Instructions

2. Dark blue cells on the template contain instructions for entering episode data.3. Enter the requested data into the light blue cells.

5. The last worksheet in this workbook provides references for chemical and physical property data for organic liquids, if needed.

6. Questions? Contact Danielle Nesvacil at (512) 239-2102 or by e-mail at DNesvaci@tceq.state.tx.us.

Landing Loss Emissions

Introduction

Floating-Roof Tank Designs

• internal floating-roof tanks (IFRTs) with a full or partial liquid heel, • external floating-roof tanks (EFRTs) with a full or partial liquid heel, and• IFRTs and EFRTs that drain dry.

This workbook provides a template for reporting landing loss sample calculation data to the TCEQ. This workbook does NOT calculate landing loss emissions. Please use the template in conjunction with the detailed guidance provided below.

1. For each landing loss episode, use one template worksheet to report the associated sample calculation data. Workbooks may contain as many episode worksheets as you prefer, but please format workbooks logically according to tank number, time period, etc.

4. Data entry cells may contain formatting checks to ensure valid data is reported. If data with invalid formatting are entered, the error message will provide instructions to correct the format.

Landing losses occur from floating-roof tanks whenever the tank is drained to a level where its roof lands on its deck legs or other supports (including roof suspension cables). When a floating roof lands on its supports or legs, it creates a vapor space underneath the roof. Liquid remaining in the bottom of the tank provides a continuous source of vapors to replace those expelled by breathing (in the case of internal floating roof tanks) or wind action (in the case of external floating roof tanks). These emissions, referred to as standing idle losses, occur daily as long as the tank roof remains landed.

Additional emissions occur when incoming stock liquid fills a tank with a landed roof; the incoming liquid not only displaces those vapors remaining under the floating roof, but also generates its own set of vapors that are displaced during the filling process. These two types of emissions are collectively referred to as filling losses.

For a given roof landing event, total landing loss emissions are therefore the sum of the filling losses and the daily standing idle losses over the entire period that the roof remained landed. Landing losses are inherently episodic in nature, and must be determined each time a tank's floating roof is landed.

Currently, no storage tank emissions software, including EPA's TANKS program, determines landing loss emissions as part of routine program operation. However, landing loss emissions may be determined using the guidance outlined in American Petroleum Institute (API) Technical Report (TR) 2567, Evaporative Loss from Storage Tank Floating Roof Landings (hereafter referred to as API TR 2567).

Tank design considerations will impact both standing idle and filling loss emissions. Therefore, API TR 2567 separates floating-roof tanks into the following three categories for emissions determination purposes:

• tanks that drain to a sump that retains a liquid heel, • tanks whose sumps have baffles or similar fittings that retain liquid, or • flat-bottom tanks whose contents have been removed by a vacuum truck, since liquid typically will still remain in irregular surfaces along the tank bottom.

Required Data for Landing Loss Emissions DeterminationsAfter you have correctly determined your tank type, you must collect the following information about the tank and its contents for each episode when the roof is landed:

• tank diameter• tank color• height of the vapor space under the floating roof• height of the stock liquid• atmospheric pressure at the tank's location• average temperature of the vapor and liquid below the floating roof• physical and chemical properties of the stored liquid (such as density, molecular weight, and vapor pressure)• physical and chemical properties of the liquid that the tank is refilled with, if different from the previously stored liquid • number of days that the tank stands idle while its floating roof is landed

Reporting Landing Loss Emissions within the Emissions Inventory

http://www.tceq.state.tx.us/comm_exec/forms_pubs/pubs/rg/rg-360_05/index.html

Submitting Landing Loss Sample Calculations

• tank FIN,

API TR 2567 presents standing idle and filling loss equations for each different tank category listed above. To accurately use these equations, you must first classify the storage tank in question into one of the above categories. Care must be taken when classifying a tank as drain-dry; API states that a tank is only a drain-dry tank if all of its free-standing liquid has been removed. The following tank configurations qualify as tanks with a partial liquid heel, according to API:

For each tank category listed above, API presents different saturation factors that have been validated through field studies to use in the landing loss equations. These saturation factors represent the stratification of vapors in the vapor space underneath the floating roof; therefore, no modification to these saturation factors based upon tank shell height is necessary.

