Solutions and Hints to the Worksheets
Case Study of Applesoft Kneedafix Inc.
Table of Contents
1.0
Worksheet 9 A
Developing a Process Flow Diagram
2.0
Worksheet 9 B
Developing an Eco-map of Water and Solid Waste
3.0
Worksheet 9 C
Developing the Material Balance for Apples and Water
4.0
Worksheet 9 D
Conducting Cause Diagnosis for Low Productivity
5.0
Worksheet 9 E
Identifying and Screening Cleaner Production Options
6.0
Worksheet 10
Preparing a Proposal for Demonstration Project and for
Securing Financial Assistance
1
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 9A:
Developing a Process Flow Diagram
Process Flow Diagram for Applesoft Kneedafix Inc.
Apples from Orchards
Weighing and Storage 20 °C
in cold room
Loading on Conveyor
Fresh
Water
Fresh
Water
Boiler
Boiler
Washing
Washing
(Automatic
(Automatic spraying
spraying
++ Manual)
Manual)
Wastewater
Damaged
apples
Sorting
Sorting
Peeling
Peeling ++ Coring
Coring
++ Dicing
Dicing
Batch
98 °C
Steam
Blanching
Blanching
Peels and Core
fleshings
Juice extract with
condensate
Continuous
Loading on Conveyor
Fresh
Water
Hot Air
Cooling
Cooling
Hot
Hot air
air drying
drying
Wastewater
Air emissions
Inspection
Inspection
Packaging
Packaging
2
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 9B:
Developing an Eco-map of Water and Solid Waste
Receiving
area
Waste water
due to manual
washing
Raw material
storage
(cold room)
Floor and
machine
washing
C
o
m
m
u
n
i
t
y
Solid
waste dump
Weighing
Municipal water supply
Ecomap of water for AKI
Washing
Apple juice and
condensate as
waste water
High water
consumption
Boiler
Cooling
with
water
Air
Drying
20%
calms
Packaging
Inspection
Bore
well
Weighing
To municipal sewers
Blanching
Wastewater
treatment plant
Administration
Peeling
Coring &
Dicing
C
o
m
m
u
n
i
t
y
Legend
Water for washing/cleaning apples
Steam line
Waste water
Water line for floor washing
20%
calms
Wind rose
3
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Wooden
crates
Receiving
area
Raw material
storage
(cold room)
Bad
practice
C
o
m
m
u
n
i
t
y
Solid
waste dump
Weighing
Municipal water supply
Ecomap of solid waste for AKI
Washing
Bad handling
High solid
waste
generation
Waste water
treatment sludge
Blanching
Boiler
Wastewater
treatment plant
Cooling
with
water
Air
Drying
20%
calms
Packaging
Inspection
Bore
well
Weighing
Packaging
waste
To municipal sewers
Administration
Peeling
Coring &
Dicing
C
o
m
m
u
n
i
t
y
Legend
Water for washing/cleaning apples
Steam line
Waste water
Water line for floor washing
20%
calms
Wind rose
4
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 9C:
Developing the Material Balance for Apples
Material Balance for Applesoft Kneedafix Inc.
For Apples
Apples from Orchards
Weighing and Storage 20 °C
in cold room
Loading on Conveyor
4000 kg/d
Washing
Washing
(Automatic
(Automatic spraying
spraying
++ Manual)
Manual)
Fresh
Water
Sorting
Sorting
Wastewater
400 kg/d
Damaged
apples
3600 kg/d
Air
emissions
Fuel
Water
Boiler
Boiler
Steam
720 kg/d
Peeling
Peeling ++ Coring
Coring
++ Dicing
Dicing
Peels and
Core fleshings
2880 kg/d
Juice extract
with
condensate
Blanching
Blanching
Loading on Conveyor
Fresh
Water
Air heated by
heat exchange
from
condensate
Cooling
Cooling
Hot
Hot air
air drying
drying
Wastewater
Air emissions
Inspection
Inspection
Packaging
Packaging
2880 kg/d of final product
In 288 boxes of 10 kg each
5
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 9C:
Developing the Material Balance for Water
Material Balance for Applesoft Kneedafix Inc.
