Retrofitting The Existing Flare / Burnery For Smoke Less Operations

1. Retrofitting The Existing Flare / Burnery For Smoke Less Operations Presented by K.S.SABAPATHI Sr. specialist, KNPC & J.Nataraj Engineer, KNPC

2. NECESSITY OF FLARE / BURNERY • Flaring provides a safety mechanism and emission control option , where flared gases cannot be recovered due to uncertain or intermittent releases during process upsets/emergencies. • Off spec products and hydrocarbons drained from Gas plant have very high vapor pressure. It is not possible to store the same, due to high vapor pressure and low temperature. Therefore they have to be burnt immediately.

3. NECESSITY OF FLARE / BURNERY • Flaring is preferable to venting because, it aids in • Odor control. • Reduced VOC emissions (ozone and PM2.5 precursor, air toxics). • Reduced GHG emissions (by a factor of 8).

4. Typical Flaring Breakdown

5. Flare Reduction Strategies Flare/burnery Management Hierarchy of Approach • Prevention: Any hydrocarbon to flare / burnery is to be prevented by automatic instrumentation, operating procedure and good design. • Recovery: Recovery system is to be installed and hydrocarbon recovered should be re-used either for process or as fuel. • Upgradation: Upgrade the existing disposal facility to smokeless system, using latest technology.

6. CODES USED FOR FLARES /BURNERIES FLARES / BURNERIES ARE DESIGNED USING THE FOLLOWING CODES • API RP 521, Guide for Pressure Relieving and Depressuring Systems. • API 537, Flare Details for General Refinery and Petrochemical Service.

7. PREVENTION • Flare capacity, an essential safety design feature, is typically set by the largest single contingency for a unit. • Conventional design of overpressure protection systems require additional flare capacity either by installing another flare system or reducing contingencies of existing flare systems.

8. An alternative is to apply High Integrity Protective System (HIPS) to reduce some single contingencies to double contingencies, requiring additional expansion or investment in the flare system. • Some significant advantages of High Integrity Protective System (HIPS) are, • Significant downtime can be avoided for flare expansion • Low capital cost compared to flare system piping upgrades • Process flaring and purging will be significantly reduced. • API and ASME standards and ANSI/ISA S84.01-199-6 and IEC -61508 allow HIPS.

9. PREVENTION From the above it is clear, instruments have become as reliable as safety valve and instrument can be used in place of safety valve.

10. PREVENTION

11. PREVENTION • In oil and gas processing facilities a cause of overpressure could be a common failure affecting a number of pressure systems simultaneously. For eg. simultaneous loss of overhead condensing capacity on a number of columns due to loss of cooling medium (either loss of cooling water supply or loss of all air cooler fans due to power failure). • To reduce the total load on the common relief system, it may be considered to use Instrumented Protective Functions (IPFs) consisting of high pressure initiators on each pressure system to close the heat input and thus prevent the individual relief case.

12. RECOVERYFLARE GAS RECOVERY

13. RECOVERYFLARE GAS RECOVERY

14. RECOVERYFLARE GAS RECOVERY

15. RECOVERYFLARE GAS RECOVERY

16. RECOVERYBLOW DOWN RECOVERY

17. RECOVERYNON CONVENTIONAL

18. SYSTEM UPGRADATIONTO SMOKELESS FLARE • Definition: Smokeless Flare Smokeless flare" means a combustion unit and the stack to which it is affixed in which organic material achieves combustion by burning in the atmosphere such that the smoke or other particulate matter emitted to the atmosphere from such combustion does not have an appearance density or shade darker than that of No. 1 of the Ringlemann Chart.

19. SYSTEM UPGRADATIONTO SMOKELESS FLARE • TYPES OF NON-SMOKING FLARES • SONIC FLARES • AIR ASSISTED FLARE • STEAM ASSISTED FLARE • NON-ASSISTED STAGED MATRIX FLARES • GROUND LEVEL • ELEVATED

20. SYSTEM UPGRADATIONTO SMOKELESS FLARE SONIC FLARES • High pressure Sonic Flares combine the best features with the longevity of multi-arm flares. • This flare is capable of providing low heat radiation flaring while maintaining the design principles required ensuring longevity.

