A Research For Deep Desulfurization Of Diesel By Ni, Ce Ions Exchanged SBA-15 Mesoporous Materials

In this paper, sorbents were prepared by exchanging Ni and Ce ions onto the aluminized SBA-15 by elevating metal ion-exchanging temperature, increasing metal ion-exchanging number of times and using large pore SBA-15(~11.55 nm) as the support. We characterized the different adsorbents with XRD and N2 adsorption, tested the content of metal ion in the adsorbents with ICP. The adsorption desulfurization experiments of the model diesel(300 ppmw S) and the commercial diesel(187.2 ppmw S) were carried out in a fixed bed with different adsorbents. The desulfurization capability of regenerated adsorbent was also reseached.Model diesel desulfurization result showed that adsorbent Ni/AS60-4 prepared by elevating metal ion-exchanging temperature and increasing metal ion-exchanging number of times were capable of removing 0.1757 mmol of total sulfur per gram at breakthrough(less than 1.0 ppmw S), the desulfurization capability of Ni/AS60-4 enhanced 103.83 % compared with Ni/AS20-1. Sorbent Ni/ASL60-4, which was prepared by exchanging Ni ions onto the aluminized large pore SBA-15, were capable of removing 0.1954 mmol of total sulfur per gram at breakthrough, the desulfurization capability of Ni/ASL60-4 enhanced 126.68 % compared with Ni/AS20-1. The desulfurization capability of Ce-based sorbents was also enhanced with elevating metal ion-exchanging temperature and increasing the Ni ion exchanging number of times.It can be concluded that the high desulfurization capability of Ni/ASL60-4 are prepare a Ni-based sorbent was exchanging the Ni ion to Al-SBA-15 with 4 times at 60 oC onto the large pore SBA-15. Commercial diesel desulfurization result showed that the produced clean diesel(less than 1.0 ppmw S) was 7.0 ml over 1.0 g of Ni/ASL60-4 sorbent, the sulfur capacity of Ni/ASL60-4 was 0.0286 mmol of total sulfur per gram at breakthrough, it can enhance a total of 248.78 % compared with Ni/AS20-1 sorbent. The saturated Ni/ASL60-4 for commercial diesel was regenerated by heating in air at 350 oC for 5 h, and the regenerated adsorbent was tested for re-use. The results showed that 100 % of the sulfur capacity could be recovered completely.The Ni-based adsorbents were characterized by XRD, N2 adsorption, ICP-AES. The ICP results showed that enhancement of desulfurization capability of Ni-based sorbents resulted mainly from the increase of Ni loadings on the sorbents. The NiO particles were not found on the fresh and regenerated Ni-based sorbents by XRD test. This showed that metal Ni was in the form of Ni ions and there is no loss of Ni ions on the Ni/ASL60-4 happened after desulfurization and regeneration. Hence, it can be inferred that the Ni ions were anchored firmly onto the aluminized SBA-15. And then, it can be concluded that no Ni ions were introduced into the product diesel and the quality of clean diesel will not be influenced by the desulfurization procedure.