For a given tank, you can then use this information in conjunction with the appropriate standing idle and filling loss equations to determine the emissions for each roof landing episode. The annual landing loss emissions can then be determined by summing the emissions from each episode occurring within a given calendar year. Emissions from each roof landing episode must be individually determined using accurate temperature data and stored liquid properties for the time of year when the roof landing occurred.

Avoid using certain default parameters presented within API TR 2567 that may not accurately reflect a given storage tank. For example, the default daily vapor temperature range specified within the document is 20 degrees Rankine; however, this default value is only appropriate for storage tanks that are painted white. For storage tanks painted other colors, the daily vapor temperature range must be calculated from the appropriate equation presented within the document, since solar insolation will cause the daily vapor temperature range to increase.

Report landing losses for each storage tank on the appropriate path within the emissions inventory questionnaire (EIQ). If your site determines that landing loss emissions occurred due to normal, routine operation, revise annual and ozone season emissions accordingly. For specific procedural guidance on reporting emissions on the EIQ, please consult Chapter 4 of 2005 Emissions Inventory Guidelines. This document is available on the TCEQ's website at:

Per 30 TAC Section 101.10(c), representative sample calculations are required to be submitted with these calendar year 2002, 2003, and 2004 EIQ revisions. For each landing loss episode experienced at your site, submit the following information with your EIQ revisions:

• tank EPN,• API category (as outlined in the "Floating-Roof Tank Designs" section above);• the dates when each landing loss episode occurred, and•

QuestionsAny questions about the use of API TR 2567 equations may be directed to Danielle Nesvacil at (512) 239-2102 or by e-mail at dnesvaci@tceq.state.tx.us.

all of the information listed under the "Required Data for Landing Loss Emissions Determinations" section above.

To facilitate the submission of this information, you may use the "Landing loss episode template" worksheet contained in this workbook to provide the requested data for each landing loss episode.

5. The last worksheet in this workbook provides references for chemical and physical property data for organic liquids, if needed.

6. Questions? Contact Danielle Nesvacil at (512) 239-2102 or by e-mail at DNesvaci@tceq.state.tx.us.

This workbook provides a template for reporting landing loss sample calculation data to the TCEQ. This workbook does NOT calculate Please use the template in conjunction with the detailed guidance provided below.

template worksheet to report the associated sample calculation data. Workbooks may contain as many episode worksheets as you prefer, but please format workbooks logically according to tank number, time period, etc.

4. Data entry cells may contain formatting checks to ensure valid data is reported. If data with invalid formatting are entered, the error message will provide instructions

Landing losses occur from floating-roof tanks whenever the tank is drained to a level where its roof lands on its deck legs or other supports (including roof suspension cables). When a floating roof lands on its supports or legs, it creates a vapor space underneath the roof. Liquid remaining in the bottom of the tank provides a continuous source of vapors to replace those expelled by breathing (in the case of internal floating roof tanks) or wind action (in the case of external floating roof tanks). These emissions, referred to

Additional emissions occur when incoming stock liquid fills a tank with a landed roof; the incoming liquid not only displaces those vapors remaining under the floating roof, but also generates its own set of vapors that are displaced during the filling process. These two types of emissions are collectively referred to as filling losses.

For a given roof landing event, total landing loss emissions are therefore the sum of the filling losses and the daily standing idle losses over the entire period that the roof remained landed. Landing losses are inherently episodic in nature, and must be determined each time a tank's floating roof is landed.

Currently, no storage tank emissions software, including EPA's TANKS program, determines landing loss emissions as part of routine program operation. However, landing loss emissions may be determined using the guidance outlined in American Petroleum Institute (API) Technical Report (TR) 2567, Evaporative Loss from Storage Tank Floating Roof

Tank design considerations will impact both standing idle and filling loss emissions. Therefore, API TR 2567 separates floating-roof tanks into the following three categories for

flat-bottom tanks whose contents have been removed by a vacuum truck, since liquid typically will still remain in irregular surfaces along the tank bottom.

