basics Flashcards
Density:
Definition: Mass per unit volume (ρ=m/V)
Importance: Used in calculations for mass and volume balances, and understanding fluid behavior in processes.
Typical Units: kg/m³ or g/cm³.
Definition: Mass per unit volume of a substance.
Importance:
Fluid Flow Calculations: Determines pressure drop and flow rates.
Mass Balances: Essential for accurate process design and scaling.
Applications: Designing pipelines, storage tanks, and separation units.
Heat Transfer: definition, applications, types
Definition: Transfer of thermal energy between physical systems.
Applications: Designing heat exchangers, managing temperature control in processes, and energy recovery systems.
Types:
Conduction: Heat transfer through solids (Fourier’s law).
Convection: Heat transfer between a solid surface and a fluid (Newton’s law of cooling).
Radiation: Heat transfer through electromagnetic waves.
Key Equipment: Heat exchangers (transfer heat between two or more fluids).
Mass and Energy Balances:
Mass Balance: Conservation of mass, often applied in steady-state processes where input = output.
Energy Balance: Conservation of energy, used to calculate energy requirements or output in processes involving heating, cooling, reactions, etc.
Definition: Accounting for all materials and energy entering and leaving a system.
Importance: Ensures process efficiency and compliance with environmental regulations.
Applications: Designing new processes, scaling up from pilot to industrial scale, and troubleshooting operational issues.
Mass Transfer (definition, diffusion, mass transfer coefficient, application)
Definition: Movement of mass from one location to another, often involving phase changes.
Key Concepts:
Diffusion: Movement of molecules from high to low concentration.
Mass Transfer Coefficients: Measure the rate of mass transfer.
Applications: Absorption, distillation, extraction, and drying processes.
Fluid Mechanic ( definition, types of flow, berniullis equation? Applications, viscosity, laminar vs turbulent, Reynolds number
Definition: Behavior of fluids (liquids and gases) at rest and in motion.
Key Topics:
Flow Types: Laminar vs. turbulent flow.
Bernoulli’s Equation: Relationship between pressure, velocity, and elevation.
Applications: Pump and compressor selection, pipeline design, and fluid transport in refineries.
Key Concepts:
Viscosity: Measure of a fluid’s resistance to flow.
Laminar vs. Turbulent Flow: Laminar flow is smooth, while turbulent flow is chaotic and irregular.
Bernoulli’s Principle: Relates pressure, velocity, and height in a flowing fluid.
Reynolds Number: Used to predict whether flow is laminar or turbulent.
Pumps and Compressors: Move fluids through pipes; pumps are used for liquids, and compressors for gases
Thermodynamics
Definition: Study of energy, heat, work, and how they interact within a system.
Key Principles:
First Law: Energy conservation.
Second Law: Entropy and the direction of processes.
Applications: Designing processes like distillation, refrigeration, and energy integration in refineries.
First Law: Conservation of energy – energy cannot be created or destroyed.
Second Law: Entropy increases – energy spontaneously disperses if not hindered.
Enthalpy (H): Total heat content of a system.
Entropy (S): A measure of disorder in a system.
Gibbs Free Energy (G):
ΔG=ΔH−TΔS, indicates whether a process is spontaneous
Chemical Kinetics
Definition: Study of the rates of chemical reactions.
Key Topics:
Reaction Mechanisms: Step-by-step sequence of elementary reactions.
Rate Laws: Mathematical expressions describing reaction rates.
Applications: Reactor design, optimizing reaction conditions, and scaling up processes from lab to industrial scale.
Process Control
Definition: Regulation of process variables to maintain desired output.
Key Components:
Sensors and Transmitters: Measure process variables.
Controllers: Adjust inputs based on feedback.
Actuators: Implement control actions.
Applications: Ensuring stable and efficient operation of refinery processes, maintaining safety standards.
Viscosity
Definition: Measure of a fluid’s resistance to flow.
Importance:
Flow Dynamics: Influences pressure drop and energy requirements.
Heat and Mass Transfer: Affects efficiency of heat exchangers and mixing processes.
Applications: Pump selection, pipeline design, and lubrication systems.
Heat Exchangers:
Purpose: Transfer heat between two or more fluids without mixing them.
Types: Shell-and-tube, plate, and air-cooled exchangers.
Applications: Cooling process streams, heating reactants, and energy recovery systems.
How it Works: Typically operates with counter-current or co-current flow, where hot and cold fluids exchange heat through a solid barrier.
Distillation Columns:
Purpose: Separate mixtures based on differences in boiling points/ volatilities.
