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The effective and efficient use of biomass briquettes is strongly influenced by the type of stove used and the way it is used. This study aims to design a briquette stove by adding an adjuster: the test fuel used honeycomb briquettes and forest fern charcoal. The heat transfer from burning honeycomb briquettes to a pot of water needs to be maintained so that the heat (temperature) remains constant during the combustion process. In the current use of briquettes, the distance between the briquette flame and the pot of water is unstable because the space is getting further away from the pool of cooking water. The combustion distance is getting farther because the bottom of the initial honeycomb briquettes burns out, causing the surface of the briquettes to decrease and move away from the surface of the water pot. Thus the heat given to the pool of water will reduce. The briquette stove needs to be added with an adjuster to overcome this problem. This adjuster serves to raise the honeycomb briquettes if the surface of the briquettes decreases. With the addition of an adjuster, it will be analyzed how much the heat transfer rate and the stability of the burning distance of the honeycomb briquettes will be. In this study, 2 test models will be used: a stove with an adjuster and a stove without an adjuster, using 14 holes in honeycomb briquettes made from forest ferns using starch (tapioca) adhesive. The distance between the surface of the briquettes and the pot of boiled water is 5 cm. The results showed that the briquette stove using an adjuster could maintain the stability of the combustion distance between the surface of the briquette and the pot of water being cooked with an average temperature t = 567.83 0C and conduction heat transfer q = 5285.699 Watt.

Alternative fuels were developed by blending crude coconut oil and bio-graphene nanoparticles. Bio-graphene, derived from sago waste via pyrolysis and ground using a ball mill, underwent FTIR testing to assess its energy absorption capabilities. SEM analysis was conducted to examine the surface morphology of bio-graphene with and without crude coconut oil. The findings indicate that incorporating bio-graphene can enhance mechanical properties, facilitating rapid heat absorption, as evidenced by reduced flashpoint and viscosity. In addition, the results show an increase in fuel mass, broadening of molecular contacts, increased reactivity, and increased heat absorption for easier ignition. This phenomenon indicates that BioGNPs have great potential for biofuel use as a homogeneous combustion catalyst.

Experimental research has been conducted on the effect of ignition timings on the characteristics and performance of gasohol engines such as power, torque, specific fuel consumption, and thermal efficiency. The fuel used in this research is pure gasoline and a mixture of 50% bioethanol (BE50). The results show that the ignition timing that gives the maximum effect occurs at the top and bottom dead points of 9 degrees for gasoline and 12 degrees for BE50 fuel. Furthermore, the maximum power is obtained at 6,500 rpm, and at an ignition time of 12 degrees BTDC the maximum power generated is 4.63 hp, while for an ignition time of 9 degrees BTDC the power generated is 3.38 hp which occurs at 6500 rpm. These results indicate that there is an increase in power of 6.4%. Moreover, the results also show that for optimal gasoline conditions, the amount of energy consumed at an engine speed of 7000 rpm is around 15705.78 kcal/hour, and for BE-50 it is around 12582.03 kcal/hour, where there is a reduction of about 25.44 %. However, in general, it can be seen that during optimal ignition, there is a saving in fuel consumption in the gasoline-BE50 mixture, while at the same time producing a fairly large thermal efficiency. These results indicate that BE50 has the potential to be used as an alternative fuel in small gasoline engines.

The burning rate of coconut oil droplets has been investigated experimentally by adding bio-additives of clove oil and eucalyptus oil. Tests were carried out with single droplets suspended on thermocouples at room atmospheric pressure, and room temperature and ignited with a hot wire. The addition of clove oil and eucalyptus oil as bio-additives into coconut oil was 100 ppm and 300 ppm, respectively. The droplet combustion method was chosen to increase the contact area between the air and fuel so that the reactivity of the fuel molecules increases. The results showed that the eugenol compounds contained in clove oil and cineol compounds in eucalyptus oil were both aromatic, and had an unsymmetrical carbon chain geometry structure. Furthermore, this factor can potentially accelerate the occurrence of effective collisions between fuel molecules. Therefore the fuel is combustible, as evidenced by the increased burning rate, where the results show that without bio-additives, the burning rate of crude coconut oil (CCO) is about 0.7 seconds. These results are 0.15 to 0.2 seconds slower than CCO with bio-additive, which is around 0.55 to 0.6 seconds. Moreover, from the observations, it was found that the highest burning rate was achieved in both bio-additives with a concentration of 300 ppm.

