Modified Two-Step Dimethyl Ether (DME) Synthesis Simulation From Indonesian Brown Coal

A theoretical study was conducted to investigate the performance of dimethyl ether (DME) synthesis from coal. This paper presents a model for two-step DME synthesis from brown coal represented by the following processes: drying, gasification, water-gas reaction, acid gas removal, and DME synthesis reactions. The results of the simulation suggest that a feedstock ratio of coal : oxygen : steam of 1 : 0.13 : 0.821 produces the highest DME concentration. The water-gas reactor simulation at a temperature of 400°C and a pressure of 20 bar gave the ratio of H2/CO closest to 2, the optimal value for two-step DME synthesis. As for the DME synthesis reactor simulation, high pressure and low temperature promote a high DME concentration. It is predicted that a temperature of 300°C and a pressure of 140 bar are the optimum conditions for the DME synthesis reaction. This study also showed that the DME concentration produced by the two-step route is higher than that produced by one-step DME synthesis, implying that further improvement and research are needed to apply two-step DME synthesis to production of this liquid fuel

Karakterisasi Produk Biosolubilisasi Lignit Oleh Kapang Indigenus Dari Tanah Pertambangan Batubara Di Sumatera Selatan

Characterization of Lignite Biosolubilization Products by Indigenous Moulds from Soil ofCoal Mining in South Sumatera. Biosolubilization of coal is a potential technology of convertingsolid coal to liquid fuel and chemicals at ambient condition. Our previous research hassuccessfully isolated four moulds from soil at coal mining - South Sumatera and has potency aslignite biosolubilization agent, i.e. T1, T2, T4, T5. The objective of this research was to characterizeof lignite biosolubilization products by four isolates. The method used was sub-mergedculture. Cultivation medium was MSS+ (minimal salt + sucrose 0,1% + yeast extract 0,01% +lignite 5 %). Incubation was conducted at room temperature for 28 days. The result showed thatall indigenos moulds have different ability in lignite biosolubilization. The highestbiosolubilization occurred after 7 days of incubation belonging to T1 isolate. However, GC-MSanalysis showed the largest percentage of hydrocarbon compound which equivalent to gasolineand diesel was T5 after 7 days of incubation