Design and optimisation of chemical plants 6 CFU (48 h)
SSD Ing-Ind/25 – Impianti chimici – Rossetti Ilenia
The material of the course is available on the Ariel platform (https://ariel.unimi.it/)
The lectures will provide the students (from an Industrial Chemistry or Chemistry background) the basic concepts for the design of industrial scale chemical processes. The course will provide the fundamentals for sizing and rating of the main equipments found in a chemical process, in order to evaluate efficiency, yield, cost and to provide suggestions for integration and de-bottlenecking.
The concepts for sizing and rating will be provided during the course, so no entry level knowledge of chemical plants is required. This makes the course suitable for those chemists who want to have an idea about the concepts underlying the industrial process design.
The lectures will be mixed 1:1 with exercises in informatic lab to learn the use of a specific process simulation package, AspenONE, which is one of the most complete and powerful available in the market. This competence will be useful to our students as a useful visit card for industries.
The specific items that will be proposed during lectures are the following:
- Criteria for sizing and rating of different unit operations (particularly for different types of reactors) 6h
- Heuristic rules for process design 2h
- Integration of process units and criteria for optimization 4h
- Heat exchange network optimisation as a rule for energy saving and economic sustainability 2h
- Criteria for logistics and management of raw materials and utilities 2h
- Cost analysis: how to determine the economic potential of a process 4h
- Control strategy and criteria for “Hazop” 2h
- Unsteady state operation: criticisms during start up and shut-down and preventing reaction run-away 2h
The exercises in informatic lab are as follows:
- Introduction to process simulators. Available tools, limits and potentialities. 1h
- Aspen properties. Which are the compulsory physical chemical properties, what can we do to evaluate the missing ones and where to find literature data? Examples of physical properties evaluation for pure components, for the evaluation of vapor-liquid, liquid-liquid and vapor-liquid-liquid equilibria of selected strongly non-ideal mixtures. Comparison with experimental data. 4h
- Aspen Plus. Let’s start drawing a flowsheet. 1h
- Aspen Plus. Examples of separation unit operations: flash vs. rigorous distillation. 2h
- Aspen Plus. Reacting systems: which reactor can be chosen for different purposes. How to express reaction rate and thermodynamics. 4h
- Aspen Plus. Designing compressors, pumps, mixers, splitters and valves. 2h
- Aspen Plus. Heat exchangers, types, integration in the flowsheet and criteria for energy saving. 4h
- Aspen Plus. Integration of the whole process. Criteria for optimization. 2h
- Aspen Cost Evaluator. Let’s move to cost estimation. Available tools, databases, uncertainties. 2h
- Examples of process control design in Aspen. 2h
The examples will be guided by the teacher and the students will be hosted in an informatic lab with individual PCs available. Two main streams will be followed. 1) A well assessed example from a conventional refinery, where process optimisation allows the permanence on the market or not; 2) an innovative example taken from biorefinery, where reliable cost analysis and process integration and optimisation defines the success or not of emerging processes.
The evaluation will be based on the discussion of a project carried out by each student on a specific topic, aiming at evaluating its economic potential. The topics will be chosen by the students based on their interest in collaboration with the teacher. Group works may also be admitted for complex integrated processes.