The study of slurry recirculation to increase biogas productivity from Jatropha curcas Linn. capsule husk in two phase digestion

The purpose of this study was to obtain the best slurry recirculation treatment for two-phase digester system which produced the highest biogas production in the DH-JcL substrate. The study was conducted in the laboratory using 750 mL and 2 L of plasticdigester and biofilter plastic as growth immobilize. The slurry recirculation treatment consisted of the recirculation of 50 %slurry to methanogenesis digester, 50 % slurry to hydrolysis digester, and 25 % slurry to hydrolysis digester combined with 25 % to methanogenesis digester. The highest daily biogas production was obtained from the recirculation of 50 % slurry to hydrolysis digester. However, the best slurry recirculation treatment, which was more stable in longer period, was 50 % slurry to methanogenesis digester

Metamaterial Concentrator for Thermal Energy Harvester

Energy demand increases in line with rapid technological advances. Research on the harvesting of renewable energy continues to be done to make efforts to convert heat energy, which is very abundant in our daily environment. Thermoelectric technology is an alternative source in answering energy needs and can produce energy on a large and small scale. Thermoelectric technology works by converting heat energy into electricity directly, or from electricity to cold. This research presents an experimental study conducted to find out the thermoelectric characteristics of the TEC in the reversal function, with heating and cooling tests on each side of the TEC type thermoelectric element, carried out to obtain the voltage value as the electrical potential generated from this element. The result is thermoelectric potential to generate DC electricity but is very limited in the function of maintaining a heat source on the hot side element. This research then proposes thermal metamaterial that functions as a collector of thermal energy in the method of converting thermal energy into DC electrical energy for the application of low power consumption communication systems

Conceptualizing Indonesia’s ICT-based Energy Security Tracking System with Detailed Indicators from Smart City Extension

The purpose of this study is to conceptualize Indonesia’s ICT-based energy security tracking system with detailed indicators of renewable energy (RE) and energy efficiency (EE) from the smart city extension. The opportunities for improvement to the energy security system is still wide open with the support of advances in information and communication technology (ICT) to integrate the internet and smart grid. The method refers to five main dimensions: availability, efficiency, affordability, sustainability, and governance. Then, how to link the concept of energy security with detailing indicator of RE and EE to the smart city. Empirically, energy security is a function of availability, efficiency, affordability, sustainability, and governance. The most important dimension is the Government (Go) to realize the interconnectivity and the information. If the Go has been realized, the other four dimensions will be easily obtained. With the development of ICT, the energy security status will certainly be more easily accessed anytime and anywhere by the stakeholders. The concept of a smart city usually integrated with the ICT infrastructure, especially for monitoring, management and decision-making tool. This research provides an overview of how the concept of energy security system is closely related to the implementation of the smart grid

The Technical Design Concept of Hi-Tech Cook Stove for Urban Communities using Non-Wood Agricultural Waste as Fuel Sources

The purpose of this study is to conceptualize an urban Hi-Tech Cook-Stove (HTCS) design using agricultural waste. Several steps need to be carried out. First, determine the cooking activities depend on the family size and food categories. Second, calculate the energy required for cooking. Third, determine the mass of biomass fuel required. Fourth, calculate the fuel consumption rate. Fifth, design the dimensions of the stove by considering the ergonomics, easy in manufacturing, installation, etc. Sixth, estimate the volume of each component. The result shows that the fuel supply must adjust the flow rate of fuel, air to fuel ratio controlled by a simple mechanical-electric compressor, monitor the combustion chamber visually/automatically, and the dust must be collected/disposed of automatically/mechanically. HTCS must consider the pellets from the higher heating value and faster of biomass with a certain composition of chopped and fibre, also the safety and comfort, such as overheating control, air exhaust control, combustion control, cooling control. For the future, the HTCS technical design concept must be integrated with the electricity and hot water from solar energy by using a hybrid photovoltaic-thermal (PVT) collector and urban biogas digester in the development of smart grids and smart cities

Characterisation of Arabica Coffee Pulp - Hay from Kintamani - Bali as Prospective Biogas Feedstocks

The huge amount of coffee pulp waste is an environmental problem. Anaerobic fermentation is one of the alternative solutions. However, availability of coffee pulp does not appear for year-round, whereas biogas needs continuous feedstocks for digester stability. This research uses coffee pulp from Arabica Coffee Factory at Mengani, Kintamani, Bali–Indonesia. The coffee pulp was transformed into coffee pulp-hay product by sun drying for preservations to extend the raw materials through the year. Characterization of coffee pulp-hay was conducted after to keep for 15 mo for review the prospect as biogas feedstocks. Several parameters were analyzed such as C/N ratio, volatile solids, carbohydrate, protein, fat, lignocellulose content, macro-micro nutrients, and density. The review results indicated that coffee pulp-hay is prospective raw material for biogas feedstock. This well-proven preservation technology was able to fulfill the continuous supply. Furthermore, some problems were found in the recent preliminary experiment related to the density and fungi growth in the conventional laboratory digester. Further investigation was needed to implement the coffee pulp – hay as biogas feedstocks

Characterisation of Arabica Coffee Pulp - Hay from Kintamani - Bali as Prospective Biogas Feedstocks

The huge amount of coffee pulp waste is an environmental problem. Anaerobic fermentation is one of the alternative solutions. However, availability of coffee pulp does not appear for year-round, whereas biogas needs continuous feedstocks for digester stability. This research uses coffee pulp from Arabica Coffee Factory at Mengani, Kintamani, Bali–Indonesia. The coffee pulp was transformed into coffee pulp-hay product by sun drying for preservations to extend the raw materials through the year. Characterization of coffee pulp-hay was conducted after to keep for 15 mo for review the prospect as biogas feedstocks. Several parameters were analyzed such as C/N ratio, volatile solids, carbohydrate, protein, fat, lignocellulose content, macro-micro nutrients, and density. The review results indicated that coffee pulp-hay is prospective raw material for biogas feedstock. This well-proven preservation technology was able to fulfill the continuous supply. Furthermore, some problems were found in the recent preliminary experiment related to the density and fungi growth in the conventional laboratory digester. Further investigation was needed to implement the coffee pulp – hay as biogas feedstocks

Characterisation of Arabica coffee pulp - Hay from kintamani - Bali as prospective biogas feedstocks

The huge amount of coffee pulp waste is an environmental problem. Anaerobic fermentation is one of the alternative solutions. However, availability of coffee pulp does not appear for year-round, whereas biogas needs continuous feedstocks for digester stability. This research uses coffee pulp from Arabica Coffee Factory at Mengani, Kintamani, Bali–Indonesia. The coffee pulp was transformed into coffee pulp-hay product by sun drying for preservations to extend the raw materials through the year. Characterization of coffee pulp-hay was conducted after to keep for 15 mo for review the prospect as biogas feedstocks. Several parameters were analyzed such as C/N ratio, volatile solids, carbohydrate, protein, fat, lignocellulose content, macro-micro nutrients, and density. The review results indicated that coffee pulp-hay is prospective raw material for biogas feedstock. This well-proven preservation technology was able to fulfill the continuous supply. Furthermore, some problems were found in the recent preliminary experiment related to the density and fungi growth in the conventional laboratory digester. Further investigation was needed to implement the coffee pulp – hay as biogas feedstocks