Performance of an anaerobic plug-flow reactor treating agro-industrial wastes supplemented with lipids at high organic loading rate

Abstract

This study evaluated the performance of a plug-flow reactor (PFR) for high-rate anaerobic co-digestion of complex agro-industrial wastes and used cooking oil or animal fat. The PFR was successfully operated up to an organic loading rate (OLR) of 21 g L−1 d−1, yielding biogas at 0.35 L g−1 chemical oxygen demand (COD) influent. During the study period, supernatant COD at the PFR effluent remained between 4 and 7 g L−1, with negligible volatile fatty acids’ concentrations (<500 mg L−1) and no presence of foaming incidents. The biomass concentration inside the PFR, expressed as total suspended solids, remained between 30 and 60 g L−1. Moreover, the above-mentioned anaerobic digestion technology has been currently scaled-up at 50 m3 PFR, while a full-scale facility of 240 kW-el is under construction in the region of north-eastern Greece.

Techno-Economic Assessment of Anaerobic Digestion Technology for Small- and Medium-Sized Animal Husbandry Enterprises

“…The substrate-to-inoculum ratio was kept constant at 0.25 kg VS substrate per kg VS inoculum. Biogas production was monitored daily over a 30 day period using an inverse water column with acidic water (pH = 2), and the methane content of the biogas was determined using an alkaline trap [22]. BMP was calculated as the cumulative methane production per gram of VS added, converted to standard temperature and pressure conditions.…”

Techno-Economic Assessment of Anaerobic Digestion Technology for Small- and Medium-Sized Animal Husbandry Enterprises

“…During batch anaerobic digestion, mixing was applied manually once per day. Biogas production was monitored daily over a 20-day period using an inverse water column with acidic water (pH = 2), and the methane content of the biogas was determined using an alkaline trap [23]. BMP was calculated as the cumulative methane production per gram of VS added, converted to standard temperature and pressure conditions.…”

Discovery of Mixing Characteristics for Enhancing Coiled Reactor Performance Through a Bayesian Optimisation-Cfd Approach

“…Plug flows are a mixing pattern where the fluid elements undergo enhanced radial mixing and negligible axial mixing. They have a wide range of applications, including manufacturing pharmaceuticals [2], fine/bulk chemicals [3], biodiesel production [4], treatment of agro-industrial waste [5], and wastewater treatment [6]. This type of mixing pattern promotes faster reactions, good heat and mass transfer rates, better process control, and reduction of undesired byproducts [7].…”