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Councils staff has integrated the most desirable meteorological and ambient air sampling techniques for routine ambient air surveys into bulletin form. This is in the process of being updated at the present time. 6. Cooperative mill service activities
Service activities in air pollution by the regional engineers cover a wide spectrum and are increasing. Typical of these are those listed below:
(1) Collection, compilation, and dissemination of information.
(4) Conference with members on control measures as well as data inter-
Previous factors of the report have described those programs and activities which have as their main purpose generation of new knowledge in the fields of emission measurement and control technology, and pollutional effects of our atmospheric emissions. There are several additional technical areas calling for increased activity on the part of our staff. These involve (a) the continuing inventory of new emission control measures, their costs, effectiveness. and application; and (b) the continuing review of existing and proposed control regulations as an aid to member mills involved in cooperative efforts to derelop equitable control codes at the state and local lerels.
(a) Continuing review of emission control measures Traditionally, the National Council has played an important role as a clearing house of stream-improvement technical information, combining compilations of current practice with technical analysis to identify important process parameters, and to indicate which practices are worthy of extension. To an increasing degree, we are being called on to play this same role in the air pollution areas as more mills adopt control measures or begin active evaluations of alternative control systems. In this respect, mention should be made of a number of such studies performed in the areas of black liquor oxidation, eletrostatic precipitation ratings, lime-kiln, venturi-scrubber performance, total sulfur emission, and the impact of particulate emissions on ambient air quality as measured by fallout rates and suspended particulate levels. We are now completing an industry-wide enumeration of control practices employed at kraft mills and are preparing reviews of heavy black liquor oxidation practice and secondary scrubbing of recovery furnace stack gases. Some preview data is presented in Figure 3.
Air pollution control activities of kraft pulp mills Ambient air survey program.
32 High efficiency recovery furnace stack devices. High efficiency scrubbing of lime kiln stack. Black liquor oxidation--Smelt tank demistingNon-condensible oxidation.High efficiency fuel burning stack devices--
(0) Continuing review of control agency regulations We have been continually active since 1956 in providing information on proposed air pollution control legislation, particularly that involving the setting of standards of emission or of ambient air quality. Such legislation has prompted increased activity on the Council's part in evaluating existing and proposed regulations. In such states as Pennsylvania and South Carolina this has recently taken the form of:
(1) Determining what levels and forms of emission control will be required to achiere compliance with proposed regulations. These frequently include limitations on sulfur concentration in exist gases as well as total emission weight per unit of material processed. This inventory information is of great value in answering questions.
(2) Indicating under what conditions certain forms of regulation are more pertinent than others (i.e., limits on emission vs. changes in ambient air quality),
(3) Indicating the extent and type of monitoring efforts that will be required to demonstrate compliance with various regulations,
We expect to see a steady growth in the Council's efforts in these two directions which provide both a balance to our total program and a necessary link between our own investigative efforts and the mills' continuing progress in air pollution control.
C. IDENTIFICATION OF RESEARCH UNITS
1. Odor eraluation and non-sulfur odor sources
The most significant need is in the area of evaluation of source and control. While the sulfur compounds have been given credit for the typical kraft odor, little has been done in attempting to chemically characterize other compounds present in small concentrations, which are contributing factors, by the use of chromatographic isolation and infra-red spectrophotometry. Chemical characterization of odor may have merit over subjective testing by humans, whose response is variable. It is, however, becoming obvious that at least some subjective testing in connection with chemical characterization may be desirable and a necessary adjunct to study programs where various control techniques are being evaluated. 2. Role of direct contact evaporation and black liquor oridation in odor emission
and control Considerable emphasis has been placed on the role of the contact evaporator as a source of H2S emission. With present black liquor oxidation practices this component can be substantially reduced or virtually eliminated at this source. This has reduced but not eliminated the odor problem, and at least three facets of black liquor exidation are deserving of further attention. These include the following:
(1) Refined chemical characterization of gaseous effluent components present with and without black liquor oxidation.
(2) Relationship of degree of black liquor oxidation and sulfur emission or odor emission.
(3) Relationship of high-degree black liquor oxidation, odor threshold, and refined chemical characterization. The first of these is under study at the present time. It has been demonstrated that the rate of H.S evolution is inversely proportional to the degree of black liquor oxidation. There is no information to indicate whether organic sulfur or other odorous compound evolution follws a similar pattern. Since the organic sulfurs may constitute the bulk of the sulfur loss at this source, this aspect is deserving of attention.
