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An Integrated Design, Synthesis and Optimisation Approach for Efficient Chemical Process Configurations Combining Reaction and Distillation


BE95-1335 An Integrated Design Synthesis and Optimisation Approach for Efficient Chemical Pro???

Chemical processes normally consist of two major and discrete steps: reaction and separation. In the reaction step the desired chemicals are formed. Reactions are seldom complete and selective, thus the reactor effluent contains unreacted feed stocks, by-products and intermediates that must be removed from the commercial product and recycled back to the reactor. The separation step is most often carried out using a series of distillation columns.

In our approach we combine the reaction phase and the separation phase into a single reactive distillation RD step. We place the reactor inside the distillation column where reaction products are formed and simultaneously removed from the reaction zone by distillation. The raw materials and by-products are recycled inside the column. Since the products are continuously removed in the RD approach the chemical equilibrium restrictions of the traditional processes can be avoided and much higher conversion and often selectivity and yield can be achieved.

Since the cost of the separation section is high (often exceeding 50% of the investment cost and energy cost of whole unit) compared with the reactor section (often less than 10%) the combination in RD is very effective in terms of capital investment and energy utilisation. RD concept is relatively new, but there are already few outstanding commercial successes. In their methyl acetate plant Eastman Kodak replaced four distillation columns by a single RD column.

The design of RD is currently based on expensive and time consuming sequences of laboratory and pilot plant experiments, since there is no commercially available software adequately describing all relevant features of reactions (catalyst, kinetics, hold up) and distillation (VLE, thermodynamics, plate and packing behaviour) and their combinations in RD. There is also a need to improve catalysts and column internals for RD applications.

In our approach we shall create a
- a synthesis tool which allows rapid evaluation of the feasibility of RD for new products and processes, i.e. when and how to use RD. - a design tool to simulate and design RD columns.
- a predictive tool combining the synthesis and design modules for simultaneous synthesis, analysis and optimisation of RD.

We will also :
- manufacture new innovative catalysts for RD applications. - perform extensive pilot plant tests to
- obtain design data for specific RD applications.
- test commercial feasibility of RD for these test processes. - verify and improve models in synthesis and design tools.
This new approach based on computer tools will:
- shorten the time required from product idea to commercial plant by 50%. - significantly reduce and focus laboratory, bench and pilot scale experiments.
- improve the possibility to test for innovative new products and process ideas.

Our consortium consisting of partners from Research, Engineering, Refining and very broad Chemicals sector provides a unique opportunity to introduce and expand this new technology to European Chemical Industry to maintain its competitive edge over developers from Japan, East Asia, USA and Far East.


Neste Oy
02151 Espoo

Participants (7)

BP Chemical Ltd
United Kingdom
Chertsey Road
TW16 7LN Sunbury On Thames
Basf AG
67056 Ludwigshafen
Helsinki University of Technology
02150 Espoo
Hoechst AG

65926 Frankfurt-am-main
Via Maritano 26
20097 San Donato Milanese
Technische Universität Clausthal
38678 Clausthal - Zellerfeld
Universität Dortmund
70,Emil-figge Strasse
44227 Dortmund