Vapor pressure is the pressure exerted by a vapor in equilibrium with its condensed phase at a fixed temperature in a closed system, rising with temperature as kinetic energy increases.

Introduce Ja, the diffusion flux, and a reference velocity. Subtract the reference velocity from the material velocity to obtain the true diffusion flux, illustrated with a pipe example.

Use convection to model mass transfer when diffusion or fixed-law approaches fail; employ correlations with mass transfer coefficients and concentration differences, guided by Grashopper's number and Prandtl numbers.

Analyze counter-current gas-liquid contact in absorption, contrast cocurrent flow, and trace solute transfer from the gas phase to the liquid, driven by gravity and density differences affecting mass transfer.

Explore single-stage and multi-stage absorption, assessing gas–liquid interactions, tray towers, and counter-current versus co-current flow to optimize gas scrubbing and stage efficiency.

Sieve trays use a perforated flat metal sheet to allow gas-liquid contact; liquid may whip through holes at low vapor, while high flow reduces contact, offering a simple, low-cost design.

Explore tray pressure drop in binary distillation when gas flows against liquid or requires compression, and how tray design, diameter, and height influence the pressure drop.

Calculate hl, the equivalent height of clear liquid holdup on a tray, and estimate the pressure drop using ksak and clc with h_w and superficial gas velocity.

introduces packings for gas–liquid contact, emphasizing inert, non corrosive, and strong materials with high surface area; compares random packings, Tuku packing, and grid packings, and stresses replaceability and flow balance.

Stacked packing alters flow in the column, improving gas and liquid distribution while reducing pressure drop and flow path length.

Learn how liquid/vapour redistributors insert intermediate liquid feeds to improve distribution between packed sections in tall distillation columns, ensuring even liquid flow and better vapor-liquid contact.

Use a demister or mist eliminator at the top of the column to remove droplets from the gas, keeping overhead gas clean and allowing liquid to be recovered as product.

Explore the role of a vortex breaker in a distillation column, preventing vortex formation and pool buildup by redirecting liquid flow into a controlled stream toward the bottom.

Identify how hold-down plates and bed limiters retain packing in a distillation column, limit bed size, and prevent packing from shifting under high gas flow.

Explore the middle column structure, noting feed placement at the fifth stage, dunkleman dropouts, and chimney trace for collection and vapor redistribution, with attention to pressure drop and column height.

Design a benzene–toluene distillation to achieve high benzene recovery using minimum stages, determine feed tray location, and compute actual stages with 1.5× minimum stages, including efficiency and final purities.

Explore column internals, comparing trays and packings, and examine how column height, diameter, and pressure drop affect flooding and separation for water and methanol feeds.