Supercritical Carbon Dioxide Extraction

<p>The objective of this thesis is to explore the properties of supercritical carbon dioxide (CO₂). In addition, the feasibility of building a small-scale low cost system will be explained. A supercritical fluid is a fluid which exhibits properties between liquid and gas with liquid like densities and viscosities similar to a gas. Since the discovery of supercritical fluids in 1822, the use of supercritical fluids, specifically supercritical CO₂, has grown in popularity. The application of supercritical CO₂has continued to grow in industrial applications since the 1970’s. Supercritical CO₂’s has many beneficial properties as a “green” solvent. Supercritical CO₂ as a solvent is able to be implemented in a wide range of applications from aerospace, microchip manufacturing, food production, biomedical, pharmaceutical, dry-cleaning, and many more.</p> <p>This thesis project included designing, building and testing a supercritical CO₂ extraction apparatus that examines the use of supercritical CO₂ as a solvent in the extraction process of decaffeinating coffee. Due to the fact that supercritical CO₂ requires high pressure operating conditions, the apparatus design is important not only for function but also for safety. In the description portion of this paper, design considerations related to each component’s function and their specific roles in the overall system are clearly stated. Furthermore, the build process is outlined along with the overall step-by-step operation of the apparatus.</p> <p>Different methods of data measurements are taken while the system is running, in order to interpret the apparatus’ overall functionality. Through the exploration of this experimental data, the results were compared between different operating parameters. In order to determine the feasibility of the supercritical apparatus, the devise was tested by applying the supercritical CO₂ as a solvent for the extraction of caffeine from coffee beans. Analysis of the analytical data recorded from experimental testing confirms that the apparatus produced supercritical CO₂. After testing specific operating conditions, it is proven that the supercritical CO₂ is able to function as a “green” solvent in this small-scale system. The experimental results from these analytical runs are compared with theoretical maximums in order to determine the efficiency of the devise.</p> <p>Lastly, the paper presents an overview including lessons learned from the design process and from the information gathered. Data from experimental testing is interpreted and the system design is reevaluated with suggestions for future improvements.</p>

Name thesis:degree_name

MS in Mechanical Engineering

Discipline thesis:degree_discipline

Mechanical Engineering

Year dc:date.available

2017

Author dc:creator

• Carney, Kevin

Contributors dc:contributor

• Steffen Peuker

• Carbon Dioxide
• Heat Transfer, Combustion

Identifier

10.15368/theses.2017.32

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-2949