不同催化剂对煤加氢液化产率对比研究

Comparison on yield of liquid component in coal hydroliquefaction under different catalysts

利用高温高压加氢热解装置,在无催化剂及分别以氯化锌、氯化镍、三氧化二铁及二硫化钼4种不同类型催化剂条件下,阜新煤液化的产烃特征进行了研究.结果表明,尽管4种催化剂都能显著提高煤的总转化率,但不同类型催化剂显示出不同的产物选择性,且存在生成液态烃组分存在明显的不同.结合红外(IR)及X衍射(XRD)分析的结果可以得出,不同的催化剂具有不同的催化行为或机理.相对在反应体系中呈固态存在的NiCl2,熔融态的ZnCl2除了能促进煤的催化加氢反应外,还存在质量传递效应.Fe2O3表面存在的活性氧能够从H2中吸收H原子形成Brnsted酸位和氢自由基[H.],从而加速煤的裂解及加氢反应.MoS2的催化液化过程中,不仅存在Lewis酸位Mo的催化加氢,还存在中间产物H2S的自由基引发反应.

Effects and catalytic mechanisms of four different types of catalysts（ZnCl2,NiCl2,Fe2O3 and MoS2） on coal hydroliquefaction were studied.It was found that the presence of four catalysts all remarkably enhanced the total coal conversation,though different catalysts show distinct selectivity and led to different composition distributions of oils.These results,combining with IR and XRD analysis,suggest that catalytic behaviour varied for each catalyst.Relative to NiCl2,the higher total conversation for ZnCl2 should be attributed to the mass transfer effect due to its molten phase.Active oxygen on Fe2O3 surface,which Abstract atomic hydrogen from H2 to form Brnsted acid and H·,is considered to dominate the generation of products in Fe2O3 system.For MoS2 system,a mechanism,involving free radical mechanism initiated by intermediate H2S and catalytic hydrogenation by Lewis acid site Mo,is ultimately addressed.