Inherently safer design: Which inherently safer design strategy applies to each of the following?

a. A flammable solvent is used to control the temperature in a reactor. The solvent is replaced by a nonflammable solvent.

b. A valve that requires 10 turns to close is replaced by a quarter-turn valve.

c. The equipment in a process can withstand 10 bar gauge (barg) of pressure even though the actual process operates normally at 5 barg. The pressure relief valve opening pressure is reduced from 10 barg to 8 barg.

d. A plant stores a large quantity of a hazardous intermediate chemical to keep the plant operating during upsets in the upstream process. The intermediate storage is eliminated and the process reliability is improved to prevent upsets and downtime.

e. An alternative reaction pathway is used that involves less hazardous raw materials.

f. The trays on a distillation column are replaced by structured packing, which operates over a wider range of operating conditions.