ANDRITZ Wet limestone flue gas desulphurization (FGD), Neurath, Germany

Wet flue gas cleaning (FGD)

Limestone flue gas desulphurization (FGD) units are well-proven and cost-effective. ANDRITZ provides novel scrubber system (FGDplus) that maximizes SO2 and dust removal while keeping energy inputs to a minimum.

In international terms, ANDRITZ Clean Air Technologies sets new standards in limestone FGD. At the Neurath power plant (2 x 1,100 MW) in Germany, two scrubbers with a diameter of 23.6 m are being installed to accommodate a flue gas flow of 4.7 million m³/h [stp, wet].

Wet flue gas cleaning, limestone FGD

Advanced scrubber design

The nucleus of our design is the unique scrubber, which is an open spraying tower that has been enhanced in recent years using computerized simulation techniques. Former AE&E has been conducting intensive development work in this field since 1995 and today enjoys a leading position which not only allows us to simulate flow and temperature profiles, but also to calculate the distribution of SO2 concentrations in the scrubber.

During comparisons of simulator data with actual plant measurements, the flow and temperature profiles have verified our design parameters. The result is a scrubber that is characterized by minimum dimensions, adaptable scrubber entry and exit geometry, and the optimum layout of the spray nozzles and spray banks. This results in a uniform SO2 profile in combination with the highest possible superficial velocity in the scrubber – removing the most pollutants and utilizing the least power.

The scrubber also benefits from the use of the latest materials and construction methods. GRP absorbers and reinforced concrete absorbers with polypropylene linings are used in addition to the proven steel absorbers with a variety of inner linings or stainless steel.

REAplus scrubber


Key features of limestone flue gas desulphurization systems

  • Outstanding for all fuels (lignite, hard coal, oil, biomass, waste)
  • SO2 removal >99%
  • Maximum HCl and HF removal levels
  • Gypsum as a saleable end product
  • Flue gas volume flows of up to 5,000,000 m3/h [stp, wet] per scrubber
  • Limestone as a favorably priced absorption agent
  • Low operating costs and power consumption
  • Open spray tower, low pressure loss
  • Options for materials of construction (high alloy, carbon steel with rubber lining, concrete with PP-lining, glass fiber reinforced plastics)


Starting with CFD modeling and lab investigations, ANDRITZ Clean Air Technologies further developed the conventional mass transfer concept for flue gas desulphurization scrubbers. Following prototyping and test plant work, we can now refer to operation at a pilot plant under actual power station conditions. The pilot plant was installed at the Niederaußem power plant in cooperation with RWE.

Karlsruhe FGD plant, Germany


ANDRITZ Flue gas desulphurization (FGD) plant, Slovnaft  Slovakia


ANDRITZ delivers environmentally friendly flue gas cleaning solutions, tailored to the needs of our clients and their operating environments. We are an environmental technology pioneer with a history in clean air technologies spanning 30+ years. Our products range from flue gas scrubbers and SCRs for power stations to complex flue gas cleaning systems for waste-to-energy and industrial plants. Use of cutting-edge engineering tools and global R&D collaboration with a network of recognized partners and universities are the foundations of our work. Early identification of each client’s needs help us make a long-term contribution to clean air and a clean environment.


  • Utility power industry
  • Waste to Energy / Energy from Waste / Sludge incineration
  • Pulp & Paper
  • Mining & Metals industry
  • Oil & Refinery industry
  • Marine industry

ANDRITZ Pulp & Paper booth at ABTCP 2023

We look forward to talk to you personally!