1 AF&PA-AWC Responses to EPA’s questions on PRR and Railroad ties (May 2013)

In response to questions asked by EPA in early May, AF&PA and AWC are providing the responses below. We are deferring to the CMRA and BPA to respond to the questions on processed C&D.

Before we respond to these narrow questions, it is important to remind the Agency we have provided extensive information to EPA over the last three years on these two materials from the ANPRM, through t he June 2010 proposal and on to the December 2011 Reconsideration rulemaking. In addition, we have provided various “white papers”
and NCASI technical bulletins which are in the rulemaking record . These materials clearly show that these materials are highly valued fuels and are managed like other
traditional biomass fuels and burned in boilers that can accommodate a wide variety of

moister biomass materials. We remain opposed to the appl ication of a “designed to burn” test as part of the legitimacy crit eria when EPA has the discretion to consider other factors in making a determination under 241.4.

EPA Question : “Paper Recycling Residuals (PRRs) aver age Btu value is 3,700 Btu/lb as fired. You previously indi cated that some PRRs are ov er 5,000 Btu/lb; however, can you explain why there are much lower values ? For example, do the low values come from samples of PRRs burned in units that can handle high moisture content and thus, there has been very little processing, if any, to remove moisture?

Answer :

Yes, the PRRs with lower Btu va lues are combusted in units that can derive fuel value from materials with high moisture cont ent without processing those materials.

The 3,700 Btu/lb value was derived from NCASI Technical Bulletin 806 with an average dry value of 9100 BTU/lb with solids around 40%; the range of dry BTU is 8K to 12K and solids vary from 40-60% with an aver age of 50%. A survey of about 10 companies finds some reporting higher BTU values than the older 3700 BTU/ lb value and other companies reporting lower BTU values. Lowe r BTU values are due to higher moisture, less solids, types of fibers being processed (such as, satu rated), and/or fewer non-fiber packaging materials. Mills manage the moistu re content of all fuels including PRRs based on combustion efficiency of the boilers which function exceedingly well with high
moisture fuels.

EPA Question : What is the split between PRRs with BTU/lb as fired under 5000 and
over 5000?”

Answer : The BTU value of PRR is a c ontinuum that is influenced by amount of solids, fiber content, moisture, presence of non-fiber packaging materials, and combustion conditions necessary for the e ffective operation of the boiler, but most of the PRRs are2 below 5000 on a wet basis since the average is less than 5000 BTU/lb. However, wetter biomass fuels are also in that same range and can have a lower Btu value than PRR at

times. From the boiler’s vant age point, burning wet biomass or PRRs is essentially the

same and the two materials are managed similarly as well. The boilers used, like stokers and FBC, often have over-fire and/or under-grate air that assists the efficient burning of wetter fuels. Consistently wet ma terials are handled well in the boiler leading to fewer temperature swings and minimized boiler tuning adjustments. For PRR it would be inappropriate to consider a moisture le vel benchmark when determining if a material
is a non-waste fuel because the boilers at pulp and paper mills can cost-effectively recover energy from PRRs. 1

EPA Questions on Railroad ties or Rail Derived Fuel (RDF):

EPA Question : Of the AF&PA member boilers burni ng creosote-treated railroad ties, how many (or what percentage) burn or can burn fuel oil during normal operations ?

Answer : The overwhelming majority of RDF bur ned at paper mills are burned in boilers that are fully capable and permitted to burn oil at maximum capacity rating. Most of these boilers (80 percent) can or do burn oil during operating conditionsoutside of startup and shutdown periods. Ho wever, we believe start-up and shutdown are part of normal operations since they cannot be elim inated and common to all boiler systems. Therefore, if EPA considers def ining “designed to burn” further or “normal operation” it should include start-up and shutdown periods.

The percentage of oil the boile r is capable of burning varies but can be up to 100 percent of the energy load. The largest cons umer of RDF uses boi lers that are fully capable of, permitted to, and do burn fuel oil at maximum capacity rating. However, at the 20 percent of boilers that do not burn oil during normal oper ations, the use of RDF is no less legitimate. It is used as a fuel. Th us, EPA should not put any restrictions on “normal operations”

EPA Question : Are there differences among boiler ty pes (stoker boiler, traveling grate, circulating fluidized bed etc.) with regard to what it takes to modify the unit so it could
burn fuel oil?

Answer : No, these boiler types have relatively tall combustion chambers that make them ideal for burning multiple fuels from solids to liquids to gas. An oil burner system would be added that would require seve ral ports to deliver the fuel.

1 See 76 FR 15487: “While the meaningful heating value of the OCC rejects is lower than 5,000 Btu/lb, as fired, it can still meet this criterion if it can be demonstrated that the unit can cost-effectively recover energy from a non-hazardous secondary material.”3 EPA Question : Is it always as simple as inst alling a delivery system and a nozzle?

Answer: Burner systems can be inst alled because there is r oom in these tall boilers and the systems. However, engineering the system can be co mplicated and the cost of the delivery system can be significant ($100Ks) depending on the amount of fuel oil to

be burned in the boiler.

EPA Question : Do states typically require different air pollution control devices for units burning fuel oil (as hinted at by the reference to SO2 emissions in the AF&PA response)?

Answer : No, controls for solid fuels like ESPs are sufficient; oil is generally easier to

burn than solid fuels. There ar e frequently sulfur content lim its for the oil burned that varies by state and sometimes a lower NOx limit when burning multiple fuels.