diff --git a/core/presolve.gms b/core/presolve.gms
index 312c3f52a..1f20fc765 100644
--- a/core/presolve.gms
+++ b/core/presolve.gms
@@ -117,14 +117,14 @@ loop(regi,
 
 p_priceCO2(ttot,regi) = pm_taxCO2eqSum(ttot,regi) * 1000;
 
-*** Define co2 price for entities that are used in MAC. 
+*** Define co2 price for entities that are used in MAC.
 loop((enty,enty2)$emiMac2mac(enty,enty2), !! make sure that both mac sectors and mac curves have prices asigned as both sets are used in calculations below
   pm_priceCO2forMAC(ttot,regi,enty) = p_priceCO2(ttot,regi);
   pm_priceCO2forMAC(ttot,regi,enty2) = p_priceCO2(ttot,regi);
 );
 
 *** Redefine the MAC price for regions with emission tax defined by the regipol module
-$IFTHEN.emiMkt not "%cm_emiMktTarget%" == "off" 
+$IFTHEN.emiMkt not "%cm_emiMktTarget%" == "off"
  loop(ext_regi$regiEmiMktTarget(ext_regi),
   loop(regi$regi_groupExt(ext_regi,regi),
 *** average CO2 price aggregated by FE
@@ -169,7 +169,9 @@ vm_macBase.fx(ttot,regi,"ch4wsts")$(ttot.val ge 2005) = p_emineg_econometric(reg
 vm_macBase.fx(ttot,regi,"ch4wstl")$(ttot.val ge 2005) = p_emineg_econometric(regi,"ch4wstl","p1") * pm_pop(ttot,regi) * (1000*pm_gdp(ttot,regi) / (pm_pop(ttot,regi)*pm_shPPPMER(regi)))**p_emineg_econometric(regi,"ch4wstl","p2");
 vm_macBase.fx(ttot,regi,"n2owaste")$(ttot.val ge 2005) = p_emineg_econometric(regi,"n2owaste","p1") * pm_pop(ttot,regi) * (1000*pm_gdp(ttot,regi) / (pm_pop(ttot,regi)*pm_shPPPMER(regi)))**p_emineg_econometric(regi,"n2owaste","p2");
 
-vm_macBase.fx(ttot,regi,"co2cement_process")$( ttot.val ge 2005 ) 
+
+$ifthen.fixed_shares "%industry%" == "fixed_shares"
+vm_macBase.fx(ttot,regi,"co2cement_process")$( ttot.val ge 2005 )
   = ( pm_pop(ttot,regi)
     * ( (1 - p_switch_cement(ttot,regi))
       * p_emineg_econometric(regi,"co2cement_process","p1")
@@ -189,6 +191,7 @@ vm_macBase.fx(ttot,regi,"co2cement_process")$( ttot.val ge 2005 )
 
 vm_emiIndBase.fx(ttot,regi,"co2cement_process","cement")$( ttot.val ge 2005 )
 = vm_macBase.lo(ttot,regi,"co2cement_process");
+$endif.fixed_shares
 
 * *** Reduction of cement demand due to CO2 price markups *** *
 if ( NOT (cm_IndCCSscen eq 1 AND cm_CCS_cement eq 1),
@@ -202,7 +205,7 @@ if ( NOT (cm_IndCCSscen eq 1 AND cm_CCS_cement eq 1),
   display "CO2 price for computing Cement Demand Reduction [$/tC]",
           pm_CementAbatementPrice;
 
-  !! The demand reduction function a = 160 / (p + 200) + 0.2 assumes that demand 
+  !! The demand reduction function a = 160 / (p + 200) + 0.2 assumes that demand
   !!  for cement is reduced by 40% if the price doubles (CO2 price of $200) and
   !!  that demand reductions of 80% can be achieved in the limit.
   pm_ResidualCementDemand("2005",regi) = 1;
@@ -230,7 +233,7 @@ if ( NOT (cm_IndCCSscen eq 1 AND cm_CCS_cement eq 1),
   display "Cement Demand Reduction, price of limited reduction",
           pm_CementAbatementPrice;
 
-  !! Costs of cement demand reduction are the integral under the activity 
+  !! Costs of cement demand reduction are the integral under the activity
   !! reduction curve times baseline emissions.
   !! a = 160 / (p + 200) + 0.2
   !! A = 160 ln(p + 200) + 0.2p
@@ -282,7 +285,7 @@ pm_macAbat(ttot,regi,enty,steps)
 ;
 pm_macAbat(ttot,regi,enty,steps)$(ttot.val gt 2100) = pm_macAbat("2100",regi,enty,steps);
 
