(604e) A Systematic Approach for Conceptual and Sustainable Process Design: Production of Cumene

A
Systematic Approach for Conceptual and Sustainable Process Design: Production
of cumene

Diogo M.B. Sebastiao¹, Naia R. Wright¹, Sofie T. Morthensen ¹,
Rafiqul Gani¹

s111775@student.dtu.dk, s082422@student.dtu.dk, s082684@student.dtu.dk, rag@kt.dtu.dk

¹ Department of Chemical and
Biochemical Engineering, Technical University of Denmark (DTU), DK-2800 Kongens Lyngby, Denmark

Abstract

Cumene (isopropylbenzene)
is an important chemical since it is used as feed stock for acetone and phenol production, which are used in
the organic chemical industry [1]. A systematic hierarchal decomposition
method is applied to design a sustainable and environmentally friendly plant
for producing cumene from the raw materials benzene and propylene [2]. The
method consists of 12 sequential tasks which take into account all stages of
conceptual design, starting from the consideration of qualitative aspects of
the process flowsheet and preliminary calculations to
the detailed process simulations, equipment sizing, costing, economic
evaluation, sustainability and LCA assessment of the designed process. At
the end of task-9 (the economic analysis), the base case design is investigated
for improvements with respect to heat integration and process optimization. In
the final task-12, a sustainability and LCA analysis is performed to assess the
environmental impact of the process design. This is done using software: SustainPro and LCASoft that
determine the key sustainability and LCA measures such as sustainability
metrics for environment, economic and social; carbon footprint; safety index
and many more. In addition, PRO/II is used for process simulation (for
verification of design), ICAS for property prediction and analysis of design
options; ECON for cost and economic analysis. This procedure can be applied to
design and/or analysis for new or existing chemical or biochemical processes.
The process design decisions are made considering the sustainability and LCA
issues together with the process design specifications. The
conceptual process design of the cumene producing plant is performed as part of
a MSc-level course on Process Design at the Department
of Chemical and Biochemical Engineering at DTU under the supervision of
Professor Rafiqul Gani.

A production rate of 100,000 metric
tons/year of cumene is considered. The highest annual profit of base case is
obtained in the second year and is estimated to be 20 million USD with a
payback time of 1-2 years depending on the type of depreciation. The capital
and operating costs are divided into the individual cost items in order to analyze
which equipment and utilities contribute significantly to these costs. It is
found that the compressor is the most expensive equipment contributing to
capital costs and the reboiler utility is the main
contributor to the total operating cost. This information is then used as
target for process improvement by heat integration and process optimization,
thus increasing the annual profit and reducing the payback time. The
environmental impact analysis identifies impact due to the release of chemicals
and points to the need of better control mechanisms through the sustainable LCA
analysis.

In this poster the following will be
presented: Product characteristics and applications, process flow sheet, equipment
sizing, costing, economic evaluation, optimization targets, sustainability and
LCA assessment of the designed process.

References:

[1] F. Cavani,
G. Centi, S. Perathoner, F.
Trifiró. Sustainable Industrial Chemistry, John Wiley & Sons, 2009.

[2] L. T. Biegler, I. E. Grossmann and A. W.
Westerberg.
Systematic methods of
Chemical Process Design, Prentice Hall, 1997.