| Innovative Membrane Based Process
Water and Energy Use While Recycling More Waste
December 4, 2002
Sinclair Knight Merz
As Seen in: Waste
Management & Environment
Innovative membrane technology has been used in the design of an efficient new
effluent processing system for a hardboard manufacturing facility in Queensland.
In pilot trials, the new system
for Australian Hardboards Limited (AHL) reduced
industrial water consumption by 65% and enabled
the recycling of close to 100% of the process effluent,
along with offering energy savings.
The results of the pilot trials
were presented at the fifth Membranes in Drinking
and Industrial Water Production conference held
recently in Germany, arousing the interest of industry
professionals from across the globe.
The System, jointly developed
by AHL and leading consulting firm Sinclair Knight
Merz, is expected to be adaptable to other liquid?solid
separation applications in the timber, pulp and
paper, water and wastewater, mine tailings, minerals
and other wet process related industries.
AHL’s Queensland manufacturing
plant uses mixed eucalyptus species as the principal
raw material in the wet process manufacture of
a hardboard product known as ‘Masonite’.
The Plant produces around one
megalitre per day of effluent consisting principally
of suspended fibre, colloidal and dissolved organic
and inorganic materials, which are generated during
the pulping and digestion process.
AHL Managing Director, Rex Hills,
said that the thermo-mechanical pulping process
at the Plant was largely unchanged from an original
late-1950s design, and that process water effluent
had been treated and recycled using the traditional
methods of settling ponds and land irrigation.
“Recognising that these
processes could provide significant opportunities
to reduce water and energy use without adversely
affecting product quality, we commissioned Sinclair
Knight Merz to examine a variety of technologies
for upgrading the treatment and recycling processes,” Mr
“We are very pleased with
the outcome,” he said.
“Because of the resulting
increases in process efficiency, we look set not
only to achieve cost savings on our operations,
but also to make a contribution to environmental
sustainability on behalf of our industry,” Mr
Sinclair Knight Merz Process
Engineer, Lee Foster, said that a range of key
technology choices was investigated for the upgrade.
These included standard cross-flow
membranes, the Vibrating Shear Enhancement Process
(VSEP) membrane system, a membrane bioreactor,
evaporation and standard biological systems.
“Our feasibility work involved
a literature study of relevant industry practice
and an extensive economic analysis to compare each
technology option, including the impact of any
process modifications,” Ms Foster said.
“The economic analysis
demonstrated that the VSEP membrane technology
offered the lowest capital and operating costs
of all the systems investigated, while producing
the best results,” she said.
VSEP is a relatively recent innovation
in membrane-based liquid-solid separation technology.
It uses intense vibratory shear
waves on the face of the membrane to stop the buildup
of contaminants and to overcome the negative separation
performance issues associated with conventional
The vibration also improves fouling
resistance and allows for filtration rates up to
10 times higher than is achievable with conventional
“Following the favourable
economic analysis, and having also identified a
number of other key processing advantages, we carried
out extensive laboratory and pilot plant trials
on a VSEP based system,” Ms Foster said.
“In addition to superior
cost, footprint and reliability considerations,
the System demonstrated an ability to produce a
high solids concentrate which, in the AHL context,
had a positive calorific value because it was produced
as wood molasses,” she said.
“This made it potentially
suitable for reuse as boiler fuel, for composting
or as a supplement for animal feedstock,” she
In addition, the cleaned permeate
water was shown to be suitable for recycling back
to the Plant and, treated further with reverse
osmosis, to be suitable for boiler use.
With the addition of the reverse
osmosis treatment, the System would increase the
boiler feed-water temperature from ambient to about
60oC, resulting in significant energy savings.
Employing more than 3000 people
in offices across the globe, Sinclair Knight Merz
systematically applies the best people, industry
leading expertise and strong local relationships
to deliver solutions that make its clients more