The Penniman process using nitric acid is widely used in China for the production of iron oxide red pigments. On account of its formation of gaseous nitrogen oxides (NOx), as well as soluble nitrate and ammonium compounds, the process is a major challenge from an ecological perspective.
While developing an innovative and more sustainable Penniman red process, it was discovered that apart from the known nitrogen oxide emissions, significant quantities of nitrous oxide (N2O) are also generated. The impact of nitrous oxide as a critical greenhouse gas is 300 times greater than that of CO2. Thanks to comprehensive scrubbing of off-gas streams containing NOx and N2O as well as efficient biological treatment of wastewater contaminated with ammonium and nitrates, the updated Penniman red process developed by LANXESS sets new standards in the iron oxide industry.
Pigments produced by the Penniman process have a very clean color shade red with a strength in the light yellowish color shades. The New Reds produced in Ningbo will cover a part of the Copperas as well as a part of existing Penniman Red range and are an extension of the Laux range.