CPA in cupcake processing

[Type text] CLEANER PRODUCTION ASSESSMENTOF Dr. A. Culaba

A CUPCAKE PRODUCTION LINE 2nd Term 2010

Introduction

Cleaner Production is defined as the continuous application of an integrated, preventive,

environmental strategy applied to processes, products, and services to increase overall

efficiency and reduce risks to humans and the environment. It is different to the traditional

‘pollution control’ approach to environmental management. Where pollution control is an after-

the-event, ‘react and treat’ approach, Cleaner Production is a proactive, ‘anticipate and prevent’

philosophy (COWI Consulting Engineers and Planners AS).

Cleaner Production has most commonly been applied to production processes, by bringing

about the conservation of resources, the elimination of toxic raw materials, and the reduction of

wastes and emissions. However it can also be applied throughout the life cycle of a product,

from the initial design phase, through to the consumption and disposal phase. Techniques for

implementing Cleaner Production include improved housekeeping practices, process

optimization, raw material substitution, new technology or new product design (COWI

Consulting Engineers and planners AS).

Cleaner Production assessment

A Cleaner Production assessment is a methodology for identifying areas of inefficient use of

resources and poor management of wastes, by focusing on the environmental aspects and thus

the impacts of industrial processes for developing Cleaner production options.

Phase I: Planning and Organization

1. Management Commitment

Villarosa, J., Buena, J.



As part of the company’s mission statement:

“In conducting business, we will work to maintain close relations with all our partners and

suppliers. We will be a steadfast in the search for better technology and better opportunities.”

The company is aiming to be on top in the industry that uses the state of the art technology that

would enhance its production rate, increase the efficiency of the resources, and boost the

morale of the employees while continuing to be an environmental friendly food producing

company.

2. Project team

The project team is composed of two mechanical engineers with the support of a chemical

engineer and an industrial engineer of the plant.

3. Environmental policy, objectives and targets

Environment Policy

The company has no formal environmental policy. However, in search for better technology, the

company’s guidelines focus on how to maximize their resources and how to reduce wastes and

emissions.

Objectives and targets

General Objectives:

This cleaner production assessment (CPA) aims to minimize the waste generation and pollution

emission in a cup-cake producing company.

Targets:




1. To eliminate or minimize oil leak in gear-motors and thermal-oil system by maintaining

excellent working condition for all equipment and practicing good housekeeping.

2. To identify faulty design of the equipment that would contaminate the product and

correct unsafe practices in accordance to food safety and environmental aspect.

3. To check the flue gas emission of the oil heater and steam boiler in compliance with the

Department of Environment and Natural Resources (DENR) standards.

4. Plan the cleaner production assessment

The project team decided to focus on the largest cup-cake producing line of the company.

Since this is the production line that uses most of the raw materials, it has the most number

of mechanical, electrical and electronics wastes generated, it houses the biggest thermal oil

system of the company. The following steps were decided upon:

Activity

Week

1

Week

2

Week

3

Week

4

Week

5

Week

6

Week

7

Week

8

Week

9

Week

10

Ocular Visit

Obtain Company

commitment

Obtain a company

organizational chart,

Mission-Vision

Obtain process flow chart

of each production lines

Obtain a focus

Determine the process

description

Determine technical

specification of machine




used

Collection of qualitative

data

Material Balance

Identify cleaner production

opportunities

Evaluate CP options

Select Viable Options

Phase II – Pre-assessment

II.1 Company Description

The Company Logo

Lemon Square is one of the top Filipino brands that were given the prestigious Superbrands

Award by the Superbrands Asia organization.

Lemon Square has been accorded this distinction thrice since 2004 in recognition of the

company's formidable success in marketing and brand-building.




Over the years, Lemon Square products have become staples in Filipino meriendas, parties,

picnics and other special occasions. Filipino kids love to have Lemon Square goodies in their

lunch boxes. Parents regularly take home Lemon Square cakes and pastries as pasalubong.

Lemon Square's owner Dulce had always dreamed of producing the best-tasting and the

highest-quality cupcakes in the Philippines, and to make these available to millions of Filipinos

at a very reasonable price.

Lemon Square had its humble beginnings in 1985 when it started to offer local communities a

small selection of homemade-style baked goods. Then newly-married Dulce began baking

cakes to sell to her friends. Word-of-mouth soon became the primary driving force for her cakes

as demand went through the roof.

She and her husband Errol soon had to buy more cake-making machines, hire more people,

increase production and enhance its variety to keep up with demand and to cater to the

preferences of the market.

In 1991, Lemon Square had to build a larger building to accommodate its booming operation.

In 1995, Lemon Square had to thoroughly modernize its operations to keep up with the times. It

did so by acquiring a state-of-the-art baking system that enhanced its production and efficiency.

Lemon Square also adopted the latest packaging techniques used by bakers the world over.

II.2 Organizational Chart




Please see appendix.

II.3 Walk-Through Inspection

The company has a four-storey production building. Situated in the ground floor are

receiving area, warehouse, and dispatching area. Also, located in the ground floor are

the pre-mix sections where the raw ingredients for different production lines are pre-

weigh. On the second floor, four different production lines are installed. On the third floor

of the building is situated the biggest production line of the company. While on the fourth

floor is located the production line intended for reprocess products.

During the walk-in inspection, listed below are the observation taken.

1. Poor Housekeeping. The strainer that should be installed in the drainage system

was left on top of the motor housing.

2. Material loss due to leak and emission. The black portion in the oil heating

chamber is the result of the soot that comes out from the leak on the chamber.




