How to conduct cleaner production
assessments?
Presentation 7 – How to conduct cleaner production assessments?
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About Cleaner Production Assessments
Cleaner Production Assessment (CPA) is a core service of a cleaner
production centre. CPAs should be conducted in a systematic manner and
not on an adhoc basis. A structured, systematic approach is essential for
getting the best results and ensures that the outcomes of the CPA are
consistent with those identified in the organization's broader planning
process.
A generic CPA process consists of the following milestones:
1. Planning and Organization
2. Pre-assessment
3. Assessment
4. Feasibility analysis
5. Implementation
6. Monitoring
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Benefits of CPA
• Identification , characterization and quantification of waste streams and
thus environmental and economic assessments of loss of resources
(material and energy).
• Identification of easy to implement low cost cleaner production options
which may be implemented immediately.
• Preparation of investment proposals to financing institutions that
involve high cost cleaner production options of technology or
equipment change.
• In fact, conducting CPAs is an excellent method of building the
competence of the staff at the cleaner production centre.
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Generic Process of CPA
Sustain cleaner production
assessments
Prepare a cleaner
production plan
Planning &
organization
Involve employees
Organize a team
Implementation
& monitoring
Select feasible options
Preassessment
Feasibility
Analysis
Conduct a walkthrough
Screen options
Generate options
Conduct cause diagnosis
Prepare a detailed material and energy balance
Assessment
Prepare an eco-map
Prepare a preliminary material and
energy balance
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Planning and Organization
A CPA can be initiated after a conscious decision has been made by the
management to take action. Planning and organization starts once one or a few
staff members of an enterprise become interested in cleaner production. This
interest is often the result of awareness-raising and training programmes.
The elements that are important for the successful start of a CPA are:
• Obtaining the commitment of the top management of the enterprise
• Involving employees of the enterprise
• Organizing a cleaner production team
• Identifying impediments and solutions to the CPA
as a process
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Planning and Organization
Obtain commitment of
top management
Involve employees
Organize a cleaner
production team
Identify impediments and
solutions to the CPA
•
•
•
•
Signing an MoU with the centre
Directing formation of a cleaner production team
Making available the required resources and
Being responsive to the results of CPA
• All staff (top-down, with shop-floor staff)
• Across all or limited departments
• For larger enterprises – core team plus sub teams
• For smaller enterprises – owner plus sub team
• Getting the right mix is crucial
•
•
•
•
Attitudes
Information
Technical
Financial
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Organizing a Cleaner Production Team
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Identify Impediments and Solutions
to the CPA as a Process
• Impediments in obtaining
information from some
departments
• Lack of awareness amongst
staff
• Lack of appropriate skills
amongst staff
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Deciding the Focus of the CPA
Deciding the focus of the CPA involves making decisions
concerning:
• The scope; i.e. whether to include the entire plant or limit
it to certain units / departments
• The emphasis in terms of materials; e.g. water, energy or
chemicals
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Pre-Assessment
Pre-assessment consists of four important steps:
1. Compiling and preparing the basic information; i.e.
• Preparing a Process Flow Diagram or PFD
• Preparing an eco-map using layout maps of the site / unit
2. Conducting a walkthrough
3. Preparing preliminary material and energy (M&E) balances
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Compilation and Preparation of Basic Information
Preparation of Process Flow Diagram (PFD)
• Use block representation to denote operations
• Write the name of the operation, special operating conditions, Show
points of inspection or quality control, quantities (if available), use symbols
• Indicate batch or continuous operations
• Use colour codes to indicate different piping or material flow patterns
• Capture start up, shut down and maintenance related activities, seasonal
variations in production, etc. Best done by preparing a flowchart which
indicates how a process or unit operation is operated for a special situation.
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A PFD for a Wet-textile Processing Factory
These operations arebatchwiseand each
process batch comprises certain operations
such as washes etc. Fill and draw technique
is used. There are about 4 batches a day for
each process, i.e. 4 discharges / day
Loading
Storage
NaOH
water
NaOCl
water
NaOCl
water
50 kg/day
60000 L/day
50 kg/day
50000 L/day
50 kg/day
50000 L/day
Freshwater,
Alkali
Freshwater,
Sodium
Hypochlorite
Freshwater,
Chemicals
Dyes
Scouring
Liquid discharge
Bleaching
Liquid discharge
BOD
pH
400 mg/L
9.3
BOD
pH
200 mg/L
6.3
Air emission vapour
Dyeing
Dewatering
Drying
Chemicals
Indicates wastewater sampling location
Finishing
Liquid discharge
BOD
COD
pH
Temp
350 mg/L
800 mg/L
8
80 °C
Liquid discharge
Liquid discharge
Liquid discharge
BOD
pH
650 mg/L
10
to Quality Control
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A Flow Chart Indicating a Process Operation in a
Wet-textile Processing Unit for Special Situations
(i.e. whether bleaching / scouring / dyeing is required)
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Conducting a Walkthrough
• Walkthroughs are one of the best techniques for getting first-hand
information about a production operation within a short span of
time
• Walkthroughs should not be conducted on holidays, when
operations are closed, when production is low, and when equipment
is under maintenance
• Follow the PFD - Begin from the raw materials receiving area and end at the
department of finished products
• Cover all the support utilities such as boilers, power generators, fuel storage
tanks, pump-house, refrigeration plant, raw water treatment plant, wastewater
treatment facility, etc.
