Microwave coal powder to graphite…

Coal, which has been deteriorated by ancient plants buried under the ground under geothermal heat and pressure over a long period of time, has long supported industries around the world as an important fuel. However, recently, as the transition to new and renewable energy has progressed, the value of coal is falling. A research team at the University of Wyoming in the United States has developed a method to convert coal into more valuable graphite using a conventional microwave oven.

Graphite is an elemental mineral composed of carbon, which is also the main component of coal, and is used in industrial lubricants and reactor moderators. In addition, graphene, which is a single layer of graphite atoms, has various properties such as excellent thermal conductivity, so it is a material that is expected to be applied for various purposes.

Previously, research on the method of converting coal into graphite has been conducted, and it has been stated that the conversion requires elements such as reduction, catalyst, and microwave radiation filled with a reducing gas having a high temperature and oxygen deprivation property.

A research team at the University of Wyoming believes that these factors can be met in a general household microwave oven, and devised a method to convert untreated coal powder into graphite using a microwave oven.

First, the research team spread copper thinly into sheets, cut the copper film into a fork shape, and burned powdered coal on it. Subsequently, the copper film and coal powder were reduced with a mixed gas of argon and hydrogen, sealed in a glass container, and heated in a household microwave oven.

It is said that when heating is started in a microwave oven and microwaves are emitted, a spark is generated in the glass container, creating a high temperature sufficient to convert coal into polycrystalline graphite, and the coal is converted into graphite. The research team explained that doing this would trigger a spark by microwave radiation and generate an ultra-high temperature of over 1,800 degrees Celsius within a few seconds.

In the experiment, the microwave irradiation time was 3 to 45 minutes wide to investigate the conversion efficiency. As a result, it is said that the optimum microwave irradiation time was 15 minutes. Using a microwave oven to convert coal into graphite is cost effective. The research team hopes to improve and expand this technology to produce higher quantities of graphite with higher quality. Related information can be found here .