3. Material storage. Pre-weighed raw materials for producing cupcakes are stored in

an air-conditioned room. Next to it is the mixing room where these ingredients are

mixed.




4. Waste and emission from process equipment. Products on the floor caused by

missed pick-up of the robot will be considered as reject.

5. Emergency Equipment. Fire-extinguishers are placed in a strategic location where

everyone can see and has an easy access. Every fire-extinguisher is labeled just

above the located where it is visible.




II.4 Establish a focus

For a food manufacturing company, the main environmental issues are the high consumption of

energy and high volume of effluent.




Based on the figures, we decided to have our cleaner production assessment on line 5

production area which is the cupcake frostings production line. The line has the most number of

machines and consumes the largest energy resources of the company. It is the biggest

production line of the company that generates significant volume of effluent containing high

organic.. also, it has the highest consumption of gear-oil for gearbox and thermal oil for heat

transfer wherein if not manage correctly would create significant effect to the environment.

II. 5 Process overview

A frosting is an excellent delicacy for us Filipinos who love sweet foods. It is composed of the

base cake that satisfies our hunger for soft and puffy cake. There’s the cream filling inside the

cake that determines the flavor of the frostings. And also, the chocolate coating of the cake that

indulge us to a heavenly sweet craving. Not also to forget the crisp and sweet taste of candy

through the vermicelli sprinkled on top of the frosting.




Usually the processes involve in making cupcake frostings are mixing, aerating, depositing,

baking, cream injection, chocolate depositing, and cooling of the chocolate coating.

Fig1. Product flow diagram of Cupcake Frosting

All the ingredients are pre-weighed and set ready for each batter premix batch. These

ingredients are feed into the pre-mixer at a predefined mixing rate and sequence. Once the

batch is pre-mixed, the transport pump will automatically pump the whole batch into the buffer

tank. Underneath the buffer tank is the main pump that transfer cake batter to mixing head to

undergo aeration process. The aerated mixture (slurry) is then deposited in a baking cup with

the right amount of volume and density. It is then baked in an oven at a predetermined

temperature and cooled down for certain time (25minutes) before the cream filling is injected. A

melted chocolate is then deposited on top of the base cake and sprinkles with vermicelli (crispy

candy) to add more pleasure for the taste as well as for the eyes. The frosting is then chilled at

a low temperature to crystallize the chocolate topping.




Fig 2. Process flow of Cupcake Frosting production

Slurry Mixing Process (Pre-mixer Tank)

All the ingredients will be pre-weighed and set ready for handling at each batter premix batch.

After starting the pre-mixer, all the ingredients will be manually fed into the pre-mixer at a rate

and sequence as required for the specific recipe.

Once the batch is pre-mixed the valve underneath the tank will open automatically and the

transport pump will start. The transport pump will pump the whole batch into the buffer tank and

stops automatically if an empty signal is received from the pre-mixer. Now the valve underneath

the pre-mixer will close again and a signal is given “pre-mixer ready for next batch”.

Process description : This tank has been designed to plasticize and mix different

creams, consisting of fat (liquid fat or fat blocks with a temperature

of 20 degrees) which have to be mixed homogeneously with dry




ingredients, to a paste like consistency. The different ingredients

can be added manually or automatically depending on the design.

Buffer Tank

In the buffer tank the cream is kept in motion to avoid sacking of ingredients thus maintaining a

homogeneous mass throughout the production. Directly underneath the buffer tank the main

pump is placed which will pump the cream at the required capacity through the mixing head.

Process description : This tank has been designed for buffering of viscous products to

be able to go from intermittent to a continuous process. The

stirring avoids sinking of heaving ingredients. The stirring work

also has a light mixing function. However, the stirrer has not been

designed to mix different ingredients. Depending on the design the

tank can filled manually or automatically.

The Aerator

The aerator has been designed for mixing foaming products. The air, synchronized with the

main pump, is injected into the mixing head at a rate as set from the control panel. In the mixing

head the pins of both the rotor and the stator see to it that the air is homogeneously mixed with

the slurry down to the required density and structure. The cutting action of the pins of the stator

and the rotor ensure a regular distribution of air or another gas in the product.

The air/gas dosing system has been designed to reduce the density of products by injecting air

or gas. The air/gas dosing system is to be used for this purpose. The mixing head pressure is

controlled, irrespective of the length and diameter of the discharge pipe, by the mixinghead

pressure regulator. From the mixing head the aerated cake is discharged towards the slurry

depositor.

Depositor




From the hopper (1), the product will be deposited

through the piston (2) and the nozzles (3). The volume

that will be deposited depends on the hit length of the

pistons (B).

Due to the spring mechanism in the nozzles, the out

flow will be closed after the deposit hit. This way

leaking will be prevented.

With the sensor there will be checked if there is

enough slurry in the hopper. The head of the unit can

move up and down with the transport system.

Fig 3. Section view of the slurry depositor

Oven-Thermal heating system

The system consists of two basic circuits entitled Primary and Secondary. The Primary circuit

feeds two separate secondary circuits, one servicing the Thermal Oven heating plates, and one

servicing the Pan Wash Unit water-heating requirements.

Primary

Thermal oil is re-circulated around the primary side of the system by the primary re-circulation

pump. Oil; returning from the secondary circuit manifold is transferred via the primary pump to a

heat exchanger. A gas burner mounted to the heat exchanger maintains primary oil temperature

at a pre-determined set point en-route to the secondary circuit/s, thus completing the cycle.

