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Raprenox Exhaust Gas Treatment Process for NOx in Gas Turbine Engines

Office/Division Program
TAP
Project Number
179
Category
Research Initiation Date (Award Date)
Research Performing Activity
Technor, Inc.
Research Principal Investigator
Dr. Robert A. Perry
Research Contracting Agency
Description

This project continues a previous contract for the development of a patented process to reducing nitrogen oxide gases emanating from engines operating on the Outer Continental Shelf (OCS). The concept, RAPRENOx, is non-toxic and is considered the most effective means for achieving Clean Air Act NOx limitations offshore within the next few years. The process was proven effective and commercially marketable when used with diesel engines. Under the previous MMS contract, Technor showed that the RAPRENOx process can be applied to small scale gas turbine exhausts. The objective of this project is to prove the technology on large gas turbines such as those found on production platforms on the OCS. The project was originally proposed to test the technology on a 3000 hp gas turbine. Due to difficulties in obtaining an engine of this size, the contract was modified for testing on a gas turbine of approximately 300 hp. RAPRENOx is a patented process that is being commercialized in diesel engines. The process uses isocyanic acid, formed by the decomposition of cyanuric acid, a non-toxic, non-flammable, commercially available solid material. The gaseous isocyanuric acid is added to the exhaust stream whereby the NO is reduced to N2, H2O, and CO2. The raw material (cyanuric acid) needed for the RAPRENOx process is cheap, safe, and readily available. One ton of NOx can be abated by approximately 2250 lbs. Of cyanuric acid ($0.20-0.50/lb.) . Commercial diesel applications of RAPRENOx have demonstrated a 95% NOx reduction with 80% reduction of particulates and 90% reduction in reactive organic gases. Technor completed selection of a design for implementing RAPRENOx to a 6 Mwatt gas turbine. The design is cost effective and incorporates information gained while running tests at the University of California-Berkeley. The design provides flexible control of temperature in the reactor by including a duct heater to provide additional heat if the exhaust temperature falls below minimum (reaction) temperature. The technology will be tested at a test cell provided by NAC, a company that repairs and tests Allison gas turbines, in Oakland CA.

Latest progress update

Technor was granted two extensions of time to complete the project (at no additional cost to the government). Under the first extension, the project was scheduled for completion in December, 1999. The second extension granted an additional six months to complete the project. This extension of time was made necessary because of start-up problems associated with using a burner in the exhaust system.