Fig.1. Sewage sludge power plant:
1 – control system; 2 – plate power module of the RF power source; 3 – RF module;
4 – RF plasma torch; 5 – multi-stage sludge gasifier; 6 – sludge blender and feeder;
7 – air compressor for sludge atomizing; 8 – synthesis gas storage tank; 9 (1),9 (2),
9 (3) – synthesis gas cooler; 10 – fuel synthesis gas compressor; 11 – gas turbine
engine (GTE); 12 (1,2) – power generators; 13 – steam turbine (ST); 14 – steam
condenser; 15 – hot well; 16 – water treatment system; 17 (1,2) – heat-recovery steam;
generators (HRSG);18 – synthesis gas treatment module; 19 – synthesis gas compressor;
20 – oxygen production module. Working mediums: A – cooling water, B – plasma gas;
C – sewage sludge; D – air for gasification; E – water steam for gasification;
F – atmospheric air; G – fuel synthesis gas; H – GTE exhaust; J – overheated water steam;
L – feed water HRSG; O – purging oxygen; P – fresh water; S – synthesis gas after the gasifier.

Fig.2. Plasma gasifier (US Patents 7,452,513 B2 and 7,955,567 B2):
1 – plasma generation module, 2,3,4 – stages of the gasification module, 5 – starting torch
6 – starting torch plume, 7 – starting gas, 8 - starting gas vortex,9 – inductor, 10 – plasmoid,
11 – main plasma gas (air, oxygen, blends), 12 – main gas reverse vortex, 13 – feedstock 1
fraction 1,14 - feedstock 1 flow,15 - feedstock 2, 16 – feedstock 2 vortex, 17 – feedstock 1
fraction 2, 18 – feedstock 1 flow, 19 – feedstock 2 fraction 2, 20 – feedstock 1 fraction 3,
22 – feedstock 1 fraction 3 flow, 23 - reaction products – syngas.

Fig.3. Gasifier prototype - combustor coupled with 50 kW RF torch

The main objectives for the current project are to develop a demonstration plant with treatment
capacity of 10 tons/day of biosolids with about 30% water content. Subsequent 6-month field
operations with further experimental data collection, technology improvements, and up-scaling
for widened industrial operations. Potentially, these systems will each generate up to 500 kW
of electricity or total 20 MW*h of thermal energy and become the first of a kind highly efficient
and clean sewage processing plant utilizing the most recent developments in the field of plasmas.