Water Footprint in Leather Tanning and Steel Production
149
Third step: New materials such as pig iron and reduced iron oxide are formed by
putting iron coke, cokes, and limestone in the blast furnace. Water is used for blast
furnace gas treatment, slag granulation, and cooling.
Fourth step: Air separation, oxygen for steel production in the basic oxygen
furnace is produced by separating oxygen from the air. The metal–carbon is lowered
by blowing pure oxygen over the hot metal. Water is required for cooling and
electricity provides the energy required for separation.
Fifth step: It is noted that stainless steel production mostly required requires
ferrochrome and ferronickel. In this step, iron and other metals are added to the basic
oxygen furnace to produce alloyed steel. Water is employed for gas treatment, slag
granulation, and cooling.
Sixth step: The materials resulted from step 3 (pig iron from the iron ore reduction
process), roughly contains 4% carbon, are transferred to the basic oxygen furnace
carbon-reducing by blowing pure oxygen onto the hot metal. Also, water is required
in this step for gas treatment, vacuum generation, cooling, and washing [19].
Based on the above steel production chain, it is well noted that energy and water
sustainability are undeniably intertwined, and then required a huge quantity of water
in all the six compartments.
13 System Boundary in Steel Industry
The industrial sector is the second major water consumer after agriculture in the
world. Then, in order to reduce water consumption and virtual water, the designing
of a suitable system boundary is very important. A system boundary can be defined
as a scheme that takes into account the different inputs and materials involved
during the processing to obtain the final products by assessing the pollution generated by wastewater. The illustration of a system boundary depends on each study
and the components to be considered. In a recent study concerning the life cycle
of water used and wastewater discharge of steel production in China, the system
boundary was regrouped into the steel production layer, steel enterprise, and social
environment [15]. The environment in this case was encompassed in the boundary
because the water treatment footprint concept also takes into account the pollution phenomena. These three levels of steel boundary include sintering, coking,
iron making, pelletizing, hot rolling, and cold rolling processes. It was noted that
the social environment layer includes purchased electricity and upstream intermediate products (oil, coal, coking coal, purchased sinter), whereas the steel enterprise
boundary comprises auxiliary processes, electricity, and wastewater treatment plants.
Contrarily, a system boundary in a steel industry consists of iron steelmaking, continuous cast, steel rolling and other processes, water consumption of staff, mechanic
energy costs, chemicals use, and transportation was used in another study [14].
Although the life cycle can be extended to a country, spatial boundary analyses
in literature are focused on particular enterprises, and enhance a methodology to
develop a common and appropriate water footprint assessment.
149
Third step: New materials such as pig iron and reduced iron oxide are formed by
putting iron coke, cokes, and limestone in the blast furnace. Water is used for blast
furnace gas treatment, slag granulation, and cooling.
Fourth step: Air separation, oxygen for steel production in the basic oxygen
furnace is produced by separating oxygen from the air. The metal–carbon is lowered
by blowing pure oxygen over the hot metal. Water is required for cooling and
electricity provides the energy required for separation.
Fifth step: It is noted that stainless steel production mostly required requires
ferrochrome and ferronickel. In this step, iron and other metals are added to the basic
oxygen furnace to produce alloyed steel. Water is employed for gas treatment, slag
granulation, and cooling.
Sixth step: The materials resulted from step 3 (pig iron from the iron ore reduction
process), roughly contains 4% carbon, are transferred to the basic oxygen furnace
carbon-reducing by blowing pure oxygen onto the hot metal. Also, water is required
in this step for gas treatment, vacuum generation, cooling, and washing [19].
Based on the above steel production chain, it is well noted that energy and water
sustainability are undeniably intertwined, and then required a huge quantity of water
in all the six compartments.
13 System Boundary in Steel Industry
The industrial sector is the second major water consumer after agriculture in the
world. Then, in order to reduce water consumption and virtual water, the designing
of a suitable system boundary is very important. A system boundary can be defined
as a scheme that takes into account the different inputs and materials involved
during the processing to obtain the final products by assessing the pollution generated by wastewater. The illustration of a system boundary depends on each study
and the components to be considered. In a recent study concerning the life cycle
of water used and wastewater discharge of steel production in China, the system
boundary was regrouped into the steel production layer, steel enterprise, and social
environment [15]. The environment in this case was encompassed in the boundary
because the water treatment footprint concept also takes into account the pollution phenomena. These three levels of steel boundary include sintering, coking,
iron making, pelletizing, hot rolling, and cold rolling processes. It was noted that
the social environment layer includes purchased electricity and upstream intermediate products (oil, coal, coking coal, purchased sinter), whereas the steel enterprise
boundary comprises auxiliary processes, electricity, and wastewater treatment plants.
Contrarily, a system boundary in a steel industry consists of iron steelmaking, continuous cast, steel rolling and other processes, water consumption of staff, mechanic
energy costs, chemicals use, and transportation was used in another study [14].
Although the life cycle can be extended to a country, spatial boundary analyses
in literature are focused on particular enterprises, and enhance a methodology to
develop a common and appropriate water footprint assessment.