Supercritical fluid extraction of organic compounds from solids and aqueous solutions: Dissertation

Research output: ThesisDissertationCollection of Articles

Abstract

In this thesis, the extraction of organic compounds from solid and liquid matrices using supercritical carbon dioxide as a solvent was studied. Dense carbon dioxide is a very good solvent for the cyclic amide, 6-caprolactam. 6-caprolactam exhibits relatively high solubilities, i.e. up to around 17 wt% at ambient temperatures, and at pressures below 220 bar. Carbon dioxide can be used to dissolve and extract 6-caprolactam from solid and liquid matrices. The remediation of contaminated soil by carbon dioxide extraction was studied. The effect of extraction pressure, temperature, soil moisture content, pH, carbon dioxide mass flow rate, and extraction time on the residual pollutant concentration in the soil after extraction was systematically studied. The selected pollutants were phenanthrene, 2,3,4,6-tetrachlorophenol and pentachlorophenol. The results indicate that at least 80-90 % of the initial amount of pollutant can be removed at moderate temperatures even in the most difficult cases, and in many cases over 99 % of the initial amount of pollutant can be removed from the soil. Supercritical extraction is best suited to sand or silt type soils, which have a low adsorption capacity. The extraction results are found to be case-dependent, and soil remediation at moderate temperatures is observed to be difficult if the pollutant binds strongly to the soil or if the acceptable level of residual concentration is very low. A novel mechanically agitated countercurrent continuous extraction column was introduced by extracting ethanol and 1-butanol from aqueous solutions in the rotating disk column and in the Oldshue-Rushton column. Column efficiencies were measured as a function of solvent-to-feed ratio and rotor speed. Generally, the values of the height equivalent to a theoretical stage HETS were in the range of 0.4-0.8 m. Mechanical agitation enhanced the extraction only at relatively high solvent-to-feed ratios. Column capacities for both types of column were measured, and the total throughput calculated as the feed plus solvent flow rate divided by the smallest cross-sectional area was 50-80 m3h-1m-2. A mechanically agitated column successfully combines the high capacity of supercritical spray columns and the high efficiency of supercritical packed columns.
Original languageEnglish
QualificationDoctor Degree
Awarding Institution
  • Aalto University
Supervisors/Advisors
  • Hurme, Markku, Supervisor, External person
Award date21 Jan 2000
Place of PublicationEspo
Publisher
Print ISBNs951-38-5551-1
Electronic ISBNs951-38-5552-X
Publication statusPublished - 1999
MoE publication typeG5 Doctoral dissertation (article)

Fingerprint

Supercritical fluid extraction
Organic compounds
Solid solutions
Carbon Dioxide
Caprolactam
Soils
Remediation
Flow rate
Pentachlorophenol
Temperature
1-Butanol
Silt
Soil moisture
Rotating disks
Liquids
Amides
Ethanol
Moisture
Sand
Solubility

Keywords

  • organic compounds
  • extraction
  • solids
  • aqueous solutions
  • supercritical gases
  • supercritical fluids
  • carbon dioxide
  • amides
  • lactams
  • solubility

Cite this

@phdthesis{a9bbbb28b6b344e08f7ab6a02b39570a,
title = "Supercritical fluid extraction of organic compounds from solids and aqueous solutions: Dissertation",
abstract = "In this thesis, the extraction of organic compounds from solid and liquid matrices using supercritical carbon dioxide as a solvent was studied. Dense carbon dioxide is a very good solvent for the cyclic amide, 6-caprolactam. 6-caprolactam exhibits relatively high solubilities, i.e. up to around 17 wt{\%} at ambient temperatures, and at pressures below 220 bar. Carbon dioxide can be used to dissolve and extract 6-caprolactam from solid and liquid matrices. The remediation of contaminated soil by carbon dioxide extraction was studied. The effect of extraction pressure, temperature, soil moisture content, pH, carbon dioxide mass flow rate, and extraction time on the residual pollutant concentration in the soil after extraction was systematically studied. The selected pollutants were phenanthrene, 2,3,4,6-tetrachlorophenol and pentachlorophenol. The results indicate that at least 80-90 {\%} of the initial amount of pollutant can be removed at moderate temperatures even in the most difficult cases, and in many cases over 99 {\%} of the initial amount of pollutant can be removed from the soil. Supercritical extraction is best suited to sand or silt type soils, which have a low adsorption capacity. The extraction results are found to be case-dependent, and soil remediation at moderate temperatures is observed to be difficult if the pollutant binds strongly to the soil or if the acceptable level of residual concentration is very low. A novel mechanically agitated countercurrent continuous extraction column was introduced by extracting ethanol and 1-butanol from aqueous solutions in the rotating disk column and in the Oldshue-Rushton column. Column efficiencies were measured as a function of solvent-to-feed ratio and rotor speed. Generally, the values of the height equivalent to a theoretical stage HETS were in the range of 0.4-0.8 m. Mechanical agitation enhanced the extraction only at relatively high solvent-to-feed ratios. Column capacities for both types of column were measured, and the total throughput calculated as the feed plus solvent flow rate divided by the smallest cross-sectional area was 50-80 m3h-1m-2. A mechanically agitated column successfully combines the high capacity of supercritical spray columns and the high efficiency of supercritical packed columns.",
keywords = "organic compounds, extraction, solids, aqueous solutions, supercritical gases, supercritical fluids, carbon dioxide, amides, lactams, solubility",
author = "Antero Laitinen",
note = "Project code: K9SU00433",
year = "1999",
language = "English",
isbn = "951-38-5551-1",
series = "VTT Publications",
publisher = "VTT Technical Research Centre of Finland",
number = "403",
address = "Finland",
school = "Aalto University",

}

Supercritical fluid extraction of organic compounds from solids and aqueous solutions : Dissertation. / Laitinen, Antero.

