How and in what way the temperature of pyrolysis chamber affects in woodgas generation results in terms of quality and energy content of the gas?

The temperature of the pyrolysis chamber in a wood gasifier is a critical factor in determining the quality and energy content of the produced gas.

1. Pyrolysis Temperature and Gas Quality: Pyrolysis, the thermal decomposition of organic material at elevated temperatures in the absence of oxygen, begins at around 250°C and can proceed at temperatures up to 700°C or more. The precise temperature affects the proportions of gas, liquid (tar), and solid (char) products. Lower temperatures tend to produce more liquid and solid products, whereas higher temperatures favor gas production.
2. Temperature and Gas Energy Content: The temperature also affects the energy content of the gas. Higher temperatures lead to more complete breakdown of the wood, resulting in gas with higher concentrations of combustible components such as hydrogen, carbon monoxide, and methane. This translates to a higher calorific value and better overall gas quality.
3. Temperature and Tar Production: An important factor to consider is tar production. Tars are complex hydrocarbons that can condense and cause problems in engines and other equipment. Higher pyrolysis temperatures, especially above 800°C, help to crack these tars into smaller, combustible molecules, thereby reducing tar content and improving gas quality.

In conclusion, controlling the temperature of the pyrolysis chamber is crucial to optimizing the efficiency and output of a wood gasification system. Different systems may have different optimal temperature ranges, depending on the specific design and intended use of the gas. Nonetheless, maintaining a sufficiently high temperature is generally important for maximizing gas yield, energy content, and overall gas quality, while minimizing tar production.