Technical Support Document for the Titanium Dioxide Production Sector: Proposed Rule for Mandatory Reporting of Greenhouse Gases


Technical Support Document for the Titanium
Dioxide Production Sector: Proposed Rule for
Mandatory Reporting of Greenhouse Gases

Office of Air and Radiation
U.S. Environmental Protection Agency

January 22, 2009

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

CONTENTS

1.	Industry Description	1

2.	Total Emissions	2

2.1	Process Emissions	2

2.2	Stationary Combustion	2

3.	Review of Existing Programs and Methodologies	3

3.1	2006 IPCC Guidelines	3

3.2	2008 U.S. Inventory of Greenhouse Gas Emissions and Sinks	3

3.3	Australian National Greenhouse and Energy Reporting System	4

3.4	Government of Canada's Greenhouse Gas Reporting Program	4

4.	Options Considered for Reporting Threshold	5

4.1	Emissions Thresholds	5

4.2	Capacity Thresholds	6

4.3	No Emissions Threshold	7

5.	Options for Monitoring Methods	7

5.1	Option 1: Simplified Emissions Calculation	7

5.2	Option 2: Calcined Petroleum Coke (CPC) Consumed Approach (Annual
Reporting)	8

5.3	Option 3: Direct Measurement	9

6.	Procedures for Estimating Missing Data	9

6.1	Procedures for Option 1: Simplified Emissions Calculation	9

6.2	Procedures for Option 2: CPC Consumed Approach	9

6.3	Procedures for Option 3: Direct Measurement	10

7.	QA/QC Requirements	10

7.1	Stationary Emissions	10

7.2	Process Emissions	10

7.3	Data Management	11

8.	Types of Emission Information to be Reported	11

8.1	Other Information to be Reported	12

8.2	Additional Data to be Retained Onsite	12

9.	References	13

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

1. Industry Description

Titanium Dioxide (Ti02) is a metal oxide commonly used as a white pigment in paint
manufacturing, paper, plastics, rubber, ceramics, fabrics, floor covering, printing ink, and other
applications (IPCC 2006). The majority of titanium dioxide production is for the manufacturing
of white paint. National production of titanium dioxide in 2006 was approximately
1,400,000 metric tons (mt) (USGS 2006).

Titanium dioxide is produced through two processes: the chloride process and the sulfate
process. The chloride process emits process-related carbon dioxide (CO2) through the use of
petroleum coke and chlorine as raw materials, while the sulfate process does not emit any
process-related greenhouse gases (U.S. EPA 2008b, IPCC 2006). The sulfate process does not
use petroleum coke or other forms of C as a raw material and does not emit CO2 (U.S. EPA
2008b). Hence, the sulfate process may result in combustion-related emissions as calcining is
done late in the sulfate process (IPCC 2006. During the chloride process, petroleum coke is
oxidized as the reducing agent in the first reaction in the presence of chlorine and crystallized
iron titanium oxide (FeTi03)to form CO2. A special grade of petroleum coke (known as
calcined petroleum coke, CPC) is used for this chloride process (U.S. EPA 2008b). The chloride
process is based on the following chemical reactions:

2 FeTi03 + 7 Cl2 + 3 C -> 2 TiCl4 + 2 FeCl3 + 3 C02

2 TiCl4 + 2 02 -> 2 Ti02 + 4 Cl2

The titanium tetrachloride (TiCU) produced in the first reaction is oxidized at about 1,000°C, and
the resulting TiC>2 is calcinated to remove residual chlorine and any hydrochloric acid that may
have formed in the reaction (USGS 2006).

