United Conveyor Corporation (UCC) has extended its industry leadership by completing over 25,000 hours of dry sorbent injection (DSI) demonstration tests. Full-scale, on-site DSI demonstrations help UCC utility customers address regulatory requirements for the reduction of SO2, SO3, mercury and acid gases emitted from utility boilers.
UCC has the industry’s largest number of full-scale demonstration tests with 45 conducted to date; 12 tests have been completed over the last year with five more tests scheduled. Recent demonstration tests have been primarily focused on simultaneously removing SO2, HCl, and mercury to provide specific information to the plant for meeting the new Utility MACT and Cross State Air Pollutant Rule (CSAPR) requirements. These tests have been conducted on a number of large, PRB-fired units, as well as smaller, bituminous-fired units.
"Our test equipment incorporates the latest injection and milling technology which helps us to generate reliable, high-quality data that provides the answers our customers’ need to make critical compliance decisions," explains Jon Norman, DSI technology manager, UCC. "The depth of our on-site experience is a key differentiator in the market. We are excited about the increasing demand for our on-site demonstration capability."
UCC modular demonstration systems provide both flexibility and performance with minimal disruption to a plant during installation and testing. Prefabricated, mobile equipment enables rapid installation. All equipment is scalable so demonstration equipment can be rented longer term after the test or be upgraded to become the permanent system. The result is lower total installed cost and shorter lead-time.
UCC offers computational fluid dynamic (CFD) modeling of plant duct flows to best predict and enhance performance of the DSI system. CFD modeling ensures optimum sorbent distribution in the flue gas to maximize performance and minimize sorbent usage. The UCC VIPER™ Mill design incorporates proprietary technology that results in lower operating cost while improving performance. The VIPER milling technology is also tested on-site to show how the reduced sorbent particle size increases the reactive surface area to improve the emission removal efficiency and sorbent utilization.
Customized demonstration testing evaluates overall DSI performance on the system. UCC conducts baseline testing before the demonstration and during each injection run so the effects of sorbent injection on each pollutant can be accurately assessed. UCC testing includes source emission testing (stack testing). Removal results can then be compared to a database of previous testing at other coal-fired power plants. UCC DSI demonstrations illustrate clear benefits:
- Dry sorbent trona / sodium bicarbonate injection can remove over 90% SO2
- Co-benefits include enhanced ESP performance and removal of Hg, HCl, and NOx
- In-line milling (to 12 -15 micron) can provide 30% to 50% better trona utilization
- Demonstrate SO2, acid gas (HCl, HF), and Hg removal simultaneously
- Successful demonstrations for SO3 and HCl removal with hydrated lime
- DSI delivers effective emission control at a fraction of the capital cost of a scrubber