渣油加氢处理过程中硫的分布与脱除规律研究

硫是石油中质量分数最多的杂原子,国内外对硫化合物的研究甚多,但大多数是对轻质馏分的研究1].原油中70%以上的硫集中在渣油中2],由于减压渣油分子量大,组成和结构复杂,硫化物的分离和鉴定困难3].含硫化合物的危害主要表现在严重影响石油产品的使用性能和污染环境,在石油加工过程中腐蚀设备4,5].随着中国中东高硫原油进口量的增加和环保法规对硫质量分数要求越来越严格,加氢处理成为渣油深加工的主要手段之一6].脱硫受多种因素的影响7],如催化剂性能、工艺条件等,而且硫在渣油中的存在类型和分布也严重影响到硫的脱除效果.……

Distribution and removal of sulfur during hydrotreating of residue

The removal of sulfur and changes of sulfur forms in Oman vacuum residue by hydrotreating were investigated on a pilot plant. The results illustrated that the content of total sulfur in hydrotreated residue reduced gradually with the hydrotreating. Over 80% of total sulfur in the residue can be removed at three temperatures (T-5℃, T℃, T+5℃), although a higher temperature can enhance the desulfurization effect. The residue fractions of aromatic, resin, asphaltene and saturate contain about 60%, 32%, 8% and 1% of total sulfur, respectively; however, the sulfur content in each fraction is in the order of asphaltene>resin>aromatic>saturate. The sulfidic sulfur content in the residue fraction decreased and the thiophenic sulfur content increased with the heaviness of residue fraction. Sulfur forms exhibit influence on the hydrodesulfurization effect; the removal of sulfidic sulfur is much easier than that of thiophenic sulfur. The residue fractions are also different in the desulphurization effect, depending on their molecular size and structure; the sulfur removal ratio of saturate and aromatic is higher than that of resin and asphaltene.