Oxidative coupling of methane (OCM) represents a process concept for conversion of methane as a major component of natural gas into chemical intermediates such as ethylene at high temperatures between 700 and 900 degrees C. The objective of this work is to study the performance of two miniplant-scale fluidized-bed reactors made of FeCr alloy and quartz glass, respectively, with same dimension (inner diameter of 56 mm). The aim is to find the necessary reaction conditions for optimizing the C-2 yield of the process, and to study the effect of the reactor material in a larger scale. These findings are important for future industrial scale applications. 2.2%Na2WO4-2%Mn/SiO2 catalyst, tested for this study, was prepared by incipient wetness impregnation method and 55 g of it was tested for each experiment in the reactor. The maximum C-2 yield achieved at low nitrogen dilution gas composition was 23% for the quartz glass reactor and 20% for the FeCr alloy reactor at 830 degrees C. Due to the reactivity of the reactor wall in the metal reactor, the methane and oxygen conversion as well as the C-2 selectivity are influenced. However, the results were promising considering that the reactor scale under study is the largest tested for this catalyst so far. After 7 h of stability testing, the catalyst in the quartz glass reactor exhibited stable performance and high mechanical stability. (C) 2015 Elsevier B.V. All rights reserved.