Newspaper printing: case study

Purpose

To provide the newspaper printing industry with guidance on how to report to the National Pollutant Release Inventory (NPRI).

Scenario

AB Printers operates a newspaper printing facility in Hamilton, ON. The facility has 45 full-time employees. The facility may be subject to NPRI reporting criteria for the current reporting year. Therefore, the facility is required to estimate emissions from its operation to determine whether thresholds and reporting criteria were met. There is no monitoring equipment at this facility and no stack test has been performed. The first step is to identify the criteria for NPRI reporting.

The primary operation of the facility is the printing of newspapers. Besides the printing process, there are two small natural gas boilers used for facility heating and a diesel-powered generator is used during emergencies.

Step 1 - Employee Criteria

The total number of hours worked by employees at the facility exceeded the 20 000-hour employee threshold. The facility contains air emission sources in the form of boilers, a diesel generator, and printing operation. Therefore, the facility must estimate air releases from its sources to determine if it met or exceeded the NPRI thresholds.

Step 2 - Identify the emission sources at the facility

After reviewing the Guide for Reporting to the National Pollutant Release Inventory a survey of the facility's emission sources was performed. Based on the survey, the following sources were identified:

Source 1: Camera plate department

Source 2: Press room

Source 3: Printing room

Source 4: Boilers for heating

Source 5: Emergency generator

Step 3 - Calculate emissions for each source

Emission source 1: Camera plate department
Air emissions from this source are vented entirely through a stack. The camera plate department operates 89 hours per week and 50 weeks per year. The materials used and their properties are given below:

Table 1: Properties of Material Used in Camera Plate Department
Materials used* Density* (kg/litre) VOC content* (by weight) Weekly usage (litres)
Developer 0.97 100% 120
Powder fixer 0.9 0% 280
Aqueous Developer 1.05 100% 55

* obtained from the MSDS supplied by the manufacturer

Step 3a - Identify the method(s) of estimating emissions

Since there is no monitoring equipment at this facility, no stack test has been performed, and no emission factors are available for this type of operation, the appropriate estimation method is mass balance.

Step 3b - Identify the VOC in the material

To apply the mass balance approach, the VOC content in the materials used in the process must be determined. In many instances, the MSDS for the particular material will indicate the percent by weight content of the predominant VOCs. You will also need the annual consumption of the solutions used. Consumption data may be obtained from the facility's operation log or purchase order slips.

Step 3c - Calculate VOC emissions

The general equation for calculating VOC emission is:

ME = Q x D x c

Where:
ME = Total uncontrolled VOC emission, kg
Q = Total annual consumption of material, litres
D = Density of material, kg/litre
c = VOC content by weight in the material,%

VOC emission from Developer:
ME = Weekly developer consumption x weeks used per year x density x VOC%
= 120 litres/week x 50 weeks/year x 0.97 kg/litre x 100/100 VOC
= 5 820 kg
= 5.820 tonnes

VOC emission from Powder Fixer:
ME = Powder Fixer contains 0% VOC

VOC emission from Aqueous Developer:
ME = 55 litres/week x 50 weeks/year x 1.05 kg/litre x 100/100 VOC
= 2 887.5 kg
= 2.888 tonnes

Table 2: VOC Emissions of Materials Used Camera Plate Department
Materials used VOC Emissions tonnes
Developer 5.820
Powder fixer 0
Aqueous Developer 2.888
TOTAL 8.708

 

Emission source 2: Press room
Air emissions from the press room are vented through a stack. The presses operate for 140 hours/week and 50 weeks/year. The materials used and their properties are given below:

Table 3: Properties of Materials Used in Press Room
Materials used* Density* (kg/litre) VOC content* (by weight) Weekly usage (litres)
News rub 1.0 22% 20
WD-40 0.87 20% 110
Varsol 0.7 80% 230
Varn swell 0.128 50% 25
Plate cleaner 0.28 100% 200
Silicone lube 0.074 100% 150
Solvent 0.78 100% 85

* obtained from the MSDS supplied by the manufacturer.

