Search

We investigate a P1 finite element method for a two-dimensional weighted optimal control problem arising from a three-dimensional (3D) axisymmetric elliptic state-constrained optimal control problem with Dirichlet boundary conditions. [ABSTRACT FROM AUTHOR]

In this study a carbon-rich product was achieved by hydrothermal carbonization (HTC) of dead leaves at different treatment temperatures of 200-250 °C. Biomass was treated with hot deionized water for 30 min. The main objective of this study was to calculate the energy generation capability of dead leaves hydrochar by HTC process. The secondary objective was to analyze the physiochemical properties of hydrochar. There was a significant increase in the energy content and energy yield while decrease in yield of hydrochar was observed with increase in temperature. Surface area of hydrochar was maximum of 2.09 m/g which was obtained when heated at 250 °C. Feedstock was having pore diameter of 8.26 nm which begin to increase on heating. The highest was reported at 220 °C of 21.79 with 163 % of increase. At 220 °C pore volume was also highest of 9.86 × 10. The highest energy content of 19.98 MJ/kg was obtained when the feedstock was heated at 240 °C which showed 21 % increase in energy content compared to that of raw biomass. Similarly, energy yield was also highest (91.67 %) at 240 °C. Therefore, it can be concluded that high-energy content hydrochar can be recovered when carbonized at 240 °C. [ABSTRACT FROM AUTHOR]