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Conducting a Walkthrough – Dos and Don’ts
• Do not find faults – the walkthrough is not a fault finding mission
• Do not dominate the conversation
• Ask real and open questions; do not attempt to show your own
knowledge of the topic but to get information from the responsible
staff
• Ask questions only when absolutely required. Request explanations
if required
• Do not leave the group
• Conduct a closure meeting to capture findings of the walkthrough
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What to ask in a walkthrough?
What to carry with you in a walkthrough?
Ask questions related to
operating practices,
housekeeping, equipment
maintenance and control,
safety and health, waste
generation, handling etc.
Walkthrough areas…
• Workfloor or shop floor
• Machines and Operations
• Waste and Emissions
• Labor
• Storage areas
• Utilities
• A camera to take photographs
Take with
you…..
• A scrap book (A3 size) to make quick sketches, especially for layouts,
eco-maps (see next section) and the PFD
• Color pens or highlighter to mark important points
• A tape recorder to record your site observations
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Preparation of an Eco-map
• Eco-mapping is a very useful application for a cleaner production team to use
• Eco-mapping can easily capture observations made during the walkthrough
• Eco-maps visually present issues of concern, and can also note good practices
• Eco-maps are often the direct indicators of the housekeeping status of the
enterprise
• Colour coding and symbols may be used to show areas that have been monitored
or areas where problems will have to be dealt with on a priority basis
• Eco-maps can be made easily by using the layout maps of the site / unit
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Preparation of an Eco-map (continued…)
Eco-mapping may be used for specific themes, such as:
• Water consumption
• Wastewater discharge
• Solid waste generation
• Odours
• Noise
• Dust
• Safety risks
• Environmental risks
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Preparation of an Eco-map requires a Layout Map…
Preparation of layout maps
Key map: Show the location of the enterprise, access roads, neighbourhood
characteristics, and especially sensitive receptors
Layout map of the entire operations in the organization: Show the internal roads,
entry and exits, waste storage, processing, disposal facilities, utilities,
wastewater outlets
Layout map of key departments: Layout maps may be drawn for departments of
concern indicating the positions of the major equipment, water piping,
steam lines, drains and vents / stacks. Separate layout maps are required for
each floor
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Typical Layout Map for a Manufacturing Factory
N
Municipal
Water
Supply
Not to scale
Exit
Main
Entrance
Entry
ETP
Finished
Product Storage
Utilities
Raw
Material Storage
Quality Control
and Final Packaging
101.5m
30m
Stack for
emissions
Manufacturing Process Line
Prod. Capacity 10,000 product items per day
Proposed Production line of capacity 10,000 product items per day
100m
Central Highway 05
Administrative
Block
Toilet Block
Laboratories
100.5m
101m
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An Eco-map for Water for an Electroplating Factory
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Preparing Preliminary Material and Energy Balances
Inputs
Raw materials
Energy
Water
Chemicals
Enterprise
or plant
Wastes
Outputs
Air emissions
Effluents
Solid waste
Heat losses
Off-specification products
By-products
Products,
Useful byproducts
A material and energy (M&E)
balance is a basic inventory tool,
which allows for the quantitative
recording of material and energy
inputs and outputs.
The basis of the material balance is
the PFD.
An essential step in the M&E
balance is to check that "what goes in
must come out somewhere."
All inputs should thus have related
outputs.
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Understanding Material and Energy Balances
• Material balances are typically carried out to inventory of material flows
(raw materials, chemicals, water, energy etc.) entering and leaving a
manufacturing / service company.
• Energy balances are useful to find options to minimize the use of energy
or to recover the energy lost in the system.
• Preliminary M&E balances are normally set using secondary data,
supported by the information recorded during the walkthrough. Water and
energy bills paid give some idea of their consumption levels. On the output
side, production figures or orders serviced over a certain period of time
can give an estimate of average production. Often, approximate
calculations will need to be used, based on "typical" values given in the
literature.