-*** Abatement options are in steps of length sm_dmac; options at zero price are 
+*** Abatement options are in steps of length sm_dmac; options at zero price are
 *** in the first step
 pm_macStep(ttot,regi,enty)$(MacSector(enty))
   = min(801, ceil(pm_priceCO2forMAC(ttot,regi,enty) / sm_dmac) + 1);
@@ -294,8 +297,8 @@ p_priceGas(ttot,regi)=q_balPe.m(ttot,regi,"pegas")/(qm_budget.m(ttot,regi)+sm_ep
 pm_macStep(ttot,regi,"ch4gas")
   = min(801, ceil(max(pm_priceCO2forMAC(ttot,regi,"ch4gas") * (25/s_gwpCH4), max(0,(p_priceGas(ttot,regi)-p_priceGas("2005",regi))) ) / sm_dmac) + 1);
 pm_macStep(ttot,regi,"ch4coal")
-  = min(801, ceil(max(pm_priceCO2forMAC(ttot,regi,"ch4coal") * (25/s_gwpCH4), 0.5 * max(0,(p_priceGas(ttot,regi)-p_priceGas("2005",regi))) ) / sm_dmac) + 1);    
-  
+  = min(801, ceil(max(pm_priceCO2forMAC(ttot,regi,"ch4coal") * (25/s_gwpCH4), 0.5 * max(0,(p_priceGas(ttot,regi)-p_priceGas("2005",regi))) ) / sm_dmac) + 1);
+
 *** limit yearly increase of MAC usage to sm_macChange
 p_macAbat_lim(ttot,regi,enty)
   = sum(steps$(ord(steps) eq pm_macStep(ttot-1,regi,enty)),
@@ -304,7 +307,7 @@ p_macAbat_lim(ttot,regi,enty)
   + sm_macChange * pm_ts(ttot)
 ;
 
-*** if intended abatement pm_macAbat is higher than this limit, pm_macStep has to 
+*** if intended abatement pm_macAbat is higher than this limit, pm_macStep has to
 *** be set to the highest step number where pm_macAbat is still lower or equal to
 *** this limit
 loop ((ttot,regi,MacSector(enty))$(NOT sameas(enty,"co2luc")),
@@ -317,7 +320,7 @@ loop ((ttot,regi,MacSector(enty))$(NOT sameas(enty,"co2luc")),
   );
 );
 
-*** In USA, EUR and JPN, abatement measures for CH4 emissions from waste started 
+*** In USA, EUR and JPN, abatement measures for CH4 emissions from waste started
 *** in 1990. These levels of abatement are enforced as a minimum in all
 *** scenarios including BAU.
 p_macUse2005(regi,enty) = 0.0;
@@ -329,7 +332,7 @@ p_macUse2005(regi,"ch4wsts")$(pm_gdp_gdx("2005",regi)/pm_pop("2005",regi) ge 10)
 *** This includes sum of sub-categories from MAgPIE (see mapping emiMac2mac).
 pm_macAbat(ttot,regi,MacSectorMagpie(enty),"1") = 0;
 
-*** phase in use of zero cost abatement options until 2040 if there is no 
+*** phase in use of zero cost abatement options until 2040 if there is no
 *** carbon price
 p_macLevFree(ttot,regi,enty)$( ttot.val gt 2005 )
   =
@@ -391,7 +394,7 @@ loop (ttot$( ttot.val ge 2015 ),
 
 Display "computed abatement levels at carbon price", pm_macAbatLev;
 
