Relation between coal properties and acetylene yield in plasma pyrolysis

Thermodynamic Study on the Formation of Acetylene during Coal Pyrolysis in the Arc Plasma Jet

“…This conclusion was not in accordance with the literature (Bittner et al, 1985), in which acetylene formation and the production of CO mutually competed. In view of this point, the thermodynamics calculation based on the elemental composition for heterogeneous C-H-O-N-S equilibrium system may offer guidance for the direct production of acetylene from coal and choice of coal type.…”

“…The experimental results showed that formation and yield of the acetylene could be influenced by some factors such as enthalpy value of plasma jet, inter-reaction between coal and plasma jet, the property of coal, quenching speed, and coal feeding rate under plasma condition (Bond et al, 1963(Bond et al, , 1966Baumann et al, 1988;Bittner et al, 1985). Bittner et al (1981) reported the result of thermodynamic equilibrium composition for homogeneous multi-component C-H-O-Ar system under the pressure of 0.1 MPa, from which the optimal temperature for the acetylene formation was about 2,770 K. Wang and Guo (2005) uncovered the influence of oxygen, nitrogen, and helium added from outside on the maximum acetylene yield for the homogeneous C-H-O-N-Ar equilibrium system under the normal pressure by means of CEA program from NASA, from which the optimal temperature for formation of acetylene was about 1,800 K when the fat coal was used as a model substance and the mass ratio of H 2 /coal was 0.25.…”

High ash coal pyrolysis at different heating rates to analyze its char structure, kinetics and evolved species

“…The maximum temperature and the heating rate are varied in different coal utilization processes. Coal devolatilization is continued for several hours (with a heating rate of 10 −1 to 10 1 K/s) in a coking plant, order of few seconds or less (with a heating rate of 10 2 -10 4 K/s) in the processes of gasification or combustion [7], and within several milliseconds (with a heating rate of 10 4 -10 6 K/s) in a plasma process [8,9]. Hence, the basic information of coal pyrolysis under different heating rate and ultimate temperature is required to establish efficient coal utilization processes.…”

Experimental investigation on coal devolatilization at high temperatures with different heating rates

“…However, the ultimate temperature and the heating rate are much different in different coal utilization processes. Coal devolatilization is finished in several hours (with a heating rate of 10 À1 to 10 1 K/s) in a coking plant, within a few seconds or less (with a heating rate of 10 2 to 10 4 K/s) in the processes of gasification or combustion [10], and within several milliseconds (with a heating rate of 10 4 -10 6 K/s) in a plasma process [11,12]. Thus, if the fundamental knowledge of coal pyrolysis under different heating rate and ultimate temperature as well as the relationship among these coal utilization processes are well established, a simple, quick method of coal rank preliminary selection for the industrial plasma technology could be proposed.…”