Recovery of energy

TABLE 25-67 Typical Thermal Efficiency and Plant Use and Loss Factors for Individual Components and Processes Used for Recovery of Energy from Solid Wastes... 

Gas expanders are used to recover energy from high pressure process gas streams in a plant when the lower pressure is adequate for further processing. Power calculations are made in the same way as those for compressors. Usually several hundred horsepower must be involved for economic justification of an expander. In smaller plants, pressures are simply let down with throttling valves (Joule-Thomson) without attempt at recovery of energy. 

Several schemes have been put forth in the past for desalinization by use of electrolysis. They had been discarded because of the large amounts of energy required. The idea was resurrected in anticipation of much more efficient recovery of energy through the use of fuel cells. 

Drilling results in the Blake Bahama Ridge have given promise for recovery of energy from hydrate reserves. Hydrate recovery results from ODP Leg 164 in the Blake Bahama Ridge seem to confirm the large resource estimation (Pauli et al., 1997, 2000 Lorenson and Collett, 2000). 

This area of hydrated gas recovery is of very active international interest, due to its energy impact. However, because of thermodynamic and practical constraints (Moridis and Sloan, 2006) recovery of energy from low concentration (3% of pore volume) may be problematic. Clearly energy is a major driver of technology, and technology in turn is largely responsible for national economic success (Economides and Oligney, 2000 Bernstein, 2004 Sachs, 2005). 

Brown, S.D., Piantadosi, C.A. (1992). Recovery of energy metabolism in rat brain after carbon monoxide hypoxia. 

An Overview of the Department of Energy Program for the Recovery of Energy and Materials from Urban Solid Waste... 

Hathaway, S, A, Recovery of Energy from Solid Waste at Army Installations, U.S. Amy Construction Engineering Research Laboratory, Champaign, IL, Technical Manuscript E-118 (August 1977). 

Gasification is an energy efficient technique for reducing the volume of solid waste and the recovery of energy. Essentially, the process involves partial combustion of a carbonaceous fuel to generate a combustible fuel gas rich in carbon monoxide and hydrogen. The reader is referred to reference (6) for an excellent review of gasification reactions. 

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