Texas Commission on Environmental Quality(TCEQ)

Differential Absorbtion Lidar (DIAL) ProjectSummer 2007

Texas City, Texas

Project Objective Compare DIAL measurements with

emissions calculated using traditional emission factors and calculation techniques

Measure emission sources located at a bulk storage facility and a refinery in the Houston, Galveston and Brazoria, Texas area

Project Status Draft DIAL report currently under

review by TCEQ - Dec 2007 After TCEQ review, the report will

be sent to project participants for review and comment and then forwarded to EPA - January 2008

TCEQ’s final report - June 2008

Project Funding

Total project cost $650,000 $200,000 funded by new

technology EPA grant $450,000 funded by TCEQ

Project Technology DIAL- Service provided by National

Physical Laboratory (NPL) Hawk Camera - Service provided by

Leak Surveys Inc. UV-DOAS (Ultraviolet-Differential Optical

Absorption Spectroscopy) - Provided by EPA

Ambient Sampling- Performed by TCEQ staff and NPL

Bulk Storage Facility Measurements

July 16th to July 20th 3.5 days of DIAL measurements

on naptha tanks with Hawk Camera footage

One night of DIAL measurements on large naptha tank

Bulk Storage Facility Measurements cont.

One large external floater Tank recently tested and well

maintained Additional wiper seal Leg supports had fabric covers

Two internal floating roof tanks with hanging roofs

Refinery July 25th to August 18th

Operated at less than 50% capacity – hurricane damage and turn around projects

Heavily industrialized area around the refinery

Refinery Sources Fixed roof diesel tanks External floating roof crude tanks External floating roof gasoline

tanks Wastewater treatment area

including a separator Heated storage tanks Three nights of storage tank

measurements

Refinery Sources cont. Coker unit

Total VOC Benzene- during decoking process

Aromatic Recovery Unit Sulfur recovery unit Temporary flare Large process flare

Coker Unit Coker Design

4 product cuts with overhead vapor sent to a vapor recovery unit or into the refinery fuel gas system

DIAL benzene measurements Measured during decoking process

DIAL Technology Validation Techniques

UV-DOAS measurements closely agreed with DIAL measurements

Canister and tube samples agreed closely with DIAL measurements

DIAL Technology Validation Techniques cont.

Inline gas calibration cells provided by the refinery

Dial measurements very close to actual concentrations for propane, pentane and benzene

Benzene Actual 1000 ppm Predicted 900 ± 70 ppm

Questions? Contact:

Russ Nettles, Team Leader Emissions Assessment Section, Air Quality Division of the TCEQ’s Chief Engineer’s Office

512 239-1493 rnettles@tceq.state.tx.us