Example
Use the general equation to calculate VOC emissions:

ME = Q x D x c

VOC emissions from the use of varsol:
ME = 230 litres/week x 50 weeks/year x 0.7 kg/litre x 80 / 100 VOC
= 6 440 kg
= 6.44 tonnes

calculate the VOC emission for each of the seven materials used in the press room using the example calculations shown above. The following table provides VOC emissions for each of the materials used:

Table 4: VOC Emissions for Materials Used in the Press Room
Materials used VOC emissions
(tonnes)
News rub 0.22
WD-40 0.96
Varsol 6.44
Varn swell 0.08
Plate cleaner 2.8
Silicone lube 0.56
Washer Solvent 3.32
TOTAL 14.38

Emission source 3: Printing room
Air emissions from this source are vented through a general exhaust to a dedicated stack. The printing room operates 40 hours/week and 50 weeks/year. The materials used and their properties are given below:

Table 5: Properties of Materials Used in Printing Room
Materials used* Density* (kg/litre) VOC content* (by weight) Weekly usage (litres)
Plus AZ 0.091 0% 45
Rejuvenator 0.45 0% 0.5
Cleaner 0.77 0% 0.5
Adhesive 0.55 0% 0.25

* obtained from the MSDS supplied by the manufacturer

The activities in the printing room do not result in VOC emissions since there are no VOCs identified in the materials used.

Emission source 4: Heating
There are two natural gas-fired boilers used for heating and are served by a common stack. The heat output of each boiler is 4 million BTU/hr. Though the boilers are less than 10 million BTU/hr cumulative nameplate capacity, they are not exempt since there are other sources in the facility that release Criteria Air Contaminants (Part 4 Substances). Therefore, the facility must estimate emissions from the boilers.

Step 3d - Calculate boiler emissions

Since the facility does not have monitoring equipment installed and there is no stack testing performed, the appropriate method of calculating CAC emissions is to use emission factors. Determine if there are any manufacturer-supplied boiler specific emission factors for each fuel. If none are available, the emission factors published by the U.S. EPA, in the AP-42 document (see note below) or the latest version of the WebFIRE database (see note below) may be used. calculate emissions for the type of fuel (natural gas) used in the boiler using the source materials identified below:

  • AP-42: compilation of Air Pollutant Emission Factors, AP-42, Fifth Edition, Volume I: Stationary Point and Area Sources;
  • WebFIRE is a database and accessing software containing the U.S. EPA's recommended emission estimation factors for criteria and hazardous air contaminants..

Natural Gas:
Annual consumption: 1.2 x 106 cubic meters (1.2 million cubic meters)

The following table provides the emission factors (from Section 1.4 of AP-42 or WebFIRE database) for natural gas combustion:

Table 6: Uncontrolled Emission Factors for the Release of Part 4 Substances from Boiler < 100million BTU/hr SCC: 10100602
Part 4 Substance Emission factor (kg/106 cubic metres of natural gas)
TPM 30.4
PM10 30.4
PM2.5 30.4
VOC 88
NOx 1600
SO2 9.6
CO 1344

Since particulate matter emissions from natural gas combustion are less than 1.0 micron in size, the same emission factor is used for all three particulate fractions (TPM contains both PM10 and PM2.5 fractions).
Emission Factor (EF) for SCC: 10100602 Boiler < 100 million BTU/hr
EF is converted from lb/million cubic feet to kg/million cubic meters using a conversion factor of 16. Check this following Web site for details.

The general equation for estimating uncontrolled emissions from the combustion of natural gas in boilers is:

Emission = Fuel consumption (million cubic metres) x EF (kg/million cubic metres)

Example calculation
VOC emissions = 1.2 x 106 cubic metres x 88 kg/million cubic metres
= 105.6 kg
= 0.106 tonnes

Use the same method to calculate other CAC emissions using the emission factors.

The following table shows uncontrolled emissions from the boilers as a result of natural gas combustion:

Table 7: Uncontrolled Annual Part 4 Releases from the Combustion of Natural Gas
Part 4 Substance Uncontrolled Emissions from natural gas combustion (tonnes)
TPM 0.036
PM10 0.036
PM2.5 0.036
VOC 0.106
NOx 1.920
SO2 0.012
CO 1.613

Emission source 5: Emergency generator
There is a diesel-fired generator for emergency situations. It is operated only when required. The emissions are exhausted through a stack. The maximum unit rating is 200 kW. The generator was operated approximately 24 hours during the reporting year.

