PART 1
The United States faces a daunting technical challenge in meeting rapidly expanding energy, water, and waste disposal needs without undue damage to the environment. Mindful of nature’s limitations, the Obama administration has placed a high priority upon the nation’s responses to
a) the threat of climate change,
b) the need to improve air quality,
c) the continued importance of managing chemical risks,
d) the cleanup of hazardous waste sites, and
e) the protection of our vital water resources.
It will not be enough for the government to make simple pronouncements. All organizations, whether public or private, profit or nonprofit, large or small, will need to make prudent decisions to improve their stewardship of natural resources if this ambitious vision is to be realized.
Operational performance improvements typically take the form of reduced consumption of natural resources, increased energy efficiency and use of renewable energy sources, reduced greenhouse gas (GHG) emissions, or reduced waste disposal. Use of these broad strategies requires that responsible parties keep in mind the following eight guidelines:
- Consider the Lifecycle Analysis of material flows; consider substituting less carbon/energy intensive materials or processes
- Consider redesign/repackaging of products to reduce waste, increase recycling, and improve transportation efficiencies
- Reduce process water consumption; especially, eliminate once through cooling where possible
- Look for energy efficiency opportunities including waste heat recovery for immediate, short-term, and strategic improvements
- Look for high global warming potential (GWP) impact GHG reductions – HFCs, PFCs, and SF6
- Consider moving to renewable energy sources for electric power – either directly through self-generation or indirectly through the purchase of “green power”
- Consider implementing cogeneration at facilities with steady and coincident electric and thermal usage profiles
- Look for waste recycling and reduction of waste to landfills.
This two-part article will briefly highlight each of these guidelines, the benefits and difficulties posed by each, and some recent examples of their successful application. Part 1 reviews lifecycle analysis, repackaging, and water and energy efficiency opportunities, while Part 2 examines high GWP emission reductions, renewable energy and cogeneration strategies, as well as recycling and waste reduction opportunities.
1. Lifecycle analysis — minimizing your organization’s impact beyond its physical boundaries.
The raw materials and fuels used throughout industrial processes and commerce have associated material, energy, and waste footprints. This includes materials and fuels used in manufacturing goods or providing services; used in transportation, construction, operation, and maintenance of infrastructure; or simply used for communication. Efficient use of low-impact resources is becoming a business imperative. Those who are not using natural resources as efficiently as possible will inevitably see shrinking market share and falling profit margins.
All products and manufacturing processes have a lifecycle. The lifecycle begins with the extraction, collection, or harvesting of raw materials; passes through the manufacturing process; includes raw material and product transportation; extends to product use; and ends in product or waste disposal. This is commonly referred to as a cradle-to-grave lifecycle.
Lifecycle analysis, then, is a methodical process of evaluating each step in the lifecycle to quantify material and energy use, product and co-product generation, waste generation, air emissions, water use, and wastewater discharges. Environmental impacts can then be evaluated for each step in the lifecycle, uncovering opportunities to reduce impacts and improve efficiency throughout the lifecycle.
Lifecycle analysis can also be used to compare the performance and impacts of different products or processes to evaluate materials substitutions, take advantage of green marketing opportunities, and defend green marketing claims. By comparing the costs and benefits of proposed improvements in different steps of the lifecycle, the most cost-effective alternatives can be identified.
For example, a lifecycle analysis may determine that substituting environmentally friendly raw materials for those that have harmful impacts (e.g., hydrogen peroxide for chlorine in bleach products) can provide a low-impact product that performs as well or better than the original at a comparable cost to the consumer. Similarly, substituting a renewable biomass fuel, such as chipped waste wood or logging residues for bituminous coal in a heating plant boiler, reduces the net GHG emission and provides a positive return on investment (ROI).
Modifications to manufacturing processes or heating plant boilers generally require significant upfront capital cost, which can cause problems for tight budgets. Most organizations considering improvements potentially involving significant capital expenditure will have formalized capital appropriation request procedures. As such, it is important to devise a consistent, fair, and transparent means for evaluating the costs and benefits of competing solutions. Lifecycle analysis can provide that tool for evaluating the total cost and impacts and the potential benefits of a variety of solutions.
