Gas Processing Plant Operations

 

INTRODUCTION

Section 13 presents some additional recommendations that are unique to gas processing plant operations involving hydrogen sulfide (refer to Par. 4.1.). Some recommendations in other sections of this publication also are applicable to gas processing plant operations.

GENERAL CONSIDERATIONS

Gas processing plant operations typically include more complex processes than field operations (e.g., gas condition­ing facilities). Some differences include:

a. potentially higher volumes of gas containing hydrogen
sulfide,

b. potentially higher concentrations of hydrogen sulfide,

c. generally a greater number of personnel and more equip­
ment, and

d. the assignment of personnel on a more regular basis.

These differences often require special considerations to ensure safe operations involving activities such as vessel and

line openings and confined space entry. When such activities are to take place, a coordinating meeting between operations, maintenance, contractor, and other involved parties should be held to ensure that facility personnel are aware of the ac­tivities involved, their effect(s) on plant operations, and the necessary safety precautions that are to be followed.

GAS CONDITIONING FACILITIES

Many gas treating and sulfur recovery processes are em­ployed in gas processing plants. These processes can be clas­sified into chemical reaction, physical solution, and adsorption processes, and can be further subdivided into re-generable and non-regenerable processes. Regenerable type processes include amine solvents, hot potassium carbonate, molecular sieve, and chelants. Non-regenerable type pro­cesses include iron sponge, caustic scrubbers, metal oxides, direct oxidation, and various other sulfur recovery processes. Because most of these methods result in a concentrated hy­drogen sulfide stream or reaction product, operators shall be familiar with the various chemical and physical characteris­tics of the process(es) at the particular facility. The amount of hydrogen sulfide in residence within a process may be sufficient to require implementation of requirements con­tained in 29 Code of Federal Regulations Part 1910.119.

MATERIALS OF CONSTRUCTION

The failure of gas processing plant equipment components can permit the uncontrolled release of hydrogen sulfide to the atmosphere. Those equipment components in the sulfide stress cracking regime should be made from sulfide stress cracking resistant materials (refer to Par. 8.1.3).

CORROSION MONITORING

A corrosion monitoring program should be established to minimize internal and external corrosion activity which can affect equipment in hydrogen sulfide service.

LEAK DETECTION

In gas or liquid handling systems containing hydrogen sul­fide in concentrations capable of causing atmospheric con­centrations of 10 ppm or more of hydrogen sulfide, monitoring techniques or procedures (for example, visual observation, soap bubble test, portable detectors, or fixed monitoring equipment) should be employed to detect leaks. Particular attention should be given to enclosed facilities, such as control rooms, compressor buildings, cellars, and sumps (refer to Section 12). Regularly scheduled inspection of equipment for leaks, such as pump seals, is recommended. Results should be retained for a minimum of one year as a part of the facility or equipment operating and maintenance records. Fixed hydrogen sulfide ambient air monitoring sys­tems are recommended (refer to Section 10 and Appendix C)

in gas processing plants located near populated areas to facil- exposed to a release of hydrogen sulfide (refer to Appendix

itate early detection and necessary warning to the general В of API Recommended Practice 750. Operating personnel

public. must be familiar with emergency plant shutdown procedures,

rescue operations, notification procedures, briefing areas,
CONTINGENCY PLANNING ^ancl l⁰⁰^⁰¹¹⁵ °f emergency equipment (refer to Section 7).

Visitors shall be briefed on the physical layout of the gas

Contingency plans for gas processing plant facilities shall processing facility, applicable warning signals, and how to

cover plant personnel and the general public that could be respond in the event of an emergency.