Case studies

LANXESS CO₂, SOUTH AFRICA

Lanxess benefits from CO₂ capture plant for reuse in dichromate processing.

Lanxess CO2 capture plant

THE CHALLENGE

LANXESS CISA (Pty) Ltd., the world’s most modern chrome chemicals plant, needed to capture 120 tons of CO₂ per day from flue gas generated by a gas fired water tube boiler. This CO₂ would be reused within the LANXESS CISA chrome chemicals process. A project scope was developed to address, amongst others, operational problems including the unreliability of the CO₂ and poor availability of steam.

OUR SOLUTION

PROXA was responsible for the design, supply, installation and commissioning of the CO₂ capture plant, together with the associated infrastructure including the 37 ton/hr water tube boiler, cooling tower, custom designed boiler feed water treatment plant and associated water storage facilities. The process selected included an amine based CO₂ capture process, which was jointly designed and developed with Shell-Cansolv, Montreal.

HOW PROXA ADDED VALUE

PROXA embraced the specialised technology and added value in the customisation of the technology to the specific requirements of the customer. The basic engineering was jointly performed between PROXA and Shell-Cansolv.
The plant was completed in a record 22 months and achieved a recovery rate of >90% CO₂ to a final purity of >99% a few days after being commissioned. A steam consumption of 15% lower than guarantee value is achieved, confirming the overall energy efficiency of the process. What’s more, the annual amine consumption is much lower than conventional amine based processes. The combined effect of these factors is a rapid payback of the capital expenditure – primarily as a result of more consistent operation of the Sodium Dichromate production plant.
The plant, to date, employs advanced technologies in the production of sodium dichromate that minimise raw material input and waste streams.