(86g) Ethylene Cracking Furnace Burner Applications Operating with Significantly Less Than 90 mg/nm3 NOX Emissions

This abstract will focus on the field results of eight (8) ethylene cracking furnaces, which use Zeeco GLSF Enhanced-Jet burners at Petrochina Sichuan Petrochemical Company Limited (SPC) that achieve field measured NOx emissions significantly less than 100 mg/Nm³. Using ultra-low emissions burners in ethylene cracking applications have proven to be an economical solution at Zeeco for achieving lower NO_x levels than 100 mg/Nm³ from existing fired equipment. Providing a next generation low NO_x burner footprint that fits into ethylene cracking applications has proven to be a challenge in many applications. Ultra low NO_x burner flame pattern(s) or profile(s) that can operate properly within a required burner to burner spacing and heat flux limitations have also proven to be a challenge.

This paper will focus on an application, which uses the GLSF Flat Flame Enhanced-Jet Burner model operating in eight (8) ethylene cracking furnaces that achieved less than 100 mg/Nm³ in the field. For this application, NOx emissions averaged around 50 mg/Nm³ in the field. The furnace field measured NOx emissions ranged between 35 mg/Nm³ (17 ppmv) to 65 mg/Nm³ (32 ppmv) at design heat release.

For applications requiring less than 100 mg/Nm³ NOx emissions, Zeeco has developed an ultra-low NOx emissions burner technology, “GLSF Enhanced-Jet Flat Flame Burner”, which provides a very small mechanical footprint and produces an excellent heat flux profile without flame to flame interaction. The GLSF Enhanced-Jet floor burners utilize the basic “free-jet” method of mixing fuel gas and inert products of combustion to form a new combustible mixture before entering the combustion air stream. The resulting mixture, burns at a lower adiabatic flame temperature, resulting in lower thermal NO_x production. In addition, the GLSF Enhanced-Jet burner is designed to greatly reduce issues of flame interaction and flame rollover experienced with other burner designs. Flame interaction between burners can cause flame impingement upon the process tubes and increased emissions. Flame impingement can result in shorter run lengths and higher tube metal temperatures which are problematic for prolonged ethylene production.

In conclusion, Zeeco and Petrochina Sichuan Petrochemical Company Limited (SPC) will co-author the paper and provide specific application details and the resulting field emission test results. This paper will focus on an application, which uses the GLSF Flat Flame Enhanced-Jet Burner design in eight (8) ethylene cracking furnace that achieved significantly less than 100 mg/Nm³ in the field. This application will show that the field measured NO_x emissions were between 35 mg/Nm³ (17 ppmv) to 65 mg/Nm³ (32 ppmv) at design heat release for this highlighted project.