| 摘要 |
A method for pretreating a coal hydrogenation feedstock with preheated hydrogen containing a hydrogenation gas under high pressure and at elevated temperature, in a liquid phase slurry system, is disclosed. In this process a mixture of a slurry of finely ground coal and a slurry oil are fed to a preheater before being subjected to a hydrogenation and liquefaction reaction in a cascade of reactors at a pressure of from 100 to 40 bars and a temperature of 420 DEG to 490 DEG C. The reaction products are fed to a hot separator. In the process of the invention, prior to its preheating, a first partial stream of the hydrogenation gas, referred to as the slurry gas, is added to the mixture at process pressure. A second partial stream of the hydrogenation gas is heated by indirect heat exchange with a gaseous hot separator product in a gas heat exchanger. The mixture of slurry and slurry gas is preheated through indirect heat exchange in at least one heat exchanger downstream from the first gas heat exchanger, through which flows the hot separator head product after passing through the first heat exchanger. The heated second partial stream of hydrogenation gas is then added to the preheated mixture of slurry and slurry gas. This process provides improved heat transfer during the preheating of the coal-oil slurry and the mixture in a slurry with a hydrogenation gas. |
