Venkataraman Ramya, Eser Semih
Department of Energy and Mineral Engineering, The Pennsylvania State University, University Park, Pennsylvania16802, USA.
Chem Cent J. 2008 Dec 17;2:25. doi: 10.1186/1752-153X-2-25.
Solid deposits from commercially available high-pressure diesel injectors (HPDI) were analyzed to study the solid deposition from diesel fuel during engine operation. The structural and chemical properties of injector deposits were compared to those formed from the thermal oxidative stressing of a diesel fuel range model compound, n-hexadecane at 160 degrees C and 450 psi for 2.5 h in a flow reactor. Both deposits consist of polyaromatic compounds (PAH) with oxygen moieties. The similarities in structure and composition of the injector deposits and n-hexadecane deposits suggest that laboratory experiments can simulate thermal oxidative degradation of diesel in commercial injectors. The formation of PAH from n-hexadecane showed that aromatization of straight chain alkanes and polycondensation of aromatic rings was possible at temperatures as low as 160 degrees C in the presence of oxygen. A mechanism for an oxygen-assisted aromatization of cylcoalkanes is proposed.
对市售高压柴油喷油器（HPDI）产生的固体沉积物进行了分析，以研究发动机运行期间柴油燃料产生的固体沉积物。将喷油器沉积物的结构和化学性质与柴油燃料范围模型化合物正十六烷在流动反应器中于160℃和450 psi下进行2.5小时热氧化应激形成的沉积物进行了比较。两种沉积物均由带有氧部分的多环芳烃（PAH）组成。喷油器沉积物和正十六烷沉积物在结构和组成上的相似性表明，实验室实验可以模拟商用喷油器中柴油的热氧化降解。正十六烷形成PAH表明，在有氧存在的情况下，直链烷烃的芳构化和芳环的缩聚在低至160℃的温度下是可能的。提出了一种环烷烃氧辅助芳构化的机理。
