Chemical Process Terms fully solved graded A+ 2023/2024

Chemical Process TermsAbsorption - correct answer A process in which a gas mixture contacts a liquid solvent and a component (or several components) of the gas dissolves in the liquid. In an absorption column or absorption tower (or simply absorber), the solvent enters the top of a column, flows down, and emerges at the bottom, and the gas enters at the bottom, flows up (contacting the liquid), and leaves the top. Adiabatic - correct answer A term applied to a process in which no heat is transferred between the process system and its surroundings. Adsorption - correct answer A process in which a gas or liquid mixture contacts a solid (the adsorbent) and a mixture component (the adsorbate) adheres to the surface of the solid. Barometer - correct answer A device that measures atmospheric pressure. Boiler - correct answer A process unit in which tubes pass through a combustion furnace. Boiler feedwater is fed into the tubes, and the heat transferred from the hot combustion products through the tube walls converts the feedwater to steam. Boiling Point - correct answer (at a given pressure) For a pure species, the temperature at which the liquid and vapor can coexist in equilibrium at the given pressure. When applied to the heating of a mixture of liquids exposed to a gas at the given pressure, the temperature at which the mixture begins to boil. Bottoms Product - correct answer The product that leaves the bottom of the distillation column. The bottoms product is relatively rich in the less volatile components of the feed to the column. Bubble Point - correct answer (of a mixture of liquids at a given pressure) The temperature at which the first vapor bubble appears when the mixture is heated. Calibration - correct answer (of a process variable measurement instrument) A procedure in which an instrument is used to measure several independently known process variable values, and a calibration curve of known variable values versus the corresponding instrument readings is plotted. Once the instrument has been calibrated, readings obtained with it can be converted to equivalent process variable values directly from the calibration curve. Catalyst - correct answer A substance that significantly increases the rate of a chemical reaction although it is neither a reactant nor a product. Compressibility Factor - correct answer z=PV/nRT for a gas. If z=1, then PV=nRT (the ideal-gas equation of state) and the gas is said to behave ideally. Compressor - correct answer A device that raises the pressure of a gas. Condensation - correct answer A process in which an entering gas is cooled and/or compressed, causing one or more of the gas components to liquify. Uncondensed gases and liquid condensate leave the condenser as separate streams. Critical Pressure - correct answer P_c The highest pressure at which distinct vapor and liquid phases can coexist for a species. Critical Temperature - correct answer T_c The highest temperature at which distinct vapor and liquid phases can coexist for a species. The critical temperature and pressure, collectively referred to as the critical constants, are listed for various species in table B.1. Crystallization - correct answer A process in which a liquid is cooled or solvent is evaporated to an extent that solid crystals form. The crystals in a slurry (suspension of solids in a liquid) leaving the crystallizer may subsequently be separated from the liquid in a filter or centrifuge. Decanter - correct answer A device in which two liquid phases or liquid and solid phases separate by gravity.