V. Dimova*, D. Georgiev Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria (Manuscript received 22 November 2020; accepted for publication 16 April 2021) Abstract. The aim of the study is to determine the optimum thickness of

The objective of this paper is to establish the minimum thickness of heat insulation for an experimental bioreactor, developed at the Institute of Microbiology of the Bulgarian Academy of Sciences, required to ensure heating of the fermentor with its own produced biogas. The experimen