After you have correctly determined your tank type, you must collect the following information about the tank and its contents for each episode when the roof is landed:

physical and chemical properties of the stored liquid (such as density, molecular weight, and vapor pressure)physical and chemical properties of the liquid that the tank is refilled with, if different from the previously stored liquid

API TR 2567 presents standing idle and filling loss equations for each different tank category listed above. To accurately use these equations, you must first classify the storage tank in question into one of the above categories. Care must be taken when classifying a tank as drain-dry; API states that a tank is only a drain-dry tank if all of its free-standing

partial liquid heel, according to API:

For each tank category listed above, API presents different saturation factors that have been validated through field studies to use in the landing loss equations. These saturationfactors represent the stratification of vapors in the vapor space underneath the floating roof; therefore, no modification to these saturation factors based

For a given tank, you can then use this information in conjunction with the appropriate standing idle and filling loss equations to determine the emissions for each roof landing episode. The annual landing loss emissions can then be determined by summing the emissions from each episode occurring within a given calendar year. Emissions from each roof landing episode must be individually determined using accurate temperature data and stored liquid properties for the time of year when the roof landing occurred.

Avoid using certain default parameters presented within API TR 2567 that may not accurately reflect a given storage tank. For example, the default daily vapor temperature range specified within the document is 20 degrees Rankine; however, this default value is only appropriate for storage tanks that are painted white. For storage tanks painted other colors, the daily vapor temperature range must be calculated from the appropriate equation presented within the document, since solar insolation will cause the daily vapor

Report landing losses for each storage tank on the appropriate path within the emissions inventory questionnaire (EIQ). If your site determines that landing loss emissions occurred due to normal, routine operation, revise annual and ozone season emissions accordingly. For specific procedural guidance on reporting emissions on the EIQ, please consult Chapter 4 of 2005 Emissions Inventory Guidelines. This document is available on the TCEQ's website at:

Per 30 TAC Section 101.10(c), representative sample calculations are required to be submitted with these calendar year 2002, 2003, and 2004 EIQ revisions. For each landing loss

Any questions about the use of API TR 2567 equations may be directed to Danielle Nesvacil at (512) 239-2102 or by e-mail at dnesvaci@tceq.state.tx.us.

of the information listed under the "Required Data for Landing Loss Emissions Determinations" section above.

To facilitate the submission of this information, you may use the "Landing loss episode template" worksheet contained in this workbook to provide the requested data for each

Landing loss episode data

Please enter the following information:

Regulated entity reference number (RN):

Air account number:

Tank FIN in the annual emissions inventory:

Tank EPN in the annual emissions inventory:

Tank category:

Tank shell color:

Date(s) this episode occurred:

Please enter the following parameters for this episode:

Parameter description and symbol

tank diameter, D

For this landing loss episode, please enter the stored liquid's name and physical properties.

Stored liquid's name:

Number of days the tank stands idle while floating roof is landed, nd

Average temperature of vapor and liquid below floating roof, Ta

Atmospheric pressure at tank location, Pa

Height of vapor space under floating roof, hv

Effective height of stock liquid, hle

Stored liquid properties

Site and tank information

Properties:

constant from Antoine's equation, B

true vapor pressure of stored liquid, P

Refilling liquid's name:

Properties:

constant from Antoine's equation, B

true vapor pressure of stored liquid, P

Tank Category

drain-dry tank (IFR or EFR)

stock liquid density, Wl

stock vapor molecular weight, Mv

For this landing loss episode, if the liquid that the tank is refilled with is different than the previously stored liquid, please enter the following properties for the refilling liquid.

stock liquid density, Wl

stock vapor molecular weight, Mv

internal floating roof with full liquid heelinternal floating roof with partial liquid heelexternal floating roof with full liquid heelexternal floating roof with partial liquid heel

Stored liquid properties

Refilling liquid properties

RN012345678

Please enter the following parameters for this episode:

Value Units Constraints:

16 dimensionless 1

90 ° Fahrenheit 40

14.7 psia 9.346

6 feet 0

150 feet 0 <D

3 feet 0

For this landing loss episode, please enter the stored liquid's name and physical properties.