The effect of various ignition timing on spark ignition (SI) engines with bioethanol-isooctane mixtures has been widely studied. In the present studies, we used three different ignition angle positions, namely 9°, 12°, and 15° BTDC to increase the combustion pressure in the combustion chamber. In addition to macroscopic observations through engine performance, observations are also carried out from a molecular perspective, i.e.; atomic, bond, and bond angle properties of bioethanol-isooctane fuel. The result shows that more atoms of the isooctane carbon chain are non-rotatable (23 atomic bonds) than the 8 bonds of the bioethanol carbon chain. Furthermore, isooctane also has a wider bond angle (around 121.1745°) than the bond angle of ethanol (around 110.0476°). The unique properties of the atoms in the carbon chains of these two fuels have a direct impact on engine performance. The results show that the viscosity of bioethanol is lower when compared to isooctane, which indicates that the bioethanol molecules are more reactive and flammable. The result also found that at an ignition angle of 12° the BE50 engine has the best performance. Moreover, the test results also show that bioethanol produces clean combustion as evidenced by the lowest CO and HC gas emissions.

Kegiatan Program Kemitraan Masyarakat (PKM) bertujuan untuk mengatasi permasalahan yang dihadapi masyarakat kampung Nolokla (mitra) adalah memproduksi briket dari limbah ampas sagu. Briket adalah salah satu sumber energi alternatif yang dapat membantu masyarakat mengatasi kelangkaan dan kenaikan harga bahan bakar minyak. Metode yang digunakan dalam kegaitan ini adalah sosialisasi dan praktek pembuatan briket mulai dari pengambilan ampas sagu, penjemuran, sangrai ampas sagu, penghalusan arang ampas sagu, pencampuran arang ampas sagu dengan perekat, pencetakan briket, penjemuran briket dan uji coba memasak mengunakan briket sarang lebah. Hasil yang diperoleh dari Program Kemitraan Masyarakat ini adalah masyarakat kampung Nolokla mampu memiliki keterampilan dan kemampuan yang sangat baik dalam memproduksi briket sarang lebah skala rumah tangga dari limbah ampas sagu.

In previous studies, the initial process of burning briquettes still takes a long time, i.e. app 15-20 minutes. In normal briquette burning, a flame comes out from the briquette hole surface. The purpose of this research is to find a solution to accelerate the burning process and then the solution to use this process easily. The main objective of this research is to examine the amount of heat generated from the briquettes burning process with the number of holes as much as 10, 12, and 14, and to measure the time of initial briquette burning until the first time the flame came out on the briquettes surface. The basic ingredients of briquettes used in this study were sago waste. The tools used are a moisture meter to measure the water content, an infrared thermometer, a temperature measuring instrument, a Stopwatch to measure time, a digital anemometer to measure the airflow speed. From this study, the results obtained indicate that the combustion process in a forced air convection conditions, resulting in the rate of heat transfer as follows: a). For using the 10 holes briquettes, the heat transfer rate is about 8.51 watts, b). In the burning of 12 holes briquettes, the resulting heat transfer rate is about 16.57 watts, c). While on the 14 holes briquettes burning, the rate of heat transfer is about 20.43 watts. When heat energy is applied to boil 5 liters of water, with a 10-hole briquette, the water boils within 23.54 minutes. When using 12 holes briquettes, the water boils in 21.31 minutes, and in the use of 14 holes briquettes, the water boils in 20.21 minutes. It is concluded that the shortest time to boil 5 liters of water is when using briquettes with 14 holes, which boils in 23.34 minutes. These results indicate that forced convection can speed up the briquette burning process and produce a fairly high temperature.

This study aims to reveal the performance and exhaust emissions of a spark ignition (SI) engine fueled by a gasoline-bioethanol mixture. The main performance characteristics of the SI engine tested are torque, power output; thermal efficiency, brake specific fuel consumption, and brake mean effective pressure. Meanwhile, the exhaust emissions seen are carbon monoxide and hydrocarbons. The test is carried out by comparing the performance of the SI engine under standard conditions without modification with gasoline fuel, with the SI engine with modification with 85% bioethanol fuel. The mass flow of fuel is regulated by modifying the carburetor choke at 3/4 and 7/8. The results show that although slightly lower than gasoline, in general, it can be seen that bioethanol can improve SI engine performance and produce environmentally friendly exhaust emissions.

This study examines the Ignition characteristics of blended fuel droplets with crude coconut oil and rhodium liquid as a liquid metal catalyst. The ignition behavior was observed by igniting the oil droplet on a junction of a thermocouple, and the droplet evolution recorded with the high-speed camera. The results show that the addition of a liquid metal catalyst successfully reduces the molecular mass of the triglyceride and weakens the bonding force between the carbon chain, and therefore the viscosity and flash point decreases. Moreover, the addition of liquid metal catalysts increased the reactivity of fuel molecules such as C-H, C-C, C = C, and C-O. Changes in the physical properties of the fuel, the geometry of the carbon chain, and molecular mass ease the absorption of heat by the fuel droplet, thereby increasing fuel ignition performances.