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Pollution Prevention Planning Handbook

VI – Appendix E: Equipment Modifications and Process Changes


Introduction

Most processing and manufacturing companies are engaged in continuous efforts to enhance efficiency or improve quality through modifications to their equipment and processes. This appendix outlines various ways to ensure that such modifications and changes also contribute to pollution prevention. In addition, it provides examples and presents a checklist to help implement these practices.

In operating production or processing systems, the aim is typically to optimize the system in terms of production efficiency and end-product quality. However, it is often the case that production systems operate in a manner that wastes energy or generates unnecessary toxic or other non-product outputs (wastes). By modifying equipment or production processes, much can be done to reduce, prevent or even eliminate pollution. Such changes can often increase profits, enhance production efficiency and reduce permitting, storage, waste disposal and recycling costs.


Implementing Equipment Modifications and Process Changes

Most businesses and industries can make equipment modifications or process changes to improve pollution prevention. Depending on the organization, specific prevention opportunities may focus on issues related to chemicals, metals, safety, water or energy. Home offices and office buildings may make use of only water and energy audits, while laboratories, manufacturing plants and petroleum refineries may apply any number of pollution prevention practices to identify and implement economical pollution prevention measures.

Table E1: Equipment Modification and Process Change – Opportunities to Reduce Pollution from Metals Stripping
Conventional TechnologyReplacement TechnologyCoating Removal PerformanceOperating SimplicityRelative Capital CostsRelative Operating CostsEnviron-mental Health and Safety Risk
Abrasive blasting; Chlorinated substancesBlasting substitutesSame
Same/Less
Same
Better
Same
Less
Same
Less
Same/Less
Less
Abrasive blasting;
Grinding; Chlorinated substances
High-pressure waterBetter
Better
Better
Same
Better
Same
More
More
More
Same
Same
Less
Less
Less
Less
Abrasive blasting; Chlorinated substancesOrganic solventsBetter Same/LessBetter
Same
Less
Same
Less Same/LessSame/Less
Less

Chemicals

The metal fabrication industry typically supplies the automotive, defence, electronics, appliance and furniture industries with a broad range of components. The production processes associated with this industry are varied, and involve the use of numerous chemical compounds. In an assessment of 2,900 facilities in the metal fabrication industry in the United States, for example, some 195 million pounds (88 million kg) of chemicals were registered, falling into over 100 chemical groups (Freeman, 1995). There are five common processing operations in the metal products industry that can be identified as major sources of pollution generation and discharge: stripping, painting, cleaning, inorganic surface treatment, and inorganic surface finishing. Stripping, painting and cleaning are important sources of volatile organic compounds (VOCs) and ozone-depleting substances (ODSs), while inorganic surface treatment and surface finishing are sources of acids and metals.

Stripping and cleaning traditionally involve the use of abrasive blasting technologies to physically remove paints and other organic coatings from metal surfaces. Another method of stripping and painting entails the use of chemicals and solvents to soften coatings before they are removed from a surface mechanically. Due to the types of chemical and, in particular, solvents used in these processes, high levels of VOCs, ODSs, and solid and liquid wastes are generated. In addition, explosions and fire hazards are often associated with these materials.

Elite Earth-friendly Cleaners, a garment care company, modified their dry cleaning equipment to accommodate an ecologically sound water-based wet-cleaning process. This modification has eliminated the use of the solvent perchloroethylene (PERC) and the hazardous waste created through gassing off in the air in and around the plant. The new wet cleaning equipment runs on steam, which indirectly heats up the plant, and because it is more water- and energy-efficient, the plant's water and hydro consumption has been reduced by about 30% over the past decade despite doubling in size since 2002. Additionally, this modification has resulted in Elite becoming exempt from the Capital Regional District's stringent reporting regulations, which saves the company time.

Petresa Canada, a Quebec-based chemical plant, installed a liquid bulk terminal which reduced nearly 10% of greenhouse gas emissions compared to 2002 levels. The company also increased the output capacity during hot weather by optimizing the conditions in the distillation unit, eliminated more than 3000 road and railway transports per year, and improved the inventory management of raw material and finished products.

There are, however, several equipment modifications and process changes that reduce or eliminate the need for toxic compounds and, at the same time, reduce operational costs and worker heath and safety risks. Table E1 summarizes these opportunities for paint stripping.

Metals

The electroplating industry deals with the manufacture of strategic and consumer products, including printed circuit boards and automotive parts. Electroplating utilizes a wide range of chemicals, depending upon the types of metals processed for electroplating and the types of metallic coating being applied. In addition, compounds containing heavy metals are often used in the plating process. These are of considerable environmental concern.