Total U.S. production of titanium dioxide pigment through the chloride process was
approximately 1.4 million metric tons in 2006, a 7 percent increase compared to 2005 (USGS
2006). As of 2004, the last remaining sulfate-process plant in the United States had closed. As a
result, all U.S. current titanium dioxide pigment production results from the chloride process
(USGS 2005). Four companies produce of titanium dioxide pigment in the U.S.: DuPont,
Louisiana Pigment Co. L.P., Millennium Inorganic Chemicals Inc., and Tronox Inc. These
companies operate a total of eight facilities. Their titanium dioxide capacity data is presented in
Table 1.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

Table 1. U.S. Producers of Titanium Dioxide Pigment (metric tons/year)

Company

Plant Location

Year End Capacity
(metric tons)a,b

Du Pont Titanium Technologies, De Lisle Plant

De Lisle, MS

340,000

Du Pont Titanium Technologies, Edge Moor Plant

Edge Moor, DE

154,000

Du Pont Titanium Technologies, New Johnsonville Plant

New Johnsonville, TN

380,000

Louisiana Pigment Co. L.P. (a joint venture of NL Industries,
Inc. and Huntsman Corp.)

Lake Charles, LA

146,000

Millennium Inorganic Chemicals Inc., Ashtabula Plant 1 and II

Ashtabula, OH

220,000

Millennium Inorganic Chemicals Inc., Hawkins Point Plant

Baltimore, MD

50,000

Tronox Inc.

Hamilton, MS

225,000

Tronox Inc. (formerly Kerr-McGee)

Savannah, GA

110,000

Total

1,625,000

Note: Estimated operating capacity based on 7-day-per-week full production. Table does not include TOR Minerals
International Inc.'s Corpus Christi, TX, production capacity of about 26,400 mt per year of buff that is produced by
refining and fine grinding of synthetic rutile. [note that there is an emission factor for synthetic rutile in Table 2.]
a Data are rounded to no more than three significant digits; may not add to totals shown.
b All plants use the chloride process to manufacture TiC>2 pigment.

Source: USGS 2006.

2. Total Emissions

Total CO2 emissions from titanium dioxide production were approximately -3.6 MMTCC^e
(3,628,054 metric tons CO2Q) in 2006 (U.S. EPA 2008b). These emissions were closely divided
between process emissions of 1.87 MMTCC^e and combustion emissions of 1.8 MMTCC^e.
Emissions have increased 57 percent since 1990, and 7 percent since 2005 (U.S. EPA 2008b).
Emissions from on-site CO2 combustion are not currently accounted for separately in the U.S.
Inventory. However, the processing of titanium dioxide requires boilers, dryers, and other
equipment that use natural gas, and hence, results in emissions from combustion.

2.1 Process Emissions

Titanium dioxide is produced through two processes: the chloride process and the sulfate
process. The sulfate process does not produce any significant process-related greenhouse gas
emissions (IPCC 2006) although the sulfate process may produce emissions from stationary
combustion. The chloride process emits process-related carbon dioxide (CO2) through the use of
CPC and chlorine as raw materials (U.S. EPA 2008b).

2.2 Stationary Combustion

Stationary combustion emissions occur when fossil fuels are combusted to provide energy for
manufacturing equipment, as well as to provide heat for the manufacturing process. This heat is
used in the previously discussed chloride process to produce titanium dioxide. These combustion
emissions of greenhouse gases are limited to the natural gas fuel inputs used to fire boilers, spray
dryers, oxygen preheaters, TiCU vaporizer trains and other necessary equipment of the
production process.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

3. Review of Existing Programs and Methodologies

Protocols and guidance reviewed for this analysis include the 2006IPCC Guidelines, the DOE
1605(b) Reporting Program, the U.S. Greenhouse Gas Inventory system, the Australian
Government's National Mandatory Greenhouse and Energy Reporting System, and the
Government of Canada's Greenhouse Gas Reporting Program. Several of these methodologies
consider one of two approaches, based on measuring either the input or output of the production
process. The output method involves multiplying production data by emission factors. The input
method involves measuring the consumption and the carbon content of the reducing agent. The
IPCC, Australian Government's National Mandatory Greenhouse and Energy Reporting System,
the Government of Canada's Greenhouse Gas Reporting program, and U.S. Inventory guidelines
are discussed in more detail below. The DOE 1605(b) program did not list a protocol for
titanium dioxide production and therefore is not discussed below.

3.1 2006 IPCC Guidelines

The IPCC considers two different methods for calculating process-related emissions from
titanium dioxide production (IPCC 2006). The Tier 1 method uses a default emission factor per
unit of output multiplied by production activity data. The Tier 2 method calculates process
emissions through facility-level data collection. The emissions can be calculated from the
consumption of the calcined petroleum coke as well as the carbon content and oxidation factor of
the calcined petroleum coke.