Secondary circuit manifolds, pumps and control valves are situated in a cabinet/s adjacent to

the oven and pan wash.

As the thermal oil heats up and cools down during normal production phases it is allowed to

expand and contract accordingly via a system of tanks and expansion lines. A drain tank and

pump allows for overflow from the expansion tank to be contained and re-introduced into the




system should replenishment of thermal oil be required. The draining tank and pump is also

used during initial filling and priming of the system.

Secondary, Oven Heating (Zone 1 to 4)

The oven is heated by re-circulated hot thermal oil pumped continuously through heat exchange

plates mounted within the oven chamber. The layers of heat exchange plates in the oven are

divided into four separate zones of heating. The four separating zones are each serviced by an

individual secondary circuit pump which re-circulates thermal oil through respective radiator

plates. The radiator plates, located below the pan pass on each level, enable a rising bottom

heat transfer ideally suited for muffin and cake products. An extra plate above the last (top) pan

pass in the 4th zone has the ability to influence the final bake top color.

Thermal oil in the radiator plates is maintained at a set temperature via independently controlled

Baelz modulating valves, which mix incoming “hot” oil from the primary circuit supply line with

existing “cold” oil from the secondary circuits. These valves which are incorporated into the

secondary circuit govern the mix ratio between hot primary oil and re-circulated secondary oil,

depending on heat loads and selected zone temperatures. Thermocouple sensors are installed

at strategic points along the primary and secondary loops which feedback oil temperature

information to the PLC. As primary oil temperature varies due to heat loads, an on-board PLC

initiates the primary circuit burner to fire, maintaining temperature within an acceptable range.

Likewise, the secondary circuit temperatures are held at set points by PLC initiation of electric

actuators mounted directly to the modulating valves. Each zone has its own Baelz modulating

valve.

Adapted from Autobake Serpentine Thermal baking oven “Operation and Maintenance Manual”




Fig 4. Process flow of the Thermal Oil System

Cream Injector

From the hopper (1), the product will be deposited

through the piston (2) and the needles (3). The

volume that will be deposited depends on the hit

length of the pistons.

Due to the spring mechanism in the nozzles, the

out flow will be closed after the deposit hit. This

way leaking will be prevented. With the sensor

there will be checked if there is enough cream in

the hopper. The head of the unit can move up and

down with the transport system.

Fig.5 Section view of the Cream Injector




Cream Processing

Application : Cream and Mallow

Production capacity : Min. 200 kg/hr. and max. 500 kg/hr.

Incoming density : 1.1 kg/ltr. (depending on product)

Outgoing density : 0.7-0.8 kg/ltr. (depending on product)

Process description

The process starts with the open bath cooker. This cooker will be manually fed with ingredients.

After cooking the batch is dumped into the cooling tank. When the slurry has been mixed and

the correct temperature has been reached it will be pumped towards the premixer or buffer tank,

depending on the product which will be produced (Cream or Mallow).

After starting the pre-mixer, all the ingredients will be manually fed into the pre-mixer at a rate

and sequence as required for the specific recipe.

Once the batch is pre-mixed the valve underneath the tank will open automatically and the

transport pump will start. The transport pump will pump the whole batch into the buffer tank and

stops automatically if an empty signal is received from the pre-mixer. Now the valve underneath

the pre-mixer will close again and a signal is given “pre-mixer ready for next batch”.

In the buffer tank the cream is kept in motion to avoid sacking of ingredients thus maintaining a

homogeneous mass throughout the production. Directly underneath the buffer tank the main

pump is placed which will pump the cream at the required capacity through the mixing head.

The air, synchronized with the main pump, is injected into the mixing head at a rate as set from

the control panel. In the mixing head the pins of both the rotor and the stator see to it that the air

is homogeneously mixed with the cream down to the required density and structure.




Fig 6. Process flow of Cream Processing

The Pick-and-Place Robot

This robot transfers baked cupcake from the continuous tray to a conveyor system. The robot

has depanner which has needles designed to pick-up 75 cupcakes at a time. This place-and-

place sequence also helped the ease of production because it maintains the alignment of

cupcakes which is essential for the next processes.

Chocolate Depositor

The chocolate filling masses prepared by the cooking machine or tempers are fed into the tank

of the depositor head via a manifold distributor. Distribution of the compounds across the tank

width is thus automatic. The compound level in the tank is recorded by a filling level sensor.




The piston is operated volumetrically, i.e. a defined compound volume is dosed by the dosing

pistons from the mass hopper through the nozzle bed and the nozzles during each working

stroke.

The dosing pistons are driven by an eccentric shaft. The piston stroke can be set via the control

system by a servo drive simultaneously for all pistons. Individual adjustment of the pistons is

also available.

During the depositing process, the whole depositor head moves together with the transport belt.

This follow-up movement is transmitted to the depositor head via a programmable servo drive.

The follow-up movement is adapted to the speed of the transport belt.

Fig 7. Overview of the Chocolate depositor




Cooling Tunnel

The air cooling tunnel serves to cool the warm bakery and sweet products which are transferred

from an upstream installation on to the transport conveyor of the cooling tunnel.

The LK-type air cooling tunnel is designed for cooling of all types of fat coatings as well as

cooling of pastry, praline or bar fillings. The bottom (contact cooling) and top cooling (convection

cooling) is achieved by cold air in least two cooling zones.

Packaging System

The packaging system of the production line is a fully automated conveying system. It is

composed of a Product Distribution System (PDS) which distributes the individual rows out of

product flow and to the four packaging machines.