For this sector, pollution prevention alternatives through equipment modification and process change options include the addition of electrolytic recovery and ion exchange technologies to existing systems. Electrolytic recovery, for instance, is a technology that uses special electroplating equipment to lower the concentration of dissolved metals in drag-out rinses and concentrated rinse tanks. Benefits of this technology include reduced generation of sludge, some electrolyte destruction of cyanide, and reuse or sale of scrap metal plated out.

The City of Toronto's Transportation Services has prepared a Salt Management Plan in response to the growing environmental concerns regarding road salt. The City has modified existing equipment to include new electronic spreader controls for salt application and pre-wetting hardware. Staff was also trained on salt best management practices and the environmental impacts of road salt. As a result, salt spread on local roads has reduced by 35-50%, reducing the amount of road salts entering the environment. 14 000 fewer tonnes of salt were used in 2003/2004 compared to the base year 2001/2002. Costs associated with equipment modifications have all been offset by the reduced rate of salt application.

Water

Water management strategies to promote pollution prevention include water and wastewater flow reduction; recycling; by-product recovery; and water reuse. Water usage can be minimized through practices such as:

  • using high-pressure hoses or spray rinses instead of dip tanks;
  • replacing water curtain spray paint booths with an electrostatic painting system;
  • replacing a water-cooled heat exchange system with an air-cooled system;
  • replacing a cooling tower with a refrigerantbased cooling system; and
  • replacing a wet scrubber with a bag house.

Where changes in operations are concerned, practices to reduce water wastage can be grouped into three main objectives: optimize equipment cleaning operations; maximize the effective life of production water; and optimize water usage. Table E2 illustrates examples of operational changes toward each of these objectives.

The economic and environmental benefits of reducing water use can be significant. Payback periods are usually quick and the savings are often substantial, with low costs for employee training and maintenance.

Table E2: Operational Changes for Reducing Water Wastage
ObjectiveExamples of Operational Changes
Optimize equipment cleaning
  • Use mechanical cleaning devices, such as rubber wipers, prior to cleaning components with water
  • Use high-pressure spray heads to increase cleaning efficiency and reduce the amount of water required to remove wastes or dirt
  • Line tanks with non-stick materials such as Teflon to reduce adhesion and increase drainage
  • Use countercurrent rinsing cycles
  • Co-ordinate cleaning schedules
  • Use plastic or foam "pigs" to clean pipes
Maximize effective life of production water
  • Use countercurrent rinsing
  • Use de-ionized make-up water in rinse tank applications
Optimize water usage
  • Improve seals on pumps, pipes and valves
  • Use automatic flow control equipment
  • Use water level controls and splash guards
  • Place lids or silhouettes on tanks
  • Replace once-through cooling systems with closed-loop systems

Safety Assessment

The economic benefits from equipment modifications and process changes undertaken as a result of safety assessments cannot be calculated as easily as in other areas. These changes are often driven by liability and public image incentives (lessening the risk to people and/or the environment), rather than for monetary reasons. However, lost time at work resulting from employee injuries or illness, and savings from any fines resulting from non-compliance disposal may sometimes be monitored. This approach will typically apply more to larger manufacturing facilities and refineries than to office buildings.

Energy

Many technologies are available to enable a plant to use energy more efficiently, leading to a direct reduction in emissions. Typically, plant and process heating relies on steam boilers operating at efficiencies between 75% and 85%. In many cases, proven technologies can improve this efficiency to over 95%. Heat energy (both latent and sensible) leaving with stack gases is the primary heat loss in boiler processes. By recovering and applying this waste heat, a typical natural gas boiler can improve its efficiency by 10% to 15%, reducing annual carbon dioxide, nitrogen oxides and other emissions by the same amount. These technologies can also be applied to humid process exhausts to similar or greater effect.


Key Steps to Implementing Equipment Modifications and Process Changes

The largest barrier to implementing equipment modifications and process changes for pollution prevention is often the capital investment required, especially with the larger processes. A thorough review at the beginning of the process is important to ensure that all options are investigated and compared on a "level playing field." All costs and benefits should be quantified. As with any significant change to equipment or processes, an implementation and monitoring plan will help ensure that any changes made are implemented as effectively as possible, and that any problems that arise are identified and addressed as quickly as possible.

Baseline Review

The first step in considering possible equipment modifications and process changes for pollution prevention is to perform a baseline review of the environmental aspects of the product system. Before undertaking this review, it is necessary to define the system boundary to be considered. In most instances the system boundary will, at a minimum, encompass the manufacturing stage.

