(b) A 150ft3 tank containing air is to be inerted to 1% oxygen concentration. Pure nitrogen is available for the job. Because the tank's maximum allowable working pressure is 150 psia, it is possible to use either the sweep-through or a pressurization technique. For the pressurization technique, multiple pressurization cycles might be necessary, with the tank being returned to atmospheric pressure at the end of each cycle. The temperature is 80F. i) Determine the volume of nitrogen required for each technique. (3 marks) ii) For the pressurization technique, determine the number of cycles required if the pressure purge includes increasing the pressure to 140 psia with the nitrogen and then venting to 10 psig. (4 marks) iii) Determine the number of pressure purges required to reduce the vessel oxygen concentration from 21% to 1% if the nitrogen contains 9000ppm of oxygen. (3 marks) Data: Density of Nitrogen 1.251g/L(0C,101.325kPa);1bm=453.593g