Continuous distribution of the product to the packaging machine is made possible through the

aligner, dumping system and the distribution units. Undistributed rows of product are recovered

through the recycling belt.




Fig 8. Product Distribution System with two Packaging Machines

Table 1. Average weight of utilized raw materials for each cupcake frostings

Weight (g)

Percentage of Finished

product

Finished product 35 100

Paper cups 0.1 0.2857

BaseCake 21 60.0000

Cream 4 11.4286

Chocolate 8 22.8571




Vermicelli 0.9 2.5714

Packaging Material 1 2.8571

Reject Processing

Feed mill

Rejected products, contaminated raw materials and faulty-mixture of raw materials are transfer

to other plant for feed mill processing. Every day there is a truck assigned to transport these

resources for feed mill.

Toasting

Products which are about to reach their shelf life (two weeks before expiration date) are return

to the factory as “back-order” (BO). These products are reprocess as toasted products and are

sold at lower prices through “in-house sale”.

Other products such as under-baked over-baked but not burnt and trimmings are reprocessed

as toasted products.

II.6 Environmental Aspects

As for many other food processing operations, the main environmental aspects associated with

cupcake processing activities are the high consumption of water, the discharge of effluent with

high organic loads and the consumption of energy.

Water Consumption

Cupcake processing characteristically requires very large quantities of fresh water. Water is used

primarily for cleaning process equipment and work areas to maintain hygiene standards. Production

facilities like chillers, boilers and air compressors use water for their cooling system.




Table 2 shows the water consumption of each machine in a typical Clean-In-Place of the production area. It gives an indication of the extent to which each area contributes to overall water use.

Table 2. Consumption of cleaning water for the CIP of the production line

Mixing tank 4400 kg

Depositing 750 kg

Cream mixing tank 2400 kg

Cream Injector 800 kg

Chocolate depositor 50 kg

Packaging 25 kg

Effluent Discharge

The dominant environmental aspect caused by cupcake processing is the discharge of large quantities of liquid effluent. Cupcake processing effluents generally have high organic load due to the presence of milk components. They exhibit fluctuations in pH due to the presence of caustic and acidic cleaning agents and other chemicals. Figure 9 shows percentage of the effluent generated by each process.




Fig 9. Waste water generation in cupcake frosting production

Energy Consumption

Energy is used at cupcake processing plants for running electric motors on process equipment, for heating, evaporating and drying, for cooling and refrigeration, and for the generation of compressed air. Thermal energy, in the form of steam, is used for heating and cleaning.

Approximately 50 percent of electrical consumption of the plant are generated for cooling the water needed in the process and ventilation and refrigeration.




Fig 10. Electrical Consumption of Process Equipment

Table 3. Actual wattage of Process EquipmentMixer 7621 watts 7.621 kwh

Aerator 8231 watts 8.231 kwh

Slurry Depositor 11523 watts 11.523 kwh

Baking (Oven) 36581 watts 36.581 kwh

Cream Injector 11584 watts 11.584 kwh

Chocolate Depositor 12194 watts 12.194 kwh

Cooling 24387 watts 24.387 kwh

Packaging 24387 watts 24.387 kwh

Burner 15242 watts 15.242 kwh

Chiller 78497 watts 78.497 kwh

ACCU 70113 watts 70.113 kwh

Solid Waste




Raw materials for cupcake production like flour, skimmed milk, whey, and cocoa powder are

packed in multi-layered craft paper sack. Liquid raw materials are delivered in pails and plastic

containers.

Pre-weight raw materials for processing are packed in individual plastic as ready for batch. Final

product, cupcake frostings are individually packed in a fully automated packaging machine.

Low-density polypropylene is used for packaging the product. Packaging mistakes cannot be

totally avoided. Improperly packaged product can often be returned for reprocessing; however

the packaging material is generally discarded.

Emission to air

Emissions to air from cupcake processing plants are caused by the high levels of energy

consumption necessary for production. Hot water, which is generally used in jacket pipe of

chocolate and for cleaning of equipment, is generally produced in on-site boilers, and electricity

used for cooling and equipment operation is purchased from the grid. Thermal oil system of the

oven is heated using a burner which utilizes diesel as fuel.

Air pollutants, including oxides of nitrogen and sulfur and suspended particulate matter, are

formed from the combustion of fossil fuels, which are used to produce both these energy

sources.

Refrigerant

Old refrigeration systems based on chlorofluorocarbons (CFCs), the fugitive loss of these gases to the

atmosphere is an important environmental consideration, since CFCs are recognized to be a cause of

ozone depletion in the atmosphere. For such operations, the replacement of CFC-based systems with

non- or reduced-CFC systems is thus an important issue.

Hazardous waste

Hazardous wastes consist of oily sludge from gearboxes of moving machines, laboratory waste, cooling

agents, oily paper filters, batteries, paint cans etc. Preventive maintenance program of the process




equipment requires monthly lubrication for reliable operation. Both unplanned and planned replacement of

gearbox parts requires replacement of gear-oil once the gearbox is exposed and contaminated. Table 4

shows the average consumption of these lubricants per year.

During repair works of the thermal oil system of the oven, thermal oil at the lowest part of the pipes are

drained. This drained oil even if it goes to the drain pan cannot be introduced again to the system. They

are considered contaminated.