There is considerable speculation concerning the merits of indirect evaporation in controlling odor emission. The issue is by no means resolved and at least one major manufacturer is piloting a unique air-to-air heat exchanger for this purpose. Without exception the merits of indirect eraporation are based on the premise that odor emission from a furnace is, or can be, relatively nonexistent. This, to our knowledge, has not een demonstrated by subjective odor tests nor have sulfur losses from the furnace per se been adequately documented using the more refined analytical techniques now available, such as chromatography. The actual role of the recovery furnace in sulfur and odor emissions under normal load should be established in order that indirect evaporation can be properly evaluated as a pollution control device. 3. Absorption and oxidation of odor compounds
Berond the conversion of some sulfur compounds to more stable forms or major process changes, such as elimination of contact evaporation, the ultimate control of odor rests almost entirely on oxidation of malodorous compound to ones of lower odor threshold or preferably having no unpleasant odor. A multitude of odor sources exist which may ultimately require treatment. These include those listed below:
(1) Recovery furnace stacks of kraft and semi-chemical pulp mills.
(7) Lime kiln stack. This is a wide array of point-source emissions, varying both in intensity and volume. All, however, are presently under scrutiny to varying degrees by regulatory agencies, and five mills are now required to report loads from two or more of these sources on a routine basis.
(a) Chemical absorption and oridation The present status of knowledge and work in progress in the area of chemical oxidation or absorption with particular reference to chlorine and caustic was described earlier in the report. Their limited effectiveness suggests the need for further evaluation of other oxidants such as iron, ozone, and permanganate as well as oxidation catalysts such as oxides of nitrogen.
The need for development of a highly effective oxidant is increasing as the older decentralized kraft mills initiate pollution abatement at widely dispersed points. This need is not, however, confined to older mills, since it is impossible to devise a highly refined control scheme, short of thermal oxidation in the furnance or auxiliary equipment, which does not encompass chemical oxidation.
(6) Thermal oxidation Thermal oxidation in theory is the most positive means of reducing the threshold odor level of sulfur compounds as well as many other organics to a minimum. Cursory laboratory observations and sulfur measurements on lime kiln exhausts where non-condensables are being burned confirm this theory. Its use as an odor control measure on recovery stack gas may seem premature. Its effectiveness cannot be overlooked, however, and subjects such as minimum temperature requirements for oxidation of odorous compounds as well as compilation and evaluation of heat recovery schemes should be a portion of the research program. 4. Summarized odor research needs
Three areas of study have been set forth as probably being the most productive in getting at solutions to the odor problem. These include: (1) definition of full capability and limitations of black liquor oxidation; (2) evaluation of the effects of major process changes, such as elimination of the stack evaporator; and (3) evaluation of chemical and thermal oxidants. While these cover a wide spectrum, all are of major significance. 5. Particulate emission
Data tend to point to the fact that in most cases adequate means are available at present for gross particulate matter control from power boilers, as well as the bulk of the recovery operations. There exist localized situations where questions are arising concerning the role of particulate matter as nuclei in fog formation. The most significant lack of knowledge in particulate removal lies in the means to reduce discharge from stacks behind venturi recovery units to a level commensurate with that obtainable where precipitators are employed.
The question of relationship of particulate matter fallout and corrosion, particularly paint damage, arises on occasion. No controlled experimental data are available relating such factors as amount of salt cake, humidity, and time of exposure on corrosion rate of metal surfaces or paint. Constructive work could therefore be done in this area. 6. Control of 50, emissions
Finally, the increased attention being given to sulfur dioxide emissions and the sulfur content of fossil fuels suggests that we analyze our position in this matter. We are conscious of the implications, and future developments may require more emphasis on researching means of controlling sulfur dioxide.
INDEX OF NATIONAL COUNCIL FOR STREAM IMPROVEMENT RELEASES
ATMOSPHERIC POLLUTION TECHNICAL BULLETINS
Number 1. Sampling and Analysis of Air-Borne gas
eous Effluents Resulting From Sulfate Pulping--- September 24, 1957. Number 2. Present Treatment Practice of Air-Borne
Efluents in the United States Kraft Industry- November 20, 1957.
March 24, 1958.
March 31, 1938.
September 29, 19.58.
Sulfide, Sulfur Dioxide, Jercaptans and Alkyl
April 13, 1939.
Number 7. Studies on the Analysis of Kraft Mill
April 17, 1959.
