Niagara DBA Retrofit Project

The Niagara DBA Retrofit Project involved the modification and retrofit of the American Ref-Fuel energy-from-waste (EFW) facility adjacent to the Occidental Chemical (Oxychem) Plant in Niagara Falls, New York. The $120 million project essentially replaces the old refuse-derived fuel technology with new mass burn boilers, scrubbers and baghouses, including the largest individual waste-to-energy boilers in North America.

Fluor provided engineering, procurement and construction management services in retrofitting the 2,200-ton-per-day municipal solid waste-to-energy power plant utilizing Deutsche Babcock Anlagen (DBA) roller grate technology in two waste processing trains tying into two existing steam turbine generators.

Client's Challenge

The EFW facility received and processed 2,200 tons per day of municipal solid waste (MSW) into refuse-derived fuel (RDF). The RDF was combusted to recover heat in the form of steam, some of which was sold, with the remainder converted into electrical power.

The EFW RDF system was replaced with a DBA mass burn facility. The new DBA boilers were designed for a heat input rate varying with the higher heating value of municipal solid waste, and they generate steam to exit the superheaters at 1290 psig, 754 degrees Fahrenheit. The facility was designed to operate continuously and to receive solid waste 12 hours per day, six days per week.

Fluor's Solution

The project included the installation of a new refuse bunker with two refuse cranes for waste storage and handling. The combustion system in each train contains a feed chute, ram feeder, roller grates and a three pass boiler supplied under DBA license with primary and secondary forced draft fans.

A dry scrubber, fabric filters and an induced draft fan make up the balance of each train. The outlet flue gas from each train is ducted to a new common flue stack. A urea injection system was provided to control NOx emissions. An ash handling system was installed to handle bottom and fly ash. A metals recovery system was also provided to recover ferrous and nonferrous metals. A new electrical substation dedicated to the waste-to-energy plant was installed for export of electricity to the utility.

The combustion units use DBA technology incorporating the roller grate system with a parallel flow combustion chamber to combust the municipal solid waste and generate steam. The steam produced is supplied to the existing turbine generators and plant auxiliary equipment. The two existing turbine generators were each designed nominally for an inlet throttle flow of 383,000 pounds per hour of steam to generate 255 MW of electricity each. The existing RDF facilities were shut down, and the EFW boilers were converted to fossil fuel firing for backup and supplemental steam supply.

The project achieved a lost time incident rate of 0.88 compared to the western New York rate of 10.0, setting new safety milestones for the region.

Conclusion

In July 1996, the retrofit was completed under budget and two months ahead of schedule, with no interruption to plant operation. The state-of-the-art emissions control significantly improved environmental performance.