The expensive and time consuming process of the past has meanwhile turned out to be an economic way to produce oil, also with regard to raw materials shortage and increasing oil and gas prices. For countries rich in coal and poor in oil and gas, this environmentally friendly process provides energy security and autarky.
The requirements to be met by high pressure pumps for coal hydrogenation are backed by utmost reliability, long service life, low running costs and optimal life times. Hence these specific conditions require a relatively large pump, as the pumps can be operated at low speeds only, due to the critical fluid handled.
The pumps are designed for continuous operation to discharge coal slurry consisting of 50% ground coal and 50% hot carrier oil, at a pressure of 210 bar (3045 psi) and a temperature of up to 290°C (554°F). The driving power of each pump is 750 kW.
Due to the specific process requirements and conditions, the liquid end has been adapted and newly developed. The pump must be absolutely leak-proof in the range of the working area, despite a substantial thermal load - in particular during start-up. Moreover the actual discharge process is secured by a patented separation system included in the special valve block design.
High-strength, temperature resistant pump materials combined with the specially integrated cooling and heating equipment in the individual components ensure smooth thermal expansions. Hence the design, i.e. the positioning and dimensioning of the fastening bolts for the pump head, was defined by FEM–simulations.
The ingenious separation system in the liquid end in connection with a special injection pump ensures that coal particles cannot enter the plunger sealing during process. The injection pump supplies clean oil to the plunger seal during each suction stroke. Moreover, an additional sealing and flushing system prevents leakage into atmosphere.
The patented pump technology is the central part of the world’s first industrial coal liquefaction plant in China.
