Beyond Pollution Control

Article From: Products Finishing, from National Center for Manufacturing Sciences

Posted on: 10/1/2008

A Look at coatings from a life cycle perspective

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OK, you know the rules, you have all the permits you need, and you’re operating in full compliance. So you don’t have to worry about environmental issues, right?

Well, keeping the government happy will keep you out of trouble. But keeping your customers happy is what keeps you in business—and something is happening with your customers. There is a market trend on the near horizon that is putting the environment back on the radar in a way that may be unfamiliar to most finishers.

Let’s see what’s behind it, and what you may want to do about it.

The new trend is often called “product sustainability.” As the name implies, it shifts the focus of environmental concern from the manufacturing process to the finished product. It’s primarily driven primarily not by government regulation but by consumer demand. And the consumers who are driving it are not, as you might expect, a few granola-eaters driving by in their hybrids. Not any more. Some of the nation’s largest retailers, government agencies, and large corporate and institutional buyers are all climbing on board.

What’s It Mean?

In contrast to regulators, who have (at least until very recently) been concerned almost exclusively with emissions from coatings when they are applied, sustainability-conscious customers want to know about the whole life-cycle of the products they purchase. In other words, they care about the coating from cradle to grave: what environmental impacts occurred when the raw materials of the coating were extracted and refined, when the coating was formulated, when it was applied to the coated product, and when the coating solids are disposed of at the end of the product’s life.

What does this mean for finishers? First and foremost, finishers, like all manufacturers, are going to be expected to know a lot more about their supply chain.

That represents a major difference from the way things have always been, and will take some getting used to. Finishers are used to having customers judge their work on the functionality of the coatings they produce—factors like quality, durability and appearance—and, of course, on price. But they are not used to having customers judge them on their business decisions, such as which suppliers they deal with and even on how their suppliers run their own operations.

Is it fair to hold manufacturers responsible for the way their suppliers carry out their operations? After all, a finisher doesn’t control the materials choices of the paint formulator, or the practices of the solvent manufacturer.

The argument for supply chain responsibility goes like this: When you buy a coating, you pull materials out of one end of a supply pipeline. But at the same time, you are essentially drawing materials into the other end. You set in motion a train of processes to put more of those materials—solvents, pigments, etc.—into commerce. And that train of processes has impacts. In a very real sense, according to this point of view, your decision to purchase coatings from a particular supplier triggers all the impacts caused by that supplier, and by that supplier’s suppliers.

Whether you buy this argument or not, it’s a good bet that many large purchasers of coated products will. And they will be demanding more information about everything that goes into the products they buy, including the coatings.

This presents a problem for the finisher—how to get data from the supply chain? This is a particularly difficult problem for small operations, with few staff and little time to devote to data gathering exercises. But even finishing shops in large corporations, who might be expected to have more leverage with their suppliers, can find it hard to obtain reliable data, particularly when the supply chain moves offshore.

Meeting the Challenge

So what can finishers do to meet this next environmental challenge? One possible strategy is to do nothing and hope the problem goes away. Maybe customers will lose interest in topics like climate change, especially when the costs of doing anything about it become more obvious.

That may not be a safe bet. We need to dispel an old myth: the belief that, while everyone wants a healthy environment, no one is willing to pay extra for it. That belief is changing faster in some sectors than in others, but the change is starting to spread. It’s already becoming well established in parts of the building and construction industries. Architects are finding that many of their clients are willing to pay substantial premiums for buildings that are eligible for Leadership in Energy and Environmental Design (LEED) certification. In response, they are writing requirements for low-emitting coatings into their specifications.

This affects more than coatings on ceilings and floors. It also applies to coatings on products like furniture, carpets, flooring, and draperies. In response, several of these building-related sectors are beginning to establish voluntary product sustainability standards. As sustainability certification spreads to other sectors, the demand for information up the supply chain will spread with it. Finishers who are ready to respond, who can provide an accounting of the full life-cycle impacts of their coatings, will be better off than those who can’t.

But getting into the life-cycle assessment game has not been a practical option for most finishers. A company that undertakes a full life-cycle assessment can easily spend tens of thousands of dollars to assess a single product. It’s a complicated business.

The good news is that it’s becoming possible to get started without a big investment of time and money. Several projects are now underway that aim to make it much easier for companies to assess the life cycle impacts of their products, and to evaluate the potential improvements they might make by changes in design or in manufacturing operations.

