PREPARATION OF CATALYST Cu-ZnO-MgO-Al2O3 FOR DIRECT SYNTHESIS OF DME

• Main Author: SWASTIKA - NIM : 23016004, TITIS
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/31340
• Institution: Institut Teknologi Bandung

<p align="justify">Decreasing fossil energy reserves, and environmental issues resulting from the use of fossil energy resources have encouraged an increase in the utilization of environmentally friendly and renewable energy sources, including biomass. This research is related to the development of a technology for processing biomass into dimethyl ether (DME). In RUEN2017, DME has been designated as a prospective substitute for LPG in the near future, since more than 60% of LPG's needs in Indonesia are met with imports. Currently, DME is commercially produced by dehydration of methanol. While this research is related to the development of a direct synthesis of DME from synthesis gas. <br /> <br /> This research is aimed at preparation of Cu-ZnO-MgO-Al2O3 catalysts by using coprecipitation method. Two types of catalyst were prepared, i.e. CZMA0 (without Mg) and CZMA20 (with Mg 20%). Both types of catalyst were activated by using reducing gas containing 5% H2 and N2. Activated catalyst was then tested for the activity in direct synthesis of DME, by using an artificial synthesis gas with a composition (mole fraction) of 65% H2, 28% CO and 7% N2. Synthesis reaction was carried out in a fixed bed reactor at 5 bar, and temperature of 240, 250 or 260oC. <br /> <br /> The pore characterization indicated that the CZMA0 catalyst has a surface area of 285 m2/g and a pore diameter of 2018 &#506;. During activation, CZMA20 catalysts consumed more H2 and needed a longer time than the catalyst CZMA0. In the synthesis process, CZMA20 catalyst resulted a highest CO conversion of 73% and a highest H2 conversion of 66% (at 5 bar and 260oC). These CO and H2 conversions were below the thermodynamic equilibrium conversion of 93%.. From all experiments, the yield of DME was still very low. <br /> <br /> In this study, experiments on synthesis of DME were also performed using a dual-catalyst, i.e. a bed of catalyst for methanol synthesis and a bed of catalyst for methanol dehydration to DME. With this dual bed configuration, CO conversion of 93% and H2 conversion of 91% were obtained. Unfortunately the yield of DME was also still small. Pressumably, some synthesis gas converted to side products, such as methanol (as intermediate) and CO2 (through water gas shift reaction).<p align="justify">