Cooking oil is one of the basic human needs as a means of processing foodstuffs. The need for cooking oil is increasing along with the increasing population in Indonesia, so that the used cooking oil produced is also increasing. The fact that has happened so far is that most street food vendors use cooking oil over and over again, even until the oil runs out. Even though the cooking oil is no longer suitable for use and will have an impact on health if it is still consumed. Purification of used cooking oil can be done by adsorption process using an adsorbent to maintain the quality of the oil so that it can be reused. The adsorption process is carried out by adding the adsorbent and mixing it into the oil then stirred and filtered. The most widely used adsorbent is activated charcoal. Activated charcoal is one of the advanced products of shell charcoal which has a relatively high economic value, which is about 10 times the economic value of charcoal. Based on the explanation above, the author took the initiative to develop a prototype of cooking oil purification using natural absorbent materials that are ergonomic for the community, in addition to oil purifiers, this tool will also be equipped with sensors that will help traders to get what they want. level of clarity through the circulation process controlled via the Arduino Mega 2560.

Increasing fuel consumption and limited fossil fuel reserves make us need energy sources that come from Renewable Energy Sources (RES). Solar Energy Resources (Photovoltaic systems) are very strategic to be used in supplying energy to Electric Vehicles (EVs) which generally use BLDC electric motors as wheel propulsion. Photovoltaic cells are components in solar panels that convert solar energy into electricity. The solar panels mounted on the roof of the vehicle work best during the daytime. When at night, electric vehicles will work using electrical energy that has been stored in the battery. This study aims to design a battery charging system using photovoltaic technology which is used to supply power to drive BLDC electric motor in electric vehicles.

The increasing population of motorbikes has an impact on fuel needs and the resulting increase in exhaust emissions. The electrolyzer has an effect on fuel consumption and gasoline exhaust of a modified 4-stroke motorbike. This research is experimental research, starting with designing and making the tools to be studied, then conducting research. As a result, there was a decrease in fuel consumption of 31.36% at 2000 RPM rotation, 8.73% at 4000 RPM engine speed, and 15.48% at 6000 RPM rotation. While exhausting emissions, there was a decrease in CO of 47.37%, an increase in h22o of 24.37%, and a decrease in HC of 45.11% at 2000 RPM rotation. The 4000 RPM rotation decreased CO by 89.11%, CO2 increased by 35.48%, and HC decreased by 36.98%. The 6000 RPM rotation decreased CO by 41.67%, CO2 increased by 17.26% and HC decreased by 6.92%. Semakin banyak populasi sepeda motor berdampak pada kebutuhan bahan bakar dan meningkatnya emisi gas buang yang dihasilkan. Elektroliser berpengaruh pada konsumsi bahan bakar dan gas buang sepeda motor 4 langkah modifikasi injeksi. Penelitian ini merupakan penelitian eksperimen, dimulai dengan merancang dan membuat alat yang akan diteliti, kemudian dilakukan penelitian. Hasilnya, terjadi penurunan konsumsi bahan bakar sebesar 31.36% pada putaran 2000 RPM, 8.73% pada putaran mesin 4000 RPM dan 15.48% pada putaran 6000 RPM. Sedangkan emisi gas buang, terjadi penurunan CO sebesar 47.37%, kenaikan CO2 sebesar 24.37% dan penurunan HC sebesar 45.11% pada putaran 2000 RPM. Putaran 4000 RPM terjadi penurunan CO sebesar 89.11%, kenaikan CO2 sebesar 35.48%, dan penurunan HC sebesar 36.98%. Putaran 6000 RPM terjadi penurunan CO sebesar 41.67%, kenaikan CO2 sebesar 17.26% dan penurunan HC sebesar 6.92%.