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Understanding M&E Balances (continued…)
• Generally, M&E balances at the preliminary level are best set by
examining three months data and computing monthly averages.
• Care should be taken to ensure that all quantification is expressed in the
right units (preferably SI units), that they are uniform, and that the
associated costs are provided
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Assessment
• Preparation of detailed material and energy
balances
• Cause Diagnosis
• Option Generation
• Screening of Options
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Detailed Material and Energy Balances
• It is probable that the cleaner production team finds substantial discrepancies in the
preliminary M&E balance.
• This may require revising of the data used for inputs and outputs, rediscussion on
assumptions behind the numbers or conduct of measurements.
• Hence, the next task of CPA is for the team to prepare detailed material and energy
balances around the PFD.
• Developing a detailed material balance for each operation is neither practical nor
relevant. The critical operations are generally chosen based on the focus of the CPA,
the results of the preliminary M&E balance, and the types of materials and
processes used (i.e. operations where hazardous materials are used or where materials
used are expensive or where materials are used in quantities exceeding the benchmarks).
• Detailed M&E balances are often performed when the processes have long operational
sequences
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A Detailed Material Balance for a
Wet-textile Processing Factory
• An important last step in preparing an M&E balance is assigning costs to
the waste streams that have been identified in the balance.
• This could be the single most important step in convincing the
management of an enterprise about the value of cleaner production and
securing their commitment for all the further activities.
• Monetization of waste streams means that they should not only be
characterized in classical environmental terms such as BOD, COD,
concentration in liquid wastes, etc. The team needs to also characterize the
streams in terms of material content, which can then also be monetized.
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A Detailed Material Balance for a
Wet-textile Processing Factory
While charging costs to waste streams, the team should consider the
following cost items –
• Cost of raw materials / intermediate products / final products lost in
the waste streams
• Cost of energy in waste streams, in terms of the energy consumed to
heat or chill them, cost of treatment / handling / disposal of waste
streams, including tipping or discharge fees if any
• Costs incurred, if any, in protecting the workers and maintaining safe
working conditions, the potential costs from a possible accidental spill,
discharge, or leakage.
Obviously, the high-cost waste streams would be the most
interesting ones to focus on from an economic point of view.
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A Detailed Material Balance for a
Wet-textile Processing Factory
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A Detailed Energy Balance for a
Wet-textile Processing Factory
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Cause Diagnosis through the Fishbone Diagram
The cleaner production team now needs to start generating cleaner
production options.
Possible through conducting a cause diagnosis
exercise
This exercise involves asking the question “why? –
why did such a problem / outcome occur?”
Essentially an exercise to hypothesize over the root
causes of any problem / outcome
Can be conducted easily through the use of a tool
called the fishbone diagram
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Cause Diagnosis through the Fishbone Diagram (continued…)
Fishbone diagram
Four generic categories:
•Man
•Method
•Material
•Machine
Each generic
category has a
primary cause
Each primary cause has one or
more secondary causes
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Fishbone Diagram: Facilitating Cause Diagnosis for
low RFT in the Dyeing Process
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Allotting Priorities to Causes Identified
in the Fishbone Diagram
• The causes identified in the fishbone diagram are “theorized” or “probable”
causes.
• Therefore, the extent to which each cause contributes to the problem has to be
calculated before any major decisions are taken.
• The cleaner production team would need to analyze the extent to which each
of these probable causes contributes to the principal problem – i.e. Right First
Time (RFT) is low.
• Such analysis is only possible through observations, record keeping, setting up
planned and controlled experiments designed to isolate the cause of the problem,
and specific tools such as the Pareto Analysis.
• These efforts will assist the team in validating the primary and secondary
causes, and prioritizing cause elimination.
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Allotting Priorities to Causes Identified
in the Fishbone Diagram
Many cleaner production teams stumble at this juncture, since
estimating the relative importance of each probable cause
seems a wearisome task.
It cannot be stressed too much that teams should be strongly
encouraged to push through with this step completely, since it
can avoid significant wastage of time (and money) later on in
the CPA.
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Cleaner Production Option Generation
through Brainstorming
Once the points of action and priorities are understood and listed, the cleaner production team should
move on to the logical next phase; i.e. option generation.
Idea 1
Opposing
Idea 1
Idea 4
Supporting
Idea 1
Idea 2
• Option generation is a creative process, and is best
performed, as in the case of the cause diagnosis, by the
team as well as the enterprise personnel.
