Tech Focus: Surface Treatment & Repair Wuppermann’s galvanising process saves 31 % CO2
Wuppermann Group has commissioned the Fraunhofer Institute for Environmental, Safety and Energy Technology to investigate the environmental impact of the Heat-to-Coat strip galvanising process.
The Fraunhofer Institute prepared a life cycle assessment according to DIN EN ISO 14040 and evaluated the environmental effects as climate impact in kg CO2 equivalents per kg hot-dip galvanised steel strip (kg CO2-eq./kg). The result: Where the areas of application for galvanised hot strip and galvanised cold strip overlap, i.e. where it is technically possible to use both cold-rolled and hot-rolled steel for an application, the CO2 balance shows an advantage of the Wuppermann process.
The galvanising processes including after-treatment cause 0.126 kg CO2 eq/kg at the Moerdijk (NL) site and 0.105 kg CO2 eq/kg CO2 emissions at the Judenburg (AT) site. The reference process causes CO2 emissions of 0.183 kg CO2-eq/kg. This results in a CO2 saving of 31 % at the Moerdijk site and 43 % at the Judenburg site. Included in here are the emissions from the production of the zinc and electricity consumed. Not included in this so-called gate-to-gate consideration is the environmental impact of the input material hot strip.
With an annual galvanising volume of approximately 600,000 tons, this results in CO2 savings of 34,200 tons at the Moerdijk site. In Judenburg, the savings amount to 4,680 tons with a galvanising output of approximately 60,000 tons.
“We are pleased with the verification that our special Heat-to-Coat process emits less carbon dioxide than conventional galvanising processes on the market. There are two main reasons for this: Firstly, in contrast to the standard process, we do not use fossil fuels but only electricity for heating. Secondly, we are able to avoid the energy intensive annealing, whereby our maximum temperature is about 450 °C, instead of 750 °C,” says Karsten Pronk, Technical Managing Director of Wuppermann Staal Nederland B.V.
This means that every improvement in the energy mix towards renewables leads directly to a reduction in the CO2-footprint of the Heat-to-Coat galvanising process. The main contributor of CO2 emissions of the Wuppermann process — and thus the most important lever for further emission reductions — is the electrical energy required for pickling and galvanising Additionally, and the production and origin zinc are a major contributor.
“For our customers, the ecological balance sheet of steel manufacturers is becoming even more increasingly important. The Fraunhofer Institute's proof of the CO2 advantage of the Wuppermann galvanising process therefore helps not only Europe but also our customers to achieve their climate targets,” adds Johannes Nonn, Spokesman of the Executive Board of Wuppermann AG.