Step 3e - Calculate diesel generator emissions

Determine if there are any manufacturer-supplied, source-specific emission factors. If none are available, the appropriate emission factors are published by the U.S. EPA, in the AP-42 document.

The following table provides the emission factors (from Section 3.3 of AP-42, Table 3.3-1) for diesel fuel:

Table 8: Uncontrolled Emission Factors from the Combustion of Diesel Fuel SCC: 20200102
NPRI substance Emission Factor (power output kg/kW-hr)
TPM 0.00134
PM10 0.00134
PM2.5 0.00134
VOC 0.0015
NOx 0.0188
SO2 0.00125
CO 0.00406

Since Particulate Matter emissions from diesel fuel internal combustion are less than 1.0 micron in size, the same emission factor is used for all the three particulate fractions (TPM contains both PM10 and PM2.5 fractions).
Emission Factor (EF) for SCC: 20200102 and 20300101
EFs are converted from lb/hp-hr to kg/kW-hr using a conversion factor of 0.608. Check the AP-42 (Section 3.3) Web site for details.

The general equation for estimating uncontrolled emissions from diesel fuel combustion is:

Emission = Power output (kW) x EF (kg/kW-hr) x hours/year

Example calculation
NOx emission = 200 kW x 0.0188 kg/kW-hr x 24 hours/year
= 90.2 kg
= 0.090 tonnes

Use the same method to calculate other CAC emissions using the emission factors. The following table shows uncontrolled emissions from the diesel-fired generator:

Table 9: Uncontrolled Emission for Diesel Fuel Combustion
NPRI substance Emissions (tonnes)
TPM 0.006
PM10 0.006
PM2.5 0.006
VOC 0.007
NOx 0.090
SO2 0.006
CO 0.019

Step 4 - Add emissions from all sources

The next step is to add the emissions from each source and calculate the total emission from the facility in order to determine if NPRI thresholds were met.

Table 10: Total facility emissions
NPRI substance Annual camera plate Emissions (tonnes) Annual press room emissions (tonnes) Annual printing room emissions (tonnes) Annual generator emissions (tonnes) Annual boiler emissions (tonnes) Total facility emissions (tonnes)
TPM 0   0 0.006 0.036 0.042
PM10 0   0 0.006 0.036 0.042
PM2.5 0   0 0.006 0.036 0.042
VOC 8.70 14.38 0 0.007 0.106 23.193
NOx 0   0 0.09 1.920 2.01
SO2 0   0 0.006 0.012 0.018
CO 0   0 0.019 1.613 1.632
Table 11: NPRI reporting determination
NPRI substance Total facility emission (tonnes) NPRI threshold (tonnes) NPRI threshold exceeded (?) Rationale
TPM 0.042 20 No Facility emission is less than NPRI threshold
PM10 0.042 0.5 No Facility emission is less than NPRI threshold
PM2.5 0.042 0.3 No Facility emission is less than NPRI threshold
VOC 23.193 10 Yes Facility emission is greater than NPRI threshold
NOx 2.01 20 No Facility emission is less than NPRI threshold
SO2 0.018 20 No Facility emission is less than NPRI threshold
CO 1.632 20 No Facility emission is less than NPRI threshold

Conclusion:
Since the estimated VOC emissions from the facility exceeds the reporting threshold, AB Printers must submit an NPRI report for VOC. Reporting is not required for the other CACs since they did not meet the reporting thresholds.

Step 5

Reporting information for Part 5 Substances
If the facility has sources that emit VOCs, additional information may require to be reported for VOC species (Part 5 substances). Note that the speciated VOC reporting is needed only for facilities exceeding the total VOC (Part 4 substance) 10-tonne threshold. Once the total VOC criteria is met, speciated VOC reporting is required for each speciated VOC emitted facility-wide in a quantity equal to or greater than 1 tonne. VOC species (Part 5 substance), CAS number, and emission quantities from all sources must be reported in these cases.

