Background on draft legislation
Rep. Chris Cox, Chairman, House Policy Committee
CHEMICAL HYDRIDE SYSTEMS FOR FUEL CELLS - DO THEY PRODUCE HAZARDOUS WASTE?
The two well-known ways to store hydrogen are as (1) compressed gas and (2) cryogenic liquid. However, Millenium Cell (based in New Jersey) and Safe Hydrogen (a new company spun off of BASF, based in Massachusetts) have both developed alternative approaches: chemical hydride systems.
Millenium Cell stores hydrogen in a water-based solution of sodium borohydride (NaBH4) and sodium hydroxide (NaH2), at room temperature and under ambient pressure. Catalyzing the solution produces hydrogen gas to power the fuel cell, and sodium borate, a byproduct that remains in the solution. At the end of each fueling cycle (one day it will be at a fueling station), the sodium borate is removed from the vehicle, contained and either sent or picked up for recycling at a company like U.S. Borax in Boron, California.
Sodium borohydride is made from borax, a material found in substantial natural reserves around the world and domestically. Borax operates California's largest open pit mine, one of the richest borate deposits in the world. Borax reuses the sodium borate produced by Millenium Cell's chemical hydride system.
The Regulatory Issue
The sodium borate produced by Millenium Cell's chemical hydride system may be subject to regulation as a hazardous material.
Because of the presence of sodium hydroxide in the original solution, the discharged sodium borate has a pH of about 13.5, just above the threshold for determining whether a material meets the Resource Conservation and Recovery Act's (RCRA) corrosivity characteristic (a pH of 12.5), potentially making it classifiable as a hazardous waste. This would make commercializing the use of the chemical hydride system impractical, because of the burdensome handling it would require to be emptied out of the fuel cell and transported for recycling.
Millenium Cell has been trying to get EPA to clarify the status of the sodium borohydoxide and sodium borate, but EPA is deferring to the California state EPA, which claims to be running its own tests of the material. Results of those tests and a timeline for completion are unknown.
Congressman Cox's draft legislation sets a timeline for an EPA study of sodium borohydroxide and sodium borate, and exempts the industry from hazardous waste regulation until six months after the study is completed.
Millenium Cell originally asked EPA for a clarification in early 2002. A more detailed explanation of the company's regulatory argument is attached to this backgrounder.
Congressman Cox's draft legislation would apply to not only Millenium Cell, but also to Safe Hydrogen, whose lithium hydroxide "slurry" will presumably face a similar regulatory obstacle.
CAN HYDROGEN VEHICLES DRIVE THROUGH TUNNELS?
It is not clear that hydrogen-powered vehicles and vehicles transporting hydrogen as cargo are allowed to travel in tunnels.
Current state/local fire codes prevent such vehicles from being stored in garages as a safety measure. Some fuel cell experts, like Dr. Scott Samuelsen at the University of California, Irvine, expressed concern that states/localities might use this reasoning to prevent hydrogen-powered vehicles from travelling underground. Another expert said that natural gas vehicles faced a similar obstacle a few years back in the New York area.
Federal law delegates authority over tunnels to states and localities. So the Congressman Cox's draft legislation clarifies that these authorities and the Secretary of Transportation should not apply regulations more stringent than those governing gas-powered vehicles and vehicles transporting gas as cargo.
SENSE OF CONGRESS ON HYDROGEN SAFETY
Everyone involved with hydrogen is concerned about codes and standards, so the Sense of Congress in this draft legislation acknowledges that the setting of codes and standards is a long-term problem which must be addressed.
October 30, 2002
Mr. Robert Stringer, Director (5301W) Mr. Charles Corcoran, Chief Office of Solid Waste Solid Waste Identification & Recycling Section U.S. Environmental Protection Agency State Regulatory Programs Division 1200 Pennsylvania Avenue, N.W. California Environmental Protection Agency Washington, DC 20460 P.O. Box 806 Sacramento, CA 95812-0806 Re: Request for Regulatory Interpretation Regarding Use of Fuel Cell Solution in a Manufacturing Process Dear Mr. Springer and Mr. Corcoran: On behalf of Millennium Cell, Inc., and in cooperation with U.S. Borax, I am submitting this request for a clarification of the application of hazardous waste regulatory requirements to the management of hydrogen fuel cell solution. Before describing the precise fact situation at issue, it may be helpful to provide relevant background information Millennium's fuel cell technology and Borax's production process.