For water
Apples from Orchards
Weighing and Storage 20 °C
in cold room
Loading on Conveyor
Washing
Washing
Fresh 40 + 12.5 (Automatic spraying
(Automatic
spraying
Water m3/d
++ Manual)
Manual)
40 + 12.5
m3/d
Damaged
apples
Sorting
Sorting
Air
emissions
Fuel
Water
Wastewater
Peels and
Core fleshings
Peeling
Peeling ++ Coring
Coring
++ Dicing
Dicing
Boiler
Boiler
2 m3/d
Blanching
Blanching
Steam
Juice extract
with
condensate
Loading on Conveyor
Fresh 10 m3/d
Water
Air heated by
heat exchange
from
condensate
Cooling
Cooling
10 m3/d
Hot
Hot air
air drying
drying
Wastewater
Air emissions
Inspection
Inspection
Packaging
Packaging
2880 kg/d of final product
In 288 boxes of 10 kg each
6
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 9D:
Conducting Cause Diagnosis for Low Productivity
Fishbone Diagram
Excess juice from
Blancher is
considered as waste
Cores and Peels
are disposed as
wastes
Materials
Management
Poor
Housekeeping
(leakages)
Staff needs
Training on
env. Impacts
of operations
Skills on apple
sorting
and grading
to be upgraded
Maintenance
of nozzles
is inadequate
Nozzles are
inefficient
Productivity
is low (about 72%)
Methods
Handling
practices
need
improvement
Processes
exceed best
practice norms
Peeling m/c to
be improved.
Blancher could be
replaced
Machines
7
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 9E:
Identifying and Screening Cleaner Production Options
There could be several Cleaner Production options for this case
study. Options can range from low or no cost interventions, to medium
to high cost possibilities.
The options at the low or no cost end could include training of
workers to do away with sloppy handling, paying special attention to
peeling, improving the maintenance of spray nozzles, moving
inspection practices to the receiving area itself, or sending the
organic waste (peels, cores and damaged fruits) as animal feed to the
farmers, instead of mixing it with packaging waste.
Low to medium cost options could include replacing the spray nozzles
with flat nozzles; exploring reuse of water used to clean apples for
floor washing, operating the blancher by practice of holding to
minimize steam requirements, using hot air from the blancher for the
purpose of drying, etc.
Medium to high investment options could include the recovery of
sugar supplement from waste, improving the peeling machine with
spring loaded knives, and replacing the original blancher with one
having a higher product to steam ratio. This section provides the
cost-benefit analyses for some of the Cleaner Production options.
Option 1 : Sale of organic waste as cattle feed
8
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
All the solid wastes generated at the plant i.e., fruit peels, cores,
spoilt / damaged fruit and the packaging are presently dumped
together along with the plastic, packaging wastes and broken crates.
Instead of co-disposing the organic waste with the inorganic
packaging waste, the company could sell the organic waste as cattle
feed to the farmers.
Cost and benefit calculations1
Income from the sale of organic waste
= (400 + 720) kg / day x 300 days x US$ 5 / 1000 = US$1,680
Savings due to reduced disposal of waste
= (400 + 720) kg / day x 300 x US$ 10 / 1000 = US$3,360
Total savings = US$ 5,040 /year
The incremental costs to Option 1 will be training of workers,
installation of storage bins for organic waste at the company, and
marketing of the waste as cattle feed to the farmers nearby.
The environmental benefit of Option 1 will be reduced nuisance to the
neighborhood community and utilization of wastes.
Option 2 : Replacement of shower type nozzles with flat nozzles
The spray nozzles that are presently being used are shower-style and
thus, very water-intensive. By replacing them with flat nozzles, water
will be conserved. This is of great significance since there is a
proposal to increase the cost of water. In addition, the wastewater
volume will be reduced thereby resulting in savings in treatment
costs. This improvement will also eliminate the manual washing
1
1 ton = 1000 kg
9
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
practice (i.e. saving on time). Costs however will be incurred in
replacing the 25 shower style nozzles (15 on the conveyor-washing
system and 10 for cooling the blanched apples) with flat nozzles.
Cost and Benefit Calculations
Cost of flat nozzles
= US$30 / nozzle
Replacement of all 25 nozzles
= US$ 750
Maintenance costs
= US$ 250 / year
Volume of water saved by the new nozzles2
= 40% x (40 + 10) m3 / day + 12.5 m3 / day
= 32.5 m3 saved / day = 9,750 m3 / year
Savings on water conservation
= 9,750 m3 x US$ 0.2 / m3 x 1.2 (i.e. 20% anticipated increase in
water rate) / year
= US$ 2,340 / year
The wastewater volume will be reduced by 32.5 m3/day (i.e. the same
as the volume of water saved) = 9,750 m3/year
Savings on wastewater treatment = 9,750 m3 / year x US$ 0.15 / m3
= US$ 1,462.50 / year
Total costs incurred in conserving water
2
Note that manual washing of apples will be eliminated with the installation
of the new nozzles.
10
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
= Capital costs US$ 750 and annual costs of US$ 250 / year.
Total annual savings = US$ (2,340 + 1,462.50) – US$ 250
= US$ 3,802.50/ year
The payback on Option 2 is about 2.5 months and can be implemented
immediately since it requires only a small capital investment.
