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