Supercritical process technology related to energy and future directions - An introduction
Process technology comprises the application of fundamentals to processes, as for example phase equilibria and reaction kinetics, the verification of process steps, as for example in specific reactors, and the design of process sequences to produce a product (energy) from raw materials. For the special field of supercritical fluids related to energy processes it includes single process steps as well as process step sequences and whole processes. Also, process technology is not restricted to any specific application. It includes processing of renewable (bio-based) materials, fossil materials, and processes to access these materials. In general, process technology related to the application of supercritical fluids is based on the exploitation of the specific properties of supercritical fluids. This includes the varying properties of supercritical fluids and the interactions of supercritical fluids with the processes materials, such as a drastically reduced viscosity. Supercritical fluids guarantee an enclosed processing with emanations that can be adjusted. Supercritical fluids have been used in quite a number of processes and process steps related to production of energy, mostly in laboratory and demonstration scale. Among these processes are: the ROSE process, coal liquefaction and gasification, the production of oil from oil shales, and of oil from oil sands. Supercritical fluids have been proposed (and partially are used) for: enhanced oil recovery, emulsion splitting (oil-water), enhanced gas recovery, bitumen separation, recovery of hydrocarbons from particles (remediation of soil), de-asphalting, removal of fine particles, and others. Supercritical fluids are proposed for deep drilling (spallation drilling), and for the production of energy from hydrothermal flames. Process technology using supercritical fluids has to provide the equipment for the processes. Keys to future success will be: simple design, simple operation, high efficiency (higher than burning the feed), and a thorough training of the community in the specific abilities of supercritical fluids.