The mass yield from each sample was calculated as the mass of activated carbon divided by the mass of the initial dry sample. The percentage yield of the activated carbon from the raw materials as well as iodine number and adsorption of heavy metals from aqueous solutions were also determined. The experimental data which make a comparative assessment of activated carbon obtained from rice husk and saw dust were also presented. fixed carbon they both possess from the list of activated carbon prepared. The results obtained clearly show that, as expected, as H 3 PO 4 concentration increases the total yield of the process decreases. Average yield of activated carbon is 94.3%. In his study activated carbon was prepared from Helhelok stones as a raw material by using chemical activation with zinc chloride (ZnCl2) as a chemical agent with the concentration 40% for 25h at (25⁰C±2). Temperature, solid liquid ratio, digestion time and salt catalysts had a great influence on percentage yield. Table 2 Activated carbon yield . Yield percentage shows the amount of activated carbon formed from physical activation process. The percentage of total carbon present in each sample was measured using the Skalar Primacs MCS instrument.  for activated carbon production from jackfruit peel waste by chemical activation with H 3 PO 4. based activated carbon (RHAC) for the removal of Cu (II) from aqueous solutions were investigated using central composite design (CCD). Effect of Digestion time on average yield of active carbons: The data compiled in Fig. As the impregnation ratio increases, the percentage yield of the activated carbon decreases gradually due to the continuous removal of tar material from the pores . This behavior agrees with results obtained by Prahas et al. The optimum conditions were approved in having carbonization temperature 400ᵒC for 1h to get a maximum percentage of yield 56%. The Carbon Yield (C Y) of each bond is calculated at the issuer’s Green Bond Framework9 level, and thus is a weighted average of the carbon yield of each project within that Framework. The nomenclature, operation conditions, density and yield of the different samples prepared by the method of chemical activation with phosphoric acid are summarized in Table 1. The percentage fixed carbon of PMA and PSA were 84.88% and 84.80% respectively. Yield of activated carbon. Based on the CCD, a two-factor-interaction (2FI) and a quadratic models were respectively developed for RHAC yield and percentage of Cu (II) removal. from physical activation process. Dried samples were weighted in quartz crucibles and combusted at 1373 K in a pure oxygen atmosphere, and the formed CO By using the Carbon Yield investors can ensure that the mitigation impacts of their Green Bonds holdings are being calculated consistently. activated at 700ºC in the absence of air in muffle furnace and percentage yield of activated carbon was determined. No. Initial Mass (gram) Final Mass (gram) Yield (%) 1 100 94,3 94,0% 2 100 95,0 94,2% 3 101 96,1 94,5% 101 95,7 94,7% Average 94,4%.