Process intensification, minimization

The term process intensification is used synonymously with minimization. Process intensification is also often used more specifically to describe new technologies which reduce the size of unit operations equipment, particularly reactors. Innovative process intensification techniques are receiving more and more attention. Interesting possibilities for a range of unit operations, including reaction, gas-liq-... 

Minimization goes much further than storage, however. For many processes the largest inventory of hazardous materials is in the reactor. If, through radical reactor design, inventories and equipment size can be reduced whilst throughput is maintained, then this presents opportunities for improved safety and possibly reduced capital costs. This is the concept behind Process Intensification which is discussed more fully below. 

Intensification of hazardous material results in a safer process. The minimization of waste will most often bring environmental benefits. 

Minimize—Use smaller quantities of hazardous substances, including process intensification approaches. Example Use a small, continuous reaction system for the production of nitroglycerine in place of a large batch reactor. 

Additional discussion and more examples of these strategies can be found in books by Kletz (6) and CCPS (4,5). The remainder of this discussion will focus on minimization (process intensification) as an inherent safety strategy. 

This is also fully in line with the concept of process intensification (see below) and the strategy of minimizing the size of process equipment for a inherently safer process design. 

Minimize Significantly reduce the quantity of hazardous material or energy in the system, or eliminate the hazard entirely if possible. It is necessary to use small quantities of hazardous substances or energy in (i) storage, (ii) intermediate storage, (iii) piping and (iv) process equipment, as discussed in the previous sections. The benefits are to reduce the consequence of incident (explosion, fire, toxic material release), and improve the effectiveness and feasibility of other protective systems (e.g. secondary containment, reactor dump or quench systems). Process intensification (see below) is also a way to reach this objective. 

Basically, process intensification aims at replacing large, expensive, energy-intensive equipments or processes with ones that are smaller, cheaper and more efficient. At the same time, they have to minimize environmental impact, increase safety, improve remote control and automation and ensure a better product quality. 

Although there are many advantages of applying process intensification, there are some aspects that will invariably need to be managed. Some of these issues to be managed are a potential for decreased inherent safety as there will be less incentive to ehminate hazardous materials, given that the inventories are minimized a potential for reaction runaway if heat transfer is not sufficient, given a reduction of solvent used a potential for... 

Minimization or elimination of solvents, use of water where possible Process intensification... 

Section 4.3 on Process Development includes additional examples of opportunities for process minimization or intensification, including ... 

Minimize (intensification) Change from large batch reactor to a smaller continuous reactor Reduce storage inventory of raw materials Improve control to reduce inventory of hazardous intermediate chemicals Reduce process hold-up... 

---