Wednesday, January 4, 2012

biochemicalreactionengineering

UNIT OPERATIONS

process which obeys the same chemical phenomena is known as unit process different type of operations include... oxidation: addition of electrons thus increasing the oxidation number
reduction:
removal of electrons thus decreasing the oxidation number
hydrogenation:
addition of h2 molecules
dehydrogenation:
removal of hydrogen molecules
hydration: process of addition of water molecules
dehydration:
process of removal of water molecules
sulphonation: the process of addition of sulphur atoms is called sulphonation
alkylation:
the addition of alkali atoms is called alkylation
hydrolysis
breaking of water molecules is called hydrolysis
halogenation :
addition of halogens like fluorine , chlorine , bromine , iodine etc is called halogenation
nitrification
addition of oxygen molecules to ammonium molecule to become nitrates and nitrites 
in this way some other techniques include 
esterification, polymerization, catalysis ,unit operation is any part of potentially multiple-step process which can be considered to have a single function. Examples of unit operations include:
Separation Processes
Purification Processes
Mixing Processes
Reaction Processes
Power Generation Processes
Heatexchangers:a heat exchanger is a device which is used to facilitate the exchange of heat between two mixtures, from the hotter one to the cooler one. Heat exchangers very often involve steam because steam is very good at carrying heat by convection, and it also has a high heat capacity so it won't change temperature as much as another working fluid would. In addition, though steam can be expensive to produce, it is likely to be less expensive than other working fluids since it comes from water.

Separation Processes :if two immiscible liquids have significantly different densities, they can be separated by simply letting them settle, then draining the denser liquid out the bottom

Distillation, like flashing, is a process which is generally used to separate a mixture of two or more liquids based on their boiling points. However, what happens in a distillation column is essentially a series of flashes, which are connected with recycle loops. The liquid from each tray comes to equilibrium (ideally) with the vapor, and the vapor rises up to the next tray and the liquid falls to the tray beneath it. Each tray has a different temperature because a reboiler on the bottom and a condenser at the top maintain a temperature gradient across the column

Extraction is the general practice of taking something dissolved in one liquid and forcing it to become dissolved in another liquid. This is done by taking advantage of the relative solubility of a compound between two liquids.

operations which follow the same physical phenomena are called unit operations
unit operations include
fluid process : operations which include the flow of fluid and the relative operations is called fluid process
heat transfer process: the transfer of heat from one place to another place 
mass transfer process : transfer of entire mass from one place to another place 
separation process : the operations used during the step of product recovery for the process of separation of different substances
mechanical process : mechanical operations to break the particles which include the sonication or crushing, pulverizing etc
thermodynamic process : adiabatic operations play a role in the thermodynamic process
fluid process/ fluid transportation process include gas liquification process and refregeration

unsteady and steady state operations
unsteady state : which are sensitive to temperature and pressure gradients
steady state : these are insensitive to temperature and pressure gradients
operations are also classified uniform and non uniform operations
flow of fluid is classified into laminar 
and turbulent flows

heat process :
type of heat process are divided into three different modes of transfer which include 
conduction : transfer of heat from one substance to another substance with the movement of particlrs
convection: transfer of heat from one place to another place in a single of different medium 
radiation: transfer of heat from source to the point 
mass transfer operations:
there are different types of masstransfer operations like
liqud liquid extraction
solid liquid 
gas liquid gas solid operations
separation processes
these are used during the product recovery processes

there are different types of separation processes
such as
distillation
extraction
centrifugation
adsorprtion
ansorption
drying

example with biotech industry includes different steps

small scale operation : includes growth in shake flasks 
bench top bioreactor : include a normal biorecator
pilot scale operation : includes best engineer to operate
industrial scale operation : these include industrial reactors and fermentors
downstream processing : includes separation techniques like centrifugation etc
packing & marketing : last step of product recovery thus making the product to be marketed

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