Top 100 Vocabulary for Adults | Chemical Engineers
Chemical-engineering vocabulary is the language of transforming matter safely, efficiently and predictably. Chemical engineers connect chemistry to thermodynamics, fluid flow, heat transfer, reaction engineering, separations and plant-scale economics. The profession asks not only whether a reaction can happen, but whether it can happen continuously, safely, controllably and at useful scale.
This professional flagship belongs to the eduKate Adult Vocabulary for Professionals system. It complements Process Engineers, Industrial Engineers and Manufacturing Engineers.
The Four Banks
Balances & Thermodynamics: mass balance, energy balance, steady state, transient, system boundary, control volume, mole, concentration, composition, phase, equilibrium, vapour pressure, enthalpy, entropy, heat capacity, latent heat, fugacity, activity, equation of state, ideal gas, compressibility, phase diagram, dew point, bubble point, flash calculation.
Reaction & Transport: reaction rate, kinetics, rate constant, activation energy, catalyst, conversion, selectivity, yield, reactor, batch reactor, CSTR, plug-flow reactor, residence time, diffusion, convection, mass transfer, heat transfer, conduction, viscosity, Reynolds number, laminar flow, turbulent flow, pressure drop, boundary layer, transport coefficient.
Separations & Unit Operations: distillation, absorption, stripping, extraction, adsorption, filtration, centrifugation, evaporation, crystallisation, drying, membrane, reverse osmosis, exchanger, reboiler, condenser, column, tray, packing, reflux, recycle, purge, utility, steam, cooling water, compressed air.
Safety, Design & Scale-Up: PFD, P&ID, process hazard, HAZOP, relief valve, containment, flammability, toxicity, corrosivity, runaway reaction, inerting, venting, emergency shutdown, design pressure, design temperature, material compatibility, corrosion allowance, scale-up, pilot plant, debottlenecking, process economics, CAPEX, OPEX, lifecycle, process integrity.
Top 100 Chemical Engineering Vocabulary: Working Meanings
| # | Word | Professional meaning |
|---|---|---|
| 1 | Mass balance | Accounting of material entering, leaving, accumulating or reacting in a system. |
| 2 | Energy balance | Accounting of heat, work and energy changes across a system. |
| 3 | Steady state | A condition where measured system variables do not change with time. |
| 4 | Transient | A time-dependent condition during change or disturbance. |
| 5 | System boundary | The conceptual edge separating the system from its surroundings. |
| 6 | Control volume | A defined region used for mass and energy-flow analysis. |
| 7 | Mole | A chemical amount containing Avogadro’s number of entities. |
| 8 | Concentration | The amount of a component within a mixture. |
| 9 | Composition | The relative quantities of components in a mixture. |
| 10 | Phase | A physically distinct state such as solid, liquid or gas. |
| 11 | Equilibrium | A condition where opposing processes balance macroscopically. |
| 12 | Vapour pressure | The equilibrium pressure exerted by a vapour above its condensed phase. |
| 13 | Enthalpy | A thermodynamic property useful for energy-flow calculations. |
| 14 | Entropy | A thermodynamic property related to energy dispersal and irreversibility. |
| 15 | Heat capacity | The heat required to raise a material’s temperature by a specified amount. |
| 16 | Latent heat | Energy absorbed or released during a phase change without temperature change. |
| 17 | Fugacity | An effective pressure used to represent non-ideal chemical potential. |
| 18 | Activity | An effective concentration used for non-ideal thermodynamic behaviour. |
| 19 | Equation of state | A mathematical relation among pressure, volume, temperature and composition. |
| 20 | Ideal gas | A simplified gas model obeying the ideal-gas relationship. |
| 21 | Compressibility | The degree to which volume changes with pressure. |
| 22 | Phase diagram | A map of stable phases across temperature, pressure or composition. |
| 23 | Dew point | The condition at which vapour first begins to condense. |
| 24 | Bubble point | The condition at which liquid first begins to boil. |
| 25 | Flash calculation | An equilibrium calculation splitting a feed into vapour and liquid phases. |
| 26 | Reaction rate | The speed at which reactants are consumed or products formed. |
| 27 | Kinetics | The study of reaction rates and mechanisms. |
| 28 | Rate constant | A parameter relating reaction rate to reactant concentrations. |
| 29 | Activation energy | The energy barrier influencing reaction rate. |
| 30 | Catalyst | A material increasing reaction rate without being consumed overall. |
| 31 | Conversion | The fraction of a reactant transformed. |
| 32 | Selectivity | The preference for forming one product over another. |
| 33 | Yield | The amount of desired product relative to a theoretical or feed basis. |
| 34 | Reactor | Equipment in which chemical reactions are carried out. |
| 35 | Batch reactor | A reactor operated with a finite charge processed over time. |
| 36 | CSTR | Continuous stirred-tank reactor with idealised complete mixing. |
| 37 | Plug-flow reactor | A reactor model where fluid moves through with limited axial mixing. |
| 38 | Residence time | The average time material spends within equipment. |
| 39 | Diffusion | Molecular transport driven by concentration gradients. |
| 40 | Convection | Transport caused by bulk fluid motion. |
| 41 | Mass transfer | Movement of chemical species between locations or phases. |
| 42 | Heat transfer | Movement of thermal energy between systems. |
| 43 | Conduction | Heat transfer through direct molecular interaction. |
| 44 | Viscosity | A fluid’s resistance to deformation or flow. |
