What is the calculation needed to determine the height of the tray distillation column required to purify 20w% diluted methanol into 80w% purified methanol?
To calculate the height of the tray distillation column required for purifying the diluted methanol to 80w%, several calculations need to be performed. This includes determining the flow rate of the feed, estimating the flow rate of methanol in the feed, identifying the flow rate of the purified methanol, calculating the difference in flow rates, determining the number of theoretical trays required, and finally calculating the height of the distillation column. Each step is crucial in understanding the overall process and designing an efficient system for methanol purification.
Flow Rate of Feed Calculation
Determine the flow rate of the feed:
- Given 100 tons (100,000 kg) of 20w% diluted methanol produced.
- Weight of methanol in the feed: (20/100) × 100,000 kg = 20,000 kg.
Flow Rate of Methanol in Feed
Calculate the flow rate of methanol in the feed:
- Weight percentage of methanol in the feed is 20w%.
- Convert weight to liters: (20,000 kg / 0.79 g/cm³) × (1,000 cm³/1 L) = 25,316.46 L.
Flow Rate of Purified Methanol
Determine the flow rate of the purified methanol:
- Required weight percentage of methanol in the purified product is 80w%.
- Calculate volume of purified methanol: (80/100) × V_purified = 25,316.46 L
- Volume of purified methanol: V_purified = (25,316.46 L × 100) / 80 = 31,645.58 L.
Number of Theoretical Trays Required
Determine the number of theoretical trays required:
- Use Murphree Efficiency and HETP values.
- Assume E = 0.8 & HETP = 0.3 m.
- Number of theoretical trays = (Height of column) / (HETP × E).
Height of Distillation Column Calculation
Calculate the height of the distillation column:
- Height of column = Number of theoretical trays × HETP × E.
- Solve for the height required based on the calculation steps.
By following these calculations, you can estimate the necessary height of the distillation column to purify methanol efficiently.