CPA in cupcake processing

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CLEANER PRODUCTION ASSESSMENTOF A CUPCAKE PRODUCTION LINE

Dr. A. 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 afterthe-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 As part of the company’s mission statement: Villarosa, J., Buena, J.

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“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: Villarosa, J., Buena, J.

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CLEANER PRODUCTION ASSESSMENTOF

Dr. A. 2nd Term

A CUPCAKE PRODUCTION LINE 2010

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:

Week Week Week Week Week Week Week Week Week Week Activity Ocular Visit Obtain Company

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commitment Obtain a company organizational chart, Mission-Vision Obtain process flow chart of each production lines Obtain a focus Determine the process description Villarosa, J., Buena, J.

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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.

Villarosa, J., Buena, J.

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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


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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 preweigh. 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.


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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.


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4. Waste and emission from process equipment. Products on the floor caused by missed pick-up of the robot will be considered as reject.


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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.


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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.


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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.


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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”.


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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 Villarosa, J., Buena, J.

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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


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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 Villarosa, J., Buena, J.

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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


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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. Villarosa, J., Buena, J.

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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


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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-andplace 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.


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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.


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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


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Table 1. Average weight of utilized raw materials for each cupcake frostings Percentage of Finished Weight (g)

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”.


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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 Depositing Cream mixing tank Cream Injector Chocolate

4400 750 2400 800

kg kg kg kg

depositor Packaging

50 25

kg 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


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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.


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Fig 10. Electrical Consumption of Process Equipment Table 3. Actual wattage of Process Equipment watt

7.621 kwh

7621 s watt

8.231 kwh

8231 s watt

11.523

Slurry Depositor

11523 s watt

kwh 36.581

Baking (Oven)

36581 s watt

kwh 11.584

Cream Injector

11584 s watt

kwh 12.194

Chocolate Depositor

12194 s watt

kwh 24.387

Cooling

24387 s watt

kwh 24.387

Packaging

24387 s watt

kwh 15.242

Burner

15242 s

kwh

Mixer Aerator


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watt

78.497

Chiller

78497 s watt

kwh 70.113

ACCU

70113 s

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


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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

Machine Mixing motor Transport pump Buffer Tank Transport pump Aerator Depositor Oven Injector Robot Packaging

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

Percenta ge % 16 2.83 6 12

1.06 2.12

6 20 2 404 2 50 48

1.06 3.53 0.35 71.38 0.35 8.83 8.48

Phase III – Assessment Villarosa, J., Buena, J.

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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


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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: Villarosa, J., Buena, J.

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•

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

b. Environmental issue


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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.


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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

b. Environmental issue 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. c. Cleaner production opportunities 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. Villarosa, J., Buena, J.

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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

b. Environmental issue The specific environmental issue in baking process is the excess heat (175°C) that is rejected to the environment. Villarosa, J., Buena, J.

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c. Cleaner production opportunities 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

b. Environmental issue 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. Villarosa, J., Buena, J.

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c. Cleaner production opportunities 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


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b. Environmental issue 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. c. Cleaner production opportunities 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


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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

b. Environmental issue 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.


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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. c. Cleaner production opportunities 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


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b. Environmental issue 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)


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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).

c. Cleaner production opportunities 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


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Problem type

Problem description

Wastewater

CIP of Mixing tank of cream

Cleaner Production Options -

Collecting the

and slurry and transfer

remaining products

pipeline produces high

that can be recovered

organic load because

along the side of the

remaining products in the

tank

pipelines and tanks goes with the effluent

-

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

Cleaning of depositor and

-

The hose used should have a pressurized

Injector - Large volume of hot

gun installed at the

water for the cleaning and

end to increase the

sanitizing the hopper and the

pressure of the hot

depositing mechanism.

water to reduce the consumption of hot water.

Energy Consumption

During aeration process,

-

Installation of a

chilled water is used to

centralized chilled

stabilize the process.

water system for the

Individual chillers are used for

whole plant and the

each aerator.

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


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season. -


-


-

Re-designing the airconditioned space to a

The current cooling space is

smaller space to utilize

not suitable for the existing

the cold room as a pre-

systems since the

cooling system

replacement of machine Heat rejected to the

In baking process, the excess

The exhaust air from the oven

environment

heat (175°C) that is rejected

can be used in the proofing

to the environment can be a

process (90C) of the dough for

good source for heat recovery

the bread processing

system Thermal oil spill

When conducting repair of

-

A recovery pipe that is

pumps, about 10kg of thermal

installed in the lowest

oil spill and wasted because

part of the pump

of the volume that stays in the

system and connected

pipe (4” diameter).

to the oil storage will minimize oil spills during maintenance work. -


A filtering system for Page 43

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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


CIP of mixing tanks (cream

Collecting the remaining

The use of plastic scraper

and slurry)

products that can be

would not affect the quality of

recovered along the side of

the product although it would

the tank by using a long

take a longer time to finish the

plastic scraper

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


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of the personnel and machine components like level sensor. Using compressed air to push the remaining product in the

The injection of compressed

pipeline for recovery

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

Install pressure gun at the end

The installation of the

Injector

of the hose used for cleaning

pressure gun would not

the machine

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


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and alike.