Lifecycle analysis example #1: raw material substitution
In its 2004 ChemMatters article entitled, “Building a Better Bleach: A Green Chemistry Challenge,” the American Chemical Society provided an excellent discussion of the kind of innovation that leads to cleaner, better solutions. The Society explains the way that the initial limitation of hydrogen peroxide — higher required pressures and temperatures to achieve effective bleaching — could be overcome by the development of molecules, tetraamido macrocyclic ligands (TAML® ), specifically designed to act as catalysts to the hydrogen peroxide bleaching process.
Lignin is a complex array of molecules that holds the cellulose in wood together. It is also responsible for the brown color of paper, like that used for paper grocery sacks. In order to get bright white paper, the lignin must be removed. The paper industry traditionally used chlorine for this purpose. In the past 10 years, most of the industry has moved to chlorine dioxide, which minimizes the formation of dioxins that result from chlorine treatment. Bleaching with TAML® activators and hydrogen peroxide offers another advance in the greening of the process by completely eliminating the formation of dioxin waste.
Very recently the TAML® technology has been applied to laundry. One of the challenges faced in reducing laundry water usage is the problem of dye transfer. The highly selective activator uses the peroxide present in some detergents to hunt and destroy free dye molecules, while leaving those dyes bound to fabric alone. You can wash your favorite red sweater with your bright white t-shirts and have both come out looking as good as new. The principles of designing safer chemicals using selective catalysis, improving energy efficiency, and preventing hazardous waste were applied in developing this greener chemical bleaching product.
Lifecycle analysis example #2: biomass fuel substitution
John Deere Zweibruecken (Germany) installed two biomass boilers to replace 40-year-old fossil-fueled equipment in late summer 2008. The new boilers will provide steam to heat facilities, air-condition offices, and provide heat for various manufacturing processes. They will use wood chips from fast-growing trees and from pallets received with inbound material, rapeseed cake (a byproduct of the production of rapeseed oil), and forest residue.
2. Redesigning and/or repackaging products to improve transportation efficiencies.
Numerous companies, particularly those producing consumer products, are working to redesign the packaging for their products. Many of these companies are reducing packaging in response to the Wal-Mart Packaging Scorecard Initiative, while other companies are doing it for their own merit. Wal-Mart originally predicted that implementing a 5% overall packaging reduction across its 60,000 global suppliers could result in saving over 667,000 metric tons of GHGs, equivalent to removing 213,000 trucks from the roads annually.
Repackaging example #1
According to Environmental Leader, Kellogg is testing a shorter, deeper cereal box size and shape — made with 8% less packaging material — that it believes will save space in cupboards and revolutionize the cereal aisle. With 5% less volume, it will also save space on grocery store shelves.
The box is being test marketed in Kroger and Wal-Mart stores in Detroit. Upon conclusion of the testing period, the company will make a decision about a national rollout. The test affects the majority of Kellogg’s branded cereals, including Frosted Flakes, Corn Flakes, and Special K.
Repackaging example #2
Hewlett Packard (HP) introduced new print cartridge packaging for North America in 2006 that was estimated to reduce GHG emissions by 37 million pounds. The emissions savings are the result of smaller, lighter packages that both reduce the total carbon footprint of each cartridge and the truck and freighter transportation traffic required to ship them. Newer packaging also contains more recyclable and recycled content. For retailers, the new packaging is also expected to save significant transportation and storage costs.
HP estimated that its redesigned print cartridge packaging would eliminate the use of nearly 15 million pounds of materials, including 3 million pounds of corrugated cardboard in 2007. The packaging is also expected to eliminate the use of more than 6.8 million pounds of polyvinyl chloride plastic through material reduction and substitution of recycled content plastic and paperboard.
According to HP, the new HP LaserJet toner cartridge packaging uses 45% less packaging material by weight. The smaller boxes can be shipped 30% more efficiently — a standard shipping pallet holds 203 cartridges instead of the previous 144.
Overall, HP estimates that the more efficient packaging is expected to reduce truck traffic in the U.S. and Canada by an estimated 1.5 million miles in 2007.
3. Reducing process water consumption by replacing once-through cooling with “gray water” systems to reduce environmental footprint.
