Based On The Microwave Under The Action Of Tar Model Compounds Pyrolysis Research

Dipole steering of microwave is to rely on the medium polarization and interface in the microwave field in the dielectric loss of body heat, "hot spots" form is higher than the surrounding temperature, heating rate faster, but in a non polar molecule does not produce heating effect, the heating of the choice can save energy; In addition, the existence of the microwave field may cause orientation effect of molecular motion, the reactant molecules on the defiled line motion relative to strengthen, cause the effective collision frequency increases, the reaction rate was accelerated. Because the microwave has thermal effect, the above cause thermal effect and inducing the particularity of the mechanism, such as catalytic effect making the microwave chemical reaction engineering in the field of a new kind of heating way possible.How to remove the tar in the process of biomass gasification is one of the key technology of large-scale application of biomass, because of the complexity of the composition of biomass tar, at present, the water decoking method to produce a large number of secondary pollution of waste water, catalytic cracking remove coke for producing carbon deposit is easy to make the catalyst deactivation, and produces a large amount of waste residue, considering that the coke on the absorption of microwave has a good performance, have certain catalytic cracking of tar and coke itself performance, but also a certain ability of resistance to carbon deposition. Therefore, whether to carbon-based materials as microwave absorbing carrier, in the microwave to choose the effect of heating catalytic pyrolysis tar idea became the source of this topic research.Based on toluene tar model compounds and different life waste oil as the research object, studied their thermal cracking behavior under microwave heating method, examines the different carbon sources and different carrier gas composition and flow rate affect the performance of their cracking, and they are on the cracking behavior of conventional electric heating mode were compared. Concrete research content is as follows:1. Compared with three different microwave absorption of activated carbon, charcoal, bamboo charcoal of model compounds under the action of microwave heating, the thermal cracking behavior of toluene, the experiment results show that the particle size, nitrogen carrier gas flow rate under the condition of the same set of heating temperature and, in three different carbon as absorbing microwave carrier, its reaction turbidity are not up to the specified temperature, maximum of 500?, and large temperature fluctuation; This is mainly because at the beginning of toluene into the reactor in the gasification, soon after the gasification of toluene with carrier gas uniformLy distributed in the coal bed reactor, and toluene as the polarity itself is small, not only cannot themselves better microwave, and the carbon bed for shielding effect, hindered the microwave absorption and make the carbon bed temperature stability, coupled with toluene cracking is an endothermic reaction, lead to cannot achieve the specified pyrolysis temperature, reaction temperature and toluene cracking is low, can't fully cracking.Will find only under the condition of nitrogen gas into the air, activated carbon can make the reactor temperature kept at 900? and stable for a long time, and have good cracking effect, this is because the oxygen in the air and toluene or carbon oxidation reaction happened, on the one hand gives off heat oxidation reaction; On the other hand, due to the oxidation of toluene elimination or cracking it for carbon bed absorbing microwave shielding effect. Therefore, in regulating the right into the amount of air flow and toluene obtained good experimental results. Under the effect of microwave, when the air flow for the 50 mL/min, cracking of CO, H2 gas components in the volume fraction is 26%,8.36% respectively, both the sum of 34.36%, CO2 volume fraction is 9.6%, the volume fraction of the air flow of syngas is highest, the volume fraction of CO2 is lesser, and adjust the air flow from 30 mL/min to 60 mL/min, the H2 content increased to 26%, the air flow to 60 min/min, the H2 volume fraction to 19.95%.In addition, the activated carbon for the elemental analysis, XRD and SEM analysis and characterization, structure of block found charcoal, bamboo charcoal although large hole but give difficult adsorption of reactants, but present sleeping loose cloud, activated carbon has a larger surface area, and active carbon heating behavior is best, XRD analysis shows that the reaction in front of the activated carbon containing silica and carbon,72-2091,80-2146 after reaction carbon activated carbon have generated new 46-943.2. Life waste oil was studied in different carrier gas flow rate, small molecules to produce the distribution of gas composition, when the air flow for the 50 mL/min, the H2 content as high as 35%, when the air flow is 40 mL/min, the front H2 content is 26%, after a period of 8%, when the air flow for 30 mL/min, the front H2 content is 32%, after a period of H2 was 11%, in the first 50 mL/min basic not clear division, through living waste oil of GC-MS analysis showed that most of the ingredients for the polarity of the big material, reaction temperature in the process of maintaining time is longer than toluene reaction time, just as to eliminate the effect of carbon is good, life waste oil conversion rate is very high, almost 100%.3. The traditional heating mode thermal cracking test, the distribution of the microwave neating experiments both proauce gas composition contrast, can be round tnat the traditional heating, air flow rate of 30 mL/min, the H2 as high as 8.5%,40 mL/min, the CO as high as 10.54%, and the microwave heating, the H2 content up to 26%, highest CO is 21.22, is more than twice, under the traditional is more than three times the traditional heating, the traditional heating, the toluene conversion rate as high as 75.4%, the lowest was 56.3%, and the microwave heating, the toluene conversion rate up to 100%, the lowest 90%, so the microwave heating can not only improve the waste maximum conversion rate of the organic matter, and get the gas composition of cracking is high, more inclined to into H2 and CO.