Final Report: Data for Design of Vapor Recovery Units for Crude Oil Stock Tank Emissions

EPA Grant Number: R827015C023
Subproject: this is subproject number 023 , established and managed by the Center Director under grant R827015
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: IPEC University of Tulsa (TU)
Center Director: Sublette, Kerry L.
Title: Data for Design of Vapor Recovery Units for Crude Oil Stock Tank Emissions
Investigators: Babcock, Robert E.
Institution: University of Arkansas - Fayetteville
EPA Project Officer: Lasat, Mitch
Project Period: January 27, 2003 through August 30, 2003
RFA: Integrated Petroleum Environmental Consortium (IPEC) (1999) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Targeted Research

Objective:

The objectives of this research project were to:

  • Develop a model for estimating emissions from crude oil stock tanks based on the solubility of gases in the crude oil characterized by its boiling point distribution curve and its API gravity.
  • Compare the emissions estimates from the model to field measured emissions on four different field lease sites having varying oil characteristics and weather conditions over 36-hour field tests.
  • Develop the protocols for conducting boiling point distribution analysis on the crude oil samples and the protocols for component analysis of the collected emission samples.
  • Develop the field site protocols for measuring gas emissions as a function of operating conditions and ambient weather conditions.

Summary/Accomplishments (Outputs/Outcomes):

The model was developed using the Scatchard-Hildebrand equation taking into account the considerations presented by Prausnitz and Shair for the solubility of gases above their critical point in a mixed solvent:

δ = the Hildebrand solubility parameter.
fG = the fugacity of the gaseous solute at the initial state.
FiL = the fugacity of the solute (hypothetical as a pure liquid at the defined temperature.
Xi = the solubility of gas component “i” expressed as mole fraction in the solvent.
Subscript “i” refers to the gas phase.

The fugacity of the liquid phase and the average solubility parameter of the crude oil were estimated from the boiling point distribution curve, API gravity, and physical properties of hydrocarbons presented in API publications. As mentioned before, solubilities (Rs) for each compound in the emissions in crude oil were estimated using regular solution theory following the established work of Prausnitz and Shair, including the necessary modifications for which:

Here Rsi is the solubility of one of the vent gas components in SCF/BBL
ρoil is the density for the stored crude oil in kg/m3
MWoil is the molecular weight of the crude oil
P is the pressure of the crude oil (bar)
fpureL is the fugacity of the solute (hypothetical) as a pure liquid at the defined temperature (bar)
vL is the hypothetical molar liquid volume of the solute (cm3/gmol)
δi is the solubility parameter of the gaseous solute (J)
δ is the solubility parameter for the crude oil at the established temperature (J)
R is the universal gas constant
T is absolute temperature
132.86 is a unit conveRsion constant (SCF/BBL)

The fugacity parameter of the gas at the initial state fG was considered to be equal to the product of the gas fraction and the total pressure of the system. For each compound in the gas, the solubility was calculated independently, so the fraction is equal to one.

The total solubility was then obtained by adding the values of Rsi calculated for each of the C1-C5 compounds mentioned previously. Values of Rsi estimated by the model for the crude oil samples studied herein were approximately 1,200–1,400 SCF/STB.

The field measurements of emissions were inconclusive due to lease site operating malfunctions, difficulty in isolating the stock tank, and the brevity of the field test (36 hours). Vapor emissions were not existent at one site, and significant but highly variable at another site, making the results inconclusive for the short period of monitoring. It was determined that weekly or even monthly field tests should be conducted. This requires the automation of emissions flow measurements. The protocols for this type field test have been developed and tested at one field site to be utilized in a follow-on study.

The necessary analytical protocols were developed and applied to field samples with excellent results.

Journal Articles:

No journal articles submitted with this report: View all 3 publications for this subproject

Supplemental Keywords:

atmosphere, modeling, measurement methods, monitoring, VOC,, Health, Scientific Discipline, Air, POLLUTANTS/TOXICS, air toxics, Environmental Chemistry, Health Risk Assessment, Chemicals, Risk Assessments, Atmospheric Sciences, Engineering, Engineering, Chemistry, & Physics, Environmental Engineering, vapor recovery, air pollutants, hydrocarbon, hazardous air pollutants, air pollution control, air pollution, human exposure, emissions control, crude oil stock tank emissions, hydrocarbons, air pollution control technology, petroleum stock tank emissions, emissions contol engineering

Relevant Websites:

http://ipec.utulsa.edu/ Exit


Main Center Abstract and Reports:

R827015    IPEC University of Tulsa (TU)