The use of water for cooling in industrial applications represents one of the largest water uses in the United States. Water is typically used to cool heat-generating equipment or to condense gases in a thermodynamic cycle. The most water-intensive cooling method used in industrial applications is once-through cooling, where water contacts and lowers the temperature of a heat source and is then discharged.
Recycling water with a recirculating cooling system can greatly reduce water use by using the same water to perform several cooling operations. Industrial water reuse does carry some water quality concerns, including scaling, corrosion, biological growth, and fouling. However, these concerns are often interrelated with one another and can be prevented by reducing dissolved suspended solids, salts, ammonia, phosphorous, and residual organics through treatment like flocculation and filtration. In the end, the savings from industrial water reuse are sufficiently substantial to result in overall cost savings to the industry.
Industrial process water reuse example #1: rinse water
The Global Environment Center of Japan describes a process for the automated recycling of parts wash and rinse water that utilizes various membrane technologies, as shown in the flow diagram below. In this water reuse system, oil and dirt are separated from the rinse water by an ultrafiltration (UF) membrane. The detergent is subsequently removed from the UF discharge water by reverse osmosis (RO) and reused in the washing process. The ion-exchange (IE) resin can be used to treat water to be recycled as rinse water, as needed.
The environmental and economic benefits of this process are significant. For example, the volume of water usage and discharge is 0.5% of the previous process. The running cost is 1/10 of an alternative adsorption treatment that uses activated carbon and IE resin. In addition, the maintenance requirement is once a month or less. (Asahi Engineering, 1999.)
Industrial process water reuse example #2: condensate recovery improvement
Dow Chemical’s St. Charles facility in Hahnville, LA, has been in operation since 1966. With nearly 3,000 employees, the St. Charles site produces approximately 10 billion pounds of glycol ethers and amines annually. Because steam is required for many processes — including electricity generation, distillation, evaporation and concentration, process heating, and catalytic cracking — it is critical to the site’s production.
ReliablePlant.com recounts the results of a Save Energy Now energy assessment conducted at the St. Charles site under the sponsorship of the U.S. Dept of Energy’s Industrial Technologies Program (ITP). It involved an Energy Expert, who is a qualified specialist on the use of DOE’s Steam System Assessment Tool (SSAT). Because a secondary objective of the assessment was to teach steam system analysis using the SSAT software, the Energy Expert formed an assessment team with six of the site’s employees and installed the SSAT software on their computers. This enabled the project team to learn the software, model the facility, and perform “what-if” scenarios to determine the most optimal implementation measures for energy savings.
One of several recommendations arising from the study was a measure to increase overall steam system condensate recovery. At the time of the assessment, about 50% of the low-pressure condensate was being recovered. Based on the analysis done using the SSAT, a condensate recovery rate of 75% was found to be possible for the entire site. Annual natural gas and cost savings from the increased condensate recovery were estimated at 87,600 MMBtu and $649,000.
4. Energy efficiency — recovering energy from high temperature exhaust gases to lower fuel costs and decrease air pollution.
Many industrial plants operate processes at high temperatures and allow hot exhaust gas to escape the process and/or facility. Thermal energy leaving the building in this way has long been known to increase operating costs in the form of added fuel bills. However, the carbon cost, which will soon be tacked onto the steadily increasing fuel commodity cost, as well as the available energy efficiency incentive dollars, are adding impetus and driving decisions to implement energy recovery projects now.
Thermal energy recovery example #1: immediate payback
A North American battery manufacturing facility conducted a facility-wide study to identify energy savings measures that would also provide cost-effective GHG reductions. The facility had three ventilation units that were capable of recirculating indoor air but were operating on a once-through basis in order to maintain indoor air quality. Each unit was a custom-designed Recirculating Air Dust Collector installed during the energy crisis of the 1970s.
The study revealed that if a real-time particulate sensor were installed to monitor recirculated air quality, the system would then meet industrial hygiene requirements for recirculation of cleaned exhaust air into the workplace. It was estimated that a net energy savings of 80% of the energy requirement for once-through makeup air was achievable.
