Ion exchange resins for the chemical and petrochemical industry
Steam is an important energy carrier in the chemical and petrochemical industries. Generated centrally, it is conveyed via pipe bridges to the points of consumption. Ion exchangers protect this infrastructure of boilers, pipelines and heat exchangers against scale formation and corrosion.
As well as steam, process water is also required and must conform to certain specifications. Lewatit® ion exchangers are used to soften or demineralize the process water and can be combined with each other to beneficial effect. This allows the water required for the various processes to be obtained in a reliable and economical way. Our LewaPlus® design software can model various combinations on a made-to-measure basis and thus provides users with maximum confidence that they will find the optimum treatment solution.
Waste water from chemical production facilities must also be treated thoroughly and reliably to prevent polluting nature and the environment. LANXESS’ ion exchangers can play an important part here too.
Further applications
Another application for Lewatit® ion exchangers is selective adsorption of carbon dioxide, a greenhouse gas, from flue gas or the air.
Basic chemicals such as sodium hydroxide, chlorine gas and hydrogen gas are needed in the production of materials and liquids such as PVC, paper, cellulose, disinfectants, bleach and aluminum compounds. These are obtained from chloralkali electrolysis of sodium chloride brine. Ion exchangers have proved their worth under extreme conditions, such as the treatment of these highly concentrated hot brines for chloralkali electrolysis. They reliably remove alkaline earth or heavy metal ions, protecting the membranes used in eco-friendly and energy-efficient membrane techniques against contamination. Other process solutions, such as pickling acids, rinse water and electroplating baths, can be treated in a similar way.
Very few processes in the chemical industry work without catalysts. They speed up reactions and control their selectivity. In particular, energy-efficient processes that conserve resources are often dependent on catalysts. Ion exchangers are firmly established in the chemical industry as versatile and efficient catalysts. They are used, for instance, in acid-catalyzed ester/ether synthesis and condensation reactions, such as in the production of bisphenol A, but also – with noble metal ions – in hydrogenation reactions. The catalyst can always be removed quickly and easily after the reaction.
We are working continuously with customers to identify new, innovative applications for such polymer catalysts and to develop new, customized product types.
Bisphenol A – a feedstock for polycarbonate plastics and epoxy resins – is produced through condensation of phenol with acetone, catalyzed with strongly acidic Lewatit® ion exchangers in gel form.
The antiknock agents for gasoline – MTBE, TAME, etc. – are produced through an addition reaction of olefins with alcohols, catalyzed with strongly acidic, macroporous Lewatit® cation exchangers.
Fatty acid methyl esters that are used as biodiesel or as feedstock for fatty alcohols are produced through the esterification of fatty acids and methanol, catalyzed with our strongly acidic, macroporous Lewatit® GF 101 ion exchanger or with concentrated mineral acids. In addition, our Lewatit® GF 202 is used for anhydrous biodiesel purification.
The chloralkali electrolysis membranes used in the membrane technique are extremely sensitive. Targeted treatment of the brines with ion exchange resins is necessary to protect these costly fluorinated membranes against contamination, which would irreversibly damage the membranes.
Two types of chelating ion exchange resins are used to treat the brines: IDA (iminodiacetic acid) and AMPA (aminomethylphosphonic acid). Our product range for brine softening and removal of alkaline earth metals comprises: Lewatit® MonoPlus TP 208 and Lewatit® MonoPlus TP 260, supplemented by the highly efficient finely dispersed types Lewatit® MDS TP 208 and Lewatit® MDS TP 260.
The reaction of carboxylic acids such as acetic acid, fatty acids or (meth-) acrylic acid with alcohols such as methanol, ethanol or butanol to produce the corresponding ester is catalyzed with strongly acidic, macroporous Lewatit® ion exchangers.
Phenol and acetone are produced through air oxidation of cumene followed by acid decomposition in the Hock process. This gives rise to by-products that cannot be separated from phenol. These by-products are converted into high boilers using Lewatit® K 2431 or Lewatit® K 2420, which can be removed from the phenol by distillation.
It is possible to remove oxygen efficiently from water or other solvents by reacting it with hydrogen, catalyzed with palladium-doped weakly or strongly alkaline Lewatit® anion exchangers. Other reducing agents such as hydrazine or formic acid can also be used as an alternative to hydrogen. In addition, palladium-doped strongly acidic Lewatit® cation exchangers are used in the hydrogenation of unsaturated organic substrates and simultaneously enable acid-catalyzed addition and elimination reactions.
Selective adsorption of carbon dioxide from the air or from flue or exhaust gases is carried out on our Lewatit® VP OC 1065 at room temperature. Raising the temperature and applying a vacuum allow the pure carbon dioxide to be recovered and used as a raw material in the production of chemicals such as methanol or fuels such as “e-fuels”.
