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The aluminum (Al) leaching kinetics from peat clay was investigated using various acid concentrations 1 M to 6 M, particle sizes +70-120 mesh to +200-325 mesh and temperatures 30 °C to 90 °C. They all have significant effects on aluminum leaching process. The Al leaching recovery was best found to be 91.3 % at 4 M hydrochloric acid (HCl), using a particle size of +200-325 mesh with solid/liquid of 0.02 g·ml-1. Leaching kinetic study was applied to the two rate equations proposed that is acid diffusion via product layer and surface chemical reaction using the shrinking core (SC) model to analyze the leaching data. The product layer diffusion is controlling Al leaching process for one-stage model, while for two-stage model, it was controlled by surface chemical reaction. The activation energy in the two rate controlling step was 82.79 kJ mol-1 and 27.08 kJ mol-1, respectively.

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The aim of this research is to get the optimum operating condition of crude distillation unit in order to get the highest profit for the crude oil refinery industry. Feed's specification data are taken from an Indonesian crude oil refinery. Simulation was done by using ASPEN PLUS (Aspen Technology, Inc, Burlington, MA, USA). The design variable for this research is the temperature of preflash column furnace. Optimization was done by considering the maximum profit. Based on the result in part one, where intermediate and light cold test molar flowrates and the quality of heavy naphtha in the 95% liquid volume ASTM D86 at 415 K and light kerosene distillate in the 95% liquid volume ASTM D86 at 469 K are held constant, the optimum condition is found at the furnace preflash temperature of 572 K with a profit of US$ 9.62 per m 3 crude oil. While in part two, where heavy naphtha and light kerosene distillate molar flowrates and the quality of intermediate in the 95% liquid volume ASTM D86 at 443 K and light cold test in the 95% liquid volume ASTM D86 at 605 K are held constant, the optimum condition is found at the furnace preflash temperature of 533 K with a profit of US$ 7.74 per m 3 crude oil.