Thermal energy recovery example #2: short-term payback
A southern pulp and paper mill plant had an older natural gas-fired boiler modified to burn wood bark fuel. A combustion air preheat system utilizing the energy from the plant’s steam system and blowdown tank was installed. The system was comprised of a multi-coil heat exchanger, which transferred energy from the hot liquid blowdown (650 psig, 495°F), as well as saturated steam from a 250 psig plant steam line to preheat combustion air to the boiler from 80°F to 350°F. The estimated boiler efficiency improvement after the installation was 6%.
Thermal energy recovery example #3: strategic
A boiler economizer takes the energy from boiler exit gases and transfers it to the boiler feedwater. Many manufacturers provide economizers as options or add-on modifications for their standard boiler configurations that do not include feedwater preheating. Although generally a longer-term payback than combustion air preheat or recirculated ventilation air (for a system already designed to recirculate), this type of modification is relatively simple to implement and the results are highly predictable.
PART 2
5. Reducing high global warming potential (GWP) greenhouse gases — hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) — for significant benefit at reasonable cost.
If you have an operation that emits or has the potential to emit significant quantities of any of the high GWP GHGs, then you may already be aware of several existing programs, as described below, specifically designed to mitigate their impact.
PFC reduction. The primary aluminum industry is continually working to improve production efficiency, reduce energy consumption, and enhance environmental performance. As part of EPA's Voluntary Aluminum Industrial Partnership (VAIP) Program, eleven U.S. primary producers are focusing on reducing the duration and frequency of anode effects (AEs), which reduce production efficiency and generate two PFCs — CF4 and C2F6. These compounds have GWPs of 6,500 and 9,200, respectively, and are much more potent than carbon dioxide, methane, or N2O, which have GWPs of 1, 21, and 310, respectively.
The industry has a voluntary PFC reduction goal of 80% relative to the 1990 baseline by 2010. Between 1990 and 2005, PFC emissions were reduced by 76% per metric ton of aluminum produced, according to Aluminum Recycling and Processing (Green, et al, 2007).
HFC reduction. The HFCs are a class of replacements for chlorofluorocarbons (CFCs), which included the well-known refrigerants R-11, R-12, R-113, R-114, and R-115. Because they do not contain chlorine or bromine, they do not deplete the ozone layer. All HFCs have an ozone depletion potential of zero. Some HFCs have high GWPs. HFCs are numbered according to a standard scheme. The National Oceanic and Atmospheric Administration (NOAA) provides more detailed information about HFCs on their website.
Regular, careful measurements of air from remote locations during the past 10 years clearly show that global concentrations of HFCs have increased rapidly over this period. This increase can be attributed to enhanced use of HFCs (in particular, HFC-134a) as substitutes for CFCs, HCFCs, and other chemicals as solvent/cleaning agents, refrigerants, foam-blowing agents, air conditioning fluids, etc., beginning in the late 1980s and early 1990s.
On June 21, 2007, the California Air Resources Board (ARB) approved four early action measures to reduce HFC emissions from mobile air conditioning (MAC) systems. These measures will control HFC release from do-it-yourself motor vehicle air conditioning (MVAC) servicing, require addition of air conditioning leak tightness test/repair to smog check, enforce the federal regulations on banning HFC release from MVAC servicing/dismantling, and require using low-GWP refrigerants for new MVAC.
On October 25, 2007, the ARB approved another early action measure to establish tracking, reporting, and recovery protocols for high-GWP refrigerants, which includes refrigerant recovery from decommissioned refrigerated shipping containers.
ARB staff, in collaboration with other state and local agencies, industry, environmental groups, and other stakeholders, is developing control strategies to implement these early action measures, which are becoming mandatory in 2009.
SF6 reduction. SF6 is a GHG that traps heat in the atmosphere at a rate of about 23,000 times higher than carbon dioxide. One pound of SF6 has the same global warming impact of nearly 11 tons of carbon dioxide. Once emitted, SF6 remains in the atmosphere for over 3,000 years, resulting in an essentially irreversible impact on the climate.
SF6 is used by the electric power industry as an insulator in the high-voltage equipment that transmits and distributes electricity between generating stations and customer load centers. The SF6 Emission Reduction Partnership for Electric Power Systems is a collaborative effort between EPA and the electric power industry to identify and implement cost-effective solutions to reduce SF6 emissions. Currently 81 utilities participate in this voluntary program.