Millennium Cell's Hydrogen Storage Technology
Millennium Cell has developed a hydrogen storage and delivery technology that provides a viable alternative to fossil fuel combustion. This technology allows for the storage of hydrogen in a non-flammable aqueous solution and the delivery of safe and zero-emission power to transportation vehicles, commercial sites, and residences.
Within the context of fuel cell vehicles, the technology functions by providing an on-board hydrogen-releasing system. The hydrogen is typically stored in a solution consisting of water, sodium borohydride, and sodium hydroxide. The sodium borohydride/water mixture is the hydrogen source, while the sodium hydroxide is added simply to stabilize the solution at elevated temperatures. The fuel solution exists at room temperature and is under ambient pressure.
The sodium borohydride/sodium hydroxide solution is catalyzed to produce hydrogen gas for the fuel cell and sodium borate, which remains in the solution. At the end of each fueling cycle, the sodium borate is removed from the vehicle and containerized. Because of the presence of sodium hydroxide in the virgin solution, the discharged sodium borate has a pH of about 13.5, just above the threshold for determining whether a material meets RCRA's corrosivity characteristic (i.e., a pH of 12.5).
The Borax Production Process
Borax, acknowledged as the world leader in borate technology, research, and development, operates a borate mine in Boron California -- one of the richest borate deposits on Earth. At the borate plant, ore is crushed and mixed with a hot aqueous solution to dissolve the sodium borates into water. This mixture undergoes screening and settling to remove the ore solids. The resulting solution is cooled to crystallize the borates and then filtered to remove the borates for drying and packaging. The remaining aqueous solution is returned to the first step to repeat this cycle. The ore used in the first step of these operations is predominately sodium borate ore, but a small amount of Trona ore is also added at this step to prevent scaling and maintain the pH of the circulating solution at 9.25. Maintenance of this pH is important to ensure that the borates crystallize in the preferred shape.
Proposed Management of the Materials at Issue
Millennium Cell has partnered with automobile manufacturers to develop a hydrogen-based alternative to current forms of transporation. These manufacturers have produced hydrogen fuel cell vehicles, which have been successfully tested and used in different parts of the country. As the technology takes hold, more and more of the discharged fuel cell solution will need to be properly managed.
Currently, the most sensible management option for the solution is to charge it directly into Borax's production process. The solution provides an ideal substitute for the soda ash in the sodium borate plant operations. Dissolution of the sodium borate ore essentially creates a sodium metaborate solution. Dissolution of Trona ore and soda ash increases the carbonate content of the solution to reduce scaling. Dissolution of soda ash increases the sodium hydroxide concentration to maintain the desired pH. The fuel cell solution is in effect a pure solution of the beneficial components otherwise derived from the ores and soda ash in the sodium borate plant (i.e., sodium metaborate and sodium hydroxide). Thus, the fuel cell solution is perfectly suited to substitute for a portion of the soda ash because the solution's high sodium hydroxide content can serve to maintain the pH of the sodium metaborate solution in the plant at 9.25 without adding any constituents except beneficial compounds otherwise derived from the ores at the plant.
Indeed, the elements of the fuel cell solution correspond directly to the components of the material it replaces. After use in a hydrogen fuel cell vehicle, the solution contains approximately 21% sodium oxide, corresponding to 20% sodium oxide in the Trona ore. The solution contains approximately 21% boric oxide, compared to 23% boric oxide in the borate ore. The remaining component of the fuel cell solution is water. The remaining components in the Trona ore are water, carbon dioxide, and certain insolubles.
Applicability of Hazardous Waste Requirements
Millennium Cell and U.S. Borax believe that the fuel cell solution charged into the Borax production process would not be subject to regulation as a hazardous waste. This is so because the fuel cell solution is simply not a solid waste, either because it is not a secondary material or because it is being used as a substitute for a commercial product.
Whether the Solution is a Secondary Material
The fuel cell solution does not fit the definition of any of the types of secondary materials subject to regulation upon reuse. The solution is not a spent material because the initial use of the solution in the fuel cell simply releases hydrogen atoms from the solution and does not add any physical or chemical impurities. In addition, nothing else occurs in the fuel cell that would require the solution to be processed or reclaimed before further use in the Borax operations. Following use in the fuel cell, the solution contains no constituents other than beneficial compounds (i.e., sodium metaborate, sodium hydroxide and water) that would otherwise be derived from raw materials used in the sodium borate process. Thus, the solution can be used directly for pH adjustment. EPA has recognized that a material may serve a purpose that need not be identical to the material's initial use if the material can be used directly without being reclaimed. See 50 Fed. Reg. 614, 624 (1985).
