A comparative assessment of open flame flares and enclosed ground flares for cleaner and safer hydrocarbon production in Mexico

Abstract

Hydrocarbon industry flaring practices emit large amounts of unburned hydrocarbons and climate forcers, creating environmental and social impacts. The objective of this study is to thoroughly compare different flaring technologies in situations where the industry is unable to avoid flaring. An integrated methodology for assessing two flare technologies in terms of Health-Environment-Safety (HES) impacts, economic performance, and safety benefits is proposed. The methodology includes stoichiometric calculations of combustion reactions, pollutants emission estimation, flare dimensioning for an equivalent inflow stream to be flared, and economic scenarios for assessing Enclosed Ground Flares (EGFs) versus Open Flame Flares (OFFs). The methodology was applied to a Mexican hydrocarbon installation that currently operates OFFs with a historical record of low combustion efficiency. If an EGF were to replace the existing OFF, there would be a significant emissions abatement that depends on their realistic operating efficiencies. Furthermore, the EGF has the potential to utilize 1.55thermal GW for energy applications, which is currently being wasted as the OFF releases it into the environment by flaring 3.75 Mm3/d. The safety radius required for the OFF is 9.3 times that required for the EGF of equivalent capacity. Over a 30-year period for the case study, the cumulative investment and O&M costs for EGF are about 23% less than for OFF. The consequence analysis with the PHAST software found that various failure conditions can be contained within the EGF combustion chamber without causing significant damage to the facility. However, the impacts of disturbances in the OFF such as gas clouds, flash fires, and explosions are around the torch. All these findings indicate that replacing OFF with EGF would be a safer and more economical solution in the future, as it also helps reduce pollutant emissions.