SF6 reduction example
On February 4, 2009, EPA recognized two electric power companies for their actions to reduce emissions of SF6 by the equivalent of the emissions from 1.5 million cars. The two winners, Consolidated Edison Co. of New York (ConEdison) and Arizona Public Service (APS), were announced at an EPA workshop on SF6 emission reduction strategies in Phoenix, AZ.
By replacing equipment and improving leak detection, ConEdison prevented 670,000 pounds of SF6 from entering the atmosphere from 1999 to 2007, equivalent to the annual emissions from over 1.3 million cars. In Phoenix, APS prevented more than 100,000 pounds of SF6 from entering the atmosphere during the period from 2001 to 2007 by adopting improved handling and maintenance practices and increasing SF6 recycling. These actions prevented the equivalent of the annual emissions from over 200,000 cars.
6. Adding a renewable electric power portfolio to help hedge your energy bets.
Generating electricity with wind, solar, or biomass energy requires long-term thinking and stable circumstances. Yet the number of installations is on the rise, particularly where utility rates are poised to increase significantly over the next few years (i.e., in states where rate caps that have been in place since the early days of deregulation are set to expire). As firms and public sector organizations look to offset their GHG emissions, they are quickly finding that renewable electric generation can pay for itself through long-term energy price certainty and the associated Renewable Energy Credits (RECs).
A REC is a tradable environmental commodity that certifies that 1 MWh of electricity was generated from an eligible renewable resource. A certifying agency gives each REC a unique identification number to make sure it doesn’t get double-counted. The green energy is fed into the electrical grid (by mandate), and the accompanying REC can then be sold on the open market. Owners may also decide simply to purchase RECs from companies that operate renewable power generation facilities such as wind farms, solar arrays, or biomass plants.
Renewable energy example: onsite generation
A Simpson Tacoma Kraft LLC liner board and pulp plant is shutting down for a month to install a steam turbine and 55 MW power generator to squeeze more energy out of the wood waste that the company already burns. The plant will still produce liner board and paper pulp, and will continue to use steam to dry paper products and do work in the mill. The steam turbine will be installed at the front end of those steam lines.
According to a Simpson spokesman, the company will upgrade its existing boilers to higher pressures to accommodate the new steam turbine. “Much of the biomass — the wood residuals — for this project come from our sawmill operation,” the spokesman said. “So, it’s integrated with our business, where we make the fuel that makes the steam that makes the power.”
Simpson will sell the power to Iberdrola Renewables (formerly PPM Energy). Tacoma Power partnered with Simpson to define the infrastructure and power needs to support the cogeneration facility. The utility, which provides power to Simpson's operations in Tacoma, will provide transmission service to Iberdrola for the renewable power purchased from Simpson. Simpson will invest $100 million to build the project — $20 million of which will be in new jobs for construction of the facility. That investment will pay off because state laws require states to source certain portions of power from renewable sources.
7. Implementing cogeneration at facilities with steady and coincident electric and thermal usage profiles to improve overall efficiency and reduce environmental emissions.
Before the days of inexpensive fossil fuels, cogeneration was commonplace in communities and industrial plants. Despite the high initial cost and complex operations resulting from such systems, there are many reasons to consider converting to cogeneration — particularly where electrical and thermal requirements occur simultaneously, or nearly so, and where the cost of electricity purchased from the grid is relatively high and the cost of fuel for the cogeneration facility is relatively low.
The average power plant today generates electricity at an energy efficiency of 33%. The average boiler converts the energy of fuel to useful thermal output (often in the form of steam) at a typical efficiency of about 85%. Generating steam at high enough pressure to turn a turbine takes little more energy than generating steam at saturated conditions or slightly above, as is currently the practice at many industrial and commercial central steam generation plants. For example, the enthalpy of 900 psig, 900°F superheated steam is approximately 1,450 Btu/lb, whereas the enthalpy of saturated steam at 250 psig is 1,195 Btu/lb. The added energy input, about 255 Btu/lb, is only about 25% of the latent heat of vaporization — the amount necessary to convert liquid water to steam at constant temperature.