The IPCC Tier 1 method was used to determine process-related CO2 emissions from the facilities
presented in Table 1, because production capacity was the only facility-level data available (see
note on Table 1). IPCC guidance supports the use of default emission factors when plant-level
information on calcined petroleum coke use is not available (IPCC 2006). These factors are
presented in Table 2.

Table 2. Default Emission Factors for Titanium Dioxide Production

Product

Emission Factor (mtC02perton product)

Titanium slag a

Not available

Synthetic rutile

1.43

Rutile titanium dioxide (chloride route)

1.34

a A default emission factor is not available because there are only two plants using this production method and they
are outside of the US in Richards Bay (South Africa) and Allard Lake (Canada), and plant data are confidential.

Source: 2006 IPCC Guidelines for National Greenhouse Gas Inventories

3.2 2008 U.S. Inventory of Greenhouse Gas Emissions and Sinks

The U.S. Greenhouse Gas Inventory system requires reporting of CO2 emissions from titanium
dioxide production. This program is not a industry reporting program but instead utilizes the
national titanium dioxide production data and percent of industry using the chloride process
(100%) (USGS 2006).

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

3.3 Australian National Greenhouse and Energy Reporting System

The Australian Government's National Greenhouse and Energy Reporting System (NGER 2007)
requires reporting of CO2 emissions from titanium dioxide production. Registration and reporting
under this system is required for corporations if: they control facilities that emit at least 25,000
metric tons C02e, or produce or consume at least 100 terajoules of energy; or their corporate
group emits at least 125,000 metric tons C02e, or it produces or consumes at least 500 terajoules
of energy (Australian DCC 2007). The method used for estimating emissions is based on the
National Greenhouse Account (NGA) default method, which uses the following equation:

E = AxECxEF/ 1000

Where:

E	= CO2 emissions from the production of titanium dioxide (MTCC^e)

A	= carbon reducing agent usage (metric tons)

EC	= energy content of the reducing agent (gigajoules/mt)

EF	= emission factor for the reducing agent (including effects of oxidation) (kg/

gigajoule)

Facilities may use the default emission factors (presented in Table 3), but the higher-order
method would be to develop facility-specific emission factors from the carbon content of the
reducing agent.

Table 3. Australian National Greenhouse Account Default Emission Factors

Reducing Agent Used

Energy Content (gross) GJ/t

Emission Factor kg C02e/GJ (all gases)

Lignite-Brown coal

10.2

93.2

Coking coal (metallurgical coal)

30.0

90.2

Black coal

27.0

88.5

Brown coal briquettes

22.1

93.6

Coke oven gas

27.0

117.4

Coal tar

37.5

81.3

Source: Australia National Greenhouse and Energy Reporting System 2007

(http://www.areenhouse.aov.au/reportina/publications/pubs/naer-techauidelines.pdfi

3.4 Government of Canada's Greenhouse Gas Reporting Program

The Government of Canada's Greenhouse Gas Reporting Program (EC 2006) uses the same
approach to the 2006 IPCC guidelines. Rather than offering specific guidance, the program
references the 2006 IPCC guidelines.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

4. Options Considered for Reporting Threshold
4.1 Emissions Thresholds

For the reporting of process CO2 emissions from titanium dioxide production, threshold options
considered included emissions-based thresholds of 100,000, 25,000, 10,000, and 1,000 metric
tons CC>2e for both combustion and process emissions. The results of the threshold analysis are
summarized in Table 4.

A summary of the emissions and facilities covered per option is presented in Table 4. Emission
estimates were calculated based on the 2006 CO2 Emissions from Titanium Dioxide provided by
the Inventory of U.S. Greenhouse Gas Emissions and Sinks 1990-2006 (EPA 2008b) and
individual plant capacity data (USGS 2006). At the threshold levels of 1,000, 10,000, and 25,000
metric tons, all facilities exceed the threshold, therefore covering 100 percent of total emissions.
However, at the 100,000 metric ton level, one facility would not exceed the threshold - the
Baltimore, Maryland plant of Millennium Inorganic Chemicals Inc., which produces an
estimated 57,723 metric tons C02e emissions per year. At the 100,000 metric ton threshold level,
98 percent of emissions would be covered.