Option 3 : Use of high-grade spring mounted knives for apple peeling
Based on the brochure, the maximum peel loss will be 100 kg /ton.
Hence, production will increase as follows:
4000 kg – 400 kg ( spoilt and damaged apples) = 3600 kg / day
Present loss of raw material in peels and core fleshings = 200 /1000 x
3600 = 720 kg
Net salable production = 3600 kg – 720 kg = 2880 kg / day
After upgrading the peeling equipment:
Loss of raw material in peels and fleshings
= 100/1000 x 3600 = 360 kg
Net salable production = 3600kg – 360 kg = 3,240 kg / day
The productivity will thus be close to 78%; closer to the target of
80% set by the company.
11
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Incremental production = 360 kg / day = 36 boxes /day
Incremental earnings = 36 x 8 x 300 = US$ 86,400 / year
Cost of upgrading the peeling machine = US$ 80,000
Payback period for Option 4 will be about 11 months.
This option will also help in reducing the disposal costs of organic
waste. However implementation of this option will influence the
benefits computed for other options.
12
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Solution to Worksheet 10:
Preparing a Proposal for Demonstration Project and For
Securing Financial Assistance
One of the Cleaner Production options may be considered for the
purpose of demonstration. Given the potential economic and
environmental benefits, and (at the same time) the uncertainties, the
option of recovery of sugar supplement from waste is recommended
as a demonstration project.
Option 4 : Recovery of the excess juice from blanching through
concentration, for use as a sugar supplement
The excess juice from the blanching process is a valuable resource
since it contains sugars and fine apple pieces. The collected juice can
be concentrated together with peelings and cores in a crusher-cumevaporator, and sold as a by-product to the food industry, where it
can be used as a sugar supplement in jams and preserves.
Apart from generating revenue due to the recovery of a by-product,
the implementation of Option 3 will result in substantial reduction in
the BOD of the wastewater, thereby lowering the wastewater
treatment costs.
Moreover, since the peelings and cores can also be concentrated with
the excess juice, the solid waste generated will be reduced
extensively. These benefits can be also be quantified and included in
the overall cost-benefit analyses. Costs incurred would be for the
crusher-cum-evaporator equipment and worker time.
As there is no present operating data available on this technology
option, this project may be considered as a demonstration project.
13
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Cost and Benefit Calculations
For screening the demonstration project, two types of cost-benefit
analyses could be done.
Optimistic scenario
Cost of the crusher-cum-evaporator = US$ 100,000
The amount of sugar supplement that can be recovered per day3
= (15% of 2000 kg4 from the juice) + 15%(40% of 720 kg from the
peelings and cores) = 344 kg
Revenue generated per day5 = 344 kg x US$ 0.6 / kg
= US$ 206.8 / day = US$ 61,920 / year
15% of the capital of the crusher-cum-evaporator is the operational
cost = US$15,000
Net revenue generated per year
= US$ 61,920 – US$ 15,000 = US$ 46,920
Hence, the payback period will be nearly 26 months.
Given that such an equipment can deliver sugar concentrate at an efficiency
of up to 15% on a weight basis, and that the moisture content of peelings
and cores is 40%
3
4
Referring to Table 1, 2 m3 of excess juice (including the condensate) is
drained from the blanching process; 2 m3 = 2000 kg
5
Taking the market price for the sugar supplement as US$ 0.6 per kg
14
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Pessimistic scenario
Cost of the crusher-cum-evaporator = US$ 120,000
The amount of sugar supplement that can be recovered per day
= (10% of 2000 kg from the juice) + 10%(40% of 720 kg from the
peelings and cores) = 228.8 kg
Revenue generated per day
= 228.8 kg x 0.5 = US$ 114.4 / day = US$ 34,320 / year
15% of the capital of the crusher-cum-evaporator is the operational
cost = US$18,000
Net revenue generated per year
= US$34,320 – US$18,000 = US$ 16,320
Hence, the payback period will be nearly 88 months.
15
S O L U T I O N S
A N D
H I N T S :
A P P L E S S O F T
K N E E D A F I X
I N C .
Summary of Options
A summary of all options with associated costs is presented below.
No.
Option title
Savings
made
Payback
period
(US $/year)
(months)
1
Sale of organic waste as cattle feed
5,040
-
2
Replacement of shower type nozzles with flat
nozzles - recommended for internal finance
3,802.5
2.5
3
Recovery of the excess juice from blanching
through concentration, for use as a sugar
supplement - recommended for demonstration
project
46,920
26
16,320
88
86,400
11
4

Optimistic scenario

Pessimistic scenario
Use of high-grade spring mounted knives for
apple peeling - recommended for external
finance
16