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R827015C001 Evaluation of Road Base Material Derived from Tank Bottom Sludges
R827015C002 Passive Sampling Devices (PSDs) for Bioavailability Screening of Soils Containing Petrochemicals
R827015C003 Demonstration of a Subsurface Drainage System for the Remediation of Brine-Impacted Soil
R827015C004 Anaerobic Intrinsic Bioremediation of Whole Gasoline
R827015C005 Microflora Involved in Phytoremediation of Polyaromatic Hydrocarbons
R827015C006 Microbial Treatment of Naturally Occurring Radioactive Material (NORM)
R827015C007 Using Plants to Remediate Petroleum-Contaminated Soil
R827015C008 The Use of Nitrate for the Control of Sulfide Formation in Oklahoma Oil Fields
R827015C009 Surfactant-Enhanced Treatment of Oil-Contaminated Soils and Oil-Based Drill Cuttings
R827015C010 Novel Materials for Facile Separation of Petroleum Products from Aqueous Mixtures Via Magnetic Filtration
R827015C011 Development of Relevant Ecological Screening Criteria (RESC) for Petroleum Hydrocarbon-Contaminated Exploration and Production Sites
R827015C012 Humate-Induced Remediation of Petroleum Contaminated Surface Soils
R827015C013 New Process for Plugging Abandoned Wells
R827015C014 Enhancement of Microbial Sulfate Reduction for the Remediation of Hydrocarbon Contaminated Aquifers - A Laboratory and Field Scale Demonstration
R827015C015 Locating Oil-Water Interfaces in Process Vessels
R827015C016 Remediation of Brine Spills with Hay
R827015C017 Continuation of an Investigation into the Anaerobic Intrinsic Bioremediation of Whole Gasoline
R827015C018 Using Plants to Remediate Petroleum-Contaminated Soil
R827015C019 Biodegradation of Petroleum Hydrocarbons in Salt-Impacted Soil by Native Halophiles or Halotolerants and Strategies for Enhanced Degradation
R827015C020 Anaerobic Intrinsic Bioremediation of MTBE
R827015C021 Evaluation of Commercial, Microbial-Based Products to Treat Paraffin Deposition in Tank Bottoms and Oil Production Equipment
R827015C022 A Continuation: Humate-Induced Remediation of Petroleum Contaminated Surface Soils
R827015C023 Data for Design of Vapor Recovery Units for Crude Oil Stock Tank Emissions
R827015C024 Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells
R827015C025 A Continuation of Remediation of Brine Spills with Hay
R827015C026 Identifying the Signature of the Natural Attenuation of MTBE in Goundwater Using Molecular Methods and "Bug Traps"
R827015C027 Identifying the Signature of Natural Attenuation in the Microbial Ecology of Hydrocarbon Contaminated Groundwater Using Molecular Methods and "Bug Traps"
R827015C028 Using Plants to Remediate Petroleum-Contaminated Soil: Project Continuation
R827015C030 Effective Stormwater and Sediment Control During Pipeline Construction Using a New Filter Fence Concept
R827015C031 Evaluation of Sub-micellar Synthetic Surfactants versus Biosurfactants for Enhanced LNAPL Recovery
R827015C032 Utilization of the Carbon and Hydrogen Isotopic Composition of Individual Compounds in Refined Hydrocarbon Products To Monitor Their Fate in the Environment
R830633 Integrated Petroleum Environmental Consortium (IPEC)
R830633C001 Development of an Environmentally Friendly and Economical Process for Plugging Abandoned Wells (Phase II)
R830633C002 A Continuation of Remediation of Brine Spills with Hay
R830633C003 Effective Stormwater and Sediment Control During Pipeline Construction Using a New Filter Fence Concept
R830633C004 Evaluation of Sub-micellar Synthetic Surfactants versus Biosurfactants for Enhanced LNAPL Recovery
R830633C005 Utilization of the Carbon and Hydrogen Isotopic Composition of Individual Compounds in Refined Hydrocarbon Products To Monitor Their Fate in the Environment
R830633C006 Evaluation of Commercial, Microbial-Based Products to Treat Paraffin Deposition in Tank Bottoms and Oil Production Equipment
R830633C007 Identifying the Signature of the Natural Attenuation in the Microbial Ecology of Hydrocarbon Contaminated Groundwater Using Molecular Methods and “Bug Traps”
R830633C008 Using Plants to Remediate Petroleum-Contaminated Soil: Project Continuation
R830633C009 Use of Earthworms to Accelerate the Restoration of Oil and Brine Impacted Sites