The metal product P is produced in plant C$,$ where metal sheets are cut and pressed to form the product P$.$ Plant B produces the metal sheets, via melting and rolling of ingots. The ingots come from plant A where the mineral is extracted, turned into metal and cast into ingots. Plant B is situated $1000$ km from plant C$.$ Transportation occurs by truck, consuming on average $0\mathrm{.}019$ kg of diesel per km and per ton of material transported. Plant A and plant B are neighbouring plants; the distance between them is small and hence transportation is negligible. In the production of P in plant C there is also some process scrap $($pieces of metal clippings from the cutting of the metal sheets$).$ Three quarters of the process scrap generated by plant C is sent back to plant B where it is melted together with the $$new$$ metal and then rolled into sheets.

Plant A produces $1400$ tonnes of ingots per year using $4800$ tonnes of raw minerals and $12$x$106$ MJ of electricity; the plant releases $700$ kg$/$year of HCl to atmosphere and $700$ kg$/$year of Cu to freshwater. Plant B produces $1600$ tonnes of metal sheets per year, consuming $4\mathrm{.}8$x$106$ MJ of electricity; emissions to air from plant B are equal to $480$ kg$/$year of HC $($generic hydrocarbons$).$ Plant C produces $500$ tonnes of product P per year using $1\mathrm{.}2$x$106$ MJ of electricity; emissions to air from plant C are equal to $250$ kg$/$year of HC$.$

The Functional Unit equals $1000$ pieces of P$.$ Each product P weights $50$ g$.$ To produce $1000$ pieces of P$,10$ m$2$ of metal sheet is needed in plant C; the thickness of the metal sheet is $1\mathrm{.}5$ mm and the density of the metal is $8000$ kg$/$m$3.$