Physicochemical Properties and Gasification Reactivity of Chars from Different Carbonization Processes

Three kinds of high temperature carbonization chars (gas-phase carbonization chars [GPCCs], solid-phase carbonization chars [SPCCs], and high temperature calcination chars from liquid-phase carbonization cokes [HLPCCs]) were prepared at the carbonization temperature of 800–1,600°C, and their physicochemical properties and CO2 gasification reactivity were mainly investigated. The increasing carbonization temperature was favorable for chars produced from different carbonization processes to form more ordered carbon crystallite structures. At the same carbonization temperature, the regularity of carbon crystalline structures of different chars presented the following order: GPCCs > HLPCCs > SPCCs. The increasing carbonization temperature resulted in the increase of surface areas of HLPCCs as a whole and the decrease of surface areas of SPCCs, while those of GPCCs initially increase and then decrease with the increasing carbonization temperature. Brunauer-Emmett-Teller surface areas of different chars, as a whole, presented the following order: SPCCs > GPCCs ≥ HLPCCs. The increasing carbonization temperature was adverse to the gasification activities of SPCCs and GPCCs, while those of HLPCCs initially decrease and then increase with the increasing carbonization temperature. The ordering of the gasification reactivity of different chars was SPCCs > GPCCs > HLPCCs.