Direct drive nitric acid compressor train boosts efficiency

MAN Diesel & Turbo has introduced a turbomachinery concept for the fertilizer industry which raises production efficiency of nitric acid. The heart of the concept known as NAMAX is a type AG-MAX1 axial compressor.

MAN Diesel & Turbo will supply a NAMAX train to end customer Grupa Azoty in Poland for the licensor Thyssenkrupp Industrial Solutions.

Grupa Azoty will use the ultra-modern concept to expand its fertilizer production in Pulawy, in eastern Poland. "Nitric acid is one of the most important feedstocks in the industry worldwide," explains Lothar Wallscheid, Vice President at MAN Diesel & Turbo in Oberhausen (Germany). "For the energy-intensive production process we have created a highly efficient train concept based on the MAX1 as air compressor. Among its many advantages, this means one thing in particular for the production of nitric acid: far greater efficiency with reduced investment."

While previous concepts used an intermediate gearbox to couple the machines in the train, the great advantage of the NAMAX concept is its direct drive, meaning there is no longer need for a gearbox. Compared to the machine trains to date, this allows efficiency to be boosted by several percentage points – at the same time allowing the energy input and the operating costs for HNO3 production to be greatly reduced . Besides the MAX1 as air compressor, the NAMAX concept consists of other proven machines: a centrifugal compressor for NOx compression, an MAN steam turbine and an MAN axial expander providing the drive power.

The fact that all four machines come from a single source means that the complete train can be perfectly matched, allowing the demanding process of nitric acid production to be trimmed for maximum efficiency.