Otong Nurhilal

Combustion quality analysis of briquettes from variety of agricultural waste as source of alternative fuels

The increasing in world population and the industrial sector led to increased demand for energy sources. To do this by utilizing the agricultural waste as a fuel source of alternative energy in the form of bio briquette. The aim at this study was to obtain data onto the characteristics of a wide variety of biomass briquettes from waste agricultural industry. The basic ingredients used are biomass waste from coconut husks, sawdust, rice husks and coffee husks. Each of these biomass residues are dried, crushed, then mixed with starch adhesives. This mixture is molded and dried using sunlight. Each type of briquettes was characterized and analyzed the physical-chemical properties, including calorific value, water content, fixed carbon content and the results were compared with charcoal and coal that was used as fuel in public. The results showed that bio briquettes from coconut husks get the highest calorific value of 4,451 cal/g.

The simulation of organic rankine cycle power plant with n-pentane working fluid

In the steam power plant in Indonesia the dry steam from separator directly used to drive the turbin. Meanwhile, brine from the separator with low grade temperature reinjected to the earth. The brine with low grade temperature can be converted indirectly to electrical power by organic Rankine cycle (ORC) methods. In ORC power plant the steam are released from vaporization of organic working fluid by brine. The steam released are used to drive an turbine which in connected to generator to convert the mechanical energy into electric energy. The objective of this research is the simulation ORC power plant with n-pentane as organic working fluid. The result of the simulation for brine temperature around 165°C and the pressure 8.001 bar optained the net electric power around 1173 kW with the cycle thermal efficiency 14.61% and the flow rate of n-pentane around 15.51 kg/s. This result enable to applied in any geothermal source in Indonesia.

Optimal design of an atmospheric water generator (AWG) based on thermo-electric cooler (TEC) for drought in rural area

Drinking water availability is a major issue in some rural area in Indonesia during the summer season due to lack of rainfall, which peoples in this area have to fetch the water a few kilometers away from home. The Atmospheric Water Generator (AWG) is one of the alternative solution for fresh water recovery from atmosphere which is directly condensed the moisture content of water vapor from the air. This paper presents the method to develop a prototype of an AWG based on Thermo-electric cooler (TEC) that used 12 Volt DC, hence its suitability for using renewable energy resource. Computational Fluid Dynamics (CFD) is utilized to optimize the design process in the flow region only, it’s not suitable for recent CFD software to use in Multi physics, because inaccuracy, cost and time saving. Some parameters such as temperature, moisture content, air flow, pressure, form of air flow channel and the water productivity per unit input of energy are to be considered. The result is presented as an experimental proto...

Simulation Analysis of Damage Mechanism on Ferritic Material SA-213 T22 Type Using Finite Element Method Program

Material with good mechanical resistance in the high temperature operation is needed in the power generation industry. Due to the influence of stress, high temperatures and long operation of time, unpredictable failure often occurs resulting plant stopped working. The cause of failure, associated with some changes in mechanical properties of the material can be represented by microstructural conditions. Ferritic material SA-213 T22 is widely used in power plants. To get more information of those mechanical properties, the study of damage mechanisms has been conducted by analysis simulation. The Benefits of this study is to get proper operating condition to avoid unpredictable failures. Using finite element method, it is found that in constant temperature 580 °C with the load rate of 23.03MPa per second the strain is 55.25%. When the load rate is decreased to 3.84MPa per second the strain is 63.57%. In the constant temperature 300 °C with load rate 11,52MPa per second the strain is 27.55%. When the temperature increased to 560 °C the strain is 32.02%. In the constant temperature, the decreased of load rate give impact the increased of ductility. Otherwise in the constant load rate, the increased of temperature give impact only small amount to increase the ductility. To prevent the unpredictable failure the sudden increase of load rate should be avoided.