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Green Chemistry and Design Demonstration Project

Intent: Demonstrate the extent to which state grant support can stimulate green chemistry and design projects in the private sector.

This web page will serve as a clearinghouse for updates on the implementation of ongoing projects and for other information supporting or generated by the demonstration projects.

MPCA staff thanks the U.S. Environmental Protection Agency's Pollution Prevention Program for its grant that helped support this project.

Case studies

Cortec Corporation

Developing Low-VOC metal primers

Cortec Corporation (White Bear Township, MN) is a coatings manufacturer specializing in anti-corrosion products that conducted a green chemistry demonstration project in 2011-2012 as part of a grant with the MPCA.

Background

VOCs serve in coating formulations to spread a protective or decorative film. Oil and alkyd coatings often have preferred coating properties to latex coatings but also require higher VOC content to achieve suitable coating properties. Alkyd-based formulations are typically used in metal primers because latex formulations have not shown sufficient durability.

Incentives for change

Recently commercialized alkyd-latex resins offer the possibility of developing a low-VOC waterborne coating for the metal primer market with performance similar to a traditional alkyd coating and the convenience and environmental benefits of a latex paint. Cortec sought to develop a commercially viable, water-borne, corrosion resistant metal primer, with a volatile organic compound (VOC) level of less than 25 g/l. This would represent a dramatic (tenfold) reduction in VOCs compared to current products.

Pollutant concerns

The VOCs used in coating formulations are generally petrochemicals such as mineral spirits, xylenes, toluene or methyl ethyl ketone. These solvents are both an environmental and health concern. Emissions of VOCs contribute to the formation of ground-level ozone (smog) and can aggravate a number of respiratory problems, including asthma.  

Implementation

Cortec developed an initial primer composition for testing along with a control formulation with suitable film forming properties. Functional additives were selected for inclusion in the study; test formulations were produced and applied to panels to be subjected to the salt fog and humidity chamber tests, which measure the ability of a coating to maintain integrity in a moisture and corrosive environment. Target performance was a minimum of 336 hours and preferably 500 hours at 1-1.5 mil thickness. The process was repeated with adjusted formulations based on analysis of test results.

Findings

Initial test formulations focused on a renewable content resin optimizing the anti-corrosive and extender pigment combinations to meet salt fog and humidity test requirements. While salt fog performance was acceptable, the performance in the humidity chamber fell well short of the mark needed for commercial viability. After determining that technical options had been exhausted with the initial resin system, the scope of the project was revised to authorize the investigation of additional resin systems, one based on polyvinylidene co-polymers (PVDC) and the other on self-crosslinking acrylic emulsions.

PVDC based formulations have long been used in metal primers due to high performance in adhesion, moisture resistance and corrosion inhibition. Work focused on minimizing VOC levels (targeting less than 100 g/l and application thickness (targeting less than 1.5 mils compared to 3.0 or more mils for standard PVDC formulations) while reaching 500+ hours performance in both the Salt Spray and Humidity Chamber tests. As a result, a low VOC (~150 g/l) alkyd/PVDC formulation was developed that can replace industrial primers that contain as much as 480 g/l while also achieving a 50 percent reduction in film thickness. The new formulation was introduced as a Cortec product in October 2012 and is designed for applications such as under the hood automotive, shop primers and structural steel applications.

The self-crosslinking acrylic emulsion resin showed promise as  a sealer for wood and concrete, but only worked with metals when applied at heavy dry films (4-5 mils), which negates what was trying to be accomplished. These formulations also were unable to achieve desired salt fog test results and so were discontinued in favor of a similar system using self-crosslinking aliphatic urethanes. This material was able to meet the targeted 336 hours of salt spray at a VOC level of ~132 g/l and dry coating thickness of less than 1.5 mil. An additional benefit of the urethane resin is that it is N-Methyl-Pyrrolidone (NMP)-free and alkylphenol ethoxylate (APEO)-free. NMP has been identified as a reproductive toxicant and APEO is a hormone disruptor as well as being toxic to aquatic organisms.  This new formulation is the basis of a new coating introduced as VpCI-392 in the Cortec product line and was introduced internationally in October 2012. It can be applied directly to a number of metals, including carbon steel, stainless steel, galvanized steel, aluminum, brass and copper and is designed to compete with the 2-part urethane and high-end acrylic market. Typical 2-part urethanes have VOCs of 250 g/l, so this represents a 47 percent decrease.

