Proposed Air Emission Standards For Kraft Pulp Mills

Written By: Caltha LLP | Published On: 23rd May 2013 | Category: Air Quality | RSS Feed

The EPA is proposing revisions to the new source performance standards (NSPS) for kraft pulp mills. These revised standards include particulate matter emission limits for recovery furnaces, smelt dissolving tanks and lime kilns, which apply to emission units commencing construction, reconstruction or modification after May 23, 2013 that are different than those required under the existing standards for kraft pulp mills. The exemptions to opacity standards do not apply to the proposed standards for kraft pulp mills. The proposed rule also removes the exemption for periods of startup and shutdown (SSM) resulting in a standard that applies at all times. The proposed rule includes additional testing requirements and updated monitoring, recordkeeping and reporting requirements for affected sources. Comments on the proposed rules must be received on or before July 8, 2013.

As background, the Clean Air Act (CAA) requires the EPA to review and, if appropriate, revise existing NSPS at least every 8 years. The NSPS for kraft pulp mills (40 CFR part 60, subpart BB) were promulgated in 1978 and last reviewed in 1986. As part of the review, the EPA considers what degree of emission limitation is achievable through the application of the BSER, and the emission limitations and reductions that have been achieved in practice.
In addition to conducting the NSPS review, the EPA is evaluating the SSM provisions in the rule in light of a recent D.C. Circuit Court of Appeals decision which held that the SSM exemption in the General Provisions in 40 CFR part 63 violated the CAA’s requirement that some standard apply continuously. In this case, the Court vacated the SSM exemption provisions in the General Provisions of 40 CFR part 63 for non-opacity and opacity standards.
To address the NSPS review, SSM exemptions and other changes, the EPA is proposing new standards, which will apply to affected sources at kraft pulp mills for which construction, modification or reconstruction commences on or after May 23, 2013. The affected sources under the proposed NSPS are new, modified or reconstructed digester systems, brown stock washer systems, evaporator systems, condensate stripper systems, recovery furnaces, SDTs, and lime kilns at kraft pulp mills. The requirements for these new, modified or reconstructed sources will be included in a new subpart-40 CFR part 60, subpart BBa. The EPA is also proposing testing, monitoring, recordkeeping and reporting requirements for subpart BBa that are in some ways different from what is required under subpart BB.
Based on the results of the NSPS review, the EPA is proposing the standards for filterable PM, opacity and TRS compounds:

  • Reducing the filterable PM emission limit for new and reconstructed recovery furnaces and lime kilns and new and reconstructed SDTs associated with new or reconstructed recovery furnaces to levels equivalent to the new source PM limits in the NESHAP for chemical recovery combustion sources at kraft, soda, sulfite and stand-alone semichemical pulp mills (40 CFR part 63, subpart MM), to which these sources would already be subject;
  • Maintaining the filterable PM emission limit for modified recovery furnaces and lime kilns and for modified SDTs and new and reconstructed SDTs not associated with a new or reconstructed recovery furnace at their current NSPS levels;
  • Reducing the opacity limit for recovery furnaces to the 20 % corrective action level in NESHAP subpart MM and reducing the opacity monitoring allowance from 6 % to 2 %;
  • Adding an opacity limit of 20 % for lime kilns equipped with ESPs with an opacity monitoring allowance of 1 %; and
  • Maintaining the TRS emission limit for digester systems, brown stock washer systems, evaporator systems, condensate stripper systems, recovery furnaces, SDTs, and lime kilns at their current levels, but restricting the TRS monitoring allowance of 1 % for recovery furnaces to 30 ppmdv and adding a TRS monitoring allowance of 1 % for lime kilns, restricted to 22 ppmdv.

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