40+ Chemical Engineer Interview Questions and Answers

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

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

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

Aarti Industries is a leading company in the chemical industry with a strong reputation for innovation and growth.

• Aarti Industries is known for its diverse product portfolio, including specialty chemicals, pharmaceuticals, and agrochemicals.

• The company has a strong focus on research and development, offering opportunities for career growth and learning.

• Aarti Industries has a global presence, providing exposure to international markets and opportunities for cross-cultural coll...read more

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

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.

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

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

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

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

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

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

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

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

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

The units in cpcl refer to specific heat capacity at constant pressure and specific heat capacity at constant volume.

• Units in cpcl are typically in J/(kg*K) or kJ/(kg*K).

• Specific heat capacity at constant pressure is denoted as cp.

• Specific heat capacity at constant volume is denoted as cv.

• The ratio of cp to cv is denoted as gamma (γ).

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

An exothermic process is a chemical reaction or process that releases energy in the form of heat.

• Exothermic reactions release heat to the surroundings

• They have a negative change in enthalpy (ΔH)

• Examples include combustion reactions, neutralization reactions, and some oxidation reactions

DAF stands for Dissolved Air Flotation, a water treatment process used to remove suspended solids, oils, and other contaminants.

• DAF involves the introduction of fine air bubbles into a water stream to float the particles to the surface for removal.

• It is commonly used in industrial wastewater treatment plants.

• DAF is effective in removing contaminants such as oils, grease, and suspended solids.

• The floated particles are then skimmed off the surface for disposal.

• DAF is a cost-eff...read more

Organisation can be managed through effective communication, delegation, setting clear goals, and prioritizing tasks.

• Establish clear goals and objectives for the organization

• Communicate effectively with team members to ensure everyone is on the same page

• Delegate tasks appropriately to ensure efficiency and productivity

• Prioritize tasks based on importance and deadlines

• Implement systems and processes to streamline operations

• Regularly review and assess progress towards goals

• Prov...read more

A chiller works by removing heat from a liquid through a refrigeration cycle.

• Chillers use a refrigerant to absorb heat from the liquid being cooled.

• The refrigerant then goes through a compressor to increase its pressure and temperature.

• The hot refrigerant is then passed through a condenser where it releases heat to the surroundings.

• The cooled refrigerant then goes through an expansion valve to reduce its pressure and temperature.

• Finally, the refrigerant absorbs heat from the ...read more

Heat transfer is the process of energy moving from a warmer object to a cooler object.

• Heat transfer can occur through conduction, convection, or radiation.

• Conduction is the transfer of heat through direct contact between materials, like a metal spoon heating up in hot soup.

• Convection is the transfer of heat through the movement of fluids, like boiling water in a pot.

• Radiation is the transfer of heat through electromagnetic waves, like the sun warming the Earth.

• Heat transfer i...read more

Flash point is the temperature at which a solvent gives off enough vapor to ignite in air.

• Flash point is a safety measure for handling solvents.

• Different solvents have different flash points.

• Examples: Acetone (−20 °C), Ethanol (13 °C), Gasoline (-40 °C)

I graduated from ABC University with a CGPA of 3.8

• Graduated from ABC University

• CGPA of 3.8

• Received honors for academic performance

Chemical engineering involves applying principles of chemistry and engineering to solve problems in various industries.

• Chemical engineers work in industries such as pharmaceuticals, petrochemicals, food and beverage, and environmental engineering.

• They design processes and equipment for large-scale manufacturing of chemicals and products.

• Chemical engineers also work on improving existing processes, ensuring safety and efficiency.

• Examples include designing a new drug manufactur...read more

Distillation is a process used to separate mixtures based on differences in boiling points.

• Distillation is used in various industries such as petroleum refining, chemical production, and beverage distillation.

• Types of distillation include simple distillation, fractional distillation, and steam distillation.

• Simple distillation is used to separate liquids with significantly different boiling points.

• Fractional distillation is used when the boiling points of the components are cl...read more

HAZOP stands for Hazard and Operability Study, while NFPA stands for National Fire Protection Association.

• HAZOP is a structured and systematic examination of a process to identify potential hazards and operability issues.

• NFPA develops and publishes fire protection codes and standards to minimize the risk and effects of fire and other hazards.

• HAZOP involves a team of experts analyzing the process using guidewords like 'no', 'more', 'less', 'reverse', etc.

• NFPA codes cover areas...read more

H2SO4 stands for sulfuric acid, a highly corrosive and strong acid commonly used in various industrial processes.

• H2SO4 is the chemical formula for sulfuric acid.

• It is a colorless, odorless, and highly corrosive liquid.

• Sulfuric acid is commonly used in the production of fertilizers, dyes, detergents, and explosives.

• It is also used in the petroleum industry for refining crude oil.

• Sulfuric acid has a wide range of applications in various industries due to its strong acidic prope...read more

Chemical engineers need a strong understanding of chemistry, physics, and engineering principles to design and optimize processes for producing chemicals and materials.

• Strong understanding of chemistry, physics, and engineering principles

• Ability to design and optimize processes for producing chemicals and materials

• Knowledge of safety regulations and environmental considerations

• Problem-solving skills to troubleshoot issues in production processes

• Effective communication skills ...read more

Cooling towers are heat removal devices used to transfer process waste heat to the atmosphere.

• Cooling towers use evaporation to remove heat from the water being circulated through the tower.

• The warm water is pumped to the top of the tower and distributed over the fill or packing material.

• As the water flows over the fill, it is exposed to air, which causes some of the water to evaporate and remove heat.

• The cooled water is collected at the bottom of the tower and recirculated b...read more

pH is a measure of the acidity or alkalinity of a solution on a scale of 0 to 14.

• pH stands for 'potential of Hydrogen'

• pH scale ranges from 0 (most acidic) to 14 (most alkaline)

• Neutral pH is 7, like pure water

• Acids have pH values below 7, bases have pH values above 7

• pH is important in various industries like water treatment, food processing, and pharmaceuticals

Iron carbon diagram shows the phases of iron-carbon alloys at different temperatures and compositions.

• Shows the phases of iron-carbon alloys at different temperatures and compositions

• Consists of regions for austenite, ferrite, cementite, and pearlite

• Helps in understanding the microstructure and properties of steel

• Used in heat treatment processes to control the final properties of steel

I have 5 years of experience working in the chemical engineering field, with a focus on process optimization and design.

• 5 years of experience in chemical engineering

• Specialize in process optimization and design

• Worked on projects involving chemical reactions and material synthesis