Table 4. Emissions Threshold Analysis for Titanium Dioxide

Threshold
Level
(metric
tons
C02e/yr)

Process
Emissions
(metric
tons
C02e/yr)

Combustion

C02
Emissions
(metric tons
C02e/yr)

Total
National
Emissions

(metric
tons C02e)

Number

of
Entities

Emissions Covered

Entities Covered

Metric
tons
C02e/yr

Percent

Number

Percent

100,000

1,876,000

1,809,777

3,685,777

3,628,054

98%

88%

25,000

1,876,000

1,809,777

3,685,777

100%

10,000

1,876,000

1,809,777

3,685,777

100%

1,000

1,876,000

1,809,777

3,685,777

100%

In order to determine stationary combustion CO2 emissions from combustion related to the
titanium dioxide process, background research was conducted on several of the facilities. GHG
emissions from on-site fossil fuel combustion were estimated using data collected through Title
V permitting for two representative facilities, Tronox (Savannah, GA) and Millennium Inorganic
Chemicals, Inc. (Ashtabula, OH) with high capacity (225,000 mt/year) and medium capacity
(154,000 mt/year), respectively. The Tronox facility reported 17 small natural gas devices with
the following ratings: 10 MMBtu/hour (4 devices), 5 MMBtu/hour (11 devices), 1 MMBtu/hour
(2 devices) as well as two large natural gas boilers of 181 MMBtu/hour and 128 MMBtu/hour
ratings (Georgia DNR 2002). These devices were assumed to run 24 hours/day, 365 days/year at
90 percent of capacity, totaling 3,200,904 MMBtu/year and GHG emissions of 146,466
MTC02e.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

The Millennium facility reported two titanium dioxide facilities. The first plant operates natural
gas boilers of 69 MMBtu/hour rating and one natural gas boiler of 90 MMBtu/hour rating as well
as five spray dryers of 5.9, 7, 9.5, 24 and 37 MMBtu/hour ratings; a chlorination unit of 17.6
MMBtu/hour rating; an oxygen preheater of 14.6 MMBtu/hour rating; and TiCU Vaporizer Train
of 7 MMBtu/hour rating (Ohio EPA 2002). The second plant operates three natural-gas fired
combustion turbines of 65, 37, and 21 MMBtu/year, as well as a 55 MMBtu/hour heater, 16.8
MMBtu/hour TiCU Vaporizer, a 9.5 MMBtu/year oxygen preheater, a 2.2 MMBtu/hour oxygen
preheater and a 6 MMBtu/hour dryer (Ohio EPA 2004). The devices in these plants were
assumed to run 24 hours/day, 365 days/year at 90 percent of capacity, totaling 4,440,269
MMBtu/year and GHG emissions of 203,176 metric tons C02e.

The energy requirements of the Tronox Facility and Millennium Facility were weighted based on
their respective capacities. This factor was to determine an average energy requirement for a
titanium dioxide facility and applied to the remaining 6 facilities based on their capacity. The
average energy requirements are 7,641,173 MMBtu/year. The average emissions per unit of
capacity is 1.13 metric tons C02e per ton of capacity. The weighted energy requirements are
likely overestimates of actual requirements because: 1) no information is known concerning the
chlorine production process used by these facilities; 2) the facilities are assumed to operate at
near capacity; and 3) the Millennium Facility is also believed to operate a cogeneration unit. The
total estimated CO2 emissions from combustion totaled approximately 1,809,777 metric tons
C02e. This amount, combined with the total facility-level calculated emissions, produced a sum
of 3,685,777 metric tons C02e or total national emissions.

