Method for producing silicic acid and its use as a plant nutrient, insulating and dampening material and filter aid

摘要

Producing silicic acid using plants or plant parts, preferably of grass family (Poaceae) and algae family (Diatomeae), comprises: (a) carbonizing phytomass by pyrolysis under reducing conditions and in the absence of oxygen to an intermediate comprising biomass coke; and (b) converting the biomass coke in a subsequent oxidative post-combustion in presence of oxygen to a completely mineralized phytoash enriched with silicic acid or silicic acid compounds. An independent claim is also included for silicic acid or silicic acid compound produced by the above method.