The ambi­tious yet urgent cli­ma­te tar­gets of the Paris Agree­ment call for swift action from natio­nal and regio­nal poli­cy­ma­kers as well as indus­try. Saint-Gobain has set its­elf the goal of achie­ving CO₂ neu­tra­li­ty world­wi­de by 2050. This tar­get is a par­ti­cu­lar chall­enge for the ener­gy-inten­si­ve glass industry.
The Saint-Gobain (SG) site in Her­zo­gen­rath, with its flat glass pro­duc­tion (float glass) and fur­ther pro­ces­sing into auto­mo­ti­ve glass, has set its­elf the goal of achie­ving CO₂ neu­tra­li­ty by 2030 and taking on a pio­nee­ring role both regio­nal­ly and inter­na­tio­nal­ly. On the one hand, this ser­ves to secu­re the loca­ti­on, and on the other hand, it should simul­ta­neous­ly pro­vi­de the bench­mark of the fea­si­bi­li­ty of such a pro­ject by 2030.
The over­all goal of the pro­ject is to achie­ve CO₂ neu­tra­li­ty accor­ding to Scope 1 and 2 by 2030 for the enti­re site. The Her­zo­gen­rath site wants to lead the way in this radi­cal trans­for­ma­ti­on pro­cess in order to posi­ti­on the loca­ti­on for the future and to secu­re the long-term future of the site and the appro­xi­m­ate­ly 1,000 jobs.
The acti­vi­ties plan­ned at the Saint-Gobain site fol­low two paths that com­ple­ment each other to form a holi­stic con­cept. In addi­ti­on to the deve­lo­p­ment of a new glass fur­nace tech­no­lo­gy (“CO₂-neu­tral glass mel­ting fur­nace”), an opti­mi­sed ener­gy effi­ci­en­cy of the over­all ener­gy sys­tem at the site is to be achieved.
One work packa­ge is aimed at flat glass pro­duc­tion as the main emit­ter of CO₂ with more than 80% of the ener­gy demand at the site, so that the first indus­tri­al CO₂-neu­tral glass mel­ting fur­nace (float glass) is to be built at the site by 2030. Today, the ener­ge­tic power demand is cover­ed by natu­ral gas and a small share of elec­tri­ci­ty. In future, e‑boosting (elec­tric auxi­lia­ry hea­ting of the glass melt) is to be increased to the tech­ni­cal maxi­mum, which, howe­ver, seems to be limi­t­ed by the high demands on glass qua­li­ty accor­ding to cur­rent know­ledge. The ener­gy requi­red in addi­ti­on is to be cover­ed by an emis­si­on-free fuel, pre­fer­a­b­ly hydro­gen, ins­tead of natu­ral gas as befo­re. The use of oxy­gen in com­bus­ti­on is also con­side­red, sin­ce the neces­sa­ry hydro­gen must be pro­du­ced decen­tral­ly at the site due to a lack of infra­struc­tu­re, and oxy­gen would thus be pro­du­ced as a usable by-pro­duct of electrolysis.
The exact design of this hybrid tech­no­lo­gy and its influence on, among other things, the chan­ged com­bus­ti­on pro­per­ties in the com­bus­ti­on cham­ber, NO_x for­ma­ti­on, heat trans­fer, chan­ged flow of the glass melt with influence on the glass qua­li­ty as well as the impli­ca­ti­ons for the refrac­to­ry mate­ri­als must be cla­ri­fied in advan­ce within the frame­work of fea­si­bi­li­ty studies.
In addi­ti­on to the tech­no­lo­gi­cal rede­sign of flat glass pro­duc­tion, the ther­mal pro­ces­ses in the area of auto­mo­ti­ve glass pro­duc­tion at SG Seku­rit are to be opti­mi­sed as part of a “smart infra­struc­tu­re”, and a com­pre­hen­si­ve ener­gy sys­tem ana­ly­sis and opti­mi­sa­ti­on of the enti­re site is to be car­ri­ed out.
In this con­text, ano­ther work packa­ge aims to iden­ti­fy and quan­ti­fy fur­ther ener­gy saving poten­ti­al in auto­mo­ti­ve glass pro­duc­tion. In par­ti­cu­lar, the line for lami­na­ted safe­ty glass (winds­creens and roofs) that has exis­ted at the site sin­ce 2020 and was trans­fer­red from the SG site in Stol­berg has increased ener­gy demand and is to be ana­ly­sed in terms of its ener­gy effi­ci­en­cy. But also, the alre­a­dy exis­ting lines for sin­gle-pane safe­ty glass (side win­dows, rear win­dows and roofs) are to be ana­ly­sed and eva­lua­ted holi­sti­cal­ly with regard to their ener­gy demand.
Final­ly, a detail­ed ana­ly­sis of the enti­re site, all requi­red mate­ri­al and ener­gy flows of the three units SG Glass, SG Seku­rit and SG Rese­arch Ger­ma­ny is to be recor­ded, the fea­si­bi­li­ty of CO₂ neu­tra­li­ty of the enti­re sys­tem is to be work­ed out and an ener­ge­tic simu­la­ti­on model of the enti­re site is to be crea­ted for design and effi­ci­en­cy opti­mi­sa­ti­on. This is to be trans­fer­red to other loca­ti­ons in the future.
For ener­gy opti­mi­sa­ti­on, opti­ons for ener­gy con­ver­si­on are to be con­side­red, in par­ti­cu­lar through impro­ved resour­ce effi­ci­en­cy and impro­ved was­te heat uti­li­sa­ti­on as well as sec­tor cou­pling. The aim is also to design the ener­gy sys­tem for maxi­mum secu­ri­ty of sup­p­ly. The ener­gy net­wor­king of the site must result in an eco­no­mic­al­ly via­ble con­cept in the medi­um term, so it should also be pos­si­ble to map pos­si­ble inter­faces with the city of Her­zo­gen­rath, e.g. with regard to a dis­trict hea­ting net­work, as part of the opti­mi­sa­ti­on model that is being developed.