Table 4. Average annual consumption of lubricants

MachineLiters of lubricant (gear-oil, grease, chain oil)

Percentage %

Mixing motor 16 2.83Transport pump 6 1.06Buffer Tank 12 2.12Transport pump 6 1.06Aerator 20 3.53Depositor 2 0.35Oven 404 71.38Injector 2 0.35Robot 50 8.83Packaging 48 8.48

Phase III – Assessment

III. 1 Material Balance

1. Mixing and product transfer (Slurry and Cream)

All the pre-weight ingredients for each batch (slurry and cream) are manually dump

into the pre-mixing tank. It is then mixed at a pre-set time, rate of spin and sequence.

The motor with installed gearbox that is located at the bottom of the tank mixes the

first set of ingredients at low speed and pre-defined time. After the first sequence, the

remaining ingredients are dumped into the tank and mix for a predefined time at a




faster speed of mixing. This switching of speed is occurring simultaneously through

the aid of the PLC and the frequency converter installed.

Once the batch is pre-mixed the transport pump automatically transfer the product in

a buffer tank at a synchronous speed. This is possible because of the stator design

that maintains the accurately the pre-set speed of the pump.

a. Inputs-outputs

Fig. Inputs and outputs of Mixing process

b. Environmental issue

Water is used in cleaning and sanitizing the mixing tank, buffer tank and transfer lines.

The resulting effluent from cleaning and rinsing contains pre-mixed product and cleaning

agents which has high organic load.




c.Cleaner production opportunities

Cleaner production opportunities related to this area are related to reducing the amount

of pre-mixed product that stays in the mixing tank, buffer tank and transfer lines. Ways of

achieving this includes:

Collecting the remaining product along the sides of the tanks

Using compressed air to push the remaining product in the pipeline for recovery

2. Aeration – The pre-mixed product from the buffer tank is injected with clean

compressed air to reduce the density of the product. The air, synchronized with the

main pump, is injected into the mixing head at a pre-defined rate. In the mixing head

the pins of both the rotor and the stator see to it that the air is homogeneously mixed

with the slurry down to the required density and structure. The mixing head is double

walled wherein cooling water continuously stabilized the foaming of the product.

a. Inputs-outputs





The main environmental issue associated with aeration of the slurry is the high level s of

energy consumed for cooling the slurry as well as the generation of compressed air for

air injection.

In addition, machine components like pump and mixing stator, silicon hose and electrical

components are damaged because of faulty operation and poor maintenance.

c. Cleaner production opportunities

Cleaner production opportunities in this area focus on improving energy efficiency. Ways

of achieving this includes:

Installation of a centralized chilled water system for the whole plant and

the existing chiller will only be used as back-up chiller especially during

summer season.

Replacement of old piping insulation of the chilled water pipeline

Routine check and replacement of mixing head jacket

Execute routine maintenance of machines and comply with standard

operating procedures

3. Slurry and cream depositing

Slurry and cream depositor are two different machines; however they have the same

operating concept. Before the slurry/cream is transported to the hopper the density of

the slurry/cream must be determined first. After obtaining the correct density, the

hopper will be filled with slurry/cream and ready for depositing.

After the operation, the slurry and cream depositor are detached from the production

line and transferred to the washing area for cleaning and sanitizing. Hot water

around 60C is utilized in cleaning and sanitizing. The hose that is connected in the

hot water line is being covered with a finger at the end to increase the pressure of

the water.

a. Inputs-outputs





The environmental issue specific for the depositing process is the large volume of hot

water for the cleaning and sanitizing the hopper and the depositing mechanism.


The hose used should have a pressurized gun installed at the end to increase the

pressure of the hot water to reduce the consumption of hot water.

4. Baking (Thermal oil Oven)

The oven is operating at 300°C through a thermal oil system which has a primary

and secondary oil circuit. The thermal oil used was changed from synthetic oil to

mineral-based thermal oil due to price variation.

The oven consists of four (4) different zones where individual temperatures can be

assigned and dynamically modulated by the motorized control valve. The hot air

circuit is being maintained by the fresh-exhaust air system. The exhaust air from the

oven is around 175°C.




a. Inputs-outputs


The specific environmental issue in baking process is the excess heat (175°C) that is

rejected to the environment.


The hot air that the exhaust system of the oven introduces to the environment can be

a valuable resource for a heat-recovery system.

5. Cooling Tunnel

Melted chocolate generally crystallized at 20-30 degrees Celsius. For commercial

chocolate production, it is being chilled to a temperature of 5-10°C in a continuous

transport conveyor.

a. Inputs-outputs





The main environment issue associated with cooling of cupcake with chocolate coating

is the energy consumed for the chiller and the potential loss of refrigerant in the

atmosphere.


Cleaner production opportunities in this area focus on improving the energy efficiency of

the chiller. Ways of achieving this includes:

Ensuring that the insulation are undamaged

Re-designing the air-conditioned space to a smaller space to utilize the

cold room as a pre-cooling system

Undertaking regular maintenance of the refrigeration system

6. Packaging

Final product, cupcake frostings are individually packed in a fully automated

packaging machine. Low-density polypropylene is used for packaging the product.

An out-feed conveyor manages the distribution of the product for outer-packaging

(10pcs/pack) and simultaneously box for distribution.




a. Inputs-outputs


The major waste from packaging of cupcake products are solid wastes, including

rejected cupcakes, machine cut cupcakes, and damaged packaging materials.

In addition there liquid discharges from cleaning of packaging machines, work surfaces

and conveyors.


All rejected cupcakes should be collected separately from other waste and either sold for

in-house sale at lower price or sold as animal feed.