Results

Immediate

Long-term

Developed new alkyl/PVDC primer for use in industrial applications

40 percent reduction in VOC content compared to typical primers

Potential reductions of VOC emissions by 4,187-8,375 tons per year based on the markets that will be targeted with this product

Developed new self-crosslinking aliphatic urethane primer for use in industrial applications

47 percent reduction in VOC content compared to typical primers

New formulation is NMP-free and APEO-free

Potential reductions of VOC emissions by 2,500-5,000 tons per year based on estimated market share for this product

Salo Manufacturing

MPCA Contact: Mark Snyder  (for referrals to company contacts)

Shower shop looks at resins, mold releases and more

Salo Manufacturing Inc. is a fiber-reinforced plastics facility located in Menahga, Minnesota that manufactures bathing systems. Salo conducted a demonstration project in 2011 as part of a grant with the MPCA. A Minnesota Technical Assistance Program intern worked with them to conduct this project

Incentives for change

Salo’s owner and their general manager wanted to determine whether they could economically manufacture bathtub and shower units with low/soy-based or non-styrene resins and gel coats, and at the same time maintain the structural and cosmetic characteristics of the units manufactured with their normally used raw materials. Their ultimate goal was to come up with ways in which they could become more environmentally conscious. Reducing waste and emissions were part of their considerations.

Pollutant concerns

The facility emits 12,120 pounds/year of styrene due to flashing off during standard manufacturing procedures.
Styrene is a Hazardous Air Pollutant. It is a pollutant that causes or may cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental and ecological effects. Acute (short-term) exposure to styrene in humans results in mucus membrane and eye irritation, and gastrointestinal effects. Chronic (long-term) exposure to styrene in humans results in effects on the central nervous system, such as headache, fatigue, and weakness.

Styrene is a Volatile Organic Compound. Emissions of VOCs contribute to the formation of ground-level ozone (smog) and can aggravate a number of respiratory problems, including asthma.

In January 2011, the Minnesota Department of Health listed styrene as one of the state’s Chemicals of High Concern as defined by the 2009 Minnesota Toxic Free Kids Act.

On June 10, 2011, the Honorable Kathleen Sebelius, Secretary of Health and Human Services, approved the 12th Report on Carcinogens, listing styrene as reasonably anticipated to be a human carcinogen.

Minnesota Occupational Safety and Health Administration has Permissible Exposure Limits for styrene with an 8 hour Time Weighted Average of 50 parts per million (ppm) and 15 minute Short Term Exposure Limit of 100 ppm.

Background

Salo began their project by researching several different potential raw materials for experimentation including choices of resins, gel coats, and mold releases. They were able to find alternative resins containing a percentage of recycled content and also a styrene-free resin. They were not able to find a low or styrene-free gel coat.

Implementation

Selections were made and alternative resins were purchased for analysis. Best operating conditions and product formulations were determined for each alternative resin. This was difficult. Salo used 60 percent filler with their standard resin system; these alternative resins were not meant to be filled.

Sample panels and full production units were made. Employees found it difficult to work with some of the formulations, meaning they were very sticky, too hard to roll out, or the lamination was runny. Some rolled out similarly to their standard resin system and performed well with their spray equipment.

Findings

A test unit made from a styrene-free resin, NOVOC® 8124, was evaluated by the National Association of Home Builders Research Center and failed base deflection testing under the ANSI Z124.1.2 test methods. The material deflected 50 percent higher than the allowed tolerance under a considerable static load. The resin did not provide them with a product that met industry standards.

It is possible that the resin could be formulated differently or used with a different catalyst to assist the finished product in having less deflection. Hi-Point 90 MEKP was the catalyst during testing. NOVOC suggested catalysts such as Norac 9H, 925, 925H, or M50 from Arkema if further testing is done.

The cost of switching from their current resin system to an alternative resin system was not economically feasible.

Additional steps

Salo is furthering the development of pre-fabricated foam bases for their handicap accessible shower units. Building code requirements do not allow for more than a ¾ inch threshold on a handicap accessible shower. The shower unit cannot be recessed into the construction floor because it is not allowed to penetrate the required thickness of the concrete-poured layer needed to provide the proper fire rating for the building.

Typically, the installer would mix and pour a bedding compound to set the unit in place and support the underside of the floor. Salo wants to avoid having the installer go through this process. Attempts at using their standard resin, gypsum, and concrete were unsuccessful. They sampled a two-part pouring foam, which gave a good finished product, but was too labor intensive and time consuming.

This process also emitted isocyanate emissions which Salo wanted to avoid. The best solution has been to use pads of compression foam in different thicknesses to accommodate the slope of the shower floor. They are fine tuning this process to find a configuration or material that is suitable.

