Principal Technology sulfur recovery units pre-engineered SRU
Environmental Systems Portfolio

Principal Technology offers total system solutions for refining, chemical, process and manufacturing facilities. Our Sulfur Recovery and Tail Gas Treating projects include detailed engineering and design, procurement, module fabrication, and construction or construction support for new units and revamps. Principal Technology can also provide single point of control lump-sum, turn-key, and EPC services.

Our Sulfur Recovery and Tail Gas Treating Unit portfolio includes (partial listing):

  • 2 Units x 500 LTPD SRU Front End Revamp
  • 2 Units x 150 LTPD SRU Revamp
  • 1 Unit x 225 LTPD TGTU Revamp
  • 1 Unit x 100 LTPD SRU and TGTU Revamp
  • 1 Unit x 30 LTPD SRU and TGTU New Construction
  • 1 Unit x 30 LTPD SRU Revamp and 50% Capacity Increase
  • 1 Unit x 8 LTPD SRU and TGTU New Construction

Following are highlights of our recent projects:


Principal Technology supplied an 8.6 LTPD Sulfur Recovery Unit (SRU), Tail Gas Treating Unit (TGTU), and Incinerator as a part of Countrymark Energy Resources’ Diesel Fuel Processing Complex in Mount Vernon, Indiana. Countrymark Energy Resources is the oil exploration and production division of Countrymark, Indiana’s only American-owned oil exploration, production, refining and marketing company. In addition to the Mount Vernon refinery, the company owns and operates several fuel terminal locations in Indiana and Kentucky.

The Diesel Fuel Processing Complex allows Countrymark to produce Ultra Low Sulfur Diesel (ULSD) fuels that meet the reduced sulfur content levels required by the EPA as of June 1, 2006. Countrymark’s flagship products include Super Dieselex-4, off-road diesel fuel; Premium Diesel-R, on-road diesel fuel; PLUS gasoline; and Countrymark Advantage Lubricants. Countrymark distributes fuels and lubricants to farms, fleets and families through a network of member cooperatives. These cooperatives own and operate more than 90 Countrymark branded fuel stations and more than 200 fuel and lubricant delivery routes located in Indiana, Ohio, Michigan, Illinois and Kentucky.

Principal Technology supplied the sulfur recovery equipment on eight modules that were fabricated off-site and shipped by barge and truck for on-site installation. Principal Technology’s scope included all engineering, design, procurement, fabrication, construction support, operator training, and start-up assistance. Taking advantage of our modularized packaged systems, the project was completed on budget and was operating several months prior to the EPA deadline.

Principal Technology Countrymark Energy Resources environmental systems


Principal Technology provided the Tesoro Corporation with all engineering, design, procurement, fabrication, construction support and start-up assistance to upgrade their existing 20 LTPD Sulfur Recovery Unit to 30 LTPD. This project supported the expansion of their Kenai, Alaska refinery, which included the addition of a Distillate Desulfurization Unit.

Based in San Antonio, Texas, Tesoro Corporation, a Fortune 150 company, is an independent refiner and marketer of petroleum products. Tesoro, through its subsidiaries, operates seven refineries in the western United States with a combined capacity of approximately 665,000 barrels per day. Tesoro’s retail-marketing system includes more than 1,215 branded retail stations, of which more than 425 are company operated.

Principal Technology delivered all the equipment required for the upgrade in modules fabricated off-site. To minimize on-site construction, the modules arrived in "set and go" condition with all the equipment, instruments, electrical, piping, and insulation fully inspected and tested prior to departure from the fabrication shop. Once on-site, we merely attached a few interconnecting lines to complete the installation prior to commissioning.

The module also featured an SRU Controls Enclosure containing everything required to control the unit on-site including the Foxboro DCS processor and I/O, Allen Bradley Control Logix Shutdown System, and local control panel functions. On-site, Principal Technology connected the control system to the Central Control Room through a redundant fiber optic network.

Principal Technology Tesoro Corporation sulfur recovery unit