Installing Gas Turbines for Air Compression

Most of the older ammonia plants have steam turbine driven process air compressors, which have generally low efficiencies. When using a condensation steam turbine to drive the process air compressor, more than 50% of the energy contained in the steam is transferred to the cooling medium through condensation and lost. An alternative is to install a gas turbine for driving the process air compressor, where the exhaust gases (with temperature around  500 °C) are used as hot combustion air for the radiant burners in the primary reformer. This exhaust gas still contains sufficient oxygen (roughly 15 vol%). Using the hot exhaust gas in the primary reformer leads to fuel savings for the firing of the reformer, though higher flame temperatures might increase the NOx formation (IPTS/EC, 2007 p.71; Verduijn and de Wit, 2001). An overall efficiency, for the driving and preheat operations, of more than 90% can be achieved using a gas turbine with its exhaust gas fed to the primary reformer. Some excess steam may be available for export when using a gas turbine for process air compression. 

This is a typical technique applied in reduced primary reforming plants. Apart from preheated combustion air in the reformer, the hot exhaust gases can also be used for the generation of steam and for other preheating purposes (Ullmann’s, 2011 p.190). 

This measure can be applied in both new and old plants.

Development Status Products
Commercial
Ammonia

Installing Gas Turbines for Air CompressionCosts & Benefits

Parent Process: General Measures for Ammonia Plants
Energy Savings Potential
CO2 Emission Reduction Potential
Costs

Installing Gas Turbines for Air Compression Reference Documents

Reference Document on Best Available Techniques for the Manufacture of Large Volume Inorganic Chemicals - Ammonia, Acids and Fertilisers

Prepared by the Institute for Prospective Technical Studies of European Commision, this document provides detalied information on Best Available Technologies applicable to Ammonia production – as well as on the production of Acids and Fertilizers.  

Page Number: 

71

Installing Gas Turbines for Air Compression Tools

Assessment to Action (A2A) Toolkit

Developed by IIP, in collaboration with energy expertsat ICF Marbek, members of the IFA and experts in China, the A2A (Assessment to Action) Toolkit is a free suite of resources on energy management and technology best practices created for ammonia companies. The A2A Toolkit provides a first-order, high-level assessment to identify and prioritize energy efficiency opportunities. It does so by drawing on various assessment modules on technical best practices, management best practices (based on ISO 50001 standard) and productivity improvements. 

Installing Gas Turbines for Air Compression Journal Articles