Emission Source 1: Camera Plate Department Operation
A review of the Material Safety Data Sheet of the materials used (e.g. developer) in this department indicate that there are no Part 5 substances.

Emission Source 2: Press Room
Using the total VOC emission from Press Room operation, calculate the emission for VOC substance contained in the total VOC stream. Using the Material Safety Data Sheet of the materials used (e.g.WD-40) calculate the individual VOC species emission using the weight percent of each substance.

Example Calculation

Material: WD-40
VOC substance contained- Methyl Ethyl Ketone (MEK)
Emission of MEK = 110 litres/week x 50 weeks/year x 0.87 kg/litres x 10/100
= 478.5 kg
= 0.479 tonnes

The following table provides details of the ingredients contained in the materials used along with their CAS number, weight percent, and emissions. An analysis of the Material Safety Data Sheet of the material News rub indicates that there are no Part 5 substances.

Material: WD-40
  CAS Wt.% Substance Emission
Methyl Ethyl Ketone 78-93-3 10 0.479
Material: Varsol
  CAS Wt.% Substance Emission
Methyl Ethyl Ketone 78-93-3 40 3.22
Xylene 1330-20-7 40 3.22
Material: Varn swell
  CAS Wt.% Substance Emission
Methyl Ethyl Ketone 78-93-3 25 0.04
Xylene 1330-20-7 25 0.04
Material: Plate cleaner
  CAS Wt.% Substances
Methyl Ethyl Ketone 78-93-3 50 1.4
Material: Silicone Lube
  CAS Wt.% Substances
Methyl Ethyl Ketone 78-93-3 50 0.28
Material: Washer Solvent
  CAS Wt.% Substances
Methyl Ethyl Ketone 78-93-3 50 1.66

Emission Source 3: Printing Room
The activities in the printing room do not result in VOC emissions since there is no VOC identified in the materials used. Hence VOC speciation is not required for this source.

The VOC emissions from the natural gas boiler and the diesel generator will also have to be calculated. These emissions will then be added to the VOC emissions from each source and any individual VOC species emitted at a quantity greater than one tonne will have to be reported.

Step 6 - Reporting information for stacks with a height >= 50 metres above grade

If the facility has a stack with a height greater than or equal to 50 metres above grade, and that stack emits CACs above the stack thresholds, additional reporting may be required.

This facility does not have any stacks that are equal to or greater than 50 metres above grade, and as such stack reporting is not required.

Step 7 - Calculate the monthly breakdown of annual releases to air by percentage

Detailed emissions estimates show that the facility is required to report to the NPRI. Additional reporting, including the monthly breakdown of emission by percentage for each pollutant, is needed.

Example Calculation
Material usage for each source per month is obtained from records kept at the facility. Emission can be calculated for each month and then added to get the annual total. Using this annual total, calculate the monthly emission percentage using the following equation:

January emission percentage = (January emission / Annual emissions) x 100

For example, add the VOC emission from each source for the month of January. If the January emission of VOCs from the sources was 2.33 tonnes, the January percentage of VOC emission was:

2.33 tonnes / 23.193 tonnes x 100 = 10.05%

Step 8 - Reasons for Change in Quantities Released from Previous Year

In the "Reasons for Changes in Quantities Released from Previous Year" section in the "Releases" tab you are required to select all applicable reasons for changes in substance releases from the previous reporting year (check the applicable boxes).

Step 9 - Anticipated Releases to Air

Users are required to estimate anticipated releases for each substance released to the air from the facility for the three upcoming years. Reporting anticipated releases for two following years are optional. Enter the information for each substance in the "Anticipated Releases (tonnes)" section in the "Releases" tab.

Step 10 - Pollution Prevention (P2) Activities

If the facility has employed P2 activities, it should be noted in the "Pollution Prevention" tab (check the applicable boxes).

References

US EPA AP-42: compilation of Air Pollution Emission Factors, AP-42, Fifth Edition, Volume 1: Stationary Point Area Sources, 2004

US EPA WebFIRE version December 2005

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