Supercritical Extraction for Valuable Carbon Materials

UW ID: 17-107/108

Description of Technology

There has recently been an increase in interest in the development of technologies that utilize coal for purposes other than direct combustion.  There have been recent studies on efficient non-fuel utilization approaches, with minimal environmental impact, for producing high-value-added chemicals and high-performance carbon materials from coal.

Researchers at the University of Wyoming have extracted liquid tar from Powder River Basin (PRB) coal. They have done this by using a super critical Fluid Technologies, Inc. carbon dioxide (CO₂)-ethanol extractor. Compared to other extraction methods, supercritical CO₂-ethanol extraction can proceed under mild conditions (<400°C).

During their experiments, many different experimental conditions were tested. During these test, ethanol was decided to be the best for extracting from PRB coal. The best yield from extraction was nearly 50 wt.% which is much higher than the conventional processes. The liquid tar can then be further separated into different products such as light oil and asphaltene. The invention can also be used to make carbon fiber from coal. When it’s used in conjunction with the electrospinning technology, a relatively simple and low cost technology, it can produce continuous carbon fiber nanofibers.

Applications

• This technology can be used to lessen the direct combustion of coal since this technology can create high-value-added chemicals from coal. It can also create high-performance, continuous, nanostrands of carbon fiber when used in conjunction with the electrospinning technology. 

Features & Benefits

• Alternative use of coal, other than direct combustion
• Produces high-value-added chemicals from coal
• Produces high-performance carbon materials
• Proceeds under mild conditions compared to traditional extraction methods
• May result in higher yield than conventional processes

Downloadable PDF: 17-107/108