Integrating Pyrolysis and Anaerobic Digestion in a Novel Biorefinery Concept

摘要

Contacting fiber with a CaCl_2 solutions prior to pyrolysis significantly increased the adsorption capacity of resulting chars. Increasing the equilibrium pH of solutions during contacting further increased both the rate and equilibrium adsorption capacity of the char. Chars prepared from fiber equilibrated at pH 9.35 effectively removed more than 50% of ionic phosphate after 7.5 hours and 80% after 36 hours. Minerals of both calcium and magnesium are involved in the adsorption of phosphates Chars modified with calcium did not show high levels of leaching during the adsorption tests, indicating that the mineral matter was converted to a stable form All oxidation methods tested resulted in varying degrees of acid group formation and carbon gasification. Air at temperatures of 250-300 ℃ was effective at generating carboxylic acid groups, at 350 ℃ carboxylic groups were not detected. This process can be easily integrated to a pyrolysis units during bio-char cooling. Increasing the number of carboxylic groups on various char surfaces was found to have a near 1:1 correlation with CEC and ammonium adsorption Oxidation by air results in the formation of a significant fraction of small molecules and particles soluble in basic solutions that require further study Shorter oxidation times and possibly lower oxygen concentration are required to mitigate destruction of the surface.