Recent questions tagged mass-transfer

A binary mixture of butane and butadiene is to be separated in an extractive distillation using furfural. Furfural lowers the activity of butadiene more than it does for ...

Consider a non-reactive binary mixture of two ideal gases $\text{A}$ and $\text{B}$ in an isothermal horizontal closed tube. Due to the concentration difference at the tw...

$K$ value is defined as the ratio of mole fraction of a component in the vapor phase to that in the liquid phase. The $K$ values of propane and iso-butane at $293$ $K$ ar...

A volatile organic compound $\text{(VOC)}$ is to be adsorbed from air onto a bed of activated carbon. The equilibrium capacity of activated carbon at the feed conditions ...

A continuous distillation column is used to separate an equimolar mixture of diethylamine (DEA) and methanol. The feed enters the column as saturated liquid at a flow rat...

A gas stream with $2.01 \mathrm{~mol} \%$ ammonia is to be scrubbed in a counter-current isothermal packed bed absorber using pure water to reduce its concentration to $0...

The flooding velocity curves for two different structured packings are shown in the figure. The ratio of mass velocities of liquid $\left(G_{x}\right)$ to that of the gas...

​​​​​If $k$ is the mass transfer coefficient and $D_{v}$ is the molecular diffusivity, which one of the following statements is NOT CORRECT with respect to mass transfer ...

Oil is extracted from mustard seeds having $20 \: \mathrm{wt} \%$ oil and $80 \: \mathrm{wt} \%$ solids, using hexane as a solvent. After extraction, the hexane-free resi...

​​​​$500 \: \mathrm{mg}$ of a dry adsorbent is added to a beaker containing $100 \: \mathrm{mL}$ solution of concentration $100 \: \mathrm{mg \: phenol/ (L \: solution)}$...

Gas containing $0.8\: \mathrm{~mol} \%$ component $\text{A}$ is to be scrubbed with pure water in a packed bed column to reduce the concentration of $\text{A}$ to $0.1 \...

Solute $A$ is absorbed from a gas into water in a packed bed operating at steady state. The absorber operating pressure and temperature are $1 \: \mathrm{atm}$ and $300 \...

Components $A$ and $B$ form an azeotrope. The saturation vapour pressures of $A$ and $B$ at the boiling temperature of the azeotrope are $87 \: \mathrm{kPa}$ and $72.7 \:...

A wet solid of $100 \:\textsf{kg}$ containing $30 \: \mathrm{wt} \%$ moisture is to be dried to $2 \: \mathrm{wt} \%$ moisture in a tray dryer. The critical moisture cont...

​​​​​Consider the steady, uni-directional diffusion of a binary mixture of $A$ and $B$ across a vertical slab of dimensions $0.2 \mathrm{~m} \times 0.1 \mathrm{~m} \times...

Which one of the given statements is correct with reference to gas-liquid contactors for mass transfer applications?A tray tower is more suitable for foaming systems than...

​​​​​​A gas stream containing $95 \mathrm{~mol} \% \mathrm{CO}_{2}$ and $5 \mathrm{~mol} \%$ ethanol is to be scrubbed with pure water in a counter-current, isothermal ab...

​​​​​Sulfur dioxide $\left(\mathrm{SO}_{2}\right)$ gas diffuses through a stagnant air-film of thickness $2 \mathrm{~mm}$ at 1 bar and $30^{\circ} \mathrm{C}$. The diffus...

​​​​​A simple distillation column separates a binary mixture of $A$ and $B$. The relative volatility of $A$ with respect to $B$ is $2$. The steady-state composition of $A...

A liquid $\boldsymbol{L}$ containing a dissolved gas $\boldsymbol{S}$ is stripped in a countercurrent operation using a pure carrier gas $\boldsymbol{V}$. The liquid phas...

In a binary gas-liquid system, $N_{A, E M D}$ is the molar flux of a gas $A$ for equimolar counter diffusion with a liquid $B . N_{A, U M D}$ is the molar flux of $A$ for...

Which one of the following represents the $\text{CORRECT}$ effects of concentration polarization in a reverse osmosis process?Reduced water flux and reduced solute reject...

Consider two stationary spherical pure water droplets of diameters $d_{1}$ and $2d_{1}$. $CO_{2}$ diffuses into the droplets from the surroundings. If the rate of diffusi...

Consider steady-state diffusion in a binary $\text{A-B}$ liquid at constant temperature and pressure. The mole-fraction of $A$ at two different locations is $0.8$ and $0....

Consider interphase mass transfer of a species $S$ between two immiscible liquids $A$ and $B$. The interfacial mass transfer coefficient ot $S$ in liquid $A$ is twice of ...

A wet solid containing $20\%$ $\text{(w/w)}$ moisture (based on mass of bone-dry solid) is dried in a tray-dryer. The critical moisture content of the solid is $10\%$ $\t...

In reverse osmosis, the hydraulic pressure and osmotic pressure at the feed side of the membrane are $P_1$ and $\pi_1$, respectively. The corresponding values are $P_2$ a...

Feed solution $\textbf{F}$ is contacted with solvent $\textbf{B}$ in an extraction process. Carrier liquid in the feed if $\textbf{A}$ and the solute is $\textbf{C}$. The...

In a solvent regeneration process, a gas is used to strip a solute from a liquid in a countercurrent packed tower operating under isothermal condition. Pure gas is used i...

A distillation column handling a binary mixture of $A$ and $B$ is operating at total reflux. It has two ideal stages including the reboiler. The mole fraction of the more...

In a batch drying experiment, a solid with a critical moisture content of $0.2 \: kg$ $H_2O/kg$ dry solid is dried from an initial moisture content of $0.35 \: kg$ $H_2O/...

$SO_2$ from air is absorbed by pure water in a counter current packed column operating at constant pressure. The compositions and the flow rates of the streams are shown ...

Two film theory applies for absorption of a solute from a gas mixture into a liquid solvent. The interfacial mass transfer coefficient (in $mol \: m^{-2} \: s^{-1}$) for ...

Consider the equilibrium data for methanol-water system at $1$ bar given in the future below.A distillation column operating at $1.0$ bar is required to produce $92 \: mo...

Equilibrium data for a binary mixture of $E$ and $F$ at two different pressure is shown in the figure.It is desired to process a feed containing $80 \text{ mol } \% E$ an...

Two ideal cross-current stages operate to extract $P$ from a feed containing $P$ and $Q$, as shown below.The mass flow rates of $P$ and $Q$ fed to Stage $1$ are $1,000 \:...

Consider a vertically falling film of water over an impermeable wall. The film is in contact with a static pool of an non-reactive pure gas. The gas diffuses into the wat...

Pure gas $\textbf{P}$ is being absorbed into a liquid. The dissolved $\textbf{P}$ undergoes an irreversible reaction in the liquid film. The reaction is first order with ...

Consider a batch distillation process for an equimolar mixture of benzene and toluene at atmospheric pressure. The mole fraction of benzene in the distillate collected af...