<![CDATA[The quality of biodiesel produced from waste cooking oil (WCO) is confirmed by compliance with the ASTM D6751 standard specification to ensure the products meet commercial fuel standards. Compared with batch reactors, microreactors offer several benefits, including reduced residence time, lower specific energy consumption (SEC), and improved processing of low-quality WCO feedstock with high viscosity and free fatty acid (FFA) content. However, a knowledge gap remains regarding the capacity of reactor systems to handle highly degraded WCO feedstock while complying with ASTM D6751, especially total glycerin limits (≤ 0.240 wt%) and minimum ester content. In addition, comparative data between batch reactors and microchannel reactors for low-quality oil processing remain limited. This research aims to establish an evaluation framework for assessing reactor tolerance to highly degraded WCO feedstock by comparing the performance of batch reactors and microchannel reactors under slug flow conditions. Results indicate that the microchannel reactor, with an 80-second residence time, achieved a peak FAME conversion of 98.2% under optimal conditions (1.0 wt% KOH, HH oil) and consistently maintained high conversion (91.1%-98.2%) across all tested feedstocks. Conversely, the batch reactor, with a one-hour reaction time, achieved a conversion of only 68.2%- 88.4% and could not reach the high FAME content required to exceed the total glycerin limit based on ASTM D6751 (> 1.0% berat). The SEC of the microchannel reactor was also 98.96% lower than that of the batch reactor. Consequently, the microchannel reactor demonstrated superior efficiency compared to the batch reactor in transforming lower-quality WCO into biodiesel that meets the ASTM D6751 standard in terms of FAME conversion, energy efficiency, and processing time. Future research may explore the design and optimisation of microchannel reactors for industrial-scale applications, as well as test a wider range of WCO quality variations to establish a more stable and sustainable biodiesel production system.]]>
