50+ Chemical Engineer Interview Questions and Answers

Pump power is calculated using the affinity law, heat exchanger design involves Kern method, and column diameter changes under pressure and vacuum.

• Pump power is calculated using the affinity law formula: P2/P1 = (N2/N1)^3 * (D2/D1)^5

• Heat exchanger design involves using the Kern method to determine the heat transfer area and overall heat transfer coefficient

• Types of heat exchangers include shell and tube, plate heat exchangers, and double pipe heat exchangers

• When a column is r...read more

I encountered a technical problem while working on a chemical process optimization project.

• During the project, I faced a challenge with a reactor that was not achieving the desired conversion rate.

• I conducted a thorough analysis of the process parameters and identified a potential issue with the catalyst.

• To confirm my hypothesis, I performed various tests and experiments to evaluate the catalyst's performance.

• Based on the results, I determined that the catalyst had lost its a...read more

Blowing a balloon violates Boyle's Law because the pressure inside the balloon increases as the volume decreases.

• Blowing air into a balloon increases the pressure inside the balloon.

• Boyle's Law states that at constant temperature, the pressure of a gas is inversely proportional to its volume.

• By blowing air into the balloon, the volume decreases while the pressure increases, violating Boyle's Law.

The equation commonly used for transporting fluid from one place to another is the Bernoulli's equation.

• Bernoulli's equation relates the pressure, velocity, and height of a fluid along a streamline.

• It is commonly used in fluid mechanics to analyze the flow of fluids in pipes, pumps, and other systems.

• The equation is: P + (1/2)ρv^2 + ρgh = constant, where P is pressure, ρ is density, v is velocity, and h is height.

• It helps in understanding the energy balance of a fluid as it m...read more

Calculating heat transfer area involves using formulas based on heat transfer coefficients, temperature differences, and overall heat transfer.

• Basic Formula: A = Q / (U * ΔT), where A is the heat transfer area, Q is the heat transfer rate, U is the overall heat transfer coefficient, and ΔT is the temperature difference.

• Example: For a heat exchanger with Q = 5000 W, U = 200 W/m²K, and ΔT = 50 K, the area A = 5000 / (200 * 50) = 0.5 m².

• Log Mean Temperature Difference (LMTD): Fo...read more

Chemical engineering plays a crucial role in the chemical industry by designing processes, optimizing production, and ensuring safety and efficiency.

• Designing and optimizing chemical processes for production

• Developing new materials and products

• Ensuring safety and environmental compliance

• Improving efficiency and reducing costs

• Troubleshooting and problem-solving in production

• Collaborating with other engineers and scientists

The design process for a distillation column involves several steps to ensure efficient separation of components based on volatility.

• Define Separation Requirements: Determine the desired purity and recovery of the components to be separated, such as separating ethanol from water.

• Select Distillation Type: Choose between continuous or batch distillation based on the process needs; for example, continuous for large-scale operations.

• Determine Operating Conditions: Establish tempe...read more

ETP unit BDT unit is a part of petroleum refining process.

• ETP stands for Effluent Treatment Plant.

• BDT stands for Biological Desulfurization Tower.

• ETP unit is responsible for treating and purifying the wastewater generated during the refining process.

• BDT unit is used for removing sulfur compounds from the petroleum products.

• Both units play a crucial role in ensuring environmental compliance and producing high-quality petroleum products.

Assumptions of Bernoulli's equation in fluid dynamics

• Incompressible flow (density is constant)

• Steady flow (velocity does not change with time)

• No viscous effects (no friction losses)

• No heat transfer (adiabatic process)

• Flow along a streamline (no cross-flow mixing)

• Potential flow (irrotational flow)

• Negligible changes in elevation (no significant height differences)

The Bernoulli equation relates the pressure, velocity, and elevation of a fluid in a moving streamline.

• The Bernoulli equation is P + 1/2 * rho * v^2 + rho * g * h = constant

• P represents the pressure of the fluid

• rho is the density of the fluid

• v is the velocity of the fluid

• g is the acceleration due to gravity

• h is the height of the fluid above a reference point

• The equation is based on the principle of conservation of energy for flowing fluids

RT in wastewater treatment plant refers to the retention time, which is the amount of time wastewater remains in a treatment system.

• RT is a critical parameter in wastewater treatment plants as it determines the efficiency of the treatment process.

• It is calculated by dividing the volume of the reactor by the flow rate of influent wastewater.

• A longer retention time allows for more thorough treatment of contaminants in the wastewater.

• Shorter retention times may result in incompl...read more

I am interested in refineries because of their crucial role in the production of various petroleum products.

• Fascinated by the complex processes involved in refining crude oil into usable products

• Passionate about contributing to the development of cleaner and more efficient refining technologies

• Excited about the opportunity to work with a diverse range of chemicals and processes

• Interested in the challenges of optimizing refinery operations to maximize output and minimize envir...read more

Pump suction head is calculated by adding the atmospheric pressure, the vapor pressure of the liquid being pumped, and the elevation difference between the pump and the liquid source.

• Calculate the atmospheric pressure at the pump location

• Determine the vapor pressure of the liquid being pumped

• Find the elevation difference between the pump and the liquid source

• Add the atmospheric pressure, vapor pressure, and elevation difference to get the pump suction head

Sizing control valves involves flow requirements, pressure drop, and valve characteristics for optimal performance.

