nan Subagjo

Process assessment of small scale low temperature methanol synthesis

Biomass is a renewable energy resource and has the potential to make a significant impact on domestic fuel supplies. Biomass can be converted to fuel like methanol via several step process. The process can be split into following main steps: biomass preparation, gasification, gas cooling and cleaning, gas shift and methanol synthesis. Untill now these configuration still has a problem like high production cost, catalyst deactivation, economy of scale and a huge energy requirements. These problems become the leading inhibition for biomass conversion to methanol, which should be resolved to move towards the economical. To address these issues, we developed various process and new configurations for methanol synthesis via methyl formate. This configuration combining two reactors: the one reactor for the carbonylation of methanol and CO to form methyl formate, and the second for the hydrogenolysis of methyl formate and H2 to form two molecule of methanol. Four plant process configurations were compared with t...

Atmospheric hydrogenolysis of methyl formate to bio-methanol using Cu/MgO catalyst

Activity at various operating condition on the hydrogenolysis of methyl formate to bio-metanol using Cu/MgO catalyst were tested in the range of 19.7 ± 75.5%-wt Cu, 120±180°C, 1±2 molar feed ratio (H2/HCOOCH3) and 1.4±4.3 kg.h/kmol. Methanol was produced under the studied conditions. Copper concentration have a significant effect on the activity of the catalyst. A maximum conversion of hydrogen was obtained at 51.7%-wt of Cu (C75M25). Higher temperatures and space time enhanced methanol productivity, while higher molar feed ratio decreased productivity. Kinetic experiments of hydrogenolysis of methyl formate were carried out using a C75M25 catalyst. Kinetic studies, interpreted by applying the basis of the Langmuir–Hinshelwood model, suggested that the rate-determining step involves the reaction of adsorbed methyl formate with adsorbed H atoms. The activation energy of this reaction was measured to be about 57 kJ.mol−1.

Thermal decomposition of dolomite under CO2-air atmosphere

This paper reports a study on thermal decomposition of dolomite under CO2-air. Calcination was carried out non-isothermally by using thermogravimetry analysis-differential scanning calorimetry (TGA-DSC) with a heating rate of 10°C/minute in an air atmosphere as well as 10 vol% CO2 and 90 vol% air atmosphere from 25 to 950°C. In addition, a thermodynamic modeling was also carried out to simulate dolomite calcination in different level of CO2−air atmosphere by using FactSage® 7.0. The the main constituents of typical dolomite from Gresik, East Java include MgCO3 (magnesite), CaCO3 (calcite), Ca(OH)2, CaO, MgO, and less than 1% of metal impurities. Based on the kinetics analysis from TGA results, it is found that non-isothermal dolomite calcination in 10 vol% CO2 atmosphere is occurred in a two-stage reaction; the first stage is the decomposition of magnesite at 650-740 °C with activation energy of 161.23 kJ/mol, and the second stage is the decomposition of calcite at 775-820 °C with activation energy of 162...