21. SONICFLARE SONIC FLARES The Sonic flare uses the energy associated with pressurized gas to entrain and mix large quantities of air. The difference in this multi-arm sonic flare is in the nozzle. The annulus design of the nozzle enhances the mixing rate of the entrained air into the primary mixing zone of flame. This highly aerated gas and air stream burns with a clean short flame.

22. SYSTEM UPGRADATIONTO SMOKELESS FLARE • AIR ASSISTED FLARE When pressure is not available, an assist medium is required to achieve clean combustion of the waste gas. The air assisted flare uses forced air via a low-pressure blower to provide smokeless flaring. The air assisted flare tip includes mixing vanes which ensure that the air and gas are kept separate until both exit the tip of the flare. These vanes improve efficiency by maximizing the air to gas surface area contact.

23. SYSTEM UPGRADATIONTO SMOKELESS FLARE AIR ASSISTED FLARE Maintaining the philosophy of annulus flaring, the Air assisted mixing head allows the gas to be channeled to the outer annulus and the air to be fed through the center of the flame. This decreases the thickness of the waste gas stream, allows the surface of the waste gas stream to come in contact with surrounding air, and further increases overall efficiency. Additionally, the forced air ensures continuous internal cooling which extends the life of the flare tip.

24. SYSTEM UPGRADATIONTO SMOKELESS FLARE • STEAM ASSISTED FLARE The steam assisted flare relies on the energy associated with pressurized steam to entrain air and provide the mixing required for smokeless flaring. Additionally, the water / gas reaction improves the hydrocarbon combustion breakdown while reducing the flame temperatures. Both enhance the steam flare’s ability to reduce smoke formation.

25. SYSTEM UPGRADATIONTO SMOKELESS FLARE • STEAM ASSISTED FLARE The steam assist flare is part of the utility line of flares. This flare uses a ring of nozzles to inject steam into the base of the waste gas flame. The nozzles are angled to improve the air entrainment and maximize the air / gas mixing. For larger flares, a center stream nozzle can easily be incorporated. For more stringent applications, the Steam assisted flare provides low noise and high efficiency.

26. SYSTEM UPGRADATIONTO SMOKELESS FLARE NON-ASSISTED STAGED MATRIX FLARES Smokeless turn-down is enhanced by staging the flow to the unit. This ensures that the minimum of burners are in operation at any time, keeping the pressure in the operational stage high enough to provide sufficient turbulence so that the flare will be smokeless throughout its entire operating range.

27. SYSTEM UPGRADATIONTO SMOKELESS FLARE GROUND LEVEL MATRIX FLARE SYSTEM • Staged matrix flares are designed to burn very large quantities of gas smokeless through-out the entire operating range. • Smokeless performance is achieved using high pressure, high turbulence burners, arranged in a matrix so that combustion air is available to each burner. These flares can be used to burn a very wide range of gases smokelessly.

28. SYSTEM UPGRADATIONTO SMOKELESS FLARE GROUND LEVEL MATRIX FLARE SYSTEM A typical large matrix flare will have from 6 to 8 stages, using fast-acting, tight shut-off butterfly valves with rupture disk bypass to divert gas to each successive stage. This image is of the burners and manifolds during construction they will later be covered with a layer of gravel for radiation protection. A significant benefit of putting the burner matrix in an elevated structure is that it becomes more compact since combustion air more easily brought to each of the burners.The plot area taken up by the system is also much reduced.

29. SYSTEM UPGRADATIONTO SMOKELESS FLARE LIQUID BURNERY • Wide range of liquid flares and burners are available .  • Depending on the nature of the liquid waste, simple mechanical atomization/vaporization burners to thermal vaporizer burners to steam/compressed air atomized burners.  • Most preferred option is to pump the liquid at high pressure and using the high pressure to atomize the fuel to avoid smoke formation.

30. Flaring Management • Alternatives to Flaring • Thermal oxidation using high efficiency combustion systems (e.g., incinerators, enclosed flares or heaters). • Onsite electric power generation. • Co-generation. • Re-injection into producing reservoir. • Injection with produced water. • Produce into nearby gas gathering system. • Cluster with gas from other nearby facilities. • Flaring Management Decision Tree. • Supplemental to EUB Guide -60.

31. Thank You