Tactical Garbage to Energy Refinery (TGER) - Sustainable Biotechnology: Sources of Renewable Energy - page 87

Keywords Biofuel · Tactical energy · Synthetic gas · Fermentation · Downdraft

gasifier

1 Introduction

The initial challenge was to mate the waste streams produced by small tactical units
with technologies that were net energy positive at that scale. The TGER system was
the result of a high level of optimization “from the trash up” and required a thorough
scientific analysis and technology selection process with full consideration of the
context within which it would be operating.
There are numerous waste to energy technologies, each with varying efficiencies
and capabilities to digest complex waste streams [1]. Figure 1 breaks the problem
set down to net power output (x axis) verses the type of waste (y axis), and shows
the range of applications from landfill to onsite or tactical utilities. Incineration, for
example, will handle all waste types including hazardous materials and metals, but
has only 10% net power output at best and is most suited to large static operations
such as landfills. By contrast, biocatalytic (i.e. enzymatic) approaches have much
more limited ability to handle waste but are relatively efficient (~75%) in terms of
net power output [2].
Biocatalytic approaches are therefore more suited to operations in which the
waste stream is predominantly food waste and biomass. These two technologies
occupy the extremes of this energy return spectrum.

WASTE TO ENERGY TECHNOLOGIES

TYPE WASTE Other factors - Time; Cost; Environmental

Metal Incineration

Glass SCWO

HazMat Plasma Arc

Pyrolysis

Construction

Hybrid

Plastics Gasification

Cellulosic Anaerobic Digestion

Biocatalytic

Biomass

Other Food

Carbohydrates

10 % 50 % 90 % 100 %

NET POWER OUTPUT %

Landfill Onsite Utilities

NOT AUTHORITATIVE - Data from Open Source Publications

Fig. 1 Waste to energy technologies