Emissions were estimated by multiplying the energy consumption (MMBtu/year) by the carbon
content of natural gas (14.47 Tg C/QBtu) provided by the Inventory of U.S. Greenhouse Gas
Emissions and Sinks 1990-2006 (EPA 2008b) as well as CH4 and N2O emission factors provided
by Table 2.3 of the 2006IPCC Guidelines for National Greenhouse Gas Inventories (IPCC
2006) (Table 6). These emissions were then multiplied by the national capacity utilization rate of
86 percent. The utilization rate was calculated using total titanium dioxide production for 2006
(1,400,000 metric tons), which was provided by the Inventory of U.S. Greenhouse Gas Emissions
and Sinks 1990-2006 (EPA 2008b), and total titanium dioxide capacity (1,625,000 metric tons),
which was provided by the USGS 2006 Minerals Yearbook: Titanium Dioxide Annual Report
(USGS 2006).

Table 5. Default Emission Factors for Stationary Combustion in Manufacturing Industries and

Construction

Fuel

CH4 Default Emission Factor
(kg/TJ)

N20 Default Emission Factor
(kg/TJ)

Natural Gas

0.1

Source: From Table 2.3 of 2006 IPCC Guidelines for National Greenhouse Gas Inventories.

4.2 Capacity Thresholds

Four capacity threshold levels were considered for the titanium dioxide production sector. These
thresholds were 300,000, 200,000, 100,000, and 50,000 metric tons of titanium dioxide produced
per year. The results of the capacity threshold analysis are shown in Table 6.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

For the capacity thresholds analysis for titanium dioxide production, EPA considered four
different capacities of titanium dioxide production. Capacity is the largest amount of titanium
dioxide that a facility can produce on an annual basis. The thresholds considered were 300,000,
200,000, 100,000, and 50,000 metric tons of titanium dioxide produced per year. A threshold of
50,000 metric tons captures all facilities in the inventory. A threshold of 100,000 metric tons
captures 97 percent of emissions, and 88 percent of the facilities. A threshold of 200,000 metric
tons captures 72 percent of emissions, 50 percent of the facilities. A threshold of 300,000 metric
tons captures 44 percent of emissions, 25 percent of the facilities. Note: capacities as provided
by USGS (2006) analysis were estimated based on 7-day-per-week full production. Facility-level
CO2 process emissions (based on capacity) were calculated by multiplying facility capacity by
the emission factor for rutile Ti02 (1.34) in order to determine estimated facility process
emissions. These results are presented in Table 6. At the 50,000 metric tons threshold level, 100
percent of emissions would be covered.

Table 6. Capacity Threshold Analysis for Titanium Dioxide

Capacity Threshold
Level (metric
tons/titanium
dioxide/yr)

Process
Emissions
(metric tons
C02e/yr)

Number

of
Entities

Emissions Covered

Entities Covered

Metric tons
TC02e/yr

Percent

Number

Percent

300,000

2,177,500

964,800

44%

25%

200,000

2,177,500

1,561,100

72%

50%

100,000

2,177,500

2,110,500

97%

88%

50,000

2,177,500

100%

4.3 No Emissions Threshold

The no emissions threshold includes all titanium dioxide production facilities regardless of their
emissions or capacity.

5. Options for Monitoring Methods

Two separate monitoring methods were considered for this technical support document. One
option uses a simplified emission calculation (Option 1) and the other option estimates CO2
emissions based on the facility-specific quantity of calcined petroleum coke consumed (Option
2). Both of these options require annual reporting. Continuous emissions monitoring systems
(CEMS) and/or stack testing were not recommended in the IPCC 2006 for this industry and are
thus not discussed further in this technical support document.

5.1 Option 1: Simplified Emissions Calculation

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

A simplified emissions calculation is based upon the IPCC Tier 1 methodology (IPCC 2006).
The Tier 1 method is an output-based approach. The Tier 1 equation is as follows:

ECo2 = AD x EF

Where:

Eco2 = Emissions of CO2 (metric tons)

AD = Production of rutile TiC>2 (metric tons)

EF = CO2 emissions per unit of production of rutile TiC>2 (metric ton CCVmetric ton of
product)

Because the chloride process is used exclusively in the U.S., this method relies upon the rutile
TiC>2 emission factor (i.e., 1.34) presented earlier in Table 2.