• Determine the flow rate: Calculate the required flow rate in GPM or L/min based on the process needs.

• Assess pressure drop: Evaluate the allowable pressure drop across the valve to ensure efficient operation.

• Consider fluid properties: Analyze the type of fluid (liquid, gas, or vapor) and its characteristics (density, viscosity).

• Select valve type: Choose between gl...read more

Distillation is a process of separating components of a mixture based on their boiling points.

• It involves heating the mixture to vaporize the component with the lowest boiling point.

• The vapor is then condensed and collected as a separate liquid.

• This process can be used to purify liquids, separate different components of a mixture, and extract desired substances from natural sources.

• Examples include the production of ethanol from fermented grains, the separation of crude oil i...read more

Yes, I have experience in commissioning chemical projects.

• I have worked on commissioning a chemical plant for a new production line

• I was involved in the startup and testing of equipment to ensure proper functioning

• I collaborated with a team of engineers to troubleshoot any issues that arose during commissioning

The two laws of thermodynamics are the first law, which states that energy cannot be created or destroyed, only transferred or converted, and the second law, which states that the entropy of an isolated system always increases over time.

• First law of thermodynamics: Energy cannot be created or destroyed, only transferred or converted.

• Second law of thermodynamics: The entropy of an isolated system always increases over time.

• The first law is often summarized as 'energy conservat...read more

HIRA stands for Hazard Identification and Risk Assessment. It is a process used to identify potential hazards and assess the associated risks in a workplace or project.

• HIRA involves identifying hazards, evaluating the risks associated with those hazards, and implementing control measures to mitigate the risks.

• The process typically includes hazard identification, risk assessment, risk control, and monitoring and review.

• Examples of hazards that may be identified in HIRA include...read more

Distillation column separates components in a mixture based on differences in boiling points.

• Distillation column is used to separate components in a mixture based on differences in boiling points.

• Feedback control adjusts operating conditions based on output to maintain desired separation efficiency.

• Feedforward control predicts disturbances and adjusts operating conditions proactively to maintain separation efficiency.

• Examples of feedback control in distillation column include...read more

Yes, I have plans for further studies to enhance my knowledge and skills in chemical engineering.

• I am considering pursuing a master's degree in chemical engineering to specialize in a specific area of interest.

• I am also interested in attending workshops and conferences to stay updated with the latest advancements in the field.

• Continuing education courses and certifications are also on my radar to broaden my skillset.

• I believe further studies will not only enhance my career pr...read more

Chemical reaction engineering is the study of chemical reactions and their design and optimization in industrial processes.

• It involves the application of chemical kinetics, thermodynamics, and transport phenomena to design and optimize chemical reactors.

• Chemical reaction engineering is used in industries such as petrochemicals, pharmaceuticals, and food processing.

• Examples of chemical reactions include combustion, polymerization, and fermentation.

• The goal of chemical reaction...read more

A catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process, while a non-catalyst does not participate in the reaction.

• Catalysts lower the activation energy required for a reaction to occur

• Non-catalysts do not alter the activation energy of a reaction

• Examples of catalysts include enzymes, transition metals, and acids

• Examples of non-catalysts include solvents and inert gases

Diesel hydrotreating unit is a process used to remove impurities from diesel fuel through hydrogenation.

• Diesel hydrotreating unit uses hydrogen to remove sulfur, nitrogen, and other impurities from diesel fuel.

• The process involves passing the diesel fuel over a catalyst in the presence of hydrogen gas.

• The catalyst helps to break down the impurities into simpler, more stable compounds.

• The treated diesel fuel has improved quality in terms of sulfur content, which is important f...read more

Refineries convert crude oil into various products like fuels, lubricants, and chemicals through distillation and processing.

• Gasoline: Used as fuel for vehicles.

• Diesel: Fuel for trucks, buses, and machinery.

• Jet Fuel: Aviation fuel for aircraft.

• Kerosene: Used for heating and lighting.

• Liquefied Petroleum Gas (LPG): Used for cooking and heating.

• Asphalt: Used in road construction.

• Lubricating Oils: Used in engines and machinery.

• Petrochemical Feedstocks: Raw materials for chemicals...read more

Distillation was first described by the ancient Greeks and was further developed by Islamic scholars in the Middle Ages.

• Distillation was first mentioned by the ancient Greek philosopher Aristotle.

• Islamic scholars such as Jabir ibn Hayyan and Al-Kindi made significant advancements in distillation techniques.

• The first detailed description of distillation was provided by the Persian alchemist Muhammad ibn Zakariya al-Razi.

• Distillation techniques were further refined by European ...read more

Li Ion batteries work based on the movement of lithium ions between the anode and cathode.

• Lithium ions move from the anode to the cathode during discharge and in the reverse direction during charging.

• The anode is typically made of graphite, while the cathode is made of a lithium metal oxide.

• Electrolytes allow the movement of lithium ions while preventing the direct contact of the anode and cathode.

• The separator between the anode and cathode prevents short circuits.

• Li Ion batt...read more

Sludge waste can be calculated by determining the volume or weight of sludge produced and multiplying it by the density of the sludge.

• Calculate the volume or weight of sludge produced

• Determine the density of the sludge

• Multiply the volume or weight by the density to get the total sludge waste