Module 1 Unit 1 Flashcards
Industries, in which the raw materials undergo chemical conversion during their processing into finished products, as well as the physical conversions common to industry in general.
Chemical process industries
Chemical reactions applied to chemical processing.
Chemical conversions
the burning of a fuel and oxidant to produce heat and/or work.
Combustion
the process of heating a substance to a high temperature but below the melting or fusing point, causing loss of moisture, reduction or oxidation, and dissociation into simpler substances.
Calcination
a thermochemical decomposition of organic material at elevated temperatures without the participation of oxygen. It involves the simultaneous change of chemical composition and physical phase, and is irreversible.
Cracking or Pyrolysis
a reaction in which hydrogen is detached from a molecule. The reaction is strongly endothermic, and therefore heat must be supplied to maintain the reaction temperature.
Dehydrogenation
a chemical reaction or process which results in the formation of a chemical bond between a halogen atom and another atom.
Halogenation
a chemical reaction in which water is used to break down a compound; this is achieved by breaking a covalent bond in the compound by inserting a water molecule across the bond.
Hydrolysis
a chemical reaction involving the addition of oxygen, the removal of hydrogen, or the removal of an electron from a substance.
Oxidation
a chemical reaction in which two or more molecules combine to form larger molecules that contain repeating structural units
Polymerization
the complete transfer of one or more electrons to a molecular entity (also called “electronation”), and, more generally, the reverse of the processes described under oxidation
Reduction
PHYSICAL CONVERSIONS
changes are of a strictly physical nature
a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture
Distillation
the mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass.
Filtration
the adhesion of atoms, ions, or molecules from a gas, liquid, or dissolved solid to a surface
Adsorption
the spread of particles through random motion from regions of higher concentration to regions of lower concentration.
Diffusion
the (natural or artificial) process for the formation of solid crystals from a uniform solution. Crystallization is in general the last chemical purification step in the production of ingredients.
Crystallization
the physical operations necessary for manufacturing chemicals
Unit Operations
fluids filtration and solid fluidization
transportation,
Fluid flow processes
evaporation, condensation
Heat transfer processes
absorption, distillation, extraction, adsorption and drying
Mass transfer processes
gas liquefaction and refrigeration
Thermodynamic processes
transportation, crushing and pulverization and screening
Mechanical processes
chemical operations - e.q. sulfonation, nitration, oxidation
Unit Processes
fraction of raw material recovered as the desired product.
Yield
fraction changed to something else – by-products as well as products
- used to indicate the amount changed by a single pass through an apparatus when multiple passes are used.
Conversion
used in manufacturing, in which the object in question is created stage by stage over a series of workstations, and different batches of products are made.
Batch Process
used to manufacture, produce, or process materials without interruption.
Continuous Process
a set of boxes interconnected to one another by arrows to show the flow of steps involved in the conversion of raw materials into finished products.
FLOW CHARTS
– for the purpose of studying the process
- often show only material and energy flows and operating conditions
Rough-block diagram (simple)
– for actual plant construction
- show such details as fire lines, instruments and control systems, air lines, drains, etc.
Complex-flow diagram
a specialist in current aspects of chemical process design
Process Engineer
a small-scale unit designed to allow experiments that obtain design data for larger plants and sometimes to produce significant quantities of a new product to permit user evaluation
Pilot plant
Type of instrument that shows results by mechanical movement of some type of device which is proportional to the quantity being measured.
Analog instrument
a device to convert the quantity being measured into some type of signal
Digital instrument
includes convenient information concerning the actual equipment that can be supplied by various manufacturers
Chemical Engineering Catalog
Judgment based on comparative facts must be exerted in most of the important discussions of the chemical engineer.
Competing Processes
Yields and conversions of the chemical process form the basis for the material balances, which in turn are the foundation for cost determination.
Material Balances
Is a frequently a major cost in chemical plants, but it is often possible to reduce energy use by altering processing procedures.
Energy
Skilled operators contribute as much to a plant’s success as excellence in design. The chemical process industries have moved rapidly into labor – saving techniques
Labor
- An experienced chemical engineer can closely estimate the cost of processing.
- The single largest cost is usually raw material, with energy, labor, overhead, and depreciation all being significant.
Overall Cost
The physical condition of the products has a great influence on marketability
Purity and Uniformity of Product
Packaging and storing are expensive and should be avoided whenever possible.
Packaging
Customer service people are able to instruct customers concerning the profitable use of their employer’s products. Sales and customer service form the major contact between buyer and seller.
Sales and Customer Service
