Abstract
New method of environmental load estimation for scraps and by-products production in Life cycle inventory (LCI) based on Input-Output table (I/O table) has been developed. And a new description method of I/O table with scraps and by-products sections for the estimation is developed. In this study, both scraps and by-products are regarded as products, and are dealt with as an independent section in I/O table, respectively. By means of this method, the energy consumption and CO2 emission of process-scrap steel production are estimated as an example study. And a weighted average value of energy consumption and that of CO2 emission with consideration to the monetary amounts of production of process-scrap steel were calculated by using the estimated data, respectively. Moreover, a reliability of the estimated data is analyzed. And LCI of converter steel and EAF steel are done in order to evaluate an influence by differences of data. As a result, when the value of a process scrap was assumed to be zero, the energy consumption rates of zero against the maximum is estimated 0.5% for the converter steel, and 20.4% for the EAF steel, respectively. Therefore, in case of converter, it is possible to treat the environmental load of a process scrap for nothing in approximation.
