Conversion of waste algae from biodiesel production to valuable gas, liquid and solid products

A novel procedure for the conversion of waste algae waste, remaining from biodiesel production, into gas, liquid products and porous carbon has been developed. The precursor, algae waste is studied by thermogravimetric and differential thermal analysis. First algae material is subjected to pyrolysis at 550 °C, and the composition of evolving gas and liquid products is studied—dominant content of polar compounds in the liquid products is determined. The solid product after pyrolysis is subjected to hydro-pyrolysis (physical activation with water vapor) at different temperatures. The pore structure of the obtained carbon after activation at pre-determined optimal temperature is investigated by nitrogen adsorption porosimetry, which demonstrate moderate surface area, microporosity and mesoporosity, developed during activation process. Presence of oxygen functional groups with weak acidic and basic nature is established.