| 45 | Reynolds number | A dimensionless quantity used to characterise flow regime. |
| 46 | Laminar flow | Flow dominated by orderly fluid motion. |
| 47 | Turbulent flow | Flow characterised by fluctuations and mixing. |
| 48 | Pressure drop | Reduction in fluid pressure along a flow path. |
| 49 | Boundary layer | The near-surface region where velocity or concentration gradients are strong. |
| 50 | Transport coefficient | A parameter relating transfer rate to a driving force. |
| 51 | Distillation | Separation based on volatility differences. |
| 52 | Absorption | Transfer of a gas component into a liquid. |
| 53 | Stripping | Removal of a dissolved component from a liquid into a gas. |
| 54 | Extraction | Transfer of a solute between immiscible phases. |
| 55 | Adsorption | Accumulation of molecules on a surface. |
| 56 | Filtration | Separation of solids from fluid using a porous medium. |
| 57 | Centrifugation | Separation using centrifugal force. |
| 58 | Evaporation | Removal of solvent by vaporisation. |
| 59 | Crystallisation | Formation and recovery of solid crystals from a solution or melt. |
| 60 | Drying | Removal of moisture or solvent from a solid or product. |
| 61 | Membrane | A selective barrier used to separate components. |
| 62 | Reverse osmosis | A pressure-driven membrane process rejecting dissolved species. |
| 63 | Exchanger | Equipment transferring heat between process streams. |
| 64 | Reboiler | A heat exchanger supplying vapour to a distillation column. |
| 65 | Condenser | Equipment removing heat to condense vapour. |
| 66 | Column | Vertical process equipment used for separation or contacting. |
| 67 | Tray | An internal column stage promoting vapour-liquid contact. |
| 68 | Packing | Column internals providing surface area for mass transfer. |
| 69 | Reflux | Condensed overhead liquid returned to a distillation column. |
| 70 | Recycle | A process stream returned to an earlier stage. |
| 71 | Purge | A stream removed to prevent accumulation of unwanted components. |
| 72 | Utility | A supporting service such as steam, cooling water or power. |
| 73 | Steam | Water vapour used widely for process heating. |
| 74 | Cooling water | Water circulated to remove heat from process equipment. |
| 75 | Compressed air | Pressurised air used for instruments or process services. |
| 76 | PFD | Process Flow Diagram showing major equipment and process streams. |
| 77 | P&ID | Piping and Instrumentation Diagram showing equipment, piping, controls and safeguards. |
| 78 | Process hazard | A condition capable of causing fire, explosion, toxicity or major loss. |
| 79 | HAZOP | Hazard and Operability Study systematically examining process deviations. |
| 80 | Relief valve | A protective device releasing pressure above a set condition. |
| 81 | Containment | Keeping hazardous material within intended equipment and piping. |
| 82 | Flammability | The tendency of a substance to ignite and burn. |
| 83 | Toxicity | The capacity of a substance to cause biological harm. |
| 84 | Corrosivity | The tendency of a substance to chemically attack materials. |
| 85 | Runaway reaction | An accelerating reaction in which heat generation exceeds removal. |
| 86 | Inerting | Replacing reactive atmosphere with a less reactive gas. |
| 87 | Venting | Controlled release of gas or vapour from equipment. |
| 88 | Emergency shutdown | A protective system stopping process operation under hazardous conditions. |
| 89 | Design pressure | The pressure used to define mechanical design requirements. |
| 90 | Design temperature | The temperature used to define equipment design requirements. |
| 91 | Material compatibility | The suitability of a material for contact with process chemicals and conditions. |
| 92 | Corrosion allowance | Additional material thickness provided for expected corrosion loss. |
| 93 | Scale-up | Increasing process size while preserving required performance and safety. |
| 94 | Pilot plant | A smaller-scale facility used to test process behaviour before full scale. |
| 95 | Debottlenecking | Removing constraints that limit process capacity. |
| 96 | Process economics | Analysis of the financial performance of process alternatives. |
| 97 | CAPEX | Capital expenditure required to create or expand plant assets. |
| 98 | OPEX | Operating expenditure required to run the process. |
| 99 | Lifecycle | The full period from design and construction through operation and retirement. |
| 100 | Process integrity | The condition in which process equipment and safeguards remain fit for intended operation. |
Chemistry Changes at Scale
A reaction that behaves neatly in a flask may generate heat too quickly, mix poorly or transfer mass differently in a large vessel. Chemical engineering exists partly because scale changes the balance among reaction, transport and safety.
Scenario: Conversion Falls After Scale-Up
Check mixing, residence-time distribution, heat removal, mass-transfer resistance and catalyst condition before changing chemistry. The same recipe can produce different results when transport phenomena change.
Seven-Day Chemical Engineering Vocabulary Plan
| Day | Practice |
|---|---|
| 1 | Build mass and energy balances around one process. |
| 2 | Map thermodynamic states and phase behaviour. |
| 3 | Connect kinetics with reactor choice. |
| 4 | Trace one separation train. |
| 5 | Review hazards, safeguards and scale-up. |
| 6 | Recall 75+ chemical-engineering terms. |
| 7 | Write a one-page process review linking chemistry, transport, safety and economics. |
Continue the Process & Production Wing
Conclusion
Chemical-engineering vocabulary helps professionals connect molecular behaviour to industrial reality. It makes reaction, transport, separation, safety and economics part of one coherent transformation system.