CO2-neutral process heat generation

Stu­dy com­mis­sio­ned by the Fede­ral Envi­ron­ment Agen­cy (Umwelt­bun­des­amt), 1 June 2019 til end of May 2023

Project description

The Ger­man govern­ment is pur­suing the goal of redu­cing green­house gas (GHG) emis­si­ons in Ger­ma­ny by 80 to 95% below 1990 levels by 2050, ther­eby hel­ping to pro­tect the cli­ma­te. The set­ting of inte­rim tar­gets and the use of various poli­cy instru­ments con­tri­bu­te to the achie­ve­ment of this goal. The goal is to achie­ve a 40% reduc­tion in green­house gas emis­si­ons below 1990 levels by 2020. Fur­ther­mo­re, as part of the ener­gy con­cept, the Ger­man govern­ment has deci­ded to redu­ce pri­ma­ry ener­gy con­sump­ti­on by 20% by 2020 and by 50% by 2050 com­pared to 2008 levels. For far-rea­ching decar­bo­niza­ti­on, the con­tri­bu­ti­on of indus­try in the form of great­ly redu­ced emis­si­ons is indis­pensable. A reduc­tion in Germany’s GHG emis­si­ons of 80–95% by 2050 also requi­res a simi­lar­ly high reduc­tion from the indus­tri­al sector.

Depic­tion of the work packa­ges (WP) with their respec­ti­ve main topics as well as WP manage­ment and infor­ma­ti­on flow

The indus­tri­al sec­tor had GHG emis­si­ons of 189 mil­li­on tons in 2015. Of the­se, 127 mil­li­on tons were ener­gy-rela­ted emis­si­ons and 62 mil­li­on tons were pro­cess- and pro­duct-rela­ted emis­si­ons. Ener­gy-rela­ted emis­si­ons are almost exclu­si­ve­ly attri­bu­ta­ble to the gene­ra­ti­on of pro­cess heat in almost all indus­tri­al sec­tors. In the manu­fac­tu­ring sec­tor, the majo­ri­ty of ener­gy requi­re­ments have so far been met by fos­sil fuels and elec­tri­ci­ty from con­ven­tio­nal ener­gy sources.

The gene­ra­ti­on of pro­cess heat in indus­tri­al fur­naces and steam gene­ra­tors is very appli­ca­ti­on-spe­ci­fic and depends on the par­ti­cu­lar con­di­ti­ons and requi­re­ments of the dif­fe­rent pro­duc­tion pro­ces­ses. The tem­pe­ra­tu­re levels and the mode of ope­ra­ti­on of the plants dif­fer signi­fi­cant­ly bet­ween the appli­ca­ti­ons. Accor­ding to the cur­rent sta­te of sci­ence, only iso­la­ted approa­ches to solu­ti­ons for the use of ener­gy from fluc­tua­ting rene­wa­ble ener­gy sources exist in the field of indus­tri­al fur­nace tech­no­lo­gy. Alt­hough tech­ni­cal pro­ces­ses are con­ceiva­ble for all are­as of pro­cess heat gene­ra­ti­on that allow a con­ver­si­on from fos­sil ener­gy sources to (rege­ne­ra­ti­ve) Power-to-Heat (PtH) or Power-to-Gas (PtG)/ Power-to-Liquid (PtL), the­se pro­ces­ses are still far from eco­no­mic via­bi­li­ty. This is part­ly due to the com­pa­ra­tively high elec­tri­ci­ty pri­ces, which is why the­se tech­no­lo­gies are curr­ent­ly only used for niche appli­ca­ti­ons or are still in the tech­ni­cal deve­lo­p­ment stage. In addi­ti­on to cost-effec­ti­ve­ness, other pro­per­ties of the ener­gy sources are equal­ly important for com­pa­nies when making invest­ment decis­i­ons. The­se include, for exam­p­le, secu­ri­ty of sup­p­ly, qua­li­ty, the effort requi­red for on-site pro­ces­sing, local pol­lutant emis­si­ons or the pre­cis­i­on with which the com­bus­ti­on pro­cess can be con­trol­led. New con­cepts for CO2-neu­tral pro­cess heat gene­ra­ti­on must be supe­ri­or to exis­ting sup­p­ly tech­no­lo­gies in the­se fac­tors in order to beco­me attrac­ti­ve to com­pa­nies and achie­ve broad mar­ket introduction.

The objec­ti­ves of the pro­ject are to deter­mi­ne the cur­rent sta­te of the art and the need for fur­ther action in the area of rese­arch and deve­lo­p­ment for the use of CO2-neu­tral pro­cess hea­ting sys­tems for the respec­ti­ve indus­tries and are­as of appli­ca­ti­on. A fur­ther objec­ti­ve is to esti­ma­te the eco­no­mic via­bi­li­ty of exem­pla­ry, par­ti­cu­lar­ly rele­vant tech­no­lo­gies. In addi­ti­on, the tech­no­lo­gies iden­ti­fied will be eva­lua­ted on the basis of tech­ni­cal, eco­no­mic and eco­lo­gi­cal cri­te­ria in order to deri­ve initi­al recom­men­da­ti­ons for their future appli­ca­ti­on that are as holi­stic as pos­si­ble. Final­ly, an over­all pic­tu­re of the cur­rent sta­tus and essen­ti­al ele­ments of an over­all stra­tegy for the future wide­spread use of CO2-neu­tral pro­cess hea­ting sys­tems in the indus­tri­al sec­tor will be deve­lo­ped on the basis of the fin­dings obtained.

Model sche­me of the eco­no­mic evaluation

Project goals

  • What is the cur­rent sta­te of the art of pro­cess heat gene­ra­ti­on in the sel­ec­ted industries?
  • Which PtH, PtG/PtL plants and pro­ces­ses are available, what is the deve­lo­p­ment sta­tus, how is the sub­sti­tu­ti­on of fos­sil refe­rence tech­no­lo­gies to be tech­ni­cal­ly asses­sed and what is the need for action?
  • How eco­no­mic­al are PtH, PtG/PtL plants com­pared to con­ven­tio­nal refe­rence plants?
  • How are PtH, PtG/PtL tech­no­lo­gies to be eva­lua­ted under holi­stic con­side­ra­ti­on of eco­lo­gi­cal, eco­no­mic and tech­ni­cal cri­te­ria in com­pa­ri­son to the fos­sil refe­rence technology?
  • How is the use of PtH, PtG/PtL for pro­cess heat gene­ra­ti­on to be clas­si­fied in an over­all pic­tu­re and strategy?

The­se ques­ti­ons are addres­sed on the basis of 15 sel­ec­ted tech­no­lo­gies from various sec­tors. A time per­spec­ti­ve up to the year 2050 is taken.

Project participants


Dr.-Ing. Chris­ti­an Schwotzer

+49 241 80–26068

Felix Kai­ser, M.Sc.

+49 241 80–25943

Cars­ten Gon­dorf, M.Sc.

+49 241 80–26074


This pro­ject was com­mis­sio­ned by the Fede­ral Envi­ron­ment Agen­cy and is being car­ri­ed out tog­e­ther with the Fraun­ho­fer Insti­tu­te for Sys­tems and Inno­va­ti­on Rese­arch (ISI).