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The global energy crisis and climate change are driving the development of biodiesel as a renewable energy source. Graphite as an additive shows significant potential in improving the efficiency and reducing emissions of biodiesel. This study maps graphite-biodiesel research in Southeast Asia using a meta analysis of systematic reviews of 68 publications from Scopus, Web of Science, and ScienceDirect from 2015-2024. The results show that Malaysia leads in publication contributions (32%), followed by Thailand (28%) and Indonesia (18%). The optimal graphite concentration of 50 ppm increases brake thermal efficiency by 8.3% and reduces CO (15.7%), HC (12.4%), and smoke (18.9%) emissions, although there is an increase in NOx (6.8%). Palm oil methyl ester dominated the research (56%). Indonesia has strategic opportunities with abundant feedstock and graphite deposits, but faces challenges in research infrastructure, limited international collaboration, and the absence of an integrated national roadmap. Infrastructure investment, human resource strengthening, and industry academia collaboration are needed to accelerate national biodiesel research.

The production process of graphite glass at ABC faces challenges in the form of waste that has an impact on low operational efficiency. Waste in production activities can affect the quality, cost, and timeliness of product completion. This study aims to identify the most dominant types of waste and provide relevant improvement recommendations to improve production efficiency. The method used is Value Stream Mapping (VSM), a visual approach that maps the flow of the production process from raw materials to final products. The research stage is carried out through direct observation on the production floor, time study, interviews with employees, and documentation of production activities. The results of the analysis show that the most dominant form of waste is overprocessing, which is a repetitive activity that does not add value to the product. This causes longer production cycle times and reduces the effectiveness of resource use. To overcome this, this study provides several recommendations, including: combining production processes that have similar functions, redesigning workflows to make them more concise, and eliminating activities that do not provide added value. The implementation of this improvement has proven to be effective by increasing the Process Cycle Efficiency (PCE) value from 45% to 67%. The increase in PCE reflects that the production process has become more efficient, the workflow is smoother, and the rate of waste has decreased significantly. In addition, the results of this study also confirm that the application of the VSM method can be a strategic solution in identifying sources of inefficiency, designing continuous improvements, and increasing the competitiveness of companies. Thus, the company is expected to continue to evaluate, control, innovate, and improve technology so that efficiency achievements can be maintained, expanded, and improved consistently and sustainably in the future.

The research method used was a qualitative experiment, starting with taking broken piston rings No. 2 and 3, cutting the piston rings and testing them with hardness tests and composition tests carried out at the Indonesian State Maritime Polytechnic and Undip Central Java Integrated Lab. From the results of this research, it can be concluded that the used broken ring number 3 has the highest hardness of 140.26 HB and the used ring number 2 is 131.50 HB, so it can be concluded that the piston ring that has been used and exposed to high heat causes an increase in hardness and causes it to break. The composition test results showed that the carbon content of the new ring no. 2 was the highest at 15.30% and that in the used ring no. 2 was 12.08% because the compression ring was in direct contact with the compression chamber or in contact with heat. For the used number 3 piston ring, the carbon content is 10.43 and the new one is 11.02 because it is positioned below the compression ring and is not in direct contact with heat. for the used ring no.2, the Silicon (Si) content is low, namely 2.15% compared to the new one, 2.75% because the nature of Silicium is that it is resistant to high temperatures and as a compression ring compared to ring no.3, fracture occurs because there are no Manganese or Phosphate elements. which is wear resistant, strong and elastic. The microstructure of piston ring No. 2 is broken and the new two piston rings are less dense and have rough gaps. The broken piston ring structure of No. 3 and the new one looks a bit gray and has high levels of graphite iron and carbon elements.