Air Quality Program

The NCASI air quality program primarily focuses on emissions from forest products manufacturing facilities.

One key aspect of NCASI’s air quality program is the characterization of source emissions and identification of factors affecting these emissions. NCASI carries out field studies at member company mills to obtain essential emissions data. These data are often supplemented with member company-generated testing information to broaden the available database. NCASI also analyzes emission data, in conjunction with relevant equipment design and associated process operating information, to develop an understanding of factors affecting emissions. Results from these targeted NCASI investigations are published in the form of Technical Bulletins and Special Reports and are widely used by the industry for evaluating the performance of air pollution control technologies, for examining emission reduction options through process modifications, for preparing air quality permit applications, for meeting emission reporting obligations, and for assessing the impact of emerging federal, state or provincial emission regulations.

NCASI also conducts laboratory and field evaluations of stack sampling and analytical methods to determine if they are appropriate for characterizing emissions from sources commonly found at pulp and paper mills, panel plants, and lumber mills. When suitable measurement techniques are lacking, NCASI develops and validates sampling and analytical methodologies that can be used on industry emission sources. Sampling and analytical methods developed by NCASI are published in the NCASI Methods Manual.

Emission data from NCASI studies address data gaps and better inform regulatory agencies during rulemakings. NCASI carried out two extensive studies in the 1990s to develop data on Hazardous Air Pollutant (HAP) and volatile organic compounds (VOC) emissions from Pulp and Paper mills and Wood Products plants. The data from these studies were instrumental in the development of Maximum Achievable Control Technology (MACT) standards for pulp and paper mills and wood products plants (PCWP MACT). The results from these studies were also published in a multi-part series of Technical Bulletins.

Recent technical studies in the air quality program have focused on particulate matter (PM), nitrogen oxides (NOx), total reduced sulfur (TRS) compounds, sulfur oxides (SOx), and volatile organic compounds (VOC).

Recent technical studies in the Air Quality program have focused on nitrogen oxides (NOx), total reduced sulfur (TRS) compounds, sulfur oxides (SOx), particulate matter (PM), and VOC. NCASI studies have examined NOx emissions from bark-fired boilers and wood-fired combustion sources at panel plants and their relationship to the nitrogen content of fuels being burned. NOx emissions from lime kilns, kraft recovery furnaces, kraft mill thermal oxidizers, and various combustion devices at kraft mills burning stripper off-gases (SOG) containing ammonia have also been studied. A major investigation of reduced sulfur compound releases from kraft mill wastewater treatment systems was completed in 2007; the study involved sampling of liquid effluents, primary and secondary sludge, and ambient air in the vicinity of clarifiers, aeration basins, and polishing ponds. NCASI also evaluated a spatial ambient air sampling technique and developed multiple analytical methods in conjunction with this project.

The measurement of total particulate matter, PM10, PM2.5, and condensable particulate matter (CPM) is an active area of research. Recent NCASI studies are expanding the database for PM emissions from boilers, recovery furnaces, and lime kilns equipped with dry control devices of varying PM capture efficiencies. Evaluations of methods for measuring PM emissions from sources with extremely low emission rates (e.g., paper machines, natural gas boilers) have also been undertaken. A field evaluation of a modified method for measuring filterable PM2.5 emissions from wet sources is also underway.

In recent years, NCASI has also addressed the measurement of speciated volatile organic compounds (VOCs). This study focused on the use of multiple VOC measurement methods on panel plant emission sources like formers, blenders, and sanders and developed a methodology to report mass emissions of VOCs. Studies have been completed on wood products sources utilizing southern pine and are underway for sources utilizing western softwood and various hardwood species. NCASI has also carried out VOC emission testing on lumber kilns.

NCASI is also compiling all emission data, from targeted internal studies and member companies, into extensive emission databases. The pulp and paper air toxics and criteria pollutant databases were released in 2009 and updated in September 2018. The wood products air emission database was released in May 2009 and updated in March 2013.