Salo had a structural evaluation completed on a shower floor with foam pads. It did not pass deflection requirements. If Salo can make this work, it would save the installer time, material and labor by not having to set each shower in a bedding compound. The unit would have a prefilled floor; the installer could simply set the unit in place.

Salo is converting mold cleaners, mold sealers, mold releases and acetone to water based products that perform similarly to the products they are replacing. Although the product cost is a little higher, the water-based products should last longer, as they will not evaporate as quickly as their previous products. Salo estimates that the longer life of the product will even out the higher cost.

Salo is converting from acetone to Polychem Acrastrip, which was developed in partnership with EPA’s Design for the Environment program. Elimination of acetone reduces Salo’s hazardous waste generation.

Results

Immediate

Long-term

Direct toxic material replaced

Replaced 8,000 pounds/year of acetone with AcraStrip

Replace 14,000 pounds/year of acetone with AcraStrip

Production waste avoided

Replaced Acetone with Acrastrip
1.5 barrels or 600 pounds/year of acetone related hazardous waste

Replace Acetone with Acrastrip
900 pounds/year of acetone-related hazardous waste
Foam slab material component
470 pounds/year polyurethane
5.8 grams/year isocyanate
Switch to VOC release agents
100 pounds/year VOCs

Savings

Replaced Acetone with Acrastrip
$400 - $600 annual savings in hazardous waste disposal fees

Replace Acetone with Acrastrip
$850 annual savings in hazardous waste disposal fees

Ecolab

Cleaning products maker improves several hard surface cleaners

Ecolab, Inc, based in St. Paul, Minnesota, serves businesses in the foodservice, food processing, hospitality, healthcare, industrial, and oil and gas markets.  The company’s Institutional business unit, which carried out this project, offers products and product/equipment/service support programs to restaurants, hotels, long-term care facilities, schools, commercial buildings, and military facilities.

Supported by a demonstration grant from MPCA, the project sought to design hard surface cleaning chemistries and the packaging of those products for enhanced human health, environmental safety, and sustainability while maintaining optimum cleaning performance.

Incentives for change

Ecolab strives to lead the institutional cleaning products sector in performance and lowest health and environmental impact, through a continuous product improvement process.  For the most part, Ecolab no longer uses priority chemicals in their products, so their drivers are market-based rather than regulatory.  Ecolab perceived customer demand moving towards renewable and bio-based raw materials to increase cycling of existing atmospheric carbon and avoid adding fossilized carbon.

Issues considered

There are several dimensions to the product improvement Ecolab seeks in design projects:

  • Cleaning performance as good or better than Ecolab and/or industry benchmarks;
  • Increased product chemistry  and packaging derived from renewable materials;
  • Meet the Green Seal 37 standard Exit to Web for aquatic and acute human toxicity, and biodegradability;
  • Minimize the amount of product chemistry that is volatile organic compounds (VOCs);
  • Reduce the amount of packaging required for a given amount of cleaning capacity delivered;
  • Achieve the least amount of personal protection needed and the most benign labeling;
  • Perform well on cleaning performance, odor, and level of irritation to eyes, airways and skin.

Project design

Ecolab entered the project seeking to develop a new line  of hard-surface cleaners they already were providing to institutional customers, primarily by moving to renewable and bio-based raw materials for chemicals.  This new line would include development of several types of new hard surface cleaners to replace Ecolab incumbents and compete with similar products from other companies:

  • Glass cleaner;
  • All-purpose cleaner;
  • Neutral bath cleaner;
  • Alkaline bath cleaner development was originally intended, either EPA-registered (disinfecting) or non-EPA registered.  While exploring an EPA-registered alkaline bath cleaner based on renewable materials, the team found more feasible options in the acidic range and switched to development of an acidic bath cleaner, intended for EPA registration.
  • Acid bath cleaner (not intended for EPA registration).
  • In addition, Ecolab would investigate more sustainable or renewable materials for its product packaging, and reduced packaging intensity overall.

Implementation

Since Ecolab had no chemicals of environmental or human health concern (such as triclosan or nonylphenol ethoxylates) in their hard surface cleaner line, activity in this project was primarily finding bio-based, renewable sources for chemicals already in use (citric acid, sodium citrate, alkylpolyglucoside, sodium lauryl sulfate, cocamidopropylbetaine, d-limonene, sodium laureth sulfate, and glycerine).  Sources of non-petroleum raw material from which these chemicals can be derived include corn oil, soy oil, palm kernel oil, coconut oil, vegetable oil, sugar and minerals.  Once the chemicals and sourcing was identified, Ecolab would determine if supply and price would be reliable and low enough to justify full product development and launch.  From there, the basic steps for developing each product type were prototype development, bench (performance) testing, field testing, regulatory review, internal reporting and preparation of launch plans.

