Green and Sustainable Remediation

With continued focus on global warming and the effects thereof, the contaminated land industry is now looking to itself to find ways of improving remediation technologies so as to be either less power intensive or to utilise sustainable and renewable energy sources available to provide the necessary power.

There is significant debate amongst the remediation industry as to what sustainable remediation actually is. However, it is generally accepted that sustainable remediation is integral to sustainable development and is best represented in the Figure below.

Elements of Sustainable Development taken from CL:AIRE, 2009

Remediation and Sustainability

SiteSite size

m2

Power Kilovolt-amps

Peak power needs Amps

Peak Power needs converted to kW

WIND ENERGY SOLAR ENERGY BIOFUELS

Set up costs £

Size of wind turbine that

would meet power

requirements

output

capacity

(kW)

Set up

costs £

Size of solar cell

array that would

meet power

requirements

Generator Purchase

cost. Fuel costs

Size of

Generator

required

Output kW

A 2100 m2

65.58196 112 425,000

Wind world 170/27

Hub height 31.5 m

Rotor diameter

27 m

170 kW 448,000 2,800 m2

£18,000

35.6 Litres per Hr

running @ 0.50

pence per ltr

JSP BD 160 128

B20,000 m2 556.5

1328.2 760 680,000

Vestas V52 850/52

Hub height 44 m

Rotor diameter

52 m

850 kW 3,040,00018,750m2 NA

No single

generator

available

NA

C3750 m2 78.50

161.6 112 425,000

Wind world 170/27

Hub height 31.5 m

Rotor diameter

27 m

170 kW 448,000 2,800 m2

£18,000

35.6 Litres per Hr

running @ 0.50

pence per ltr

JSP BD 160 128

D56,000 m2 94.57

80 112 425,000

Wind world 170/27

Hub height 31.5 m

Rotor diameter

27 m

170 kW 448,000 2,800 m2

£18,000

35.6 Litres per Hr

running @ 0.50

pence per ltr

JSP BD 160 128

E135,000 m2 281.4

711.05 408 400,000

NEG Micon 500/43

Hub height 30m

Rotor diameter

33.4 m

500 kW 1,632,000 7,500 m2 NA

No single

generator

available

NA

Attempting to match energy intensive remediation technologies and renewable energy sources can be difficult when taking into account factors such as costs, size, construction issues, planning permission, coupled with the environmental, social and economic impact.

Renewable energy Costs

Renewable energy options such as Wind and solar power can in most cases require their own large construction projects with significant initial capital outlay with no guarantee that the wind or sunlight needed to power the remediation technology will be consistent enough without the need to utilise grid connected electricity. Bio-diesel, depending on its source, can be more harmful to the planet due to the associated effects on biodiversity and the destruction of the Amazon and Atlantic forest’s.

Copyright Boston Globe(Chris Neill/Marine Biological Laboratory)

Sustainability

Remediation Service Int’l (RSI) have designed a remediation technology ICE (Internal Combustion Engine) that will power itself by utilizing volatile gases from well vapour stream. Case studies confirm that the RSI dual phase remediation system also provides a >99% contaminant destruction rate. ICE units can also supply up to 37 kVa of electricity

Exhaust Gases from the engine are passed through the unit’s catalytic converter resulting in little or no pollution vented to atmosphere. The RSI Engine is capable to both generate its own power requirements and to power ancillary equipment such as PulseOx ISCO, A/S's, pumps low power DM-VEX (vacuum blowers) and other peripherals.

RSI’s specially engineered ICE RSI’s Catalytic Oxidation Module

ICE Technology

Recently Groundwater Technology (GT) were invited to tender for the remediation of a large site in The Netherlands.

Information gathered during site investigations and subsequent dealings with the client showed that various remediation technologies would need to be utilized to ensure all contaminants at the site were either destroyed or removed.

The regulatory authority overseeing the preparation of the remediation strategy have stipulated that remediation of this site should reflect a greener more sustainable approach and as such no electricity was to be used from the clients supply as this was deemed to be “grey electricity”

GT researched ways of ensuring that the remediation of this site could indeed be greener and sustainable it was decided that incorporating two of Remediation Service International’s (RSI) Internal Combustion Engines (ICE) at the site would provide a greener more sustainable approach due in no small part to the units ability to destroy the contaminant and produce electricity

Application

It is proposed that the use of these ICE units for remediation on specific areas of the site coupled with the production of approximately 74 kVa of Green sustainable electricity will assist in the powering and augment the operation of the following chosen additional technologies:

• Steam injection (ancillary electrical equipment)

•Ozone and Hydrogen Peroxide injection (power for pumps and ancillary electrical equipment)

• Additional Soil Vapour Extraction system (power for DM-VEX vacuum extraction and ancillary electrical equipment)

It is anticipated that any surplus electricity generated by the ICE units will be fed back into the clients grid network to help in offsetting the power required to produce steam

Application

•Combines vapour extraction and contaminate vapour destruction in a single technology

•Uses a modified automobile engine with automated computer monitored operation and emissions control

•Catalytic convertor completes fuel oxidation

•Remote monitoring / operation options

•On board computer to monitor engine performance

•Automated air-fuel ratio control system

•Automated engine shutdown systems

•No external power required

•Can produce up to 37 kVa of green sustainable electricity (per unit)

ICE Technology features

Soil Vapour Extraction

RSI's patented systems use the vacuum from the engine's intake manifold to extract the soil

vapours. Air flow rate is governed by the litres displacement of the engine, rpm, system load,

and site specific conditions. For large sites with multiple wells, positive displacement

blowers driven by the ICE can provide extraction flow rates up to 3679 Nm3/hr. Blower

capacity in terms of total flow and vacuum pressure can be sized to meet each specific

remediation design. For sites requiring higher vacuum (greater than 18” Hg,) liquid ring

vacuum pumps can be driven by the ICE. With the ability to deliver up to 156 brake horse

power with the eight cylinder engine allows ICE to meet individual site specific

requirements.

ICE and SVE

Schematic of SVE using ICE

Feature V3 Basic V3 Loaded V4 Loaded

Max. Hydrocarbon destruction rate

7 kg / hr 22 kg / hr 44 kg / hr

Destruction efficiency for TVH/ BTEX

>99% >99% >99%

Engine size 7.5 litre 7.5 litre 15 litre (2 x 7.5)

Max. vapour flow 84 m3 / hr 250 m3 / hr 500 m3 / hr

Max. Vacuum (inches Mercury / water

20 /270 20 /270 20 /270

Soil gas hydrocarbon concentrations (ppmV as

gasoline) required to eliminate supplemental fuel

use

16,529 16,529 16,529

ICE performance specifications

ICE Technology considerations

•Soil vapour extraction flow rates dependent on site conditions

•Auxiliary fuel required (propane or natural gas) below optimum influent TVH vapour concentrations

•Recommended maintenance is twice monthly

•Can treat only low concentrations of chlorinated hydrocarbons

•The RSI Engine is a Versatile remediation tool

•Is small compact and portable

•Lends itself to be used at remote or urban areas

•Is unobtrusive (small footprint)

•Has a relatively small capital outlay (when compared to large non movable renewable energy sources such as wind and solar arrays)

•Is cost effective when considering rising fuel costs

•Can be used to power site offices and other remediation technologies

•Electricity produced can be fed back into the clients electrical grid or sold back to energy companies

ICE Technology summary