Publication detail

Development of a novel vacuum evaporator for liquid digestate treatment

VONDRA, M. KONEČNÁ, E. MÁŠA, V. TOUŠ, M.

Original Title

Development of a novel vacuum evaporator for liquid digestate treatment

Type

abstract

Language

English

Original Abstract

Vacuum evaporation is a proven technology for a liquid digestate treatment with the advantage of simple construction, robust operation and waste heat utilization. Evaporators are capable of significant dewatering of the liquid digestate up to the 15 % of dry matter content (without a stirrer). However, high investment cost, chemicals consumption and utilization of subsidized and thus expensive electricity are the main obstacles for its expansion in the Czech Republic. To be acceptable for plant operators, beside price and reliability, a vacuum evaporator must meet all requirements for its product’s (concentrate, separated water) quality. Separated water should be purified enough so it could be directly discharged. The concentrate should contain most of original nutrients and must be usable as a fertilizer. To meet rising demand for feasible digestate treatment technology in the Czech Republic, a multi-stage flash (MSF) evaporator has been subjected to an extensive development, which is further described in this study. The reasons for the choice of the MSF evaporator are as follows: low energy consumption, good operational experience in the field of desalination, its simple construction, modularity and evaporation outside the heat transfer surface. The MSF prototype, which is currently under development, consists of three evaporation chambers and is capable of a stable liquid digestate flow rate (0.4–0.5 m3/h) and continuous distillate production (5 to 10 kg/h). In the full-scale projection, the evaporator should consume approx. 14 kWhel and 240 kWhth per m3 of the distillate produced. To reach the desired product’s quality, the MSF evaporator had to be supplemented by a system for ammonia degassing and absorption. This study presents obtained experimental results as well as future work, which will consists mainly of the technology optimization and investment cost reduction.

Keywords

liquid digestate; vacuum evaporation; waste heat; anaerobic digestion; ammonia recovery

Authors

VONDRA, M.; KONEČNÁ, E.; MÁŠA, V.; TOUŠ, M.

Released

16. 10. 2018

Location

Schwäbisch Hall, Deutschland

Pages from

49

Pages to

49

Pages count

1

BibTex

@misc{BUT152212,
  author="Marek {Vondra} and Eva {Konečná} and Vítězslav {Máša} and Michal {Touš}",
  title="Development of a novel vacuum evaporator for liquid digestate treatment",
  booktitle="Progress in the treatment and application of manure and digestate products - Abstracts booklet",
  year="2018",
  pages="49--49",
  address="Schwäbisch Hall, Deutschland",
  note="abstract"
}