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)


  • Acid gas: SO2


Packaged Combustion Systems

Introducing Process Combustion Corporation's line of Packaged Combustion Systems (PCS).  These pre-engineered, standardized combustion systems have been designed to perform in a variety of applications with impressive fuel efficiency, VOC destruction, and a compact footprint.  Each model was created with respect to common flow rates and compositions from a variety of industries.  The PCS Series of thermal oxidizers are also ideal for biogas, landfill gas, and digester gas.


PCC's PCS models were designed with attention to the customers' needs.  Honestly, these are simple, effective systems that are budget-friendly.  Each system is completely "plug and play" and skid-mounted to minimize field work and installation costs.  Contact us today to discuss your next project and how we can help.

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