The current research endeavored to boost the applicability of methanol in CI engines utilizing n-octanol, diethyl ether (DEE), and different nanoparticle additives (at a concentration of 50 ppm), mainly aluminum oxide, titanium oxide, multiwalled carbon nanotube, graphene oxide, and graphene nanoplatelets as cosolvents and ignition improvers. The work was split into binary phases. First, the stabilities of pure methanol (M100) and hydrous methanol (MH10), with diesel as a reference fuel, were examined by applying various temperatures: 10 °C, 20 °C, and 30 °C. The findings showed that the M100/diesel and MH10/diesel combinations were unstable. To overcome this issue, n-octanol was utilized as a cosolvent. Following by the engine burning and emission characteristics were evaluated by manipulating three proportions of M100/diesel mixtures with n-octanol and DEE. The three mixtures included 5, 10, and 15% of M100 with 25% n-octanol and 5% DEE, which are denoted as DM5, DM10, and DM15, correspondingly. Then, 50 ppm of each nanoparticle was inserted separately into DM5 and DM10 blends to augment the ignition characteristics. The tested mixtures were assessed via thermogravimetric analysis, and their physicochemical properties were assessed corresponding to the ASTM. The results indicated that the maximum Pcyl., HRR, and dp/dθ diminished for the M100/diesel/n-octanol/DEE combinations compared with the diesel. Similarly, they were lowered by inserting nanoparticles. Moreover, the BTE lowered, whereas the BSFC enlarged for the tested mixtures compared with the diesel. The opposite trend was remarked with manipulating nanoparticles. Concerning engine emissions, the NOx and smoke opacity levels also diminished, whereas the CO and UHC enlarged for the DM5, DM10, and DM15 blends compared to the diesel. Inserting nanoparticles into DM5 and DM10 mixtures reduced NOx, CO, UHC, and smoke opacity levels by up to 35%, 20%, 60, and 40%, respectively, compared with DM5 and DM10. It can be concluded that applying n-octanol, Diethyl ether, and nanoparticles as cosolvents and improvers with diesel-methanol blends demonstrated a considerable enhancement in phase stability issue, combustion, and emission characteristics of the diesel engine. |
