Study On The Preparation Of Mesoporous Activated Carbon From Black Liquor

The mesoporous activated carbon was prepared from black liquor by water vapor.In this experiment, the lignin was separated from black liquor of paper-aking by adding HC1, The recovered lignin was carbonized at the operational temperature, then some amount of ferrocene as catalysts was loaded into the carbonization material after it was comminuted to definite granularity. The mesoporous activated carbon was obtained after it is activated for some time in the steam atmosphere at the operational temperature. The mesopore ratio was more than 55% in the production. It is showed that the mesoporous activated carbon was suitable as a good adsorbent for VB12 because it has more mesopore.Firstly, the process of recovering lignin from the alkaline paper-making black liquor by acidulation precipitation was studied. The effect of pH, reactivity temperature and reactivity time was discussed in detail ,while the optimum condition was obtained : pH=2, reactivity temperature=60 Cand reactivity time=60min. The acid flow rate was controlled not to form a lot of froth. Under the above condition, the lignin recovery impact was the best .The recovery amount was 190. 03g/L .The effect of carbonization temperature , carbonization time , carbonization calefactive velocity , activation temperature , activation time , the amount of catalysts on the ability of adsorption to VB12 was studied .The optimum condition was achieved by putting emphasis on studying the condition of carbonization and activation : carbonization time=30min, carbonization temperature =550 C , activation temperature =850 C , activation time=3h.The activation with steam mainly generated microspore firstly, while the average pore size was increased due to the excess burn-off which made the microspore transfer into mesopore or macropore .