• The option generation exercise is conducted through
brainstorming, a commonly used tool for generating
ideas
Supporting
Idea 3
Extension
to Idea 1
Idea 3
based on 1
and 2
• Given a particular item which needs to be resolved, the
team and the enterprise personnel have to deliberate on
the ways and means of obtaining a solution to it
Supporting
Idea 3
• The principle question to be asked during the
brainstorming session would be "how - how does one
solve this particular problem effectively?"
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Cleaner Production Options - Categories
• Housekeeping
• Management and personnel practices
• Process optimization
• Raw material substitution
• New technology
• New product design
• Recovery of useful byproducts and resources
• Onsite recycling and reuse
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Important Points to Remember During
Option Generation
• The team should always remember that in general it is better to not
generate a waste in the first place, rather than generate it and later
recycle or recover / reuse it. Therefore, the team should only consider
these options once all the others that could prevent waste generation
have been examined.
• Some of the chosen options may require major changes in the processes or
equipment or product redesign. Often, these will dramatically reduce waste
generation or increase productivity, but they also often imply considerable
investments.
• Certain chosen options would require thorough laboratory / bench scale /
pilot studies to ensure that the product quality does not degrade as a result of
their application, and that it is acceptable to the market
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Feasibility Analysis
Screening of options
Environmental
evaluation
Technical evaluation
•Materials and energy
consumption
Economic evaluation
•Payback period
•Entire life cycle of the
product
•Product / byproduct
quality
•Improvement on Right
First Time (RFT)
•On-site / off-site
neighbourhood
improvements
•Human resource
requirement
•Reduction in amount of
waste / emission
•Ease of implementation
•Reduction in consumption
of natural resources
•Cross-linkages with other
options
•Time for implementation
•Net Present Value (NPV)
•Profitability Index (PI)
•Internal Rate of Return
(IRR)
•Sensitivity analysis
•Reduction in noise /
odour / safety risks
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Economic Evaluation
• Consists of analyses and computations of the evaluation criteria [e.g. pay
back period, Net Present Value (NPV), Internal Rate of Return (IRR),
etc.] based on project costs and benefits
• A simple payback period is evaluated based on the annual savings and the initial
investment. Indicates the time period to return the initial investment
Payback Period in years = (Capital Investment/Annual Savings)
• Should be generally considered only as a ballpark assessment, as it ignores
depreciation of the investment made and time value of money. Usually,
investment decisions can only be made on the basis of payback period alone
if the investment required is low and / or the returns are high so that the
payback period is less than two years
• A better approach is to use the concepts of NPV and IRR. These concepts consider
the time value of cash inflows and outflows during the useful life of the investment
made
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Economic Evaluation (continued…)
Economic evaluation therefore requires building information on:
• Capital costs associated with required investments (if any);
• Net revenue, which is computed as a difference between total revenue (that
is generally higher than the base case) and the operating costs (that are
typically lower in the changed scenario); and
• Rates of interest and depreciation to enable computation of the Present
Value
•For computation of NPV:
NPV  (CF0 )  i 0
i n
Net Cashflowi
(1  r )i
•CFo = Cash outflow in the first year (capital investment)
•r = opportunity cost of capital (i.e. for a rate of 10% ‘r’ would be 0.1)
•n = useful life of the investment in years
For an investment to be economically feasible NPV must be greater
than zero
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Economic Evaluation (continued…)
• The PI is computed as the ratio of the present value of the total cash
inflows and the present value of the total cash outflows
• For an investment to be economically feasible, the PI must be greater
than 1
• IRR is essentially the rate of return of investment during its life by
way of net cash inflows (i.e. inflows – outflows)
• IRR is to be compared with the rate of interest of the borrowings that
may be needed from the market
Also carry out a sensitivity analysis by varying input and output parameters, costs
other indicators so as to get different scenarios – pessimistic and optimistic
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Example of Cash Inflows and Outflows – Replacement of a Winch
Machine with a Jet Dyeing Machine
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Savings
(54600)
Capital
Cost
(110040)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
Operating
Costs +
Depr.
(23520)
2
3
4
5
6
7
8
9
10
1
Years
Simple Payback = 36 months, NPV = US$ 9141, IRR = 25.5%
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Implementation of Options and Sustaining CPAs
• Implement feasible cleaner production measures
• Draw up and adopt a Cleaner Production
(Implementation) Plan; prioritize options depending on
the resources available, prepare technical specifications,
allocate responsibilities, set up monitoring and review
functions
• Monitor the cleaner production implementation plan
• Sustain Cleaner Production; adopt CPAs as an ongoing activity by integrating cleaner production into the
enterprise’s management system
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