A review of the current digestate distribution models: storage and transport

Abstract

Over the past few years, the biogas sector has experienced an important growth in the number of biogas installations all over Europe, and consequently, the quantity of digestate also has had a significant increase. In Europe, biogas production by anaerobic digestion (AD) is a common source of renewable energy and the current amount of installations is around 13,000. Together with biogas, digestate is one of the two main by products resulting from the biogas process. The digested effluent is a liquid product rich in nitrogen (N), phosphorus (P), potassium (K) and micronutrients. Therefore, there is a wide variety of digestate utilization depending on the quality, the origin of the feedstock, the operating conditions of the process as well as the phase of the by-product. The most common end uses are biofertilizer and soil amendment, due to its essential characteristics and when the quality is adequate for agriculture use. Before land application, environmental and agronomic reasons affect the storage of the digestate for a required period of time, in the biogas installations or near the area of application. Hence, the increasing production of digestate, the low solids content of whole digestate and the vulnerability of several land areas to the amount of nitrate and phosphate in Europe, convert the biofertilizer into a bottleneck for the biogas sector, due to the difficulty for its management.This paper contains an extensive review of the technical literature regarding digestate distribution. The objectives of this paper were to identify and analyse the current digestate distribution systems; storage and transport in Europe.

Digestate Biofertilizers Support Similar or Higher Tomato Yields and Quality Than Mineral Fertilizer in a Subsurface Drip Fertigation System

“…However, it is unclear at this point what additional processing would be required to ensure this material's longterm suitability for drip fertigation systems. Studies on the economics of digestate processing technologies are available and highly useful but are mainly focused on European markets, where anaerobic digestion plants are more common than in the US (ADAS UK Ltd, 2013;Chiumenti et al, 2013;Delzeit and Kellner, 2013;Fuchs and Drosg, 2013;Drosg et al, 2015;Plana and Noche, 2016;Vaneeckhaute et al, 2016;Bolzonella et al, 2017). Research is needed to describe the economic conditions, costs, and availability of processing technology in the US case in order to understand the feasibility of increased US adoption of anaerobic digestion and digestate processing technologies as well as their associated biofertilizer products.…”

Treatment of Liquid By-Products of Hydrothermal Carbonization (HTC) of Agricultural Digestate Using Membrane Separation

“…However, European Nitrates Directive (91/676/EEC) introduces complications in the wide use of this practice [5]. Moreover, the state-of-the-art biogas plant has a substantial land requirement for the storage of digestate, typically 8 ha/MW of installed power, which introduces significant costs [6]. Thermal drying, along with a subsequent pelletizing, is considered as one of the management strategies, aiming at a decreased volume of digestate [7].…”

Challenges and an Implementation Framework for Sustainable Municipal Organic Waste Management Using Biogas Technology in Emerging Asian Countries

“…At the end stream of a biogas plant, digestate is recovered as well as energy of various forms. The volume of digestate is not significantly different, or usually more than the volume of substrates due to additional substances such as water [87][88][89]. Demand for digestate is, therefore, a fundamental factor that shapes the sustainability of a biogas plant.…”