Since it is relatively easy, from an energy point of view, to superheat steam, and the higher pressure steam allows for a much more useful spectrum of outputs, including the generation of electricity, for little additional capital cost, there is a strong incentive to consider cogeneration to provide both thermal and electric needs. In fact, it is not unusual to see overall cogeneration plant efficiencies in the range of 80%, or well more than double the efficiency of the average electric utility generating plant today.
Cogeneration example
Smart Papers, based in Hamilton, OH, is one of the oldest continuously operating paper mills in North America. The facility makes premium coated and uncoated printing papers for businesses and consumers. It is constructing a $30 million high-efficiency cogeneration facility adjacent to the Hamilton operation as part of its carbon management strategy. The 40-MW facility will use biomass such as wood waste and short-fiber cellulosic residuals to generate electricity and steam. The project will consist of four turbines, two condensers, a cooling tower, and auxiliary equipment.
Honeywell International supplied Smart Papers’ cogeneration system and is supervising the construction of the facility. Construction reportedly began in late April 2008, and is expected to be complete by the spring of 2009. A portion of the project’s electrical output will be traded on the open market as monetized carbon credits.
“It makes a good business proposition,” says Smart Papers’ chairman. “Carbon-neutral paper is really the future of the industry, and for us to be able to sell credits on them is also a double-positive.” (See http://www.biomassmagazine.com/article.jsp?article_id=1726)
8. Look for waste recycling and reduction of waste to landfills.
Despite the recent troubles in the recycling market, the future looks bright. More and more companies and organizations are finding ways to reduce their output of wastes to landfills. These efforts will be spurred on even more by the advent of carbon regulations, which will place a high cost upon disposal of organic materials that subsequently decay and release methane in landfills. Methane is 21 times as potent a GHG as carbon dioxide. In addition, keeping toxic materials such as mercury and other metals out of our landfills will reduce the chances that these substances could leach into groundwater and aquifers.
Recycling example #1: computer asset management
Alliant Energy has a system to manage its electronic equipment responsibly and has developed associated recycling guidelines. Any underutilized computer equipment is sent to the Information Technology Dept. at its general offices, where the equipment is reused, donated, or recycled.
To avoid contaminating landfills with lead, mercury, and cadmium from computer equipment, Alliant Energy sponsored a “Recycling Round-up” at Cascade Asset Management in Madison, WI. Employees and local residents dropped off their personal computer equipment, TVs, and cell phones to be recycled. More than 57,000 pounds (28.5 tons) of electronic equipment were recycled at the event, with more than 625 local households participating. Any equipment in working condition that was dropped off was refurbished and donated to local nonprofit organizations.
Cascade Asset Management helps businesses and government agencies properly dispose of their IT and electronic assets that have outlived their usefulness. It recycles and resells large quantities of equipment from eight facilities across the U.S. Cascade has seen a bump in business as more companies and municipalities have gone green while upgrading technological equipment. The company makes it even easier by supplying the trucks to transport the equipment and by handling the security issues associated with disposing of computer assets. The company has demonstrated that computer replacement prior to CPU failure is often economically advantageous, as the used equipment in still-working condition has significantly greater value than non-functioning equipment.
Recycling example #2: zero waste to landfill
Subaru of Indiana’s (SIA) plant was the first “zero waste to landfill” auto factory in the U.S. Fully 99% of waste from the plant is recycled; the remaining 1% is converted to electricity. With SIA's solvent recovery system, for example, paint solvents are broken down after use into their base elements and reused repeatedly. Other examples of the “reduce, reuse, recycle” philosophy include the massive plastic trays used to transport engines, and the thousands of brass lug nuts used to temporarily secure the wheels to the cars. After use, they are sent back to their point of origin for reuse.
Recycling efforts in 2006 saved more than 11,000 tons of steel, roughly 1,500 tons of cardboard/paper, 190 tons of polystyrene/other plastics, approximately 1,000 tons of wood from pallets, and nearly 11,000,000 gallons of water.
Though some processes, such as the paint solvent recovery system, are expensive (in some cases, taking up to seven years from time of purchase, according to a Subaru executive), others, such as reusing polystyrene and plastic packing pieces, cost relatively little.