Damaged packaging materials can be sold as scrap materials.

Liquid waste should be treated together with other effluent streams.

7. Ancilliary operations

7.1 Compressed air

Air is compressed in a higher pressure by an air compressor and distributed

throughout the plant in a pressurized pipe. The compressor is driven by electricity and




cooled by air. The compressed air then passed to a desiccant dryer to eliminate

moisture in the air.

a. Inputs-outputs


Small holes that causes air leak in the compressed air system can lost significant

volume of compressed air. This results to a waste of electricity because the compressor

has to run more than is necessary.

Air compressors are usually noisy causing serious risk of hearing damage to the workers

in the area.

Compressor oil is changed periodically. If the changed oil is not collected, re-used or

sold, it can cause serious pollution of soil and water.





It is very important to check the compressed air system frequently. The best time to

check the system is during no production to easily detect leaks.

Maintenance and keeping of accurate log-books will often help identify the accurate time

of changing compressor oil and eliminate unnecessary repairs.

7.2 Thermal oil System

The thermal oil system has generally two oil circuit, primary and secondary circuit.

The primary circuit is heated in the oil heater which uses fuel to heat the thermal oil.

The primary pump transports the heated thermal oil to the secondary circuit. In the

secondary circuit, five (5) pumps are individually transporting thermal oil to the plate

heat-exchanger of the oven in different zones. The thermal oils are re-circulated to

the primary circuit for reheating and ready to heat the oven again.

a. Inputs-outputs





Inefficiencies of boilers or oil heaters lead to the waste of valuable fuel resources as well as

additional operating costs. Combustion of fuel oil results in emissions of carbon dioxide (CO2),

sulfur dioxide (SO2), nitrogen oxides (NOX) and polycyclic aromatic hydrocarbons (PAHs). Some

fuel oils contain 3–5% sulfur and result in sulfur dioxide emissions of 50–85 kg per 1000 liters of

fuel oil.

Sulfur dioxide converts to sulfuric acid in the atmosphere, resulting in the formation of acid rain.

Nitrogen oxides contribute to smog and can cause lung irritation. If the combustion is not

adjusted properly, and if the air-fuel ratio is too low, there are high emissions of soot from the

burners. Soot regularly contains PAHs that are carcinogenic. (UNEP, 1996)

Thermal oil often spills during repair or maintenance of thermal oil system. When conducting

repair of pumps, about 10kg of thermal oil is wasted because of the volume that stays in the

pipe (4” diameter).





Instead of using fuel oil with high sulfur content, it is advantageous to change to a fuel oil with

low sulfur content (less than 1%). This increases the efficiency of the boiler and reduces sulfur

dioxide emissions.

It is essential to avoid oil spills and, if they occur, to clean them up properly and either reuse or

sell the oil. A procedure for handling oil and oil spills should be instituted and followed.

A recovery pipe that is installed in the lowest part of the pump system and connected to the oil

storage will minimize oil spills during maintenance work. Also, a filtration system for the thermal

oil will increase the thermal transfer efficiency and prolong the life of the thermal oil.

III. 2 Summary of identified Cleaner production Opportunities

Problem type Problem description Cleaner Production Options

Wastewater CIP of Mixing tank of cream

and slurry and transfer

pipeline produces high

organic load because

remaining products in the

pipelines and tanks goes with

the effluent

Cleaning of depositor and

Injector - Large volume of hot

water for the cleaning and

sanitizing the hopper and the

depositing mechanism.

- Collecting the

remaining products

that can be recovered

along the side of the

tank

- Using compressed air

to push the remaining

product in the pipeline

for recovery

- The hose used should

have a pressurized

gun installed at the

end to increase the

pressure of the hot




water to reduce the

consumption of hot

water.

Energy Consumption During aeration process,

chilled water is used to

stabilize the process.

Individual chillers are used for

each aerator.

The current cooling space is

not suitable for the existing

systems since the

replacement of machine

- Installation of a

centralized chilled

water system for the

whole plant and the

existing chiller will only

be used as back-up

chiller especially

during summer

season.

- Replacement of old

piping insulation of the

chilled water pipeline

- Routine check and

replacement of mixing

head jacket

- Re-designing the air-

conditioned space to a

smaller space to utilize

the cold room as a

pre-cooling system




Heat rejected to the

environment

In baking process, the excess

heat (175°C) that is rejected

to the environment can be a

good source for heat recovery

system

The exhaust air from the oven

can be used in the proofing

process (90C) of the dough

for the bread processing

Thermal oil spill When conducting repair of

pumps, about 10kg of thermal

oil spill and wasted because

of the volume that stays in the

pipe (4” diameter).

- A recovery pipe that is

installed in the lowest

part of the pump

system and connected

to the oil storage will

minimize oil spills

during maintenance

work.

- A filtering system for

the thermal oil will

increase the thermal

transfer efficiency and

prolong the life of the

thermal oil.

Phase IV – Evaluation and Feasibility study

IV.1 Technical Evaluation

Wastewater




PROCESS Option Technical Evaluation

CIP of mixing tanks (cream

and slurry)

Collecting the remaining

products that can be

recovered along the side of

the tank by using a long

plastic scraper

Using compressed air to push

the remaining product in the

pipeline for recovery

The use of plastic scraper

would not affect the quality of

the product although it would

take a longer time to finish the

CIP of the machine. The

recovered product can be

used for further process.

This option would not require

additional personnel to do the

job although supervision must

be taken to ensure the safety

of the personnel and machine

components like level sensor.

