Abstract:
The present study was conducted to determine the calorific values of different types of organic waste i.e., garden, agricultural and food waste, collected from sectors I-11 and I-10 of Islamabad, and to ascertain its potential for utilizing in energy production. A digital bomb calorimeter was utilized to calculate the calorific values (CVs) of the collected waste samples. Samples were prepared and treated at three distinct temperatures i.e., 40°C, 60°C and 80°C. A total of 18 solid pallets were formulated 9 before composting and 9 after composting. The 9 waste samples were composted for several weeks before calculating their values for post composting. Corresponding weights and moisture content were also calculated of all samples, before calculating calorific values (CVs). The results showed that garden waste had the highest calorific value (CV) at 80°C, with the highest value in the sample after composting (AC). After composting, 60°C came next highest with maximum value in waste samples. At 40°C, the sample from before composting (BC) exhibited maximum calorific value. Calorific values of before composting (BC) samples were higher than those post composting. The maximum calorific value (CV) for agricultural waste was recorded at 80°C; after composting (AC) came second. Second-highest values were at 40°C, with AC sample having maximum value. Before composting (BC) sample had highest calorific value at 60°C. In comparison, Post composted waste samples exhibited the maximum calorific values. Food waste exhibited the maximum calorific value (CV) at 60°C, particularly in the pre-composting (PC) sample. For the Post composting (PC) samples, the second-highest values were recorded at 80°C. The pre-composting (PC) sample exhibited the highest calorific value at 40°C. Calorific values (CV) were maximal prior to composting (PC); subsequently, they decreased. The study's results demonstrated that the sorting and composting stages influence the calorific values of organic waste; hence, temperature is significantly relevant. Composting garden and agricultural waste increase calorific value, especially at high temperatures. Food waste has more energy before composting, especially at low temperatures. These findings indicated that composting and temperature management must be optimized to recover energy from organic waste, improving waste-to-energy systems.
