chemical engineering calculations Flashcards
The type of process where a material enters the process during its operation accumulates in the process vessel and withdrawn only after the process is over.
Semi-batch process
The term used to report pressure being the height of a column of a liquid of known density.
Head
The material which remain unchanged in a process is called ______
Tie substance
It is the reactant that would disappear first if the reaction goes to completion.
Limiting reactant
The ratio of the partial pressure of a vapor pressure in equilibrium with the liquid.
Relative Humidity
The maximum number of independent equations that can be derived by driving the material balances for an input and output stream with two component substances is/a
2
For balances on atomic species, which of the following material balance is applied?
a. input + generation = output
b. input = output
c. input + generation = output + consumption
d. input = output + consumption
input = output
Which of the following terms could express the extent to which the limiting reactant had reacted?
a. conversion. c. degree of completion
b. yield. d. all of these
d. all of these
Type of process stream that can be used to control the composition of a final exit streams by skipping one or more stages of the process and goes directly to another downstream stage.
By-pass
The analysis of coal given in %C, %N, %S,% moisture, % net H, % combined water and % ash is called ________
Modified proximate analysis
Type of moisture in coal which assumed to be the water held within the pore system and capillaries of coal.
Inherent moisture
The empirical relation which allows one to compute for the net hydrogen in a given solid fuel is________
Dulong Formula
Coal analysis which is based upon the volatilization characteristics of the fuel.
Proximate Analysis
The combustible present in refuse.
mixture of coked and uncoked coal
In the combustion of solid fuels, the tie component between the feed and the refuse is the
Ash
An orsat analyis of the flue when pyrite is roasted is a/an
SO3-free basis
Combustion conditions which will give the highest theoretical flame temperature
Low percentge excess air, high air inlet temperature
The heating value measured when water formed from combustion is in the liquid state is the
Gross Calorific Value
The application of the physical sciences together with the principle of economics and human relations to field that pertain directly to processes and process equipment in which matter is treated to effect a change in state , energy content or composition.
Chemical Engineering
Commonly used in the engineering and scientific community, also referred to as MKS system.
Systeme Internationale d’United (SI)
A system similar to SI but uses cm, gram and seconds for length, mass and time respectively.
CGS System
A system that uses ft, pound and seconds for length, mass and time respectively.
American Engineering System (AES) or English System
Process where the feed is charged into the system at the beginning of the process and the products all atonce reoved sometime later.No mass crosses the system boundaries between the time the feed is charged and the time the product is removed.
Batch Process
Process where input and output flow continuously throughout the duration of the process.
Continuous
process wherein process variables does not vary with time.
Steady-state process
Process wherein process variables varies with time.
Transient or unsteady-state
Temperature measuring devices:
Pyrometer (spectra of emitted radiation)
Thermometer ( volume of a fixed mass of fluid)
Thermocouple (potential difference due to two welded junctions)
Resistance thermometer (elrctrical resistance of a conductor)
Pressure measuring devices
Open-end manometer - measures relative or gauge pressure
Sealed-end manometer- measures absolute pressure
Bourdon gauge- usually gives gauge pressure of the fluid
Is the pressure exerted by a column of Hg at 0 deg C given that the density of Hg at this temperature is 13.59508 g/cm3 and the acceleration due to gravity is 9.89665 m/s2.
Standard Atmospheric Pressure (ATP)
It involves removal of relatively small amount of water or liquids from the solid materials. It involves blowing hot dry air over the wet solid evaporating water , leaving a dry product and producing humid air.
Drying
Used to concentrate a solution consisting of a non volatile solute and volatile solute. Involves vaporization of portion of solvent to produce a concentrated solution or thich liquor.
Evaporator
Separation of mixtures based on differences in volatilities by utilizing vapor and liquid phases at essentially same temperature and pressure for the coexisting zones.
Distillation
Involves formation of solid particles within a homogeneous phase by either cooling or removing some of the solvents.
Crystallization
It involves quantitative relationships between reactants and products in a balanced chemical reaction.
Stoichiometry
Species present in the relationships between reaction that would be completely consumed theoretically if the reaction were proceed to completion.
Limiting reactant
Reactant present in more than its stoichiometric proportion relative to every other reactant.
Excess reactant
Ratio of the amount present in excess to the amount stoichiometrically required.
Fractional excess
Ratio of the change in the number of moles of species and its stoichiometric coefficient of the species in reaction.
Extent of reaction
Fraction of feed or some component in the feed that is converted to products.
Fractional conversion
Ratio of the moles of desired product to the moles of the undesired product or by-product.
Selectivity
Fraction of limiting reactant converted into products.
Degree of Completion
Conversion of reactant based on the amount of material that eneters and leaves the reactor.
Single pass conversion
Conversion of reactant in the process based on the amount of material that enters (fresh feed) and leaves the reactor (overall product).
Overall Conversion
Material or energy stream that leaves a downsteam process unit and returned to the same process unit or upstream unit.
Recycle
Material or energy stream bled off from a process to prevent accumulation of inert materials that may build up in the recycle streams.
Purge