Energy Consumption Process Cooling process of Slurry and

Options


-

Installation of a

The installation of the

centralized chilled

centralized system with a

water system for the

back-up would ensure a

whole plant and the

sufficient chilled water supply

existing chiller will only

for the whole line, assuring a

be used as back-up

stable aeration process even

chiller especially

during summer season.

cream during aeration

during summer season. -

It would require the expertise of contractors in HVAC

Replacement of old

system and proper training of

piping insulation of the

the personnel assigned to

chilled water pipeline

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


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material). Cooling of the processing

Re-designing the air-

Reducing the air conditioned

area. The current cooling

conditioned space to a smaller

space would not affect the

space is not suitable for the

space to utilize the cold room

process flow of the product. It

existing systems since the

as a pre-cooling system

would not restrict the

replacement of machine.

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


Heat rejected by the oven

The exhaust air (175C) from

The option would not affect

exhaust to the Environment

the oven can be used in the

the process flow of the

proofing process (40C at

product.

relative humidity of 70-80 %) of the dough for the bread processing through the use of heat exchanger

There is enough space for the installation of the heat exchanger system. The exhaust air (175C) is


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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

The recovery pipe will not

installed in the lowest

affect the process flow of the

part of the pump

thermal oil system since it will

system and connected

be closed during normal

to the oil storage will

operation.

minimize oil spills during maintenance work.

The installation would require 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


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affect the process flow of the -

A filtering system for

thermal oil system since it is

the thermal oil will

installed in the storage tank. A

maintain the thermal

portion of the system where

transfer efficiency and

there is not much activity.

prolong the life of the thermal oil.

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 Payback Process

Option Collecting the remaining

Investment Fabrication of

Benefit

products that can be

long scraper

10 kg of

recovered along the side

made of

recovered

CIP of mixing tanks

of the tank by using a

plastic = Php

product = Php

(cream and slurry)

long plastic scraper

2000

500


peroid

Less than a month

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Fifty percent savings of hot water Using compressed air to

Installation of

consumption 20kg of

push the remaining

compressed

recovered

product in the pipeline for

air line = Php

product = Php

recovery

3000 Cost of

1000 Fifty percent

compressed

savings of hot

air per CIP =

water

Php 124.00 Cleaning of

Install pressure gun at

consumption 75 percent

Depositor and

the end of the hose used

savings in hot

Injector

for cleaning the machine

water Pressure gun

consumption

= Php 800

for cleaning

Less than two months

Less than 1 week

Energy Consumption Payback Process Cooling process of

Option Installation of a

Investment A centralized

Benefit 30 percent

Slurry and cream

centralized chilled water

chilled water

savings on

during aeration

system for the whole

system for the

energy

plant and the existing

3 aerators

consumption

chiller will only be used

chilled water

including

as back-up chiller

system would

electricity,

especially during

cost Php

refrigerant,

summer season.

1,500,000 of

water


peroid

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Replacement of old

labor and

piping insulation of the

materials

chilled water pipeline -

Routine check and

including the new unit Fabrication of

replacement of mixing

a replacement

head jacket

mixing head

consumption and consumables

jacket = Php Cooling of the

1,800 Cost of labor

processing area.

and materials

The current cooling

Re-designing the air-

for the re-

space is not

conditioned space to a

location of the

suitable for the

smaller space to utilize

ACU, re-sizing

existing systems

the cold room as a pre-

of air-

since the

cooling system

conditioned

replacement of

space = Php

machine.

300 000

50 percent savings on energy consumption

Recovery System Process Heat rejected to

Option The exhaust air from the oven

Investment Installation of

Benefit Replacing the

Payback period If the company

the environment

can be used in the proofing

heat pipe heat

water heater

would just

process (90C) of the dough for

exchanger =

(8pcs) to

operate for 8

the bread processing

Php 500,000

generate heat

hours per day,

in the

the payback

proofing area

period would be

would save

as long as

Php

11years


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45,000/year

Oil spill during

Installation of

Eliminate the

repair works

recovery piping

oil spill during

A recovery pipe that is installed

system would

repair works

in the lowest part of the pump

cost Php 30,000

that nearly

system and connected to the oil

cost Php

storage will minimize oil spills

4,500 every

during maintenance work. A filtering system for the thermal Installation of

repair work.

oil will maintain the thermal

filtering system

transfer efficiency and prolong

would cost Php

the life of the thermal oil.

50,000

Initial cost Therm Investm al oil ent

Thermal Oil System Filtered oil Unfiltered oil

99000

80000

99000

IV. 3

Operating Years - Cost 1

2

3

4

0

0

0

0

5 990 00

0

0

990 00

0

0

6

Total Cost 7

8

9

10

0

0

0

0

99000

37700 0

990 00

0

0

9900 0

0

39600 0

Environmental Evaluation

Waste Water Process Villarosa, J., Buena, J.

Option

Environmental Evaluation Positive Negative Page 52

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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 Slurry Depositor and Cream Injector

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

Reduce hot water consumption by 50% therefore saving energy 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 Process During aeration process, chilled water is used to stabilize the process. Individual chillers are used for each aerator.

Reduce the amount of organic load by almost 50%

Option 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.

Minimal increase in the operating cost for compressed air

Reduce in the consumption of hot water up to 75%

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


Reduction in energy consumption

Generate solid waste


Reduction in energy consumption

Generate solid waste


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

Re-designing the airconditioned space to a smaller space to utilize the cold room as a pre-cooling system

Reduction of energy consumption

Refrigerant emission (R22) when discharging refrigerant as needed for installation

Recovery System Process

Option

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

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


Environmental Evaluation Positive Negative

Reduction of heat in the environment by up to 50%

Reduction of energy consumption

Reduction of used oil generation

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

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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


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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


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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. Villarosa, J., Buena, J.

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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


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CPA in cupcake processing

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