An Incubation System to Enhance Biogas and Methane Production: A Case Study of an Existing Biogas Plant in Umbria, Italy

Abstract

The pre-incubation of digestate and recycling of microbes inside a continuously stirred tank reactor (CSTR) are effective ways to optimize the anaerobic digestion process and improve the performance of biogas and methane production, also in existing biogas plants. In this study, a digestate incubation system using a nutrient mix to boost the activity of microbes was coupled to a CSTR to boost biogas and methane production. This system has been tested both on a lab scale and on an industrial scale. On a pilot scale, the system achieved an increase of +16.47 v% in biogas production with respect to the conventional anaerobic digestion process, and an increase of +2 v% in methane content (from 65.94 v% to 67.84 v%). On an industrial scale, the use of this incubation reactor with a capacity of 1 m3 has led to an increase in methane yield of 12 v%. This system allows to maintain the syntrophic relationship between acid-producing bacteria and methanogens and contemporary push the development of methanogens. Moreover, it is an economic system to be integrated into an existing biogas plant given the small volume and the simplicity of the incubation reactor.

Development of a tool to optimize economic and environmental feasibility of food waste chains

“…The different types of food waste considered in this study were obtained from local supermarkets. The chemical-physical properties were measured at the Analysis Lab of the Biomass Research Centre described in previous works [30][31][32][33][34]. A TGA 701 LECO has been used to perform proximate analysis and determine moisture, ash, total solid and volatile solid content, according to the following norms: UNI EN ISO 18134-2:2015, UNI EN ISO 18122:2016, and UNI EN 15,148:2010.…”

“…The inputs used in the economic feasibility analysis are the ones shown below. The methodology has been mainly taken from [19,34].…”

“…To measure the biogas yield and composition, batch bottles have been used. These are containers equipped with pressure, temperature probes, and pH meter, in order to analyze the composition of biogas samples [34].…”

Biomethanation Potential (BMP) Study of Mesophilic Anaerobic Co-Digestion of Abundant Bio-Wastes in Southern Regions of Tunisia

“…The by-products from agricultural fermentation plants that treat manure as feedstock are usually used and can be recommended as sources of inoculums [25]. In the present study, the inoculums are the primary digestate from biogas station situated in the municipality region of Perugia (Italy) [26]. As information from this biogas station, the used inoculums are composed of 62.28% maize, sorghum, and triticale silage, 16.26% humid pitted pomace, and 21.55% pig wastewater.…”

“…As shown in Table 2, the municipal waste presents the highest value of volatile matter (44.49%), whereas the inoculums have the lowest one (7.14%). This percent of volatile solids is low because the organic materials in the inoculums were digested in the anaerobic station, from where the inoculums were taken [26]. The VS inquires about the organic fraction will be degraded in anaerobic digestion [47].…”