| Arc plasma is belonged to the heat-plasma in the low temperature plasma and the temperature of electron in the given arc plasma is almost equal to the temperature of heavy particle, whose temperature can be related to 103～104K. Therefore, this kind of arc plasma is not only high temperature, but also a number of high-energy activity particles. The reaction mechanisms were changed, reaction rate was enhanced, and, output was increased, by introducing plasma jet to reaction system. A successful and complicated example is the process of plasma jet aid coal gasification, in which various free radicals are involved. Based on situation of the present developing researches at home and abroad, some important problems in this field are selected as research topics in this paper on the between vertical and horizontal experimental reaction apparatus which is a pilot-scale apparatus manufactured by Tsing Hua University, Dalian University of Technology and Taiyuan University of Technology by applying to chemical thermodynamics, chemical kinetic, statistics mechanics and quantum chemistry. They include such contents, as follows:1. The project was conducted with a full set of experimental scheme, which includes detail experiment steps, technics process and the collection and treatment method of the experimental data. Furthermore, the suitable parameters are chosen to characterize the plasma reactivity. For vertical reactor, the operating at 45 kW, and the preferred air flow-rate and the preferred coal flow-rate are 15 Nm3/h and 8.50kg/h, respectively. For horizontal reactor, the operating at 100 kW, and the preferred air flow-rate and the preferred coal flow-rate are 18Nm3/h and 7.50 kg/h, respectively. The flow-rate of water vapour are 10.00 kg/h, H2O and 8.5 kg/h, H2O for the given two reactors, respectively. Although the volume of product gas from the former is less than it from the latter, the import power and the consumed cost of coal and cold water of the former reactor are less than those of the latter rector. According to the difference between the distributing species of resultant for the experiments and the general coal gasification, one can see that the tar and methane are apt to discomposed and other substance between gas and liquid discomposed or the gasification reactions drop sharply at the temperature of the plasma torch, also. Catalytic effects of additives including CaCO3, Na2CO3, CaO, CaSO4, NaHCO3 and NH4Cl which were selected as some representative materials from ordinary catalytic coal gasification were studied. Some gasification indexes which consisted of the selectivity, and carbon conversion were examined. The results showed that the catalytic actions lied on the species, quantity and that catalytic effects of Na2CO3 and CaCO3 were worse. When the mass content of NaHCO3 was between 5% and 20%, that of CaO was 5%, that of CaSO4 was 15% andthat of NH4Cl was 15%, the catalytic effects of them were much better.2. From the analysis of thermodynamics, one can see that the suitable temperature is at～1700K, and the proportion between carbon in coal and gasification is as follow: n(H2O)∶n(O2)∶n(C)=0.2∶0.2～0.3∶1. In addition, the kinds of the coal have a little effect on the distributing of main product. According to the analysis from quantum chemistry calculation, the reaction entropy of coal vapour gasification△rS increases obviously, bring on△rG(ignite-coal)0＜0, and the reaction on high-volatile bituminous coal, anthracite, low-volatile bituminous coal, and sub-bituminous coal may carried out spontaneity at high temperature. The transition points of the temperature (Ttr) for these coals are 329.238, 353.546, 518.119 and 466.713 K, respectively.3. The fact that structure of H2O can be changed notability with the direct action of O2* and O2+ in excited state has been detected by the quantum chemistry calculation, which is benefit to the bond broke and the formation of free radial hydroxyl (OH). Furthermore, the hydroxyl can excite the coal gasification reaction and form a likelihood chemical reaction channel. The linear regression equations of relationship between oxygen concentration in the work air and contents of main products have been gained the by regression analysis the experimental data. And the likelihood chemical reaction channel is supported by the given experiment.4. By the analysis of the plasma torch aid coal gasification with the chemical kinetic method, based on gasification overall kinetics mechanism, we can get the rate equation of the main product and deduce the kinetic equation from the rate equation, which agrees well with the experiment situation. The equations are as follows: Relational expression between conversion rate of coal and gasification agent of H2O and O2 can be deduced by fitting mechanism and the factors of cylinder reactor. From the former equation, we can get the ratio (Ea/R) between reaction activation energy and the value of R of CO2 and CO are～20 000 and 9000 (8693.8), respectively. The relationship between the bulking value and coal dust grainsize is determined by the retract model of screened out carbon conVersion rate and diffuse differential equation of the primary product. The CO2 is produced by coal coke or semi-coke with small rate and the chemical reaction may be the control step, which is testified indirectly by the experiment data. However, the CO and H2 are produced by the gasification of volatilization products, and the chemical reaction is not the control step.5. Referring to the characteristic of plasma coal gasification and catalytic mechanism of ordinary coal gasification, possible catalytic mechanisms of additives were discussed. It possibly based on the coal gasification chain reaction induced by the active atom oxygen (O) and hydrogen (H) produced in the decompose process at high temperature. According to the effect that the oxide played in the process of coal gasification, the effect of catalyze is decided by the quantity, the producible difficulty and the activation degree of the oxide. The decompose temperature of calcium carbonate is lower and catalyze effect is worse. The decompose temperature of sodium carbonate is higher than calcium carbonate. Because the produced Na2O is more stable than CaO as heated the activation degree of Na2O is lower than CaO. The two action counteracted one another, so that the catalyze effect of the two substance is similar. The decompose temperature of CaSO4 is higher and it can absorb more energy in their decomposion. So the CaO decomposed can get a higher degree which is close to the atomic O decomposed. As a result, the activation of CaSO4 is prior to CaCO3, so is the catalyze effect. The sodium bicarbonate and ammonium chloride are all the substance that contained H element. They decomposed to the primary substance H2O and NH3 as heated and the atom H and OH that produced in the decompose process accelerated the gasification action. The catalyze effect is relate to the quantity of the accretion and there is a catalyze limit quantity. In a certain range, as the quantity of additive substances increasing, it accelerated the gasification and made some production content increase. But when the quantity of the additive substances exceeded the range, the system absorbed more energy as the substantial decompose, and the temperature dropped deeply. It effect the catalyze effect directly and made some production content decrease.
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