A baseline review may be relatively simple, in which case basic process and material flow diagrams are often sufficient. However, if the initial analysis suggests modifications to major pieces of equipment, or changes to substantial aspects of a process within a facility or companywide, then the review will likely be longer and more complex.

All reviews (regardless of their size) follow a sequence similar to that described in the section "How to Prepare a Pollution Prevention Plan" and in Appendix B, "Key Elements of a Baseline Review," including:

  • Perform a thorough evaluation of all material flow inputs and outputs in the system (for example, the input for a water audit could often be determined from a water bill, while the outputs could be determined from meters, applicable records, employee interviews, and evaluation and estimation of the process(es) and employee/public use of the facility's water).
  • Gather data and estimate amounts for the input and output streams.
  • Refine any estimates so that the sum of all inputs equals the sum of all outputs.
  • Determine the large consumers of materials, energy, water, etc.

Toyota Motor Manufacturing Canada (TMMC) developed a returnable packaging system and now receives parts from its suppliers in a more environmentally friendly manner. TMMC developed and funded the system, and provided training on the system to its suppliers. Working with its suppliers, it developed processes to verify that the new system was being implemented and put mechanisms in place to ensure the system remains efficient. As a result of the new packaging system, 99% of its North American-sourced parts are now delivered to TMMC in returnable packaging. This allowed TMMC to reduce its wood pallet waste by 86% and its cardboard waste by 63% since 1999. As an added benefit, the returnable packaging system streamlined TMMC's shipping and receiving processes resulting in fewer trucks on the road, shorter distances travelled, less fuel used, and fewer vehicle emissions.

Option Selection

Once the baseline review has been completed, a series of equipment modification or process change options should be developed. In most cases, the selection of options will be dictated largely by the economic impact of the change, and therefore all hidden costs should be considered and revisited while planning for implementation. Other cost areas that should be considered in the overall comparison of the options include:

  • site preparation;
  • installation and testing;
  • employee training;
  • operation of new equipment/procedures;
  • tracking of employee acceptance, and of economic and environmental benefits;
  • waste handling and treatment costs; disposal fees;
  • revision/modification of any outstanding issues; and
  • regular maintenance.

Employee Involvement and Training

It is important to solicit comments prior to and upon completion of the implementation of any equipment modifications and process changes. Employee training should also be provided, where needed. This can introduce valuable new insights and ideas, and ensure a high level of acceptance and speed of implementation, saving time and money if modifications need to be performed.

Monitoring

As with other prevention practices, equipment modifications or process changes require specific performance indicators to enable the company to monitor the implementation and progress of these changes. These indicators should link back to the initial inventory of inputs and outputs. However, since other activities may also have been implemented, there will be a need for indicators specific to the equipment or process change. This can be accomplished by scaling down the boundaries of the materials flow analysis to that piece of equipment, keeping in mind that this flow data should also be collected prior to the equipment or process changes made. Progress should be reviewed regularly to examine the root cause of any deviations from the action plan or failure to achieve targets or milestones and to determine what corrective action, if any, should be taken. All employees should receive regular progress reports to reinforce the importance of their efforts.


References and Resources

For more information on pollution prevention and pollution prevention planning:

Canadian Pollution Prevention Information Clearinghouse: http://www.ec.gc.ca/cppic

Canadian Centre for Pollution Prevention: http://www.c2p2online.com

Canadian Environmental Protection Act, 1999: http://www.ec.gc.ca/CEPARegistry

Your Environment Canada Regional Office.

For more information on equipment modifications and process changes for pollution prevention:

Freeman, Harry. 1995. Industrial Pollution Prevention Handbook. McGraw-Hill

Higgins, Thomas E. 1995. Pollution Prevention Handbook. CRC Press Inc.

Checklist for Equipment Modifications and Process Changes
TaskResponsibilityCompletion Date
Assign overall responsibility for equipment modifications and process changes to a management representative  
Establish a cross-functional team  
Map out material flows and process steps  

For each process step, identify:

  • what happens, including cleaning and maintenance type, quantity and cost of inputs
  • material and energy losses and waste generated
  • how each non-product output is disposed of and disposal costs
  

Identify, evaluate and, where appropriate, select equipment modifications and process changes:

  • assess impacts on all aspects of the operation
  • account for pollution that may result from decommissioning equipment or moving materials as a result of proposed changes
  
Establish performance targets  
Develop implementation plan  
Provide staff training  
Develop performance indicators to measure the success of specific measures and monitor progress toward targets  

Establish a formal review mechanism to:

  • evaluate the success of measures taken
  • identify new measures
  • provide feedback from the review to all employees
  
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