How it Works: A mixture is heated, and different components vaporize at different temperatures. The vapor is then condensed back into a liquid at various stages (called trays or packing).
How It Works: Vapor and liquid phases interact on trays or packing, allowing components to separate as they move up or down the column.
Applications: Refining crude oil into gasoline, diesel, and other products.
Pump
Purpose: Move fluids through the process/ pipes
Types: Centrifugal (for high flow, low viscosity) and positive displacement (for viscous fluids).
Applications: Transporting crude oil, water injection in refining, and circulation of process fluids.
How it Works: Increases pressure to move liquid through a system.
Compressors:
Purpose: Increase the pressure of gases.
How it Works: Compressors reduce the volume of the gas, increasing its pressure and temperature.
Types: Centrifugal, reciprocating, and screw compressors.
Applications: Gas injection, pressure boosting in pipelines, and process gas handling.
Reactor
Purpose: Facilitate chemical reactions under controlled conditions.
Purpose: Vessels where chemical reactions occur.
Types:
Batch Reactors: Operate in cycles, used for smaller quantities.
Continuous Stirred-Tank Reactors (CSTR): Run continuously with a steady inflow and outflow, often used for larger-scale processes.
Plug Flow Reactors (PFR): Fluid moves through a pipe-like reactor where reactions occur progressively along the length.
Applications: Synthesis of chemicals, polymerization, and catalytic reactions in refineries.
Separator
Purpose: Divide mixtures into their individual components based on density differences.
Types: Gravity separators, centrifuges, and decanters.
Applications: Oil-water separation, gas-liquid separation, and removal of solids from fluids.
Valves:
Purpose: Control the flow of fluids.
Types: Ball valves, gate valves, check valves.
How it Works: Adjust flow by opening, closing, or partially obstructing passageways.
Turbines:
Purpose: Convert fluid energy into mechanical energy.
How it Works: Fluid (steam, gas) flows through blades, causing the rotor to spin, converting the fluid’s energy into mechanical work.
Furnaces:
Purpose: Provide heat for processes like distillation or cracking.
How it Works: Burns fuel to generate high temperatures, which heat the process fluids.
Process Optimization
Definition: Enhancing process efficiency, reducing costs, and improving product quality.
Techniques:
Energy Integration: Utilizing waste heat.
Lean Manufacturing: Minimizing waste and maximizing productivity.
Applications: Improving refinery operations, enhancing safety, and increasing profitability.
Safety and Hazard Analysis
Importance: Ensuring safe operations to protect personnel, environment, and assets.
Methods:
HAZOP (Hazard and Operability Study): Identifying potential hazards.
FTA (Fault Tree Analysis): Analyzing pathways to system failures.
Applications: Designing safe processes, implementing safety protocols, and emergency response planning.
. Common Processes in Refineries
Desulfurization: Removing sulfur compounds to produce cleaner fuels.
Hydrotreating: Improving fuel quality by removing impurities.
Fluid Catalytic Cracking (FCC): Breaking down heavy hydrocarbons into lighter, more valuable products.
Reynolds Number
What to Know: It’s a dimensionless number used to predict flow patterns in fluid mechanics (whether the flow is laminar or turbulent).
Formula:
Re=ρuL/μ
(where
ρ = density,
u = velocity,
L = characteristic length,
μ = viscosity).
Importance: Often used to determine the type of flow in pipelines, which impacts the design of pumps and pipes.
Ideal Gas Law and Real Gas Behavior
What to Know: The ideal gas law
PV=nRT
PV=nRT is often used in process calculations, but gases in real-world applications often deviate from ideal behavior (especially under high pressure).
Importance: In refineries, gases like methane, ethylene, etc., behave differently from the ideal gas law, requiring correction factors (like compressibility factor,
Z).
First Law of Thermodynamics
The First Law states that energy cannot be created or destroyed, only transferred or converted from one form to another. In other words, the total energy of an isolated system remains constant.
Mathematical Expression:
ΔU=Q−W
Where:
ΔU = Change in internal energy of the system
Q = Heat added to the system
W = Work done by the system
Key Concepts:
Energy Conservation: The total energy in a closed system is conserved. If energy enters a system as heat, it can be stored as internal energy or converted to work, but the total energy remains constant.
Internal Energy: The internal energy (U) of a system refers to the total energy stored within it (due to the movement of molecules, chemical bonds, etc.).
Work and Heat: Work and heat are two ways of transferring energy. Work involves force applied over a distance, while heat is energy transferred due to a temperature difference.
