Overview
![](/assets/images/picto-drapeau-france-3a76576a5d60a512053b4612ab58dae5.png)
ABSTRACT
Liquefied gases are used as solvents to obtain high quality extracts even from fragile raw material. This article presents the main liquified gases used as extraction solvents together with their implementation at an industrial scale. Economic, regulatory, environmental and safety impacts of these new solvents are discussed. These sections are supplemented by illustrative examples of liquified gas processes for the production of different extracts (oils, aromatic extracts, colors, bioactive compounds etc.) at laboratory and industrial scales.
Read this article from a comprehensive knowledge base, updated and supplemented with articles reviewed by scientific committees.
Read the articleAUTHORS
-
Vincent RAPINEL: Engineer – Doctoral student - University of Avignon, INRA, UMR408, GREEN Extraction Team, Avignon, France - Celsius SARL, 184 Chemin du Bouray, Villette de Vienne, France
-
Natacha ROMBAUT: Doctorate in Process Engineering - University of Avignon, INRA, UMR408, GREEN Extraction Team, Avignon, France
-
Njara RAKOTOMANOMANA: Senior Lecturer - University of Avignon, INRA, UMR408, GREEN Extraction Team, Avignon, France
-
Alain VALLAGEAS: Engineer, Manager - Celsius SARL, 184 Chemin du Bouray, Villette de Vienne, France
-
Farid CHEMAT: University Professor - University of Avignon, INRA, UMR408, GREEN Extraction Team, Avignon, France
INTRODUCTION
The first known use of liquefied gases as a solvent for extracting natural products dates back to 1930 in the USA, with a process patented by E. R. EBENEZER for extracting oils from oilseeds. In France, liquefied gases were first used in 1940 to extract fragrant compounds from fragile raw materials, particularly flowers.
N-butane was the first liquefied gas to be used, as its boiling point (- 1°C) means that it can be easily liquefied at low pressure to extract lipophilic molecules, but without leaving any trace in the final product once evaporated. Since then, new liquefied gases have been tested and new applications have emerged, mainly linked to the extraction of vegetable oils and fragrant extracts. Although effective and leaving no trace in the final extract, they have been abandoned for economic reasons in favor of other petrochemical liquid organic solvents (hexane, benzene, toluene, dichloromethane...), which are simpler to use industrially.
However, the ingredients market's growing interest in high-quality products of natural origin, combined with the tightening of regulations aimed at protecting our environment but above all the health of operators and consumers, have prompted manufacturers to look for alternatives more in line with the principles of green chemistry. Academic and industrial research has led to the discovery of several alternative solvents, but none of them has yet succeeded in replacing hexane in industry. The most serious alternative is the use of supercritical CO 2 extraction processes, which can effectively extract lipophilic compounds at generally moderate temperatures (30-70°C) and without leaving traces in the extract. Nevertheless, the pressures required to reach the supercritical state (between 100 and 1,000 bar, depending on the process temperature) limit its use to very high value-added products, due to the high investment cost for an industrial installation. This hindrance to the development of supercritical CO 2 processes has enabled liquefied gases to become highly credible alternatives to existing solvents, since they too enable lipophilic compounds to be extracted at room temperature, without leaving traces in the final product, with low energy consumption and moderate pressure (1-10 bar) that facilitates its implementation on an industrial scale.
In 2018, there are very few studies dealing with the use of liquefied gases as extraction solvents on an industrial scale. In order to give readers a better overall understanding of the process, this article presents :
the main types of liquefied gases and why they are potentially good solvents;
...
Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference
KEYWORDS
extraction | green solvant | natural extracts
This article is included in
Unit operations. Chemical reaction engineering
This offer includes:
Knowledge Base
Updated and enriched with articles validated by our scientific committees
Services
A set of exclusive tools to complement the resources
Practical Path
Operational and didactic, to guarantee the acquisition of transversal skills
Doc & Quiz
Interactive articles with quizzes, for constructive reading
Liquefied gases as alternative solvents for plant eco-extraction
Bibliography
Software tools
COSMOThermX (version C30_1602 – 13.07.2016) [Software], COSMOlogic GmbH & Co. KG Imbacher Weg 46 51379 Leverkusen, Germany.
Regulations
Directive 2014/34/EU of the European Parliament and of the Council of February 26, 2014 on the harmonization of the laws of the Member States concerning equipment and protective systems intended for use in potentially explosive atmospheres (recast). OJ L 96, 29.3.2014, pp. 309-356.
Directive 2014/68/EU of the European Parliament and of the Council of 15 May 2014 on the harmonization of the laws of...
Directory
Manufacturers
CELSIUS sarl
Equipment for the process industry
Villette de Vienne, France
http://www.celsius-process.com
TECNOLAB srl
Systems for the extraction of natural products
Spello (Pg), Italy
...Exclusive to subscribers. 97% yet to be discovered!
You do not have access to this resource.
Click here to request your free trial access!
Already subscribed? Log in!
![](/assets/images/logo-eti-286623ed91fa802ce039246e516e5852.png)
The Ultimate Scientific and Technical Reference