40 CFR § 63.7297 - What emission limitations must I meet for HNR HRSG main stacks?
---
identifier: "/us/cfr/t40/s63.7297"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "40 CFR § 63.7297 - What emission limitations must I meet for HNR HRSG main stacks?"
title_number: 40
title_name: "Protection of Environment"
section_number: "63.7297"
section_name: "What emission limitations must I meet for HNR HRSG main stacks?"
chapter_name: "ENVIRONMENTAL PROTECTION AGENCY"
subchapter_number: "C"
subchapter_name: "AIR PROGRAMS"
part_number: "63"
part_name: "NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS FOR SOURCE CATEGORIES"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "42 U.S.C. 7401"
regulatory_source: "57 FR 61992, Dec. 29, 1992, unless otherwise noted."
cfr_part: "63"
---
# 63.7297 What emission limitations must I meet for HNR HRSG main stacks?
You must not discharge to the atmosphere any emissions from any HNR HRSG main stack at a new or existing HNR coke oven battery that exhibit emissions greater than the applicable limits in paragraphs (a) through (d) of this section.
(a) Emissions of particulate matter from any HNR HRSG main stack at a new HNR coke oven battery that exceeds 8.8E-04 gr/dscf at 10 percent oxygen or any HNR HRSG main stack at an existing HNR coke oven battery that exceeds 0.0049 gr/dscf at 10 percent oxygen.
(b) Emissions of mercury from any HNR HRSG main stack at a new HNR coke oven battery that exceeds 1.5E-06 gr/dscf at 10 percent oxygen or any HNR HRSG main stack at an existing HNR coke oven battery that exceeds 3.0E-06 gr/dscf at 10 percent oxygen.
(c) Emissions of total acid gases from any HNR HRSG main stack at a new HNR coke oven battery that exceeds 0.0034 gr/dscf at 10 percent oxygen or any HNR HRSG main stack at an existing HNR coke oven battery that exceeds 0.049 gr/dscf at 10 percent oxygen.
(d) Emissions of total PAHs from any HNR HRSG main stack at a new HNR coke oven battery that exceeds 4.7E-07 gr/dscf at 10 percent oxygen or any HRSG main stack at existing HNR coke oven battery that exceeds 4.8E-07 gr/dscf at 10 percent oxygen.
[89 FR 55743, July 5, 2024]