustainability point of view, renewable alternatives need to be considered, whenever feasible. In order to achieve this, tailor-made surrogate fuels need to be developed by blending the conventional materials with other chemical that can be produced from renewable resources, namely, bio-based chemicals. The advantage is the amount of fossil fuel consumption is reduced. At the same time, the chemical products are safer for humans and environment because the harmful chemicals are removed or replaced with safer chemicals from the product design method. In addition, the product attributes can be improved by adding chemicals (additives) that have potential to enhance the specific product attribute [4]. The requirements of higher performance, safety, environmental friendly and sustainability force us to design new kinds of products, and develop surrogate fuels with their ingredients and additives from renewable sources to reduce the fossil fuel consumption. Therefore, a computer-aided model is needed for tailor-made design of surrogate fuels to meet all these requirements.

In this paper, we have applied the idea of chemical product design methods to tailor-made surrogate fuels design. Generic design steps are given to help people establishing a comprehensive design model, within these steps, ingredients are generated and selected, the composition is obtained; methods and tools are integrated to assist in modeling of the design problem; solution strategy is discussed to achieve optimal results. The developed method is then applied to two case studies of tailor-made surrogate fuel design problems (gasoline blends and jet fuel blends). The design of surrogate fuels could reduce the amount of fossil fuel consumption. At the same time, the requirements of safety environmental friendly are met because the harmful chemicals are replaced with safer ones. In addition, the product attributes are improved by adding bio-based additives to enhance the specific product attributes. Two solution approaches have been developed and tested. One is a mathematical programming based blend design where a MINLP model is derived and solved for the blend design problem. Another is a hybrid method where the complex blend design problem is decomposed into smaller sub-problems, where the generate-test paradigm are mathematical programming combined with rule-knowledge based techniques. Both approaches together with the associated data, models, solvers, etc., are part of a chemical product design software, ProCAPD. The design results show the effectiveness and efficiency of the computer-aided chemical product design method.

References:

[1] Seider, W. D.; Lewin, D. R.; Seader, J. D.; Widagdo, S.; Gani, R.; Ng, K. M. Product and Process Design Principles: Synthesis, Analysis and Design, 4th ed.; Wiley, 2017.

[2] Zhang, L.; Babi, D. K.; Gani, R. New Vistas in Chemical Product and Process Design. Annual Review of Chemical and Biomolecular Engineering. 2016, 7(1), 557-582.

[3] Pitz, W. J.; Mueller, C. J. Recent Progress in the Development of Diesel Surrogate Fuels. Progress in Energy and Combustion Science. 2011, 37(3), 330-350.

[4] Yunus, N. A. B.; Gernaey, K. V.; Woodley, J. M.; Gani, R. A systematic methodology for design of tailor-made blended products. Computers & Chemical Engineering, 2014, 66, 201-213