diff --git a/config.yaml b/config.yaml
index b0f56b10..f3faa3f8 100644
--- a/config.yaml
+++ b/config.yaml
@@ -147,6 +147,12 @@ solving:
     #barrier_convergetol: 1.e-5
     #feasopt_tolerance: 1.e-6
 
+industry:
+  'DRI_ratio' : 0.5 #ratio of blast-furnace steel transformed into DRI + electric arc
+  'H2_DRI' : 1.7   #H2 consumption in Direct Reduced Iron (DRI),  MWh_H2/ton_Steel
+  'Al_to_scrap' : 0.5 # ratio of primary-route Aluminum transformed into scrap 
+  'H2_for_NH3' : 85000 # H2 for NH3 transformed from SMR to electrolyzed-H2, in GWh/year following Lechtenböhmer(2016)
+  
 plotting:
   map:
     figsize: [7, 7]
diff --git a/scripts/build_industry_sector_ratios.py b/scripts/build_industry_sector_ratios.py
index ba14c3f9..baad720b 100644
--- a/scripts/build_industry_sector_ratios.py
+++ b/scripts/build_industry_sector_ratios.py
@@ -163,8 +163,8 @@ df.loc[['elec','heat','methane'],sector] = df.loc[['elec','heat','methane'],sect
 df['Integrated steelworks']=df['Electric arc']
 
 # adding the Hydrogen necessary for the Direct Reduction of Iron. consumption 1.7 MWh H2 /ton steel
-#(0.5 becuase only half of the steel requires DRI, the rest is scrap  metal)
-df.loc['hydrogen', 'Integrated steelworks'] =1.7 * 0.5
+#(0.5 because only half of the steel requires DRI, the rest is scrap  metal)
+df.loc['hydrogen', 'Integrated steelworks'] =snakemake.config["industry"]["H2_DRI"] * snakemake.config["industry"]["DRI_ratio"]
 
 
 ## Chemicals Industry
@@ -220,8 +220,8 @@ df.loc['naphtha',sector] += s_fec['Naphtha']
 
 # natural gas
 # 85 TWh/year of methane for the ammonia industry are substituted by hydrogen
-df.loc['methane',sector] += s_fec['Natural gas'] - 85000/conv_factor
-df.loc['hydrogen',sector] += 85000/conv_factor
+df.loc['methane',sector] += s_fec['Natural gas'] - snakemake.config["industry"]["H2_for_NH3"]/conv_factor
+df.loc['hydrogen',sector] += snakemake.config["industry"]["H2_for_NH3"]/conv_factor
 # 1 ktoe = 11630 MWh
 
 # LPG and other feedstock materials are assimilated to naphtha since they will be produced trough Fischer-Tropsh process
@@ -1050,8 +1050,8 @@ df.loc[sources,sector] = df.loc[sources,sector]*conv_factor/s_out['Aluminium - s
 # 1 ktoe = 11630 MWh
 
 # primary route is divided into 50% remains as today and 50% is transformed into secondary route
-df.loc[sources,'Aluminium - primary production'] = 0.5*df.loc[sources,'Aluminium - primary production'] + 0.5*df.loc[sources,'Aluminium - secondary production']
-df.loc['process emission','Aluminium - primary production'] = 0.5*df.loc['process emission','Aluminium - primary production']
+df.loc[sources,'Aluminium - primary production'] = (1-snakemake.config["industry"]["Al_to_scrap"])*df.loc[sources,'Aluminium - primary production'] + snakemake.config["industry"]["Al_to_scrap"]*df.loc[sources,'Aluminium - secondary production']
+df.loc['process emission','Aluminium - primary production'] = (1-snakemake.config["industry"]["Al_to_scrap"])*df.loc['process emission','Aluminium - primary production']
 
 ### Other non-ferrous metals