The fuel cell solution is not a by-product because the definition of this term, on its face, appears to be limited to materials from production processes, and a fuel cell in a vehicle is not a production process in the ordinary sense of that term. However, if the fuel cell were to be considered a production process, then the solution would appropriately be considered the product or co-product of that process, rather than a by-product. One of the benefits of using the sodium borohydride solution to power the cell the is the fact that, following this use, the solution is a pure form of the beneficial compounds derived from the raw materials used in the sodium borate plant. Thus, by using sodium borohydride, the fuel cell produces not only energy, but also a solution that can be used in the form in which it is produced as a commercial commodity because the solution is essentially a pure form of beneficial components otherwise derived from the ores and soda ash used in the sodium borate plant.
Use as a Substitute for a Commerical Product
Alternatively, even if the solution from the fuel cell were characterized as a secondary material, the solution would not be a RCRA solid waste because the solution would be used as an ingredient to effective substitute for a commercial product, per 40 C.F.R. §261.2(e)(1)(ii). As explained above, because of its sodium hydroxide content and resulting high pH, the fuel cell solution can be used as an effective substitute for some of the Trona used in the sodium borate plant to maintain the desired pH and ensure appropriate crystal formation at later stages.
When evaluated against the criteria EPA employs to determine whether a material is an effective substitute, it is clear that the fuel cell solution does indeed meet the §261.2(e)(1)(ii) standard. The solution is equally effective as the soda ash in controlling pH, does not contain any constituents other than beneficial compounds otherwise derived from the raw materials used in the sodium borate operations, does not contain any Appendix VIII constituents or demonstrate any hazardous characteristics other than the desired quality of high pH, would not be used in excess amounts because of potential adverse effects on crystal shape, and can be fed directly into the process without any additional processing.
The primary purpose of charging the fuel cell solution into the Borax process is for pH control. An ancillary benefit, however, is that the borate content of the solution can be used as an ingredient to make refined borate. The fuel cell solution, as a whole, represents a step in the borate manufacturing process, rather than simply the reclamation of borate values. Crystalization of sodium borates, which may include borates that originate from the fuel cell solution, does not occur directly from the fuel cell solution, but only at later stages in the production proceess, after the other properties of the fuel cell solution have performed their functions. Thus, the fuel cell solution represents an ingredient in an industrial process, and is not characterized by reclamation. As a result, the solution escapes regulation as a solid waste under 40 C.F.R. § 261.2(e)(1)(i), in addition to the aforementioned § 261.2(e)(1)(ii).
Analagous California Requirements
DTSC's regulations classify secondary materials as wastes in essentially the same manner as do the RCRA regulations. See 22 C.C.R. § 66260.10. And, similar to RCRA, Health and Safety Code § 25143.2(b)(2) provides an exclusion from regulation as a waste for recyclable material that is "used or reused as safe and effective substitute for commercial products if the material is not being reclaimed." Policy Considerations
Reusing discharged hydrogen fuel cell solution in U.S. Borax' industrial process conserves resources and minimizes the need to dispose of materials as hazardous waste, consistent with the goals of EPA's recently announced Resource Conservation Challenge. Indeed, identifying a sensible management option for hydrogen fuel cell solution serves one of the Challenge's specific programs -- that of "encouraging less polluting vehicles." Finally, we point out that the U.S. Borax option will permit the approrpriate management of fuel cell solution for multiple years to come, given that the considerable scale of the Borax operation should allow for hundreds of millions of gallons of solution to be charged into the process on an annual basis. Once the country moves in great numbers to the hydrogen economy -- as specifically envisioned by the current Administration -- other options will need to be explored to ensure that this valuable technology is not hindered by regulatory requirements.
Thank your for your prompt attention to our request that you confirm our understanding of the status under RCRA of hydrogen fuel cell solution used in an industrial process. Please contact me if you need any additional information..
Steven L. Leifer
cc: Matt Straus, Office of Solid Waste, EPA (5101T) Charlotte Mooney, Office of Solid Waste, EPA (5304W) Donna Perla, Innovative Pilots Division, EPA (1807) David Jones, Region IX, EPA (WST-1) Terry Copeland, Millennium Cell Gerry Pepper, U.S. Borax