Fluidyne Gasification Archive

Chars and Graphitic Soot


For many years we have observed changes in the soot and charcoal waste from our wood gasification systems, but without the need, or the facilities to research these carbon wastes, they have waited in the wings to be examined. With such recent emphasis being placed on the value and properties of bio-chars as environmental modifiers, considerable effort is now being made to understand the differences hidden within these carbon structures, and apply them for maximum benefit to their designated end use.
 
It is important to acknowledge, that all chars are not equal, and even from the same process, can differ considerable if made from another biomass species. Care should be taken regarding end use recommendations, and it is always useful to provide working examples of before and after trials, especially for growing or polluted soil conditioning.
 
The char and soot that we have created, has opened up some interesting original research, which I can only share in part at this time. The following photos can give you some ideas of how to separate your soot and char using water from the carbon blacks that may have graphitic structures. Simple as it may be, it can be a useful first stage screen test, and a fun way to use magnets.
 
December 2011
 
 
 

Chars made from wood can vary across a wide spectrum, specific to the process in which they are made. This sample of char has been made in a high temperature reducing atmosphere, starting out at 12-1500C, and finishing at 900C.
Soot and carbon blacks are often more than just char, depending on how they are produced from packed carbon beds. These shown attracted to a magnet, have been identified as C57 O, a fullerene carbon.
Just to show comparative behaviour, this is a photo of black iron sand from our local beach. The grains are more even, providing a better polarized display.
One of the first photos taken of the C57 O: oxy-fullerene found in non- graphitising carbon taken at 740,000 x magnification.
Soot samples can display many factors if placed in water. Carbon blacks containing graphitic lattice, will sink immediately even if shaken (R) while the other sample remains in suspension for hours before settling. These are placed on magnets to observe polarisation behaviour of the sample.
Once settled, the left sample water remained darkened by suspended particulates, some of which can be seen to be orientated to the magnetic field.
The sample containing the graphite type carbons and C57 O (R) was tilted to allow the bottom to be exposed showing a grey deposit, probably of mineral content.
A forest of magnetized carbon glitters in the flash. There are many secrets yet to be revelled hidden in this forest.
Using these chars as a growing medium for conifer trees, may explain the strong horizontal growth of the root system of the seedling on the right, while the left hand sample has been grown in normal potting mix.