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EN
Calcium carbide waste (CCW), the rest of the carbide welding workshop industry, is available in quite a lot and is immediately disposed of into the environment. Because CWW has a high pH value and a large specific surface area, it can act as an adsorbent in removing metals from groundwater. The content of metals in groundwater is indicated by a reddish color; however, upon contact with air, groundwater oxidation causes iron ions and manganese ions to precipitate. Synthetic groundwater was prepared in this experiment using reagents containing and . Observations were made in a batch process to assess the potential and ability of CCW to reduce iron and manganese levels in groundwater. In this study, to achieve equilibrium, CCW was mixed with 100 mL of synthetic solution and shaken at 25°C with a shaker. Operating time, levels of Fe(II) and (Mn(II) metals, and the mass of CCW were some of the parameters studied in this study. CCW was very good at reducing levels of iron ions and manganese ions after 60 minutes of operation. The percentage of removal of iron and manganese ions respectively – successively increased from 93.765 to 97.99% for iron ions and manganese ions from 91.83 to 95.14% for the initial concentration range of 40 mg/L, 60 mg/L, 80 mg/L, and 100 mg/L. Furthermore, the adsorption kinetics of CCW adsorbent in a mixture of iron ion and manganese ion solutions is a second-order kinetic equation. This confirms that the adsorption of CCW on iron ions and manganese ions is a chemisorption process. Calcium carbide waste has the potential to act as an absorbent of heavy metals in groundwater, especially iron and manganese ions.
EN
The valorisation fine coal waste is still very limited in creating energy, especially syngas. This study aims to convert fine coal waste into synthetic gas via gasification using catalyst. Fine coal gasification takes place at 350–750 °C in an updraft gasifier using catalyst of 12.5–25 wt% natural zeolite. The research results show that the addition of zeolite has synergy with increasing temperature. The syngas produced at 750 °C and 12.5 wt% zeolite consisted of 32 vol% H2, 30.1 vol% CO, 27.7 vol% CH4 and 5.1 vol% CO2. The carbon conversion efficiency and high heating value (HHV) of synthetic gas are 88.34% and 18.97 MJ/Nm3. Fine coal has the potential to be reused as an energy source in the future.
EN
The rapid progress of the CPO industry in Indonesia is not in line with good waste management and utilization. Palm empty fruit bunch, as the first waste from the CPO production process in Indonesia, is mostly piled on the ground. Palm empty fruit bunch must be processed to reduce pollution and increase its use-value. This study aimed to convert oil palm empty fruit bunches solid waste through the gasification process using Indonesia’s natural zeolite into synthesis gas. Gasification takes place at 350–550°C by added 12.5% wt zeolite using a modified updraft gasifier. Good results were achieved at 550°C with a gas composition of 22.64% vol CH4, 29.22% vol CO, and 3.4% vol H2. The gasification efficiency is evaluated through carbon conversion efficiency (CCE) and cold gas efficiency (CGE). Both the highest CCE and CGE were found at 550°C by 95.74% and 81.65% respectively. The results showed that the gasification temperature has the greatest influence in driving higher carbon conversion to syngas and palm empty fruit bunches are very suitable for conversion into environmentally friendly syngas in the CPO industry.
EN
This present study contribute to provide a simple technology to early detect the phenomenon of spontaneous coal combustion. A new prototype is designated to detect the CO gas formation as a product of initial coal oxidation. Moreover, several parameters including coal quality, coal weight sample, ambient temperature, and air flow were employed to investigate the effects of each parameter to the CO formation time. The results show that the coal characterisation have a significant effect in the CO formation time where the coal having a higher fixed carbon and high grass calorific values provide the high liability of spontaneous coal combustion. However, these finding only occurred in low weight sample where in the high coal weight sample only fixed carbon plays the main role in determining the CO formation time. Furthermore, the prototype ambient temperature become the important parameter in the boosting of CO formation time where airflow only enhance the CO formation time in low temperature condition (below 29°C). Moreover, these findings opens a new sight in coal management, especially in Indonesia, where controlling the coal and atmosphere temperature could effectively prevent the spontaneous coal combustion especially in coal stockpile. Nevertheless, the other factor including airflow and coal weight sample also need perfect controlling because all of these factors potentially create a perfect environment to combust the coal spontaneously.
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