Controlling gas and vapor concentrations outside the toxicity limits is a major

Question

Controlling gas and vapor concentrations outside the toxicity limits is a major consideration in occupational safety and health. Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is slightly less dense than air. It is toxic to hemoglobin animals (including humans) when encountered in concentrations above about 35 ppm. If you are working in a lab with space around 100 m^3. You are using CO in a 300 liter cylinder with 2500psi pressure. If cylinder valve suddenly leaks, 1) please calculate the maximum concentration of CO in this lab. Will it reach the toxic limit (35ppm)? 2) Please design a venting system and calculate minimum venting flowrate in order to reduce the CO concentration below the 35ppm limit in 60 seconds. If equation of states (EOS) are used in your calculation, assume air in the lab is ideal gas, while CO in high pressure cylinder should be estimated by one of cubic equations, for instance RK equation.

Explanation / Answer

1.

PEL (Permissible Exposure Limit )for CO= 35 ppm

Density of CO= 1.14 g/ltr

MW of CO= 28.01 g/mol

Since concentration = mass/(volume of air), we need to know what mass of CO was spilled (i.e., 300 ltr = ? g) in order to compare it to the PEL

Using the density of CO, we can find the mass of CO spilled: – 300 l * 1.14 g/l = 342 g CO spilled

Now we can calculate the concentration of CO using the volume of air in the lab: – 342 g CO / 100 m3 air = 3.42 g/m3

We now have to convert this concentration to ppm, and we start by changing the units to mg/m3:

3.42 * 1000 = 3420 mg/m3

Now using the molecular weight (28.01 g/mol), we convert to ppm:

3420 * 24.45/28.01 = 2985.33 ml/m3 = 2985.33 ppm

2. Yes, easily

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.