5.2 Option 2: Calcined Petroleum Coke (CPC) Consumed Approach (Annual
Reporting)

This approach is based upon the IPCC Tier 2 method, which is an input-based approach. There is
no need to calculate the carbon content of the CPC as it is known when purchased (consistently
greater than 98 percent carbon, [RTI 2008]). Also, the carbon oxidation factor for the CPC is
assumed to be 100 percent, as any amount that is not oxidized is insignificant. The following
equation is used to calculate emissions:

Ec02 = (44/12) x CCF x COF x AD x (2000/2205)

Where:

Eco2 = Emissions of CO2 (metric tons)

44/12 = Ratio of molecular weights, CO2 to carbon

AD = Quantity of CPC input (tons)

CCF = Carbon content factor of CPC (assumed to be 1)

COF = Carbon oxidation factor for CPC, (fraction, assumed to be 100/100)

2000/2205 = Conversion factor to convert tons to metric tons.

As IPCC states, "to achieve the highest accuracy, good practice is to apply [this equation] at the
plant-level with all data input obtained from plant operators" (IPCC 2006). Therefore, the
plant-level activity data for the consumption listed above should be provided through plant
records or other available data, rather than continuous emissions monitoring or other monitoring
methods.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

5.3 Option 3: Direct Measurement

For industrial source categories for which the process emissions and/or combustion GHG
emissions are contained within a stack or vent, direct measurement constitutes either
measurements of the GHG concentration in the stack gas and the flow rate of the stack gas using
a CEMS, or periodic measurement of the GHG concentration in the stack gas and the flow rate of
the stack gas using periodic stack testing. In the case of silicon carbide, process and combustion
GHG emissions are not emitted from the same stack. Process emissions from the product
furnaces are emitted from four separate stacks and combustion emissions from the product dryer
are emitted from a fifth stack.

Elements of a CEMS include a platform and sample probe within the stack to withdraw a sample
of the stack gas, an analyzer to measure the concentration of the GHG (e.g., CO2) in the stack
gas, and a flow meter within the stack to measure the flow rate of the stack gas. The emissions
are calculated from the concentration of GHGs in the stack gas and the flow rate of the stack gas.
A CEMS continuously withdraws and analyzes a sample of the stack gas and continuously
measures the GHG concentration and flow rate of the stack gas.

For direct measurement using stack testing, sampling equipment would be periodically brought
to the site and installed temporarily in the stack to withdraw a sample of the stack gas and
measure the flow rate of the stack gas. Similar to CEMS, for stack testing the emissions are
calculated from the concentration of GHGs in the stack gas and the flow rate of the stack gas.
The difference between stack testing and continuous monitoring is that the CEMS data provide a
continuous measurement of the emissions, while a stack test provides a periodic measurement of
the emissions. A method using periodic, short-term stack testing would be appropriate for those
facilities where process inputs (e.g., carbonaceous reducing agents such as petroleum coke) and
process operating parameters remain relatively consistent over time. In cases where there is the
potential for significant variations in the process input characteristics or operating conditions,
continuous measurements would be needed to accurately record changes in the actual GHG
emissions from the sources resulting from any process variations.

6. Procedures for Estimating Missing Data

Options and considerations for missing data vary will vary depending on the monitoring method.
Each option would require a complete record of all measured parameters as well as parameters
determined from company records that are used in the GHG emissions calculations (e.g., carbon
contents, monthly fuel consumption, etc.).

6.1	Procedures for Option 1: Simplified Emissions Calculation

For process sources in the titanium dioxide production category that use Option 1, facility-
specific production data is required, therefore missing data is not allowed for this option.

6.2	Procedures for Option 2: CPC Consumed Approach

For process sources in the titanium dioxide production category that use Option 2, it is assumed
that a facility will be able to supply facility-specific data.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

6.3 Procedures for Option 3: Direct Measurement

For options involving direct measurement of CO2 emissions using CEMS, Part 75 establishes
procedures for the management of missing data. Specifically, the procedures for managing
missing CO2 concentration data are specified in §75.35. In general, missing data from the
operation of the CEMS may be replaced with substitute data to determine the CO2 emissions
during the period for which CEMS data are missing. Section 75.35(a) requires the owner or
operator of a unit with a CO2 CEMS to substitute for missing CO2 pollutant concentration data
using the procedures specified in paragraphs (b) and (d) of §75.35; paragraph (b) covers
operation of the system during the first 720 quality-assured operation hours for the CEMS, and
paragraph (d) covers operation of the system after the first 720 quality-assured operating hours
are completed.

