How to do chemical process design?

3.4 Supplementary Notes

Chemical technology majors still need to participate in the preliminary work, the main preliminary work is:

Project proposal; Preparation of feasibility report.

Project quotation; Preparation of tender and technical documents.

Introduction project: including inquiry, tender evaluation, contract technical annex negotiation.

Overall planning and design of large and medium-sized combined installations.

4 Process design method

4.1 Selection of process route

Factors to be considered: raw material source, economic and social benefits (production costs), environmental protection, other operating conditions, safety, fire protection, investment, technological advancement, feasibility and rationality opinions.

4.2 Optimization of process plan

▲ Optimization of reaction process

There are many and complicated problems to be considered in the optimization of reaction process. Such as reaction kinetics, reaction yield, catalyst characteristics, reaction course, reaction path.

The optimal operating conditions of the reactor include how to ensure the reaction temperature, reaction pressure, mixing requirements, heat transfer requirements, the ratio of each material, and the production cost under given conditions.

▲ Optimization of rectification process

If the distillation process needs to separate R components, R-1 rectification column is required.

Rectification optimization needs to consider: which component is the main product, which component is the product and the product specification requirements.

Distillation process optimization method 1) : trial method, the main rules are as follows:

Normal rectification is preferred.

Try to avoid decompression operations and use of cooling capacity.

The number of products should be minimal.

Corrosive and dangerous components should be separated first.

The components that are difficult to separate are finally separated.

The largest number of components shall be separated first.

The top of the tower and the products of the tower reactor are best separated by equal moles.

Optimization method of rectification process 2) : optimization method

Distillation process optimization method 3) : mathematical programming method

▲ Optimization of evaporation process

Single effect, double effect, triple effect evaporation.

Heat pump evaporation, membrane evaporation.

Multi-stage flash evaporation.

Forced circulation evaporation, natural circulation evaporation,.

The selection is based on the type of evaporator (standard, suspension frame, Levin, forced circulation evaporator).

4.3 Selection of process equipment

▲ Reactor

The choice of reactor should be based on material properties, stability, reaction complexity, product scale, reaction time, temperature, pressure and other factors.