Many of these projects are creating databases and software that will be made available to the general public at no cost. The ultimate vision is that companies will evaluate the sustainability impacts of their product designs and their manufacturing operations routinely, and will be able to share that information, to the extent they choose to share it, with their customers. The customers, in turn, can factor that information into their purchasing decisions. Some customers may give preference to suppliers who provide the most pertinent and reliable information. In any case, the market will determine the outcome; the system is purely voluntary. The idea is that, if the barriers to developing the information get low enough, people will use the tools.

Of course, there are tradeoffs. If you hire a trained professional to analyze your operations, you will expect a higher level of detail and precision than you can get from a simple evaluation. A professional can study your individual suppliers, can possibly obtain data from them under a confidentiality agreement, and can tailor the evaluation to your exact situation. Publicly available data is necessarily more general. The question boils down to how much accuracy you, or your customers, need for specific purposes.

In the rest of this article, we’ll take a look at one of these projects—one that happens to be focused on paints and coatings. Preliminary versions of the data and software are available now for review and comment. We’ll look at a few sample questions and see some of the kinds of data the preliminary versions can provide.

Emphasis on Practicality

In 2006, the National Center for Manufacturing Sciences received Congressional funding through the USEPA to bring together a collaboration to develop a consensus framework for carrying out life cycle assessments of paints and coatings. Now in its second year, the group includes representatives from major paint manufacturers, chemical suppliers, and large industrial users of paints and coatings.

Right from the beginning, the participants made it clear that they wanted the project to be more than just an exercise in theory. Instead, one of the first tasks of the project would be to create usable tools, so participants could plug in real-world data and see if the calculated impacts seemed to make real-world sense.

To keep the complexity manageable, the participants decided to focus on one representative process type, a single coating on a typical industrial paint line that included a mix room, a spray booth, a drying oven, and a thermal oxidizer (or other pollution control system). They would use data that was already available either publicly or through one of the proprietary databases. And they would single out a handful of environmental impacts that were particularly important for painting and coating processes. The impacts that were chosen for the pilot phase of the project were:

  • Energy used
  • Greenhouse gas emitted
  • Paint solvents emitted
  • Solid waste generated

As the project proceeded, it became clear that a few additional distinctions would be particularly useful. Energy usage was divided into electrical energy, considered separately, and total energy. And, in the paint solvent category, solvents that fall into the regulatory categories of Volatile Organic Compounds (VOCs) and Hazardous Air Pollutants (HAPs) were also distinguished from total emissions.

In keeping with the project’s practical goals, the next step was to create pilot versions of the software tools that would allow users to turn data into results. Two tools have been created so far, with two different types of users in mind. Both are available to the public for trial use and comment.

The first tool is a spreadsheet, available for download at http://LCA.ncms.org/VOC. It lists significant variables that can affect the environmental impacts associated with a typical painting or coating operation, including paint composition, equipment power and fuel requirements, production schedules, and pollution control measures for air and wastewater. The user can supply values for these variables, and the spreadsheet will calculate the life-cycle energy consumed, greenhouse gas and pollutants emitted, and solid waste generated.

General and Impact Inputs
Parameter Category
Description
Unit
Variable Name
Input Values
     
min
max
Parts
Parameters
Part name Test PartName
Selected Part
Coating system name Test CoatName
Selected Coating
Expected service life of part Year PartLife 10 15
Expected service life of coating Year CoatLife 5 10
Thickness applied mil Thick    
Coated area of part SF CoatArea 400 600
Weight gain after drying lb SolidsMass    
 
Production
Parameters
Production line hr/week Up Time 80 120
Paint consumption rate (total) gal/week PaintTotRate 2000 3000
Allocation Factor percent PaintAlloc 50% 100%
Paint consumption rate (for part) gal/week PaintRate 1000 3000
Paint production rate count/hour PartRate 40 80
Coated area production rate SF/hour SFperHr 16000 48000
 
Impact
Parameters
GG per electric kWh consumed (gCO2 eq)/kWh GGperKWh 198 794
VOCs per electric kWh consumed g/kWh VOCperKWh    
HAPs per electric kWh consumed g/kWh HAPperKWh    
NOx per electric kWh consumed g/kWh NOXperKWh 0.772 2.72
Solid waste per electric kWh consumed g/kWh SldWstperKWh 15.2 33.2
GG per SCF gas consumed (g/CO2 eq)/SCF GGperSCF 55.63 55.63
VOCs per SCF gas consumed   VOCperSCF    
HAPs per SCF gas consumed   HAPperSCF    
SolidWaste per SCF gas consumed   SldWstperSCF    
GG per mile traveled (gCO2eq)/mi GGperMi    
VOCs per mile traveled   VOCperMi    
HAPs per mile traveled   HAPsperMi    
Solid waste per mile traveled   SldWstperMi    
Section of a coating impact spreadsheet. The software lets users input variables associated with a typical coating operation, then calculates life-cycle energy consumed, greenhouse gas and pollutants emitted and solid waste generated.

