Production of microalgae biochar has been conducted by ALGECO project partner SINTEF Energy Research. The dried microalgae was pyrolyzed by using a batch tubular reactor with collection of solid biochar and liquid condensates. The microalgae was pyrolyzed with a purging of N2 at temperature 350, 400 and 500 °C at a heating of 10K/min, respectively. The solid biochar and liquid condensate were collected and weighed. The yield of gas products was calculated by difference. Figure 1 shows the dry microalgae and the biochar produced at a temperature of 400 °C. Figure 2 shows the solid, liquid and gas product distribution from the three pyrolysis experiments. The result showed that temperature had significant effects on the yield of biochar, which decreased from 33 wt% to 22 wt% as the temperature increased from 350 to 500 °C. Liquid condensate is the other main product from the pyrolysis of microalgae, which is over 50% of the products from three pyrolysis experiments. The produced biochar will be analyzed by a combination of analytical techniques to investigate key physico-chemical properties that are relevant for agriculture applications.
Production of microalgae biochar
Figure 1. Dry microalgae and microalgae produced at 400 °C.
Figure 2. Yield of products from pyrolysis of microalgae.