Advanced Plasma Gasification Systems
– Current & Emerging Technologies
The 14th Annual APGTF Workshop – 13.03.14
Dr. Ben Herbert - Director of Research &
Environment
Stopford Energy & Environment
Stopford is an international energy and environment
consultancy providing innovative multidisciplinary solutions to
a global market leveraging over 30 years of experience
Stopford is an associate company of Lancaster Environment
Centre giving its staff access to the world class research and
development facilitates on the campus.
Our Organisation
Clients
Energy from Biomass &
Waste - Our Approach
Current WtoE Climate
• Increasing energy prices
• High demand for renewable and clean electricity
• Increasing waste disposal and landfill costs
• Lack of efficient & safe waste disposal systems
• Increasingly stringent environmental regulations
• Increasing interest in novel energy generation technologies
e.g. Fuel Cells and Hydrogen Gas
The Technologies
Non-Thermal Technologies:
Anaerobic Digestion
Biodrying
Mechanical Biological Treatment
Thermal Technologies:
Incineration (Thermal Oxidation)
Pyrolysis
Gasification
Plasma Arc Gasification
The Technologies
Non-Thermal Technologies:
Anaerobic Digestion
Biodrying
Mechanical Biological Treatment
Thermal Technologies:
Incineration (Thermal Oxidation)
Pyrolysis
Gasification
Plasma Arc Gasification
Plasma-Arc Gasification
Gasification is defined as the partial thermal degradation of a substance
under sub-stoichiometric conditions (i.e in the presence of oxygen but
with insufficient oxygen to oxidise the fuel completely).
Plasma-Arc Gasification uses high electrical energy and high
temperatures to break down waste into its basic elemental composition,
under controlled oxygen conditions, producing a synthesis gas and an
inert vitrified slag.
A high temperature process with operating temperatures exceeding
5000oC
All organic materials in the feedstock of the gasifier are converted to a
syn-gas (comprising carbon monoxide and hydrogen)
All Inorganic materials are vitrified into an inert a glass-like “slag”
Plasma-Arc Gasification
The advantage of gasification process is that the production of energy
from syngas is potentially more efficient than direct combustion of the
original fuel.
The process does not convert all of the chemical energy in the fuel into
thermal energy but instead leaves some of the chemical energy in the
syn-gas and in the solid residues
Syn-gas may be burned directly for electricity production, used to
produce methanol and hydrogen, or converted via the Fischer-Tropsch
process into a second generation biofuel.
The typical NCV of the gas from gasification using oxygen is 10 to 15
MJ/Nm3
For comparison the NCV for natural gas is about 38 MJ/Nm3
Plasma
Plasma Torch
The Process
Plasma Torch for Metal Cutting
NASA Technology:
Testing Shuttle Tiles
Plasma Gasification
1. Mixed Materials Fed Into System
3. Gases Converted Into Energy
2. Organic Materials Gasified Into H2 &CO……...
Inorganic Materials Vitrified Into Inert “Slag”
Plasma-Arc Gasification
Isometric Full View Isometric Cut Away View
Direct Current Plasma
• High temperatures (~5000 °C) achievable causing
improved organic-inorganic separation efficiencies
• High calorific value syngas produced with multiple
applications
• Hazardous/Toxic compound destruction/immobilisiation
(e.g. dioxin and furans/heavy metals)
• Secondary vitrified product from inorganic content
• High CAPEX & OPEX costs
• High Parasitic Load
• Large scale to be economically viable
• Relatively few demonstration or commercial facilities
The Alternative – Microwave
Induced Plasma
• All benefits of direct current plasma
• Improved energy efficiency
• Lower CAPEX and OPEX
• Economically viable at smaller scales
• Lower maintenance requirement as no electrodes
required
• Ability to auto-strike plasma
• Proven technology (microwaves)
Microwave-Induced Plasma
for Energy from Waste
Project: Carbon Abatement Technology
Funding: Technology Strategy Board (TSB)
Phase I: 12 month project proof of concept
project to test the viability of microwave-
induced plasma for the gasification of mixed
wastes and biomass.
Phase II: 3 year project to develop a 160 tpa)
microwave-induced plasma gasification
demonstration system.
What is Microwave Induced
Plasma?
Waveguide Design
Waveguide Design
Waveguide Design
Phase I Reactor
•1 kW 2.45 GHz magnetron
•200 x 200 x 250 mm mild steel
box
•100 mm removable sight glass
•~40 g batch charge
•Plasma gas inlet (argon at
1 L min-1)
•Pressure gas inlet (nitrogen at 1
L min-1)
•Stainless steel crucible
Plasma Plume Generation
Advanced Thermal
Treatment Trials
• Aim:
– To determine the syngas composition, evolution, and
calorific value (CV) from microwave-induced plasma
treatment of mixed waste materials
• Waste Types Trialled
– Commercial & Industrial Waste (C&IW)
– Biomass
– Screenings Waste
– Sludge Cake
Thermal Trials – Calorific Value
Waste Type Waste NCV
(MJ/kg), AR
Condition Syngas NCV
Range (MJ/m3)
C&IW 9.5 Pyrolysis 11.4 – 17.4
Biomass 16.3 Pyrolysis 14.5 – 19.2
Screenings
Waste
6.1 Gasification 8.7 – 11.2
Sludge Cake 1.2 Gasification 6.5 – 10.8
Gas Evolution
Gas Evolution (Screenings)
0
10
20
30
40
50
60
70
80
011
022
033
044
055
066
077
088
099
0
1100
1210
1320
1430
1540
1650
1760
Time (s)
Vo
l % CO2
CO
0
10
20
30
40
50
60
70
80
0 66 132
198
264
330
396
462
528
594
660
726
792
858
924
Time (s)
Vo
l % CO2
CO
•Left: 1.1 % O2
•Right: 5.9 % O2
•Bottom: 10.8 % O2
0
10
20
30
40
50
60
70
80
0
88
17
6
26
4
35
2
44
0
52
8
61
6
70
4
79
2
88
0
96
8
10
56
11
44
12
32
13
20
14
08
14
96
15
84
Time (s)
Vo
l % CO2
CO
Intermediate Reactor
• 2 kg/hr
• Designed to:
– Gain more representative
gas and thermal data
– Test multiple plasma
operation
– Reduce risks associated
with scale up to
demonstration reactor
Intermediate Reactor
Commercial Analysis &
Modelling
ROO CfD
Payback (Years) IRR (%) Payback (Years) IRR (%)
Digester Cake 8.31 14 8.41 13.68
Screenings Waste 5.31 20 5.63 18.73
C&I Waste 5.82 18.73 6.51 16.49
The Future…
• To design and construct a 160 tpa demonstration
facility for commissioning in 2015
• To deploy the reactor at United Utilities WwTW in
Ellesmere Port, UK, for continuous operation
• To optimise the process to accept a range of
different waste types
• To design bespoke systems to satisfy customer
requirements for small-scale biomass/waste to
energy schemes
Acknowledgements
Stopford would like to thank its project partners:
Liverpool John Moores University
United Utilities
Finning
& project funders
Technology Strategy Board
For further information contact us
www.stopford.co.uk
+44 (0)1524 510 604
Thank you
Stopford Energy and Environment
Providers of the complete technology development solution