李攀钰,杨赫,李扬,靳立军,胡浩权
LI Panyu,YANG He,LI Yang,JIN Lijun,HU Haoquan

• 1:大连理工大学化工学院

摘要(Abstract)：

为探究硫在煤直接液化反应中的作用，基于L_9(3~4)正交实验设计，考察初压、温度、H_2S在H_2S/H_2混合气中体积分数、硫/铁（S/Fe）物质的量比等因素对上湾煤在铁基催化剂下直接液化的煤转化率、油产率、油中硫质量分数、氢耗率等的影响。结果表明：温度对油产率的影响最显著，从420～470℃油产率提高19.0%;H_2S的加入可使氢耗率略有降低，油和气产率提高，但同时使油中硫质量分数增大；当H_2S从0提高到1.0%时，氢耗率降低0.3%，油中硫质量分数从0提高至0.9%;S/Fe物质的量比在合适范围内可提升油产率，S/Fe物质的量比为0.8时油产率比S/Fe为1.6时高3.6%，比不加硫高7.2%。煤液化过程加入的单质硫大多迁移至四氢呋喃不溶物（即液化残渣，THFI),S/Fe物质的量比不为0时THFI中硫质量分数普遍高于2%。在正交实验基础上，进一步研究了纯氢气氛下不同S/Fe物质的量比、恒定S/Fe物质的量比下不同H_2S体积分数的液化过程，从硫元素在油、沥青烯的分布情况，结合产物红外光谱表征、总自由基浓度测定，推测H_2S、单质硫的作用机制及液化反应中硫的迁移规律。发现THFI总自由基浓度与油产率、氢耗率存在一定程度的关联，S/Fe物质的量比为1.2时油产率最高，与此相对应的THFI总自由基浓度存在极小值；H_2S体积分数为0.25%时氢耗明显增大，对应的THFI、沥青烯总自由基浓度亦有明显变化。H_2S易.作用于油与沥青烯的前驱体，并促进重质组分向轻质组分的转化，单质硫过量时也能与沥青烯前驱体作用。在煤直接液化过程中，H_2S、单质硫的共同点是促进气相供氢，而对沥青烯官能团结构影响不明显。
Direct coal liquefaction reactivity under sulfur's effect was studied via L_9(3~4) orthogonal experimental design.Pressure,temperature,H_2S volume content in H_2S/H_2,and S/Fe mole ratio were considered as factors while coal conversion,oil yield,sulfur content of oil,and hydrogen consumption ratio as the target indexes.The sulfur migration mechanism in the reaction was also proposed.The results showed that the temperature has a remarkable effect on oil yield.When the temperature increases from 420 to 470℃，there's an average increase of 19.0%in oil yield.H_2S plays three roles:decreasing hydrogen consumption ratio,improving light product (including oil and gas) generation,and increasing sulfur content of oil.There is a decrease of 0.3%hydrogen consumption ratio and an increase of 0.9% sulfur content of oil when H_2S content is increased from 0-1%.S/Fe molar ratio within the reasonable range can promote oil yield,and higher oil yield was obtained at the S/Fe ratio of 0.8 compared with that at S/Fe being 1.0 or 0.During the processing of DCL,elemental sulfur migrates to THFI mostly,and there's an extra 2% sulfur content of THFI if only elemental sulfur is added in the reaction system.Based on the results of the orthogonal experiment,the liquefaction experiments under different S/Fe molar ratios in pure hydrogen atmosphere,and different H_2S volume content under constant 0.4 S/Fe molar ratio were further studied.From the distribution of sulfur in oil and asphaltene,combined with the changes in functional groups and free radical concentration,the effect mechanism of H_2S and elemental sulfur and the migration rule of sulfur in coal liquefaction reaction were deduced.It was indicated that the free radical concentration of THFI is related with oil yield and hydrogen consumption to some extent.Oil yield shows a peak value at S/Fe atomic ratio being 1.2 while the free radical concentration of THFI gets its minimal value.At 0.25% H_2S content,the hydrogen consumption rises apparently while the free radical concentration of THFI reaches bottom peak.It seems to be easier for H_2S than elemental sulfur to react with the precursor of light products,and promote conversion of heavy fraction to the light products.Only in excessive amounts can elemental sulfur combine with asphaltenes slightly.The roles of H_2S and elemental sulfur promote hydrogen supply in the gas phase,but have no obvious effect on the functional groups of asphaltene.

关键词(KeyWords)： 煤直接液化;硫化氢;单质硫;硫迁移;正交实验
direct coal liquefaction;hydrogen sulfide;elemental sulfur;element migration;orthogonal experiment

Abstract:

Keywords:

基金项目(Foundation): 国家重点研发计划资助项目（2022YFB4101300）;; 中国神华煤制油化工有限公司揭榜挂帅资助项目（MZYHG-22-02）

作者(Author): 李攀钰,杨赫,李扬,靳立军,胡浩权
LI Panyu,YANG He,LI Yang,JIN Lijun,HU Haoquan

DOI: 10.13226/j.issn.1006-6772.23062701

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