-    
+
 ***--------------------------------------
 *** MAC costs
 ***--------------------------------------
diff --git a/modules/37_industry/subsectors/equations.gms b/modules/37_industry/subsectors/equations.gms
index 615662995..37de62fde 100644
--- a/modules/37_industry/subsectors/equations.gms
+++ b/modules/37_industry/subsectors/equations.gms
@@ -81,23 +81,28 @@ $endif.exogDem_scen
 *' energy mix, as that is what can be captured); vm_emiIndBase itself is not used for emission
 *' accounting, just as a CCS baseline.
 ***------------------------------------------------------
-q37_emiIndBase(t,regi,entyFe,secInd37) ..
-    vm_emiIndBase(t,regi,entyFe,secInd37)
+q37_emiIndBase(t,regi,enty,secInd37)$( entyFeCC37(enty) OR sameas(enty,"co2cement_process") ) ..
+    vm_emiIndBase(t,regi,enty,secInd37)
   =e=
-    sum((secInd37_2_pf(secInd37,ppfen_industry_dyn37(in)),fe2ppfEn(entyFeCC37(entyFe),in)),
+    sum((secInd37_2_pf(secInd37,ppfen_industry_dyn37(in)),fe2ppfEn(entyFeCC37(enty),in)),
       ( vm_cesIO(t,regi,in)
       - ( p37_chemicals_feedstock_share(t,regi)
         * vm_cesIO(t,regi,in)
         )$( in_chemicals_feedstock_37(in) )
       )
         *
-        sum(se2fe(entySeFos,entyFe,te),
-            pm_emifac(t,regi,entySeFos,entyFe,te,"co2")
+        sum(se2fe(entySeFos,enty,te),
+            pm_emifac(t,regi,entySeFos,enty,te,"co2")
         )
     )$(NOT secInd37Prc(secInd37))
     +
+    (s37_clinker_process_CO2
+    * p37_clinker_cement_ratio(t,regi)
+    * vm_cesIO(t,regi,"ue_cement")
+    / sm_c_2_co2)$(sameas(enty,"co2cement_process") AND sameas(secInd37,"cement"))
+    +
     sum((secInd37_tePrc(secInd37,tePrc),tePrc2opmoPrc(tePrc,opmoPrc)),
-        v37_emiPrc(t,regi,entyFe,tePrc,opmoPrc)
+        v37_emiPrc(t,regi,enty,tePrc,opmoPrc)
     )$(secInd37Prc(secInd37))
 ;
 
diff --git a/modules/37_industry/subsectors/presolve.gms b/modules/37_industry/subsectors/presolve.gms
deleted file mode 100644
index d18daabdb..000000000
--- a/modules/37_industry/subsectors/presolve.gms
+++ /dev/null
@@ -1,24 +0,0 @@
-*** |  (C) 2006-2023 Potsdam Institute for Climate Impact Research (PIK)
-*** |  authors, and contributors see CITATION.cff file. This file is part
-*** |  of REMIND and licensed under AGPL-3.0-or-later. Under Section 7 of
-*** |  AGPL-3.0, you are granted additional permissions described in the
-*** |  REMIND License Exception, version 1.0 (see LICENSE file).
-*** |  Contact: remind@pik-potsdam.de
-*** SOF ./modules/37_industry/subsectors/presolve.gms
-
-*' The process emissions from cement production are calculated using a fixed
-*' CO2-to-clinker ratio (0.5262 kg CO2/kg clinker), region-specific
-*' clinker-to-cement ratios, and the cement production from the production
-*' function.
-*' Last iteration's cement production value is used, since the MAC mechanism is
-*' outside of the optimisation loop.
-vm_emiIndBase.fx(ttot,regi,"co2cement_process","cement")$( ttot.val ge 2005 )
-  = s37_clinker_process_CO2
-  * p37_clinker_cement_ratio(ttot,regi)
-  * vm_cesIO.l(ttot,regi,"ue_cement")
-  / sm_c_2_co2;
-
-
-***p37_emiFac(ttot,regi,entyFe) = sum((entySe,te)$(se2fe(entySe,entyFe,te) and entySeFos(entySe)), pm_emifac(ttot,regi,entySe,entyFe,te,"co2"));
-
-*** EOF ./modules/37_industry/subsectors/presolve.gms
diff --git a/modules/37_industry/subsectors/realization.gms b/modules/37_industry/subsectors/realization.gms
index 0e0855cd0..bc70e2151 100644
--- a/modules/37_industry/subsectors/realization.gms
+++ b/modules/37_industry/subsectors/realization.gms
@@ -58,7 +58,6 @@ $Ifi "%phase%" == "datainput" $include "./modules/37_industry/subsectors/datainp
 $Ifi "%phase%" == "equations" $include "./modules/37_industry/subsectors/equations.gms"
 $Ifi "%phase%" == "preloop" $include "./modules/37_industry/subsectors/preloop.gms"
 $Ifi "%phase%" == "bounds" $include "./modules/37_industry/subsectors/bounds.gms"
-$Ifi "%phase%" == "presolve" $include "./modules/37_industry/subsectors/presolve.gms"
 $Ifi "%phase%" == "postsolve" $include "./modules/37_industry/subsectors/postsolve.gms"
 *######################## R SECTION END (PHASES) ###############################
 *** EOF ./modules/37_industry/subsectors/realization.gms