Efforts to improve the physical and chemical properties of vegetable oils as diesel fuels such as viscosity and calorific value are indispensable with the depletion of fossil oil reserves. Jatropha oil with long chain fatty acids and high degree of unsaturation is mixed with short chain saturated fatty acid coconut oil in various compositions. The mixture was heated and stirred for 30 min at 90 °C. This mixing leads to a decrease in viscosity which allows for the breaking of the bond. The fatty acid molecule structure undergoes transformation that changes the degree of unsaturation and the average length of the carbon chain. Consequently, the kinematic viscosity and flash point of the mixture decreases while its calorific value increases.

The increasing energy consumption and depletion of fossil fuels require the need for alternative source of fuels. Biodiesel is an alternative fuel developed and can replace or reduce the use of petroleum diesel. One of its development processes is to change fatty acid composition through the mixing of different raw materials namely Calophylluminophyllum and palm oil. Calophylluminophyllum oil is a non-edible raw, while palm oil is an edible raw materialwhich is abundantly produced. The research was carried out by processing palm and Calophylluminophyllum oil into biodiesel using transesterification. Furthermore, both kinds of biodiesel were mixed with 11 variations of the composition. The results showed that mixing biodiesel Calophylluminophyllum and palm oil produced positive results with decreased viscosity and increased calorific value.

Biodiesel has attracted attention as an alternative fuel in efforts to reduce emissions and dependence on fossil fuels. Among various potential sources for biodiesel production, jatropha and corn oil have stood out due to their availability and high yield potential. However, each has unique characteristics that affect their performance as fuels. Jatropha oil has relatively high viscosity, while corn oil is generally used as a food ingredient. This study aimed to explore the potential of combining jatropha and corn biodiesel in different proportions and its impact on fuel characteristics and diesel engine spray injection. Both types of oil were processed into biodiesel through esterification and transesterification processes. Subsequently, biodiesel mixtures were created in ratios of 1:4 and 4:1. Each mixture was then varied with diesel to produce B5, B10, B15, B20, B25, B30, B35, and B40. Each sample was tested for its physical properties such as density and viscosity, and injection spray angle. The results of this study indicated that the density and viscosity values of the 1:4 jatropha-corn biodiesel mixture were lower than those of the 4:1 jatropha-corn biodiesel mixture. There was a significant relationship between viscosity and density with the injection angle. The higher the density and viscosity, the narrower the injection angle.

This study was motivated by the need to understand the influence of using waste jatropha biodiesel on the physical properties of fuel and the performance of diesel engines. The primary aim was to determine the relationship between the fuel's physical properties, spray angle, and specific fuel consumption (SFC) at various load levels. The methodology employed included measurements of density, viscosity, flash point, calorific value, spray angle, and SFC for different blends of waste jatropha biodiesel and diesel (B5, B10, B15, B20). The research results demonstrate an increase in density, kinematic viscosity, and flash point, along with a decrease in calorific value, as the biodiesel content increases. The density of the biodiesel mixture ranges from 823 kg/m³ at B5 to 836.50 kg/m³ at B20. The kinematic viscosity increases from 3.9 cSt at B5 to 5.2 cSt at B20, and the flash point rises from 112.9°C at B5 to 128.7°C for B20. Meanwhile, the calorific value decreases from 10308.2670 cal/g at B5 to 10133.8280 cal/g for B20. A strong correlation exists between density and kinematic viscosity with the spray angle, exhibiting R² values of 0.9141 and 0.8287, respectively. The correlation between the fuel's physical properties and the specific fuel consumption (SFC) is also substantial, marked by high R² values above 0.93. These findings provide a solid foundation for the development of more optimal biodiesel formulations.

Panti Asuhan Al-Amin Muhamamdiyah Rejowinangun mengasuh sekitar 20 santri mukim. Mereka berusia SD sampai dengan SMA. Para santri tersebut mempunyai semangat belajar yang tinggi. Panti Asuhan Al-Amin memiliki 10 unit PC yang belum dimanfaatkan secara optimal. Kegiatan peningkatan kompetensi santri belum banyak dilakukan. Perlu dilakukan kegiatan untuk menambah kompetensi para santri. Program yang diusulkan adalah peningkatan kompetensi santri dibidang aplikasi grafis. Pelaksanaan program diawali dengan pertemuan tim pengabdi dan pengelola Panti Asuhan, selanjutnya dilakukan pemeriksaaan fasilitas. Setelah fasilitas berupa PC dan aplikasi telah disiapkan, dilakukan pelaksanaan program pelatihan aplikasi komputer grafis. Aplikasi yang digunakan adalah GIMP dan Inkscape. Kedua aplikasi tersebut gratis, banyak fitur dan bisa meningkatkan kreatifitas para santri. Luaran dari kegiatan ini adalah meningkatnya kompetensi santri Panti Asuhan Al-Amin dan artikel ilmiah di prosiding seminar atau jurnal ilmiah.

Biodisel merupakan bahan bakar alternatif untuk mesin disel yang biasanya terbuat dari minyak nabati. Minyak jatropha dan minyak jagung merupakan bahan baku biodisel yang potensial. Namun biodisel dari bahan baku minyak jatropha memiliki kelemahan, diantaranya adalah viskositas yang relatif tinggi dan nilai kalor yang relatif rendah. Salah satu upaya perbaikannya adalah pencampuran dengan minyak jagung. Penelitian ini bertujuan untuk mengetahui pengaruh dari variasi komposisi campuran terhadap karakteristik biodisel. Kedua jenis bahan baku diproses menjadi biodisel melalui reaksi transesterifikasi. Selanjutnya dilakukan pencampuran antara biodisel jatropha dan biodiesel jagung. Campuran dibuat dalam sembilan variasi komposisi. Setiap komposisi campuran diaduk dan dipanaskan pada suhu 90 °C selama 60 menit. Hasil penelitian menunjukkan bahwa campuran biodisel jatropha dan jagung memiliki viskositas yang lebih rendah daripada biodisel jatropha murni. Densitas dan titik nyala campuran biodisel tersebut juga mengalami penurunan. Hasil lainnya adalah nilai kalor biodiesel campuran lebih tinggi daripada nilai kalor biodiesel jatropha murni. Biodiesel is an alternative fuel for diesel engines that are usually made from vegetable oil. Jatropha and corn oil are potential biodiesel feedstocks. However, biodiesel from jatropha oil has disadvantages, including high viscosity and relatively low heating value. An effort to improve its properties is mixing it with corn oil. The purpose of this study was to determine the effect of the composition of the mixture on the biodiesel properties. Both raw materials were processed into biodiesel through transesterification reactions. The next step is mixing jatropha and corn biodiesel. There were nine variations of the biodiesel mixture. Each mixture was stirred and heated at 90 °C for 60 minutes. The results showed that the mixture of jatropha and corn biodiesel had lower viscosity than pure jatropha biodiesel. Density and flash point of the biodiesel mixture also decreased. The heating value of mixed biodiesel is higher than its of pure jatropha biodiesel.