During the first 720 quality-assured monitor operating hours following initial certification at a
particular unit or stack location, the owner or operator would be required to substitute CO2
pollutant concentration data according to the procedures in §75.31(b). That is, if prior quality-
assured data exist, the owner or operator would be required to substitute for each hour of missing
data, the average of the data recorded by a certified monitor for the operating hour immediately
preceding and immediately following the hour for which data are missing. If there are no prior
quality-assured data, the owner or operator would have to substitute the maximum potential CO2
concentration for the missing data.

Following the first 720 quality-assured monitor operating hours, the owner or operator would
have to follow the same missing data procedures for SO2 specified in §75.33(b). The specific
methods used to estimate missing data would depend on the monitor data availability and the
duration of the missing data period.

7. QA/QC Requirements

Facilities should conduct quality assurance and quality control of the production and
consumption data, supplier information (e.g., carbon contents), and emission estimates reported.
Facilities are encouraged to prepare an in-depth quality assurance and quality control plan which
would include checks on production data, the carbon content information received from the
supplier and from the lab analysis, and calculations performed to estimate GHG emissions.
Several examples of QA/QC procedures are listed below.

7.1 Stationary Emissions

For QA/QC options for stationary combustion refer to EPA-HQ-OAR-2008-0508-004.

7.2 Process Emissions

Options and considerations for QA/QC will vary depending on the monitoring method. Each
option would require unique QA/QC measures appropriate to the particular methodology
employed to ensure proper emission monitoring and reporting.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

7.3 Data Management

Data management procedures should be included in the QA/QC Plan. Elements of the data
management procedures plan are as follows:

•	For measurements of carbonate content, assess representativeness of the carbonate
content measurement by comparing values received from supplier and/or laboratory
analysis with IPCC default values.

•	Check for temporal consistency in production data, carbonate content data, and emission
estimate. If outliers exist, they should be explained by changes in the facility's
operations or other factors. A monitoring error is probable if differences between annual
data cannot be explained by:

o Changes in activity levels,
o Changes concerning fuels or input material,

o Changes concerning the emitting process (e.g. energy efficiency improvements)
(European Commission 2007).

•	Determine the "reasonableness" of the emission estimate by comparing it to previous
year's estimates and relative to national emission estimate for the industry:

o Comparison of data on fuel or input material consumed by specific sources with

fuel or input material purchasing data and data on stock changes,
o Comparison of fuel or input material consumption data with fuel or input material

purchasing data and data on stock changes,
o Comparison of emission factors that have been calculated or obtained from the fuel
or input material supplier, to national or international reference emission factors of
comparable fuels or input materials
o Comparison of emission factors based on fuel analyses to national or international

reference emission factors of comparable fuels, or input materials,
o Comparison of measured and calculated emissions (European Commission 2007).

•	Maintain data documentation, including comprehensive documentation of data received
through personal communication:

•	Check that changes in data or methodology are documented

8. Types of Emission Information to be Reported

Based on the existing programs and the emission sources at titanium dioxide production
facilities, GHG reporting for these facilities is limited to CO2, CH4, and N2O. Titanium dioxide
facilities should report both process (CO2) and combustion related (CO2, CH4, and N2O)
greenhouse gas emissions. The data to be reported may very depending on monitoring options
selected. However, a titanium dioxide production facility should report its annual average
petroleum coke consumption, number of chloride process lines, annual titanium dioxide
production, annual titanium dioxide production capacity, electricity usage (kilowatt-hours), and
annual operating hours. For reporting options for stationary combustion refer to EPA-HQ-OAR-
2008-0508-004.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

8.1	Other Information to be Reported

Each titanium dioxide production facility should report the following:

•	Total annual CO2 emissions from chloride process lines from monthly averages (metric
tons);

•	Number of chloride process lines;

•	Annual calcined petroleum coke consumption from monthly measurements (metric tons);

•	Annual production of titanium dioxide (metric tons);

•	Annual capacity of titanium dioxide (metric tons);

•	Electricity usage, KWhr/yr; and

•	Annual operating hours for each titanium dioxide production facility.

