The treatment and handling of sludge can represent between 20%
and 50% of a wastewater treatment facility’s costs, which has
fuelled interest in technologies that extract energy, minerals or
other materials from sludge to either help offset treatment
facilities costs or even turn a profit. Utilities and water
treatment facilities are therefore investigating various techniques
for this purpose.

As these technologies mature, the market opportunity for
resource recovery will grow from USD25 billion today to USD45
billion in 2020, according to a new Lux Research report entitled
Technologies Turn Waste into Profit. Technologies focused on
recovering energy from sludge show the most promising value
proposition, according to the report, and are expected to capture
64% of the overall market in 2020.

‘Processing and disposal of wastewater sludge is something every
utility has to deal with, and the costs associated with the task
are rising due to more stringent regulations’, said Heather Landis,
an analyst for Lux Research and the report’s lead author. ‘We
expect more utilities to search for and adopt technologies that can
help offset these costs and extract the value hidden in wastewater
sludge.’

To evaluate the technologies competing for a share of the
market, Lux Research developed ten criteria to score each
technology on both its technical merit and maturity. In its report,
it then compared the technologies within two segments: energy
recovery and nutrient/material recovery. The key observations of
the report are as follows.

Improving production of biogas from sludge: several technologies
(including ultrasonic cavitation, mechanical disintegration and
thermal hydrolysis) aim to improve on anaerobic digestion, a
well-established method for extracting biogas from sludge. These
pre-treatment technologies scored highly on technical criteria,
enhancing biogas production by 40% to 50%.

Deriving alternative fuels from sludge: Technologies such as
gasification, pyrolysis and supercritical water oxidation allow
fuels to be extracted from sludge, such as syngas and biodiesel.
These approaches scored highly on technical value due to their
favourable energy balance, relatively low capital costs and high
solids removal. However, they are also equipment-intensive and,
with a limited number of installations, they registered low on
commercial maturity.

Nutrient and material recovery technologies: Twelve of the
thirteen technologies in this category scored poorly on both
technology and maturity due, in part, to their reliance on complex,
high-energy processes to extract materials such as phosphorous from
sludge. The exception is crystallization, which uses a minimum of
chemicals and a simple process design to recover up to 85% of
phosphorus from wastewater.

‘Sludge production volumes will continue to grow with increasing
population and country wealth’, said Landis. ‘By turning sludge
from a costly material to treat into a profitable revenue stream,
recovery technologies make fertile hunting grounds for executives
and investors looking for opportunities in the hydrocosm.’

Technologies Turn Waste into Profit is part of the Lux Water
Intelligence service. Clients subscribing to this service receive
ongoing research on market and technology trends, continuous
technology scouting reports and proprietary data points in the
weekly Lux Research Water Journal, and on-