Tactical Garbage to Energy Refinery (TGER) - Sustainable Biotechnology: Sources of Renewable Energy - page 90

Ta b l e 2 Relative energy content

Energy per unit volume ∗ Energy product Energy index

Diesel 1.0 138,000 BTU 48 MJ/kg

Gasoline 0.98 125,000 BTU

Ethanol 0.69 84,600 BTU

Producer gas 0.2 10 MJ/kg

∗ Diesel

= 1.0

has 69% of the energy content that the same volume of diesel fuel has, whereas
synthetic gas has only 20% of the energy content of diesel fuel [6, 7]. Ignoring the
potential energy contained within organic food and liquid wastes would result in a
significant loss of energy and reduced diesel fuel savings.

3 Materials and Methods

The TGER prototypes were fabricated and commissioned at Purdue University and
conformed to the following selection criterion:

a. Approach the problem as a “dual optimization” to develop a system which will
simultaneously eliminate as much waste as possible while producing as much
useful energy as possible.
b. Design of the TGER must be “tuned” to the operational context to ensure an
easily available and reliable volume of military waste.
c. The TGER should be designed to be contiguous with both the input source of
wastes and the end user for the output energy product, avoiding any reprocessing
or transport costs.
d. The TGER must be operationally and tactically deployable via military airframe
and able to be transported on the ground via standard military trailer.
e. The TGER should not need additional manpower or machinery costs for waste
separation.
f. The process must minimize parasitic costs such as manpower, water, external
energy, etc.
g. The refining process should have minimal residual waste.
h. Additional concerns of hazardous waste, safety, and troop use must be consid-
ered, and operation should be amenable to unskilled labor.

The selection of gasification and biocatalytic fermentation has strategic value in
that both methods are well-demonstrated technologies supported by high levels of
research by the Department of Energy and, in the long course, are very likely to
improve as new advances are achieved.
Significant new advances in gasification include the introduction of integrated
sensors and automated computerized control systems for the process. These recent