South Coast Air Quality Management District

Report on Emission Limits for Rule 1189 - Emissions from Hydrogen Plant Process Vents

SYNOPSIS: 

On January 21, 2000, the Board adopted Rule 1189. The Board also directed staff to evaluate source test data required by the rule, and to report back to the Board no later than six months prior to January 1, 2003, on the appropriateness of the emission limit of 2.5 pounds of VOC per million cubic feet of hydrogen produced. The evaluation has now been completed and the report indicated that the emission limit is appropriate.

COMMITTEE: 

Stationary Source, May 24, 2002, Reviewed

RECOMMENDED ACTION:

Receive and file.

Barry R. Wallerstein, D.Env.
Executive Officer

Background

Rule 1189 - Emissions from Hydrogen Plant Process Vents, was adopted on January 21, 2000, to reduce VOC emissions, including methanol and non-methanol VOCs, from plants that produce hydrogen for use in refineries. Prior to Rule 1189, there were no source specific rules that regulated VOC emissions from hydrogen plant process vents.

Twelve (12) hydrogen plants located at eight (8) different sites are currently affected by this rule. The majority of these hydrogen plants are located at refineries where they provide petroleum refining processes with hydrogen for the production of gasoline and other fuels from crude oil. Hydrogen is used to remove or reduce undesirable elements such as sulfur, nitrogen, halides and aromatics in order to meet product specifications, including the reformulated gasoline regulations. In cases where plants are not part of a refinery, the hydrogen plants are constructed and operated by third parties and hydrogen is pipelined to various refineries.

The Board directed staff to evaluate the source test data collected, as required by the rule, determine the appropriateness of the VOC emission limit of the 2.5 pounds per million standard cubic feet of hydrogen produced, and report back to the board no later than six months prior to January 1, 2003.

The evaluation has now been completed. The results and staff’s recommendation are presented in this board letter, with additional information contained in the attached staff report.

Source Testing

The rule established emission limits for existing hydrogen plants to be achieved in two phases and to be verified through periodic source testing. More specifically, the rule required plant operators to:

• Perform initial source tests by July 1, 2000, to determine the emissions baseline;
• In Phase I, effective July 1, 2001, demonstrate compliance for all existing plants with one of the three options: (1) reduce total VOC emissions from all process vents of an existing hydrogen plant combined to less than 2.5 pounds per million standard cubic feet of hydrogen produced, or (2) reduce total VOC content in the process condensate by at least 80 percent from baseline levels, or (3) install low-methanol catalyst in low-temperature shift (LTS) reactors;
• In Phase II, effective January 1, 2003, limit total VOC emissions from all process vents of an existing hydrogen plant combined to less than 2.5 pounds per million cubic feet of hydrogen produced. An alternative compliance date of July 1, 2003, is provided for those who must install retrofit control equipment and have submitted applications for permits to construct as of January 1, 2003; and
• Require operators of all affected facilities to perform annual compliance testing and reporting, except that those who choose to comply with Option (3) in Phase I shall conduct testing semi-annually until complying with the Phase II requirements.

Staff developed a new test protocol to determine VOC emissions from hydrogen plant process vents. The test protocol was developed based on AQMD standard test methods and is included in the staff report as an attachment.

Results

Initial and the first annual compliance source test data from eleven of twelve existing, operating hydrogen plants have been submitted and reviewed by staff. The twelfth plant has been designed and operated in such a way that VOC emissions are directed to a furnace and not vented directly to the atmosphere.

Data indicate that ten plants have already achieved the Phase II emission limit. The two other plants are in compliance with Phase I requirements by utilizing a low-methanol catalyst in their low temperature shift reactors. However, since these two plants have not yet met the emission limit, they must take additional steps to further reduce their emissions from 3.2 and 44.9 pounds of VOC per million cubic feet of hydrogen produced, respectively, to achieve compliance as required in 2003. Staff will continue to work closely with these plants. In addition, these two plants must conduct semiannual compliance testing until full compliance has been achieved.

When the two hydrogen plants that have not currently achieved the Phase II emission limit make the necessary changes to meet the required VOC limit, the final remaining Phase II VOC emissions would approximately be 127 tons per year. This figure is very close to staff�s original estimate during the rule development of 140.4 tons per year remaining VOC emissions.

Conclusions and Recommendations

Testing shows that the use of low-methanol catalyst is an effective control technique in reducing the methanol component of VOC emissions for hydrogen plants operating a Low Temperature Shift (LTS) reactor. All twelve plants are in compliance with the Phase I requirements of Rule 1189. Ten plants are already in compliance with the Phase II requirements of Rule 1189. Two plants that have not met the Phase II limits of the rule are expected to achieve compliance in 2003 through additional steps such as further adjusting operating parameters and/or retrofit controls.

The operators of hydrogen plants are required to continue conducting annual compliance testing to demonstrate compliance with the rule requirements. The two plants that are not yet in compliance with the Phase II requirements of the rule will be conducting semi-annual compliance testing until full compliance is achieved. The District will continue to evaluate source test reports for these facilities.

Therefore, staff has concluded that the emission limit of less than 2.5 pounds of VOC per million cubic feet of hydrogen produced, as per Rule 1189, subparagraph (c)(3), is appropriate.

Attachment

Staff Report on Emission Limits for Rule 1189 – Emissions from Hydrogen Plant Process Vents

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