A mass transfer model of ammonia volatilisation from anaerobic digestate

Journal Article · Fri Oct 15 00:00:00 EDT 2010 · Waste Management

DOI:https://doi.org/10.1016/j.wasman.2009.08.012· OSTI ID:21457150

Everitt, T; Villa, R ^[1]

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1. School of Applied Sciences, Cranfield University, College Road, Cranfield, Bedfordshire, MK43 0AL (United Kingdom)

Anaerobic digestion (AD) is becoming increasingly popular for treating organic waste. The methane produced can be burned to generate electricity and the digestate, which is high in mineral nitrogen, can be used as a fertiliser. In this paper we evaluate potential losses of ammonia via volatilisation from food waste anaerobic digestate using a closed chamber system equipped with a sulphuric acid trap. Ammonia losses represent a pollution source and, over long periods could reduce the agronomic value of the digestate. Observed ammonia losses from the experimental system were linear with time. A simple non-steady-state partitioning model was developed to represent the process. After calibration, the model was able to describe the behaviour of ammonia in the digestate and in the trap very well. The average rate of volatilisation was approximately 5.2 g N m{sup -2} week{sup -1}. The model was used to extrapolate the findings of the laboratory study to a number of AD storage scenarios. The simulations highlight that open storage of digestate could result in significant losses of ammonia to the atmosphere. Losses are predicted to be relatively minor from covered facilities, particularly if depth to surface area ratio is high.

• OSTI ID: 21457150
• Journal Information: Waste Management, Vol. 30, Issue 10; Other Information: DOI: 10.1016/j.wasman.2009.08.012; PII: S0956-053X(09)00344-4; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0956-053X
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
AMMONIA
ANAEROBIC DIGESTION
CALIBRATION
DEPTH
MASS TRANSFER
METHANE
NITROGEN
ORGANIC WASTES
POLLUTION SOURCES
SIMULATION
STEADY-STATE CONDITIONS
SULFURIC ACID
SURFACE AREA
ALKANES
BIOCONVERSION
DIGESTION
DIMENSIONS
ELEMENTS
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INORGANIC COMPOUNDS
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
NONMETALS
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
SULFUR COMPOUNDS
SURFACE PROPERTIES
WASTES