Primary and Waste Oil Refineries; Asphalt Production

Envitech serves both primary refineries and waste oil re-refineries. Primary oil refineries convert crude oil into valuable petroleum products through distillation and separation processes. Waste oil re-refiners convert waste oil into base oil products and marine diesel oil (MDO). Both types of facilities can produce asphalt.

Hydrogen sulfide is found in by-product gases from refining crude oil and other industrial processes. A sulfur recovery unit (SRU) recovers sulfur from gaseous hydrogen sulfide by using a multi-step Claus process. A Tail Gas Treatment Unit (TGTU) follows the SRU to recover sulfur and return it to the SRU. An incinerator and waste heat boiler treats the TGTU off-gas oxidizing the remaining sulfur compounds to sulfur dioxide (SO₂).

Sulfur containing waste gases at waste oil re-refiners are treated by thermal oxidizers or direct fired heaters to convert sulfur compounds into SO₂. Envitech’s packed bed scrubber absorbs the SO₂ from the treated gases before exhausting to the atmosphere. Envitech’s proprietary quencher design is used to cool and saturate the gas before the packed bed section. The quencher operates at a lower pressure drop than other available technologies which reduces the system operating cost.

Exhaust Sources:

• Thermal Oxidizers
• Direct Fired Heaters
• Sulfur Recovery Units (SRU’s)

Pollutants:

• Acid gas: SO₂

Equipment:

• Quencher
• Packed Bed Absorber
• SRU Backup Scrubber