The following gases can be recovered during the carbonization of coconut shells:

1. Wood vinegar: Wood vinegar is a liquid by-product produced during the carbonization of coconut shells and is mainly composed of volatile organic compounds. It contains various organic compounds such as phenols, ketones, aldehydes, and alcohols. Wood vinegar can be used as fertilizer, pesticide, biofungicide and industrial raw material.

2. Combustion gas: The waste gas generated during the carbonization process of coconut shell contains flammable gases, such as methane, carbon monoxide and hydrogen. These gases can be used as energy sources to provide heat or drive generators, creating a self-sufficient energy cycle.

3. Water vapor: During the carbonization process of coconut shell, the high temperature generated by heating the coconut shell causes the water inside the coconut shell to evaporate into water vapor. The water vapor can be recovered and condensed to produce liquid water, which can be used as industrial water or for other purposes.

Recycling these gases not only helps improve the energy efficiency of the coconut shell carbonization process, but also reduces the need for external energy, reducing carbon emissions and environmental pollution.