Study and Research on Cleaning Procedures of Anaerobic Digestion Products / Studium A Výzkum Postupů Čištění Anaerobní Digesce

Abstract

This paper focuses on increasing quantities of digestate, a final product of anaerobic digestion, in biogas stations being built as alternative sources of energy. The potential use of digestate is limited due to its rather specific physical properties. This paper presents current approaches to digestate and digestate management. The objective is to compare the properties of digestate and the products of its separation via centrifuging, i.e. the liquid phase known as digestate liquor, and the solid phase referred to as digestate fibre. Its focus is mainly laid on techniques for dewatering digestate in low-solid anaerobic processes only, which have been tested for the effectiveness of the basic physical and chemical methods including their combinations. The measured results show that the use of coagulants and flocculants for this purpose would be very problematic in practice with regard to their high consumption as well as the need to input other elements into the process. AbstraktPředložený článek se zabývá problematikou narůstajícího množství digestátu jako konečného produktu anaerobní digesce v bioplynových stanicích, budovaných jako alternativní zdroje energie. Digestát má v současné době omezené využití, které je dáno jeho specifickými fyzikálními vlastnostmi, zejména extrémně problematickou separací jednotlivých složek, ale také chemickým a mikrobiologickým složením. Jeho vlastnosti jsou z největší části ovlivněny druhem zpracovávané biomasy. V úvodní části tato studie předkládá současné možnosti nakládání s digestátem. Předmětem experimentální části je popis odběru a analýzy vzorků digestátu včetně jeho zpracování v laboratorních podmínkách použitím odstředění a následné posouzení vlastností digestátu a produktů separace, tj. fugátu a separátu a dále testování koagulačních a flokulačních činidel pro účinnější separaci tuhé fáze z digestátu, resp. fugátu. Použití koagulantů a flokulantů pro tyto účely v praxi by bylo značně problematické s ohledem na jejich vysokou spotřebu a vnos dalších prvků do procesu.

The energy performance of vacuum evaporators for liquid digestate treatment in biogas plants

“…Rehl and Müller [29] assess evaporation of the digestate in relation to a life-cycle assessment, yet there is no operational information in the text. The same relates to a study by Heviánková et al [16] who demonstrated the option to reduce the volume of LD by evaporation down to 15 percent of its original volume. Flotats et al [30] provide facts about the economy of a plant processing slurry from animal production.…”

The Distribution of Macro- and Micronutrients in Maize Within Separated Digestate Fertilizing (Digestate Fibre and Digestate Luquor): Field Trial

“…Digestate is often considered as an organic fertilizer, but it contains stable organic matter, so it is rather a mineral fertilizer [8] and Babička [9] also confirmed this conclusion. The use of digestate as fertilizer is limited primarily by hygiene requirements, the presence of hazardous elements and salinity.…”

“…DL has a better fertilizing effect than DF due to the higher content of nitrogen (mainly mineral nitrogen) and the lower content of Fe and Al in the roots. The experimental part brought a significant finding that the organic material of DF is stable and therefore it is nearly worthless as an organic fertilizer [8].…”

Using of Organic Sludge to Improve the Efficiency of Biogas Technologies

“…Water flowing from such a system can be used for irrigation. Periodically, sediment is extracted from the bottom of artificial wetlands and used as organic fertilizer [12].…”