<nd<

<Ta<

<Pa<

<hv

<hle

Stored liquid properties

Site and tank information

Property units: Value:

lb/gallon

lb/lb-mole

psia

Property units: Value:

lb/gallon

lb/lb-mole

psia

degrees Rankine; vapor pressure equation in units of psia and degrees Rankine

For this landing loss episode, if the liquid that the tank is refilled with is different than the previously stored liquid, please enter the following properties for the refilling liquid.

degrees Rankine; vapor pressure equation in units of psia and degrees Rankine

Stored liquid properties

Refilling liquid properties

366

110

15.717

For this landing loss episode, please enter the stored liquid's name and physical properties.

For this landing loss episode, if the liquid that the tank is refilled with is different than the previously stored liquid,

References for physical/chemical data:

Other references include:

$ TANKS 4.09d chemical database. Free and available by downloading the TANKS 4.09d software program from the EPA's website:http://www.epa.gov/ttn/chief/software/tanks/index.html

$Karel Verschueren. (New York : Van Nostrand Reinhold Co.), 1983

2001 edition available at TCEQ Library 547 V61H 2001 V.1

$2000 edition available at TCEQ library 660.042 P75P 2000

$

$TCEQ Library 660.02 Y2C 1999

$

$

$

$ Antoine's coefficients are also in the NIST Chemistry workbook, which is available online at: http://webbook.nist.gov/chemistry/$

$ http://www.eng.umd.edu/~nsw/ench250/antoine.dat

Two widely available resources are the CRC Handbook of Chemistry and Physics and Perry's Chemical Engineering Handbook. API TR 2567 also contains limited data for selected petroleum stocks.

Handbook of Environmental Data on Organic Chemicals. 2nd ed.

Reid, Prausnitz and Sherwood, Properties of Liquids and Gases, McGraw Hill, 1987.

Gallant, Robert W. and Yaws, Carl L. Physical properties of hydrocarbons

Yaws, Carl L. Chemical properties handbook : physical, thermodynamic, environmental, transport, safety, and health related properties for organic and inorganic chemicals

Yaws and Yang, Property Data: To Estimate Vapor Pressure Easily, Hydrocarbon Processing,

Baublik, Fried and Hola, The Vapor Pressures of Pure Substances, Selected Values of the Temperature Dependent Vapor Pressure in the Normal and Low Pressure Regions,

Daubert and Danner, Physical and Thermodynamic Properties of Pure Chemicals

**Please note that in some resources, such as the NIST Chemistry Workbook, the Antoine's equation constants are in units of [bar, K] and

TANKS 4.09d chemical database. Free and available by downloading the TANKS 4.09d software program from the EPA's website:

Antoine's coefficients are also in the NIST Chemistry workbook, which is available online at: http://webbook.nist.gov/chemistry/

Two widely available resources are the CRC Handbook of Chemistry and Physics and Perry's Chemical Engineering Handbook. API TR 2567 also contains limited

Properties of Liquids and Gases, McGraw Hill, 1987.

Physical properties of hydrocarbons. Houston : Gulf Pub. Co., c1993-c1995.

Chemical properties handbook : physical, thermodynamic, environmental, transport, safety, and health related properties for organic and inorganic chemicals

Property Data: To Estimate Vapor Pressure Easily, Hydrocarbon Processing, October 1989.

The Vapor Pressures of Pure Substances, Selected Values of the Temperature Dependent Vapor Pressure in the Normal and Low Pressure Regions,

Physical and Thermodynamic Properties of Pure Chemicals, Taylor and Francis, Washington, D.C., 1993.

**Please note that in some resources, such as the NIST Chemistry Workbook, the Antoine's equation constants are in units of [bar, K] and must be converted.

Chemical properties handbook : physical, thermodynamic, environmental, transport, safety, and health related properties for organic and inorganic chemicals McGraw, Hill 1999.

The Vapor Pressures of Pure Substances, Selected Values of the Temperature Dependent Vapor Pressure in the Normal and Low Pressure Regions, Elsevier Science Publishers, Amsterdam, 1984.

must be converted.