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

Loading...
Thumbnail Image
Date
2018-03-01
ORCID
Advisor
Referee
Mark
Journal Title
Journal ISSN
Volume Title
Publisher
PERGAMON-ELSEVIER SCIENCE LTD
Altmetrics
Abstract
Vacuum evaporation is an efficient method for reducing the volume of liquid digestate (LD) from biogas plants (BGP). Furthermore, thickening LD in BGP contributes to the efficient utilization of waste heat and also reduces fossil fuel consumption that is needed for transporting LD. However, the utilization of vacuum evaporation must be reasonable, and a comprehensive study should precede the integration of evaporation technology in a particular BGP. For this purpose, this study compares selected parameters of three types of industrial evaporators which may be suitable for LD thickening. Furthermore, this study provides a mathematical model that describes the mass and energy balances of the chosen evaporators and is able to evaluate their energy performance for a given set of input variables. It was concluded that the forced-circulation evaporator has the highest energy requirements and also requires a high cooling performance. This type of evaporator will be interesting for the plant owners only if the cost of power generation is extremely low. In terms of consumption of energy and cooling duty, the multi-stage flash evaporator is the most efficient and it also requires the least heat transfer area. The falling-film evaporator provides only slightly worse performance.
Description
Document type
Peer-reviewed
Document version
Accepted version
Date of access to the full text
Language of document
en
Study field
Comittee
Date of acceptance
Defence
Result of defence
Document licence
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
http://creativecommons.org/licenses/by-nc-nd/4.0/
Citace PRO