8.2	Additional Data to be Retained Onsite

Facilities should be required to retain data concerning monitoring of GHG emissions onsite for a
period of at least five years from the reporting year. EPA could use such data to conduct trend
analyses and potentially to develop process or activity-specific emission factors for the process.
Facilities should retain the following information:

•	Records of annual CO2 emissions (metric tons);

•	Monthly production of titanium dioxide (metric tons);

•	Production capacity of titanium dioxide (metric tons);

•	Records of monthly calcined petroleum coke consumption (metric tons);

•	Electricity usage, KWhr/yr; and

•	Annual operating hours for each titanium dioxide production facility.

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

9. References

Australian DCC (2007) National Greenhouse and Energy Reporting System: Technical
Guidelines for the Estimation of Greenhouse Emissions and Energy at Facility Level.
Commonwealth of Australia. Canberra, Australia.

Gambogi, Joseph (2008). Personal Communication between Joseph Gambogi of USGS and
Mausami Desai of US EPA. June 25, 2008.

Georgia DNR (2002) Part 70 Operating Permit Number: 2816-051-0008-V-03-0. Georgia
Department of Natural Resources, Environmental Protection Division, Atlanta, Georgia.

EC (2006). Environment Canada. Technical Guidance on Reporting Greenhouse Gas
Emissions. 2006 Reporting Year.

European Commission (2007) Commission Decision of 18 July 2007 establishing guidelines for
the monitoring and reporting of greenhouse gas emissions pursuant to Directive 2003/87/EC of
the European Parliament and of the Council. European Commission. Brussels, Belgium.

IPCC (2006) 2006 IPCC Guidelines for National Greenhouse Gas Inventories. The National
Greenhouse Gas Inventories Programme, The Intergovernmental Panel on Climate Change, H.S.
Eggleston, L. Buenida, K. Miwa, T Ngara, and K. Tanabe (eds.). Hayama, Kanagawa, Japan.

NGER (2007). National Greenhouse and Energy Reporting System. Technical Guidelines for
the Estimation of Greenhouse Emissions and Energy at Facility Level: Energy, Industrial
Process and Waste Sectors in Australia. December 2007.

Ohio EPA (2002) Final Title V Chapter 3745-77 Permit for Facility ID 02-04-01-0193. State of
Ohio Environmental Protection Agency, Columbus, Ohio.

Ohio EPA (2004) Final Title V Chapter 3745-77 Permit for Facility ID 02-04-01-0200. State of
Ohio Environmental Protection Agency, Columbus, Ohio.

U.S. EPA (2008a) Acid Rain Program Regulations: Part 75. Available online at
http://www.epa.gov/airmarkets/emissions/consolidated.html.

U.S. EPA (2008b) Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2006. U.S.
Environmental Protection Agency, Washington D.C. USEPA #430-R-08-005.

U.S. EPA (2007) Climate Leaders Greenhouse Gas Inventory Protocol: Design Principles,
Chapter 7 "Managing Inventory Quality". Available online at:
http://www.epa.gov/climateleaders/documents/resources/design_princ_ch7.pdf.

U.S. EPA (2005) Clean Air Act National Stack Testing Guidance. U.S. Environmental
Protection Agency Office of Enforcement and Compliance Assurance, September 30, 2005.
Available online at: www.epa.gov/compliance/resources/policies/monitoring/caa/stacktesting.pdf

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Technical Support Document for Titanium Dioxide: Proposed Rule for Mandatory Reporting of Greenhouse Gases

USGS (2006) Minerals Yearbook: Titanium Dioxide Annual Report. U.S. Geological Survey,
Reston, VA. Available online at:

http://minerals.usgs.gov/minerals/pubs/commoditv/titanium/mvbl-2006-titan.pdf.

RTI (2008) Data collected from commercial web sites on the carbon content of calcined
petroleum coke available for sale to the titanium dioxide production industry
(http://www.carbonresources.in/CPCoke.htm and http://search.duckol.com/c/Calcined-
Petroleum-Coke/).

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