Understanding Coconut As A Biomass Fuel

Coconut as a Biomass Fuel

As a non-seasonal crop, coconut provides a continuous supply of fruit throughout the year, requiring little to no maintenance. Trees are long lived (up to 100 fruit-bearing years) and are a constant and long-lasting source of economically valuable materials. Coconut wastes have a high potential for energy production (see table below) but aside from niche applications for using residues the wastes are barely used. In SE Asia, some inefficient and polluting small scale processes are used to make a crude charcoal, but the vast majority of waste materials remain unexploited. Traditionally coconut farmers dispose of waste residues by burning or leaving it to rot in the fields, which is damaging for the environment. In SE Asia and Asia Pacific alone, the estimated annual waste is around 25 million tons.

Fuel Summary

Typical coconut waste averages around 50% of the total coconut production mass.

Coconut husk forms the majority of waste (~35-40%) and consists of the 5 – 10 cm of thick stringy fibre layer covering the fruit. It varies in colour depending on the ripeness of the fruit.

The husk is surrounded by coir “dust“ (~3-4%). The husks and dust make up about 40% of the fruit’s mass. The shell makes up about 12%.

The coconut palm itself regularly sheds fronds. Typically about 40 fronds, each weighing about 10kg are shed over a 5–6-year period.

The varying chemical properties and physical characteristics of each type of waste material pose challenges for effective use, and traditionally these have proved to be too difficult to overcome.

The fuel analysis below illustrates the typical moisture levels and energy value for a calculated ‘standard’ mix of coconut residues and fronds.

Excerpt from (Understanding coconut as a biomass fuel. CleanTech)