Results

Note that calculations of bio-based material percentage divide the number of “new” carbon atoms from bio-based sources by the total number of carbon atoms in the formula.  Water and inorganic materials are excluded from this calculation.  The percent of the formula that is considered renewable is similar except that the entire molecule is taken into account, not simply carbon atoms.  Inorganic materials are counted as being non-renewable and are not excluded from the calculation, although water is.

To protect confidential business information, most metrics are aggregated across product types.

  • Cleaning performance: Soil removal tests showed all new products performing equal to or better than Ecolab incumbents, and where compared, better than other companies’ products.
  • Product renewable material content: Overall renewable percentage increased from 20% to 84%, which equates to a 502,000 pound reduction in non-renewable chemicals.  All product types now measure from 65% to 85% renewable, from a mix of different plant sources and suppliers.
  • Bio-based material content: Ecolab’s calculations show the overall average bio-based material percentage moving from 22% to 83%.  All product types except the registered acidic bath cleaner are now between 60% and 85% bio-based, exceeding corresponding USDA Bio-Preferred minimums by an average of 22%.
  • Packaging renewable material content: Plant-based resins are limited in availability; polylactic acid resin is compatible with some of the products but much less cost-effective than petroleum-based sources and susceptible to heat during transport or storage.  Therefore, there were no changes to packaging design within the project.
  • Packaging sustainability: Through increased functionality and concentration, the overall product-to-package ratio has more than doubled, equivalent to 49,900 pounds less packaging for the same amount of cleaning capacity (at current sales volume).
  • Acute human oral and aquatic toxicity: All formulas in the new line exceed (are safer) than the Green Seal 37 standard.
  • Biodegradation of chemistry: All of the new product types meet the Green Seal 37 standard for readily biodegradable.  The glass, all-purpose, and registered acidic cleaners are now biodegradable.
  • Volatile organic compound content: For all product types and based on current sales, the VOC reduction calculated for product sold prior to dilution was 295,000 pounds.  This reduction was achieved by using less monoethanolamine, n-propoxypropanol, isopropyl alcohol, and ethylene glycol monobutyl ether. All product types are now under 1% VOC.
  • Safety Data Sheet (SDS) comparison: The SDS for the registered acidic bath cleaner will not be ready until EPA-defined toxicity testing is complete.  The all-purpose cleaner will require use of safety glasses, but any formula that still requires glasses is being reconsidered as Ecolab implements Safety Data Sheets aligned with the U.N. Globally Harmonized System of Classification and Labeling of Chemicals (GHS) and the resulting U.S. rules.  The three other products will have less-restrictive SDS wording and not require personal protective equipment for use of the solution after dilution.
  • Chemical life-cycle analysis: Ecolab continues to research how suppliers are extracting chemicals from plant sources; since many are also food sources, they are looking for alternative biomaterial feedstocks. 

Budget

Grant amount $52,000.00 + Matching funds/In-kind $26,950.00 = Total project budget $78,950.00

Background on metrics

In the table below, each raw material in consideration is outlined. Research is ongoing to determine exactly how chemicals are extracted from the sources below.

Raw material

Source

Citric Acid

Glucose from Corn

Sodium Citrate

Glucose from Corn

Alkylpolyglucoside

Coconut, palm kernel, or corn

Sodium Lauryl Sulfate

Coconut, palm kernel oil

Cocamidopropylbetaine

Sourcing is mixed. Part of the compound is renewably sourced from coconut. The other part of the compound is petroleum or natural gas sourced.

d-Limonene

Orange Peel Oil

Sodium Laureth Sulfate

Sourcing is mixed. Part of the compound is renewably sourced from coconut. The other part of the compound is petroleum or natural gas sourced.

Glycerine

Soy or Animal Sources

As seen in the table above, many renewable raw materials can compete with human food sources. However, chemical suppliers and universities are researching raw material feedstocks based on non-food agricultural by-products. For example, lactic acid could be based on corn pulver. Another challenge exists that some renewable materials (non-petro based) are actually harsher to the eye/skin/airway than the petro-based materials. Ecolab will continue to strive to balance this impact. Ecolab continues to research opportunities to bring these types of raw materials from non-food sources into their formulation portfolio.

Percentage of chemistry and packaging based on renewable raw materials

The Ecolab team is working with multiple raw materials across their hard surface product line which allows them to remove petroleum based raw materials and move towards renewable raw materials. Examples of renewable raw materials that they are using are listed in the table above. The formulations are striving to move away from both petroleum based materials and harsh materials which cause eye/skin/airway irritation.

