TAMPA — In mid-April 2016, RTI International successfully completed more than 3,500 hours of pre-commercial (50-MWe scale) testing of its breakthrough warm gas desulfurization process (WDP) technology at Tampa Electric Company's coal and petcoke gasification plant site in Florida. Following successful conclusion of the testing program, RTI is now in discussions with potential partners to offer the WDP technology and sorbent commercially sometime later this year.
This game-changing WDP technology enables high-sulfur gas streams, such as syngas from coal or petcoke gasification, to be cleaned at elevated temperatures, thus reducing or eliminating the need for substantial gas cooling and expensive heat recovery systems. This increases the overall process efficiency, avoids waste of valuable energy, reduces greenhouse gas emissions, and also reduces the capital and operating costs of the entire gas cleanup block by as much as 50 percent or more when compared to conventional cleanup technologies.
“We are proud of the successful scale-up of this first-of a-kind technology,” said Terri Lomax, Ph.D., executive vice president of Discovery, Science, & Technology at RTI International. “Our demonstration plant process performance replicated previous performance at lab, bench, and pilot scales. This technology is a game-changer in syngas cleanup and can have a major impact on reducing capital and operating costs, especially in energy savings. We are excited to be moving it to commercial production.”
The successful project was supported by funding from the U.S. Department of Energy (DOE) as a critical enabling technology in DOE's advanced gasification technology roadmap to produce cleaner energy from coal. The DOE has a long history of collaboration with RTI on advanced technology development.
RTI’s Energy Technology Division has been engaged in clean energy research for more than 25 years. As part of this program, RTI developed WDP technology utilizing a novel pressurized transport-bed reactor design and a proprietary attrition-resistant, high-capacity solid sorbent whose excellent performance has now been replicated at lab, pilot, and pre-commercial scales.
The pre-commercial test unit was designed and constructed (on schedule and under budget) at Tampa Electric’s Polk 1 site and was then operated safely and successfully for more than 3,500 hours utilizing approximately 20 percent of their total gasifier syngas as feed (~70,000 Nm3/hr). The project also incorporated an advanced sweet water-gas-shift process for hydrogen enrichment and a commercially available activated amine process for 90+ percent total carbon capture.
The WDP technology has been demonstrated to achieve up to 99.9 percent removal of total sulfur from syngas at temperatures as high as 600°C and over a wide range of sulfur concentrations and pressures (pressure independent performance). The integration of WDP with the downstream activated amine carbon capture process enabled further reduction of total sulfur in the syngas to sub-ppmv concentrations (as low as 0.1 ppmv, up to 99.999 percent removal), suitable for stringent syngas applications such as chemicals, fertilizers, and fuels. Slip-stream testing of the cleaned syngas using Fischer-Tropsch and methanol catalysts showed no significant deactivation from residual contaminants after several hundred hours of exposure.