The injection of compressed

air in the product would not

affect the quality of the

product. Strategic location of

the input air should be located

to ensure effectiveness.

Proper handling of the

recovered product should be

observed to assure food

safety because the recovered

product can be re-processed.

This option would not require

additional personnel but a




proper training of the

operation must be taken.

Cleaning of Depositor and

Injector

Install pressure gun at the end

of the hose used for cleaning

the machine

The installation of the

pressure gun would not

require specialized personnel

outside the company. The

technical personnel of the

company can do the job.

The pressure gun must not

corrode. It must be made from

brass, aluminum, stainless

and alike.

Energy Consumption

Process Options Technical Evaluation

Cooling process of Slurry and

cream during aeration

- Installation of a

centralized chilled

water system for the

whole plant and the

existing chiller will only

be used as back-up

chiller especially

during summer

season.

- Replacement of old


The installation of the

centralized system with a

back-up would ensure a

sufficient chilled water supply

for the whole line, assuring a

stable aeration process even

during summer season.

It would require the expertise

of contractors in HVAC

system and proper training of

the personnel assigned to





- Routine check and


head jacket

operate the new system.

The piping insulation cladding

must be of aluminum/stainless

steel.

Replacement of the mixing

head jacket would not affect

the product or the process.

The replacement jacket must

always ensure food safety

requirements (Food grade

material).

Cooling of the processing

area. The current cooling

space is not suitable for the

existing systems since the

replacement of machine.

Re-designing the air-

conditioned space to a smaller

space to utilize the cold room

as a pre-cooling system

Reducing the air conditioned

space would not affect the

process flow of the product. It

would not restrict the

movement of the personnel in

the processing area.

The conditioned air would not

contaminate the product since

the ductings to be installed

are made of stainless.

It would require the expertise

of contractors in HVAC

system and proper training of

the personnel assigned.

Recovery system




Process Options Technical Evaluation

Heat rejected by the oven

exhaust to the Environment

The exhaust air (175C) from

the oven can be used in the

proofing process (40C at

relative humidity of 70-80 %)

of the dough for the bread

processing through the use of

heat exchanger

The option would not affect

the process flow of the

product.

There is enough space for the

installation of the heat

exchanger system.

The exhaust air (175C) is

enough to produce the

necessary heat of 40C.

This would require the

expertise of contractors in

heat pipe heat exchanger.

With the case study of

Buttercup Bakery in Australia,

they developed a heat pipe

heat exchanger with good

heat transfer characteristics,

compactness, no moving

parts and no cross-

contamination between fluid

streams.

Oil spill during repair works - A recovery pipe that is

installed in the lowest

part of the pump

system and connected

to the oil storage will

minimize oil spills

The recovery pipe will not

affect the process flow of the

thermal oil system since it will

be closed during normal

operation.

The installation would require




during maintenance

work.

- A filtering system for

the thermal oil will

maintain the thermal

transfer efficiency and

prolong the life of the

thermal oil.

the expertise of contractors in

piping system.

The installation might require

a shut-down of the operation

to isolate the thermal oil in the

installation spot.

The filtering system will not

affect the process flow of the

thermal oil system since it is

installed in the storage tank. A

portion of the system where

there is not much activity.

The installation will be done

during the total change oil

period of the system.

There is enough space for the

additional system.

The installation will require the

expertise of contractors in oil

piping system, filter tank and

proper training on the new

system.

IV.2 Economic Evaluation

Wastewater

Process Option Investment Benefit Payback peroid

CIP of mixing tanks Collecting the remaining Fabrication of 10 kg of Less than a




(cream and slurry)

products that can be

recovered along the side

of the tank by using a

long plastic scraper

long scraper

made of plastic =

Php 2000

recovered

product = Php

500 month

Fifty percent

savings of hot

water

consumption

Using compressed air to

push the remaining

product in the pipeline for

recovery

Installation of

compressed air

line = Php 3000

20kg of recovered

product = Php

1000

Less than two

months

Cost of

compressed air

per CIP = Php

124.00

Fifty percent

savings of hot

water

consumption

Cleaning of

Depositor and

Injector

Install pressure gun at

the end of the hose used

for cleaning the machine

Pressure gun =

Php 800

75 percent

savings in hot

water

consumption for

cleaning Less than 1 week

Energy Consumption

Process Option Investment Benefit Payback peroid

Cooling process of

Slurry and cream

during aeration

Installation of a

centralized chilled water

system for the whole

A centralized

chilled water

system for the 3

30 percent

savings on energy

consumption




plant and the existing

chiller will only be used

as back-up chiller

especially during

summer season.

aerators chilled

water system

would cost Php

1,500,000 of labor

and materials

including the new

unit

including

electricity,

refrigerant, water

consumption and

consumables Replacement of old



- Routine check and


head jacket

Fabrication of a

replacement

mixing head

jacket = Php 1,800

Cooling of the

processing area.

The current cooling

space is not

suitable for the

existing systems

since the

replacement of

machine.

Re-designing the air-

conditioned space to a

smaller space to utilize

the cold room as a pre-

cooling system

Cost of labor and

materials for the

re-location of the

ACU, re-sizing of

air-conditioned

space = Php 300

000

50 percent

savings on energy

consumption

Recovery System

Process Option Investment Benefit Payback period

Heat rejected to the

environment The exhaust air from the oven

can be used in the proofing

process (90C) of the dough for

Installation of heat

pipe heat

exchanger = Php

Replacing the

water heater

(8pcs) to

If the company

would just operate

for 8 hours per day,




the bread processing

500,000 generate heat in

the proofing area

would save Php

45,000/year

the payback period

would be as long as

11years

Oil spill during

repair worksA recovery pipe that is installed

in the lowest part of the pump

system and connected to the oil

storage will minimize oil spills

during maintenance work.