Renewable materials (as defined for this calculation) are materials that come from a plant source. More specifically, they come from a plant source which replenishes itself approximately as quickly as it is harvested. This does not take into account the environmental consequences, unintended or not, of agricultural practices involved in growing the plants to support the renewable sourcing. The percent of the formula that is considered renewable is similar to that which is bio-based except that the entire molecules are taken into account, not simply carbon atoms. As well, inorganic materials are counted as being non-renewable and are not excluded from the calculation. Water is excluded from the calculation. A sample calculation is shown below.

Raw material

% in formula

% of molecule sourced renewably*

Water

50

Excluded

Inorganic Material

10

0

Raw Material A

19

100

Raw Material B

19

59

Dye

1

0

Fragrance

1

0

TOTAL

100

 

*Some raw materials, for example certain surfactants, are not sourced entirely from renewable materials. The hydrophilic end of the surfactant may be sourced from petroleum or natural gas, while the hydrophobic end of the surfactant may be sourced from plant sources (corn, soy, coconut, etc).

Calculation:

Total Chemistry in the Formula is 50% (exclude water).
% Renewable = (Raw Material A) + (Raw Material B * 0.59) / Total Chemistry
% Renewable = 60.4%

The team researched options for renewable packaging sources. The prime focus was on plant based resins (corn, sugar cane, cellulose). Plant based resins have very limited availability. In fact, large corporations have already locked down the current supply of sugar cane based resin from Brazil. The current cost of plant based resin is approximately twice that of similar petroleum based sources. With this in mind, Ecolab continues to work with our suppliers to find other economical sources of plant based resin.

Bio-Based Percentage of chemistry

Bio-based calculations are complete for the glass cleaner, neutral bath cleaner and acid bath cleaner. The calculations are completed based on the estimated carbon containing fraction of the raw material. However, final analysis will require a submission to the USDA bio-preferred program for testing and verification. The percent bio-based of a formula is only concerned with the amount of ‘new’ carbon contained in the formula. The number of carbon atoms from bio-based sources are calculated and divided by the total number of carbon atoms in the formula. Water and inorganic materials are excluded from this calculation. A sample calculation is shown below.

Raw material

% in formula

% of bio-based*

% non bio-based*

(a) Wt. fraction of molecule from carbon

(b) Component contribution to overall formula carbon content

(c) Fraction of carbon from the component

(d) % Carbon from bio-based source

(e) % Carbon from non bio-based source

Water

50

0

100

0

0

0

0

0

Inorganic Material

10

0

100

0

0

0

0

0

Raw Material A

19

100

0

0.375

0.07125

0.34289

34.289

0

Raw Material B

19

64

36

0.666

0.12654

0.60898

38.975

21.923

Dye

1

0

100

0.5

0.005

0.02406

0

2.406

Fragrance

1

0

100

0.5

0.005

0.02406

0

2.406

TOTAL

100

 

 

 

0.20779

 

73.264

26.735

  1. Calculated by taking the molecular weight of carbon in the molecule and dividing by the molecular weight of the entire molecule
  2. % in formula multiplied by wt. fraction of molecule from carbon
  3. Component contribution (calculated in b) divided by total carbon contribution
  4. Fraction of carbon from the component multiplied by % bio-based
  5. Fraction of carbon from the component multiplied by % non bio-based
  6. Double check that sum of (d) and (e) equals 100. This sample equals 99.999.

Final result = 73% bio-based

Background

Demonstration projects test whether grants of around $50,000 can provide threshold funding to businesses to undertake green chemistry and design changes to their products, or to the components of products they deliver to customers or supply chains.

Grants can co-fund basic chemistry research, move research or development already in progress closer to completion, or adapt off-the-shelf green chemistry technology. Actual implementation of product changes through retooled production would be ideal, but product design or redesign and testing with a commitment to carry the new design through to production could suffice. Such commitment could be demonstrated by business and capital planning and long-term metrics. 

Funds are awarded in the form of a grant to a company that controls the design of a product or component and commits to a green chemistry and design improvement of such a product or component. Internal teams and external partnerships are vital, possibly including the company designing the product or component, their customer(s), their production supply chain, and either internal or third-party (external) technical resource providers such as consultants, graduate research students, labs or testing facilities, mentoring companies, or others.

Demonstration projects are designed to support the research and development side of the product design process. Grant funds cannot be used for purchasing the equipment necessary to produce the newly designed or redesigned product. Equipment purchases may be a better fit with state low-interest loan programs, either MPCA environmental loans or those available through other state agencies.

Last modified on October 15, 2014 11:35

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