Cahyadi

Fluidized bed combustion is a promising conversion technology for solid fuels like biomass, coal, and blends. However, solid fuel combustion in fluidized beds suffers ash-related issues. The objective of this study is to investigate the effect of the CaCO3 additive on the agglomeration phenomenon using oil palm empty fruit bunches (EFB) in the fluidized bed combustion. The result showed that agglomeration occurs when EFB was burned between 800 and 900oC. In the case of the CaCO3 additive with 10%, 20%, and 30% in the sand bed, it indicated a decrease in the agglomeration phenomena during EFB combustion. The ash components formed during combustion were then analyzed using SEM-EDX (scanning electron microscopy) and XRF (x-ray fluorescence spectroscopy). The results indicated that the addition of CaCO3 increased the melting point of a compound similar to coal ash. The case of the 20% CaCO3 additive became the best case without disturbing the combustion temperature in the bed and with the fewest agglomeration clumps. An additional benefit of using CaCO3 in EFB combustion is that the composition of CO2 gas emissions from burning EFB was 2.8%, a much lower percentage than that of coal (6.4%). CaCO3 has the potential to reduce CO2 emissions slightly.

The ISO 50001 energy management system has been implemented by many organizations around the world, including in Indonesia. The purpose of this application is to sustainably improve energy performance to reduce energy consumption and energy costs. In determining the measurement of energy performance improvement, energy performance indicators and energy baseline are used. This study will analyze the energy performance indicators obtained from the energy audit results of one shopping center in Indonesia using RETScreen Expert software. Multiple linear regression is used to develop the energy baseline equation and examine the relationship between energy consumption and significantly influencing variables, such as Service Usage (person) and Cooling Degree Days (CDD). This baseline equation will be used to monitor energy performance after energy performance improvement measures are taken. From the results of this equation, the predicted value of energy consumption in 2023 after improving energy performance in 2022 is 7,014,081 kWh then from the actual measurement results obtained energy consumption value of 6,113,632 kWh the results of the calculation of energy savings obtained from the energy baseline equation using RETScreen Expert software is 900,449 kWh / year.

Stoker fired boilers have been used widely for small scale power plant in isolated region or small island in Indonesia and for industries. Nevertheless, stoker fired boilers face some operational problems related to burning low rank coal. Water cooled vibrating grate stoker has potential to minimize the problem compared to traveling grate stoker. In this study, 15 kW (th) vibrating grate stoker simulator has been developed for characterizing combustion in stoker fired boiler. Combustion characteristic such as burning out time and combustion rate can be evaluated for both fixed grate and vibrating grate types. Experimental results plotted in horizontal temperature profiles indicate important combustion steps, i.e. drying, volatile release and char burning. Peak temperature while burning sub-bituminous coal was 861 °C, higher than lignite coal of 647 °C. In vibrating grate, the combustion rate of sub-bituminous and lignite coal in vibrating grate increase 56.5% and 25.9%, respectively, compared with in fixed grate. Application of vibrating grate instead of fixed grate in boiler can minimize the furnace size room because of higher heat release rate per area.