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SPDO - Coggle Diagram

- - - - Vapor-liquid
        
        Use phase diagram
        
        Phase rule (DoF = C - P + 2)
        
        C = components
        
        P = phases
        
        Relation
        
        Raoults law
        
        yi = Ki xi
        
        Ki = distribution coefficient
        
        Selectivity
        
        aij = ki/kj
        
        Determines how easy to separate
        
        a >> 1 easy
        
        a > 1 doable
        
        a = 1 unseperable
      - Solubility
        
        Ideal solution
        
        ln(x) = -dH/R(1/T - 1/Tm)
        
        x = molar fraction
        
        dH = enthalpy of dissolution
        
        Tm = melting temperature
        
        How to measure
        
        Concentration vs T experiment
        
        Measure cloud point
        
        Metastable zone width
        
        Region between clear point and cloud point
      - Adsorbtion
        
        Types
        
        Unimolecular adsorption
        
        Given by langmuir isotherms
        
        Saturated eventually
        
        Multi-molecular adsorbtion
        
        Steadily increasing
        
        Condensation in pores
        
        Hysterysis
  - - - Continuum aproximation
        
        Liquids
        
        Gases
        
        Law of large numbers
        
        Fluctuations go with N^-1/2
      - Transfer types
        
        Molecular diffusion
        
        Eddy diffusion
        
        Convection
      - Transfer takes place across an interface
    - - Newtons law
        
        flux = mass transfer coeficient * dC
        
        Mass transfer coefficient alters when scaling the system
  - - - Can be kinetically limited
- - - - Recycle
      - Main product
      - Side Product
      - Waste
- - - - Difference in relative volatility
      - Difference is solubility
      - Difference in adsorbtivity
  - - - Distillation column
        
        Parts
        
        Condensor at top
        
        N tray in the middle
        
        Feed in the middle
        
        Boiler at the bottum
        
        Variables
        
        Reflux ratio condensor
        
        Number of stages
        
        Boilup boiler
        
        Feed position and temperature
        
        Design methods
        
        Limited stages needed
        
        Adjust variables to get vafourable operating lines and q line (draw number of stages in)
        
        Operating lines
        
        See formula in ppt for upper and lower part
        
        Q line
        
        Depends on feed position and T
        
        See slope formula in ppt
        
        Number of theoretical stages
        
        Use 7 mccale thiele rules
        
        General
        
        Multiple flash operation
        
        Vapour gradually gets more volatile component
        
        Liquid gradually gets less volatile component
      - Crystalliser
        
        Properties
        
        Advantages
        
        High purity
        
        Energy efficient
        
        Disadvantages
        
        Slurry handling is difficult
        
        Solid liquid separation needed
        
        Crystal product
        
        Phase (arrangement molecules)
        
        Purity
        
        Pure or hydrated/solvated
        
        Shape
        
        Difficult to pump pointy crystals
        
        Product size distribution
        
        Crystallisation steps
        
        Crystal growth
        
        Secondary nucleation
        
        Unwanted, gives wide size distribution of particles
        
        Can also be caused by impellers breaking the crystals
        
        Primary nucleation
        
        Types
        
        Homogeneous (in solution)
        
        Heterogeneous (on surface)
        
        Has lower surface energy to overcome --> more quickly
        
        Nucleation work
        
        Bulk formation is driving
        
        Surface formation is pushing back
        
        Depends nucleation rate and crystal size
        
        Stimulated by increased supersataration
        
        Types
        
        Cooling crystallizer
        
        Evaporative crystallizer
        
        Forced circulation
        
        Solar pond
        
        Design
        
        Basic
        
        No kinetics
        
        Mass/heat balance
        
        Detailed
        
        Kinetics
      - Adsorber
        
        Needed properties
        
        Good transport properties
        
        Stable
        
        High capacity
        
        High surface area
        
        Measured with N2 adsorption
        
        Selective
        
        Desorption strategies
        
        P
        
        T
        
        You dont want to have energy intensive desorption
        
        Application
        
        Carbon black is commonly used due to high surface area
        
        Water treatment, solvent recovery, dry gas cleaning
        
        General
        
        Transfer of solute molecules from the fluid phase to rigid particles
        
        Nomenclature
        
        Adsorbate
        
        Adsorbent
        
        Adsorptive
        
        Chemi/physisorption
    - - Liquid-Liquid separation
      - Solid-liquid mixture
      - Solute-fluid separation
- - - - 14 march = 10 page limit half report
      - 21 march: full report max 30 pages
    - - Producing a new type of fertilizer
      - Process that includes a mixing and crystallisation operation
    - - Activities
        
        Block diagram and mass/heat balance
        
        Thermodynamic state determination and composition
        
        Identify the type of mass/heat equipment
        
        Sizing of pumps, pipes, HE
        
        List of requirements for the design
      - Report
        
        All of the above activities + real process diagram
  - - - Extended block diagram
        
        Focusses on the connections between functional units
        
        Phase, temperature, pressure and composition become important
        
        Add recycle loops between functional units
        
        Add the operations needed between functional units to bridge the pressure and temperature differences
        
        Add preliminary power requirements for the system
        
        Think already about cost, sustainability and safety here
      - Functional block diagram
        
        Functional units
        
        Each unit is a main distinct operation
        
        Can consist of mixers, separators and reactors
        
        Does not contain pumps, heat exchangers, recycle loops, valves etc
        
        Mass balances
        
        Per funtional unit
        
        Total mass balance
        
        Helps to give the essense of the process
    - - Heat capacities
      - Densities
      - Viscosities
      - Molar masses
      - Heat of vaporisation, heat of mixing/dissolution/crystallisation
      - Cost prices
    - - Functional units are converted to a set of equipment to perform that function
      - Process requirements are set
      - Pump systems and heat exchanger networks are created