It may look complicated, but there’s nothing mysterious about the spreadsheet. There are a lot of variables. To encourage a broader range of potential users, the project is also developing a much simpler looking web-based tool. A demonstration version is available at http://LCA.ncms.org/CC. In the Web version, the display allows users to focus on the variables that are of greatest interest to them. Users can see exactly what the effect would be if they made specific changes in their process. If they make changes to some of the variables, the results of the changes are displayed side by side. Instead of listing all the variables in one long table, the display automatically moves the variables that have been changed to the top of the list, and puts the changes near the results. This makes it much easier to take in the information at a glance.

In short, users who want to follow the calculations in detail can use the spreadsheet. Those who want to try out different scenarios and compare the results can use the web tool. In either case, learning about the environmental impacts of coating operations will never be easy—but it has never been easier.

Using the Tools

But just having a convenient calculator doesn’t solve the fundamental problem for life-cycle calculations: how to get information from suppliers. That’s where a unique feature of these tools can help.

One of the first things you may notice when you look at either of the tools is that it never asks for just one value for any variable. There is always space for two—a maximum and a minimum. This is, first of all, a recognition of the fact that numbers in a life-cycle calculation can never be exact. For example, the fuel mix used to generate the electricity delivered by your power company can vary from minute to minute. Many other variables are even more uncertain.

One way of expressing this uncertainty would be to use average values, while at the same time providing users with a measure of how widely the actual value tends to vary around the average. There is nothing wrong with this approach except that, psychologically, we tend to pay attention to the average and forget the variation. Instead, the tools explicitly acknowledge variability by providing two numbers, a plausible maximum and a plausible minimum, for each input variable, and for each result.

Presenting the results as two numbers rather than one has another benefit. The maximum number can serve as a worst-case estimate. If you can’t get data from your suppliers, you can still perform a reasonable life-cycle calculation by making the conservative assumption that your suppliers are not making any special effort to mitigate their impacts. You can give your customers a more accurate accounting of the numbers that you can measure and control—the efficiency of the operations you carry out in your facility—and your customers can be reasonably sure that the actual life-cycle impacts of your coatings are no worse than the numbers you provide. It also gives your suppliers an incentive to be more forthcoming with their data (or gives you an incentive to find suppliers who are), which is the way the system is supposed to work.

And what about the minimum numbers? They are also useful, since they provide a good benchmark of how much you and your suppliers could reasonably expect to improve the life-cycle sustainability measures for your coatings using industry best practices. By comparing your performance with the minimum numbers for each stage of the process, you can see where the greatest improvement is possible and plan accordingly.

Each of the tools, with the initial default minimum and maximum input variables loaded into it, can provide ballpark impact values with no additional input from users. But users are free to substitute their own input values for the default values. In general, the user will be able to narrow the distance between the minimum and maximum for many of the variables, enabling the tool to more accurately estimate the impacts of the materials and processes you use.

Early Results

Although much work remains to be done, the project has already found some interesting preliminary indications of what aspects of the life cycles of coatings matters most to the environment. In closing, here are a few examples.

  • The contributions from a drying oven and from a thermal oxidizer tends to dwarf all other sources of energy use and greenhouse gas emissions. As concern about climate change becomes more prominent, it will be interesting to see whether regulators start to reconsider their previous conclusions about the tradeoffs involved in generating many pounds of carbon dioxide to destroy a few grams of VOCs.
  • For some products (furniture, for example), the impacts involved in producing the raw materials are much greater than those involved in using the finished products. For others, like automobiles, the use phase impacts dominate. A back-of-the-envelope calculation shows that painting a car body has roughly the same carbon footprint as driving the car a few thousand miles. (If that seems like a lot, consider that it’s only a few percent of the expected service life of the coating.)
  • Producing the raw materials use in coatings (solvents and solids) tends to result in the emission of somewhere between 1.5 and 4 lb of carbon dioxide for every pound of material. That’s a significant part of the total involved in a coating operation—until you factor in the drying oven and the thermal oxidizer. Once you’re finished burning off the solvent, your carbon footprint is in another ballpark entirely.

 

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