Espo : VTT Technical Research Centre of Finland, 1999. 60 p.

Research output: ThesisDissertationCollection of Articles

TY - THES

T1 - Supercritical fluid extraction of organic compounds from solids and aqueous solutions

T2 - Dissertation

AU - Laitinen, Antero

N1 - Project code: K9SU00433

PY - 1999

Y1 - 1999

N2 - In this thesis, the extraction of organic compounds from solid and liquid matrices using supercritical carbon dioxide as a solvent was studied. Dense carbon dioxide is a very good solvent for the cyclic amide, 6-caprolactam. 6-caprolactam exhibits relatively high solubilities, i.e. up to around 17 wt% at ambient temperatures, and at pressures below 220 bar. Carbon dioxide can be used to dissolve and extract 6-caprolactam from solid and liquid matrices. The remediation of contaminated soil by carbon dioxide extraction was studied. The effect of extraction pressure, temperature, soil moisture content, pH, carbon dioxide mass flow rate, and extraction time on the residual pollutant concentration in the soil after extraction was systematically studied. The selected pollutants were phenanthrene, 2,3,4,6-tetrachlorophenol and pentachlorophenol. The results indicate that at least 80-90 % of the initial amount of pollutant can be removed at moderate temperatures even in the most difficult cases, and in many cases over 99 % of the initial amount of pollutant can be removed from the soil. Supercritical extraction is best suited to sand or silt type soils, which have a low adsorption capacity. The extraction results are found to be case-dependent, and soil remediation at moderate temperatures is observed to be difficult if the pollutant binds strongly to the soil or if the acceptable level of residual concentration is very low. A novel mechanically agitated countercurrent continuous extraction column was introduced by extracting ethanol and 1-butanol from aqueous solutions in the rotating disk column and in the Oldshue-Rushton column. Column efficiencies were measured as a function of solvent-to-feed ratio and rotor speed. Generally, the values of the height equivalent to a theoretical stage HETS were in the range of 0.4-0.8 m. Mechanical agitation enhanced the extraction only at relatively high solvent-to-feed ratios. Column capacities for both types of column were measured, and the total throughput calculated as the feed plus solvent flow rate divided by the smallest cross-sectional area was 50-80 m3h-1m-2. A mechanically agitated column successfully combines the high capacity of supercritical spray columns and the high efficiency of supercritical packed columns.

AB - In this thesis, the extraction of organic compounds from solid and liquid matrices using supercritical carbon dioxide as a solvent was studied. Dense carbon dioxide is a very good solvent for the cyclic amide, 6-caprolactam. 6-caprolactam exhibits relatively high solubilities, i.e. up to around 17 wt% at ambient temperatures, and at pressures below 220 bar. Carbon dioxide can be used to dissolve and extract 6-caprolactam from solid and liquid matrices. The remediation of contaminated soil by carbon dioxide extraction was studied. The effect of extraction pressure, temperature, soil moisture content, pH, carbon dioxide mass flow rate, and extraction time on the residual pollutant concentration in the soil after extraction was systematically studied. The selected pollutants were phenanthrene, 2,3,4,6-tetrachlorophenol and pentachlorophenol. The results indicate that at least 80-90 % of the initial amount of pollutant can be removed at moderate temperatures even in the most difficult cases, and in many cases over 99 % of the initial amount of pollutant can be removed from the soil. Supercritical extraction is best suited to sand or silt type soils, which have a low adsorption capacity. The extraction results are found to be case-dependent, and soil remediation at moderate temperatures is observed to be difficult if the pollutant binds strongly to the soil or if the acceptable level of residual concentration is very low. A novel mechanically agitated countercurrent continuous extraction column was introduced by extracting ethanol and 1-butanol from aqueous solutions in the rotating disk column and in the Oldshue-Rushton column. Column efficiencies were measured as a function of solvent-to-feed ratio and rotor speed. Generally, the values of the height equivalent to a theoretical stage HETS were in the range of 0.4-0.8 m. Mechanical agitation enhanced the extraction only at relatively high solvent-to-feed ratios. Column capacities for both types of column were measured, and the total throughput calculated as the feed plus solvent flow rate divided by the smallest cross-sectional area was 50-80 m3h-1m-2. A mechanically agitated column successfully combines the high capacity of supercritical spray columns and the high efficiency of supercritical packed columns.

KW - organic compounds

KW - extraction

KW - solids

KW - aqueous solutions

KW - supercritical gases

KW - supercritical fluids

KW - carbon dioxide

KW - amides

KW - lactams

KW - solubility

M3 - Dissertation

SN - 951-38-5551-1

T3 - VTT Publications

PB - VTT Technical Research Centre of Finland

CY - Espo

ER -