1. Dry Discontinuous Anaerobic Percolation Digestion DDAPD
- Author
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Silvio Riggio, Renaud Escudie, Michel Torrijos, Giovanni Esposito, Eric D. van Hullebusch, Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA), University of Cassino and Southern Lazio (UNICAS), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), University of Cassino and Southern Lazio (UNICAS). ITA., ProdInra, Migration, Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de la Recherche Agronomique (INRA)
- Subjects
[SDV] Life Sciences [q-bio] ,[SDE] Environmental Sciences ,[SDV]Life Sciences [q-bio] ,[SDE]Environmental Sciences - Abstract
International audience; Anaerobic digestion is a natural process based on the synergy of several microbial species taking place in anaerobic and reducing environmental conditions. During that process, in which organic matter (OM) is slowly decomposed to simpler compounds, a big part of the energy contained in it is transferred in very energetic molecules like methane CH4 [1], [2]. Broadly studied over the past 50 years, Anaerobic Digestion (AD) is a very known and appreciated process because of its unique common response to several actual problems: waste management, human pollution and energy source differentiation. Technologies based on this process have never stopped to change and improve their performances since the start. If, originally, AD was created to treat liquid effluent mainly, nowadays many AD plants are designed to treat waste in their natural dry form (MSW, rural waste, green waste, etc). Dry AD is overtaking Wet Anaerobic Digestion (WAD) in last years because of some important advantages: smaller reactor size, less mechanical parts and lower investment [3]. Dry Discontinuous Anaerobic Digestion Percolation digestor (DDAPd), a reactor where the solid phase is static and the liquid one is percolating through the bulk, seems to answer better than other to the need of farmers in treating animal wastes which are often under dry form. Moreover, manure, a mixture of feces, urine and straw, is a very common resource in French farms and anaerobic digestion responds to the manure environmental disposal obligations on one side and the need in energy and good quality fertilizer on the other side. DDAPd, and in particular the adaptation of this technology to manure, is not something well studied and a lot of scientific parameters, often set empirically by industries, need nowadays to find a scientific support in order to improve their performances. Two parameters play a major role in DDAPD : first the recirculation which controls the mass transfer, and second the microbial seedling. Since the mass transfer is the major problem in dry reactor, parameters like the recirculation frequencies and the flows as well as variations of these during the digestion or the technical ways to perform it are crucial [4]–[6]. The seedling on the other side can influence the kinetics of the process; so the inoculum state (liquid or solid), the way of mixing it to fresh substrate and its origin are important to be defined [6]–[8]. A third parameter, whose role is on one side to overcome the limitation of batch reactors, a discontinuous biogas production, and on the other side the poorer performances due to nonoptimal conditions, is the coupling strategies of several reactors in what is called a multi-stage process [9], [10]. Through the study of the evoked parameters this work aims at giving a scientific base at the setting and at the process control of AD plants utilizing DDAPD technology for manure digestion.
- Published
- 2014