Flowsheet Process

1
Flowsheet Process
14
ingredients
for 100 grams
equipment
recipe
procedures

• but you need to make 100 tons

2
How to Design a Process
recipe
process diagram
design process
amounts
energy
waste
don't worry about equipment - yet
try to improve
flow diagram
3
Our Product Herbicide W
today
tomorrow (without HW)
tomorrow (with HW)
4
Product Threatened
activity
HW
HW
the competition
days
10
20
0
Your roses like it!
5
New Concept
activity
the competition
HW-Hyper
better for - the roses, - the garden, - the
customer
days
10
20
30
0
6
Swelling Microcapsules
external humidity
10-9
diffusion coefficientin gelatine
10-13
10-15
7
Capsule Design
specifications
release time
diameter
application
thickness
coverage
properties
d
strength
8
Release (1)
herbicide
thin capsule
capsule
release time
9
Release (2)
depends on
we can greatly influence release by design
10
Delivery
a spray can only delivers small (micro) capsules
HW
capsules
a plane only delivers large capsules small ones
blow away
capsules
11
Coverage
take 1 kg (10-3 m3) of capsules per hectare (104
m2)
12
Capsule Strength
equally strong
capsule strength depends mainly on
for a given strength
small particles can give very short release times
13
Coacervation
water at pH 4.5, 50 oC
arabic gum
gelatine
charge
networks
these form a polymer-rich phase
14
Making Capsules
'active' does not mix with water
stir drops to desired size
form polymer-rich phase
coat drop with polymer
happens by itself
cross-link (harden) the layer
15
Filtering
Washing
displacing liquid in cake
needs to be done twice
feed
capsules
cake
'medium'
filtrate
16
Drying
mechanical
thermal
air
hot air
blowing out
evaporating
17
Recipe
3 g gummi arabicum
dispersing
pH 9
12 mL HW (immiscible)
10 mL formaldehyde
100 mL water
mixing
cooling
cross-linking
pH 4.5
55 oC
5 oC
3 g gelatine
filtering, washing, (drying)
coacervation
18
Process Diagram
'active'
gelatine
g. arabicum
disperse
dissolve
dissolve
mix
pH lt
cool
cross link
filter
wash
dry
capsules
19
Masses
g. arabicum
11
'active'
gelatine
11
55
water380
water380
dissolve
disperse
dissolve
mix
pH lt
(acid)
cool
form-aldehyde 46
in kg
form-aldehyde
cross link
3800 ? lab
water
filter
680
20
wash
160
3
dry
30
capsules
100
20
Energy
disperse
dissolve
57 MJ
57 MJ
dissolve
mix
pH lt
164 MJ
cool
not all inputs shown
cross link
filter
wash
dry
110 MJ
21
Improving
other materials?
biopolymer quality varies
cheaper materials?
must know cost of ingredients
polymer solubility?
reduce amount of water?
solution viscosity?
separate and recycle formaldehyde?
evaporation?
membrane?
22
Improved Diagram
'active'
gelatine
g. arabicum
disperse
dissolve
dissolve
mix
pH lt
cool
formaldehyde
cross link
filter
separation
wash
dry
capsules
23
Summary
lab
recipe
process diagram
amounts
all for the amounts required for full scale
production
energy
waste
try to improve
flow diagram
24
What Went Wrong
we should have
had research on
controlled release
capsulation
most important
analysed customer needs
considered more solutions
had others in the team
marketing - application - manufacturing