Physical properties and desulfurization performanc

Physical properties and desulfurization performance of copper manganese high temperature desulfurizer (I) *

classification No. tu996.61 tq546.5 high temperature gas desulfurization, as one of the key technologies of coal gasification combined cycle power generation (IGCC), can improve the power generation efficiency by about 2%. Among several desulfurizers developed so far, zinc based desulfurizer is relatively mature. It has high desulfurization precision and large sulfur capacity, but zinc is easy to volatilize when the temperature is higher than 600 ℃, resulting in the loss of zinc, and its mechanical strength can not meet the requirements of fluidized bed. In addition, zinc based desulfurizer is easy to sulfate in the regeneration process, which limits the application of zinc based desulfurizer [1]. Copper manganese based oxide not only has the characteristics of high desulfurization accuracy and large sulfur capacity of zinc based desulfurizer, but also overcomes the shortcomings of zinc based desulfurizer. Its pressure resistance and wear resistance are greater than that of zinc based desulfurizer, and it can desulfurize at higher temperature [2]. 1 experimental part 1.1 preparation of desulfurizer

the precipitation of copper manganese compounds is obtained by coprecipitation method. After drying, extrusion molding and roasting, copper manganese desulfurizer with different proportions can be prepared

1.2 experimental device and detection method

desulfurization reaction device is shown in Figure 1. There are two types of reactors used: put desulfurizer directly into the quartz tube with a diameter of 14 mm, and pay attention to the following matters: or put a small reactor (with a diameter of 9 mm and a height of 70 mm) containing a small amount of desulfurizer into the quartz tube, which can be directly taken out, because the test report and data information may be lost after reinstallation. The reactor is placed in the tubular electric furnace, and the furnace temperature is controlled by drz-4 resistance furnace temperature controller. During the reaction, a quantitative amount of H2S, H2, N2 is used to contact the desulfurizer through the buffer bottle. The composition of reaction gas is: N2 85.0%; H2 12.5～14.5 %； H2S 0.5 ~ 2.5% figure 1 the concentration of H2S in desulfurization reaction device is detected by iodometric method. The sulfur content in solid desulfurizer is analyzed by high temperature combustion neutralization method [3]. The microporous structure of desulfurizer was determined by ASAP 2400 micromeritics. The compressive strength is measured by manual solid strength tester, and the wear resistance is measured by drum method. XRD was measured by X-ray apparatus and SEM by scanning electron microscope

the evaluation indexes of desulfurization performance of desulfurizer are as follows: 2 results and discussion 2.1 physical properties of desulfurizer

2.1.1 unit weight of desulfurizer

the unit weight of the developed Cu Mn based desulfurizer is basically about 1.0 ~ 1.2 g/ml, which varies slightly with the composition. For example, the unit weight of desulfurizer with cu:mn=1:1 is about 1.0 g/ml

2.1.2 desulfurizer strength

compared with zinc based desulfurizer, copper manganese desulfurizer has much higher pressure resistance and wear resistance, as shown in Table 1. However, the strength of different copper manganese ratios is also different, as shown in Figure 2. Table 1 mechanical strength of copper manganese desulfurizer pressure strength of desulfurizer n/mm wear resistance% zinc ferrite desulfurizer (1:0.8) 4.5251.8 copper manganese desulfurizer (1:1) 7.382.6 Figure 2 the wear resistance of desulfurizer with different proportions can be found that when copper and manganese are combined in a similar proportion, its wear resistance is low, which may be related to its crystal structure

2.1.3 specific surface area and pore volume of desulfurizer

it can be seen from table 2 that the specific surface area and pore volume of copper manganese desulfurizer are greater than that of zinc ferrite. This also affects the desulfurization performance of its desulfurizer. For copper manganese desulfurizer, its reaction internal diffusion resistance is small, so the reaction performance is better. Moreover, reducing the particle size of desulfurizer has little contribution to improving the reaction performance of desulfurizer. The specific surface area and pore volume of the desulfurized copper manganese desulfurizer decreased greatly due to the adsorption of sulfur according to the required failure mode judgment agent. Table 2 microstructure analysis of copper manganese desulfurizer

name of desulfurizer

total specific surface

product (will there be sudden fracture bet

method without significant appearance deformation) m2/g total pore volume

ml/g mesopore analysis (bjh method) BET method

average diameter

(, 4) ×

× 104) average hole diameter of

hole in bjh method (, 4

× V/S ×

104) surface area

m2/g pore volume

ml/g copper manganese desulfurization

agent (1:1) 5.3240.01925.980 5198.59 copper after vulcanization

manganese desulfurizer 0.9010.00431.120 9183.13 zinc ferrite

desulfurizer 2.5090.0031 27.8 2.1.4 XRD test

the composition of the substance can be seen from the XRD test. In order to understand the chemical structure of the prepared desulfurizer, we selected three desulfurizer with copper manganese ratio of 4:1, 1:1 and 1:4 for XRD test. From figures 3 to 6, it can be seen that although the copper manganese ratio of the desulfurizer is different in the preparation process, from the XRD diagram, the crystalline phase composition of the desulfurizer is mainly Cu2O Z (x, y at 0