In this work, a plug flow reactor was developed for continuous dry digestion processes and its efficiency was investigated using untreated manure bedded with straw at 22% total solids content. This newly developed reactor worked successfully for 230 days at increasing organic loading rates of 2.8, 4.2 and 6 gVS/L/d and retention times of 60, 40 and 28 days, respectively. Organic loading rates up to 4.2 gVS/ L/d gave a better process stability, with methane yields up to 0.163 LCH4/gVS(added)/d which is 56% of the theoretical yield. Further increase of organic loading rate to 6 gVS/L/d caused process instability with lower volatile solid removal efficiency and cellulose degradation. (C) 2016 Elsevier Ltd. All rights reserved.