May 13, 1959. Number 9. Progress Report on Studies on the Analyses of Pulp Mill Gases.
July 28, 1959.
September 31, 1939.
December 18, 1939.
April 6, 1960.
September 26, 1960.
October 20, 1960.
August 22, 1962.
October 24, 1962.
December 19, 1962. Number 18. The Chlorine Oxidation of Sulfur Compounds in Dilute Aqueous Solution---
June 14, 1963. Vinber 19. Manual for Sizing and Counting Particles from Kraft Recovery Furnaces..
July 1, 1963.
volume Air Samplers in the Measurement of Sus-
February 10, 1964.
April 30, 1961.
March 17, 1967.
Reducing Air Pollution from Sulfate Pulping and
March 18, 1965.
May 28, 1965.
August 6, 1965.
October 14, 1963.
ture Research Needs in Atmospheric Pollution Con-
June 9, 1966,
LISTING OF PHS RESEARCH PROJECTS RELATED TO KRAFT INDUSTRY
ATMOSPHERIC EMISSION PROBLEMS 1. AP 00215-03 EP. Donald F. Adams, Washington State University, Pullman,
Wash. "Kraft Odor Detection and Objectionability Thresholds,” 6-1-63 to J-31-66 $65,562 (3) terminated FY 1966.
2. AP 00023-02 ESE. Donald F. Adams, Washington State University, Pullman,
Wash. “Gas Chromatography Applied to Atmospheric Kraft Odors,” 5-1-63
to 430-66 $32,228 (3) terminated FY 1966. 3. AP 00291-03 ESE. Francis E. Murrary, British Columbia Research Council,
Vancouver, B.C. "A Study of Reactions of Sulfurous Air Pollutants," 12-1
63 to 1-30-66 $62,310 (3). 4. AP 00301-03 ESE. Jerome F. Thomas, University of California, Berkeles,
Calif. "Malodorous Products of Kraft Black luor Combustion," 9-1-63
to 8-31-60 $80,712 (3). 5. AP 00363–02 ESE. Kyosti V. Sarkanen, University of Washington, Seattle,
Wash. “Factors Influencing the Formation of Kraft Mill Odors," 10-1-64
to 9-30–67 $65.600 (3). 6. AP 00383-02 ESE. Irwin B. Douglass. University of Maine, Orono, Maine.
"Chemical Factors Related to Kraft Odor Control," 10-1-61 to 9-30-67
Oreg. “Particulate Emissions from Wood Waste Combustion," 12–1-65 to
No other industry is specially designated in this group of projects.
(2) Total funds budgeted for these seven projects are $121.605, or an average of $20,000 per project-year.
(3) This listing includes only those projects which are directly identified with kraft industry problems. It is probably not complete since it includes only those projects either active or terminated in fiscal year 1966. At a minimum, therefore, PHS-sponsored research on kraft industry problem has been budgeted at $140,000 annually for the last 3 year:
PAPERBOARD INDUSTRIES), INC., BALTIMORE, MD.
ATMOSPHERIC EMISSIONS FROM SULFATE PULPING, APRIL 23–28, 1966,
The Conference, which was co-sponsored by the Public Health Service, National Council for Stream Improvement and the University of Florida had as its purpose (1) the summarizing of current knowledge regarding the sources, effects, and control of kraft pulp mill atmospheric emissions, and (2) the identification of current research needs. The Conference was attended by 47 invited participants grouped as follows: Educational and research institutions_
9 Public Health ServiceNational Council for Stream Improvement
5 Kraft industry (United States).
11 Equipment suppliers----
3 State and local control agencies,
4 Foreign participants..
Total-----The participants are identified on the attached attendance list and program of formal papers.
A Summary Committee, consisting of members of the three sponsoring groups, and including Austin Heller (Public Health Service), Charles Spaulding (University of Florida), and Isaiah Gellman (National Council for Stream Improvement), the latter serving as chairman, met during the latter portion of the Conference to prepare a summary of the proceedings and a statement containing research needs which had been identified during the formal presentations and related discussion. The Summary Committee report was presented by Isaiah Cellman and served as a basis for the final discussions. The following is the Summary Report, and the Outline of Identitied Research Needs, as amended based on the final discussions. The Summary Report was generally contined to the prepared papers due to the difficulty of summarizing the extensive discussion. The latter will howerer be edited and included in the published conference proceedings which are scheduled to be released during the Fall of 1966.