Installation of

recovery piping

system would cost

Php 30,000

Eliminate the oil

spill during repair

works that nearly

cost Php 4,500

every repair

work.

A filtering system for the thermal

oil will maintain the thermal

transfer efficiency and prolong

the life of the thermal oil.

Installation of

filtering system

would cost Php

50,000

Thermal Oil System

Initial cost Operating Years - Cost Total CostThermal

oil Investment 1 2 3 4 5 6 7 8 9 10 Filtered oil 99000 80000 0 0 0 0 99000 0 0 0 0 99000 377000Un-filtered oil 99000 0 0 99000 0 0 99000 0 0 99000 0 396000

IV. 3 Environmental Evaluation

Waste Water

Process OptionEnvironmental Evaluation

Positive Negative




CIP of Mixing tank of cream and slurry and transfer pipeline produces high organic load because remaining products in the pipelines and tanks goes with the effluent

Collecting the remaining products that can be recovered along the side of the tank

Reduce the amount of organic load by almost 50%

Reduce hot water consumption by 50% therefore saving energy

Using compressed air to push the remaining product in the pipeline for recovery

Minimal increase in the operating cost for compressed air

Cleaning of Slurry Depositor and Cream Injector

The hose used should have a pressurized gun installed at the end to increase the pressure of the hot water to reduce the consumption of hot water.

Reduce in the consumption of hot water up to 75%

Energy Consumption


Positive NegativeDuring aeration process, chilled water is used to stabilize the process. Individual chillers are used for each aerator.

Installation of a centralized chilled water system for the whole plant and the existing chiller will only be used as back-up chiller especially during summer season.

Reduction of refrigerant emission to air by 33%. (From 3 chillers (R22) to one chiller-R134a)

Replacement of old piping

insulation of the chilled water pipeline

Reduction in energy consumption

Generate solid waste

Routine check and replacement of mixing head jacket

Reduction in energy consumption

Generate solid waste

The current cooling space is not suitable for the existing systems since the replacement of machine

Re-designing the air-conditioned space to a smaller space to utilize the cold room as a pre-cooling

Reduction of energy consumption

Refrigerant emission (R22) when discharging




system refrigerant as needed for installation

Recovery System


Positive Negative

Heat rejected by the oven exhaust to the Environment

The exhaust air (175C) from the oven can be used in the proofing process (40C at relative humidity of 70-80 %) of the dough for the bread processing through the use of heat exchanger

Reduction of heat in the environment by up to 50%

Reduction of energy consumption

Oil spill during repair works

A recovery pipe that is installed in the lowest part of the pump system and connected to the oil storage will minimize oil spills during maintenance work.

Reduction of used oil generation

A filtering system for the thermal oil will maintain the thermal transfer efficiency and prolong the life of the thermal oil.

Extending the life span of the thermal oil therefore reducing thermal oil usage

IV. 4 Select Viable options

Water Consumption




With the result of the comparative ranking analysis, it is recommended to practice first the

scraping of the remaining product on the side of the tank compared with the other options to

reduce water consumption. Obviously, the installation of pressure a gun at the end of the hose

would be very easy to implement and effective way to reduce water consumption, therefore, can

be done simultaneously.

Energy Consumption




The result of the comparative ranking analysis suggests that a routine check and in-time

replacement of mixing head jacket can be the initial action to reduce the energy consumption of

the factory. For major renovation, the installation of the centralized chilled water system is

suggested to be done.

Recovery System




For the suggested recovery systems, the installation of the filtering system of the thermal oil is

strongly suggested as the result of the comparative ranking analysis. Next to it, is the installation

of the recovery pipe from the drain port to the storage of the thermal to eliminate the spill during

repair works.

Using exhaust air for dough proofing got the lowest rank in the analysis. The main reasons for

having a low score are the high investment of the system and a low return of investment rate.

The breadline section which uses the dough proofing is only operating on an 8-hour operation

per day for 6days in a week.

Conclusion

Cleaner Production assessment (CPA) is an effective technique for reducing wastes and

effective use of resources without compromising the environmental aspects.

CPA in a cupcake producing company identifies that the main environmental issues are the high

energy consumption for the machineries and operations; and high volume of effluent generated

from cleaning of the machines. Reduction of energy consumption can be done through effective




maintenance of the machine to ensure high efficiency and reliability of the operation. Installing

appropriate recovery system saves the company a lot of resources through effective use and full

utilization.

High volume of effluent can be reduced effectively through an attitude change of the personnel

involve in the process. From the comparative ranking analysis, a simple act of removing the

remaining product that can be recovered from the system is the best way of reducing the water

consumption as well as the discharge of effluent.

References

COWI Consulting Engineers and Planners AS, 1992. Cleaner Production Opportunities in

Dairy Processing

COWI Consulting Engineers and Planners AS, 1992. Cleaner Production Opportunities in

Meat Processing

Recycling of hydraulic oil at a factory in the automotive industry.

Retrieved in www.cprac.og

Cleaner production in production of bakery and cake products. Retrieved in

www.cprac.org


http://www.cprac.org/

http://www.cprac.og/

CPA in cupcake processing

Documents

Transcript of CPA in cupcake processing