NORTH AMERICAN WOOD VINEGAR
HISTORY OF WOOD VINEGAR AND TAR
Use of wood vinegar in agriculture dates back at least two millennia in ancient China, Egypt, Greece and India. Wood vinegar also has a long history and it has been used daily, for example, in Japan as a result of numerous health claims related to the product. Since the 1930’s, wood vinegar has also been used in agriculture as a fertilizer and growth promoting agent. Although the word ancient, related to the use of wood vinegar, has been mentioned in many documents and on web pages it was difficult to find good scientific evidence to attest the first records of wood vinegar used as pesticide. Probably only few documents are available or the information has been written in languages and in countries difficult to reach via modern information retrieval
In conventional pyrolysis processes, wood is slowly heated up to the maximum temperature. Lower process temperatures (400 ºC) and longer vapour residence times favour the production of char. Besides slow pyrolysis, other terms such as carbonization, destructive distillation, and dry distillation are used for this kind of thermal process . The pyrolysis of wood was probably human’s first chemical process. It is known to have been practiced by the ancient Chinese. The Egyptians, Greeks, and Romans made charcoal by wood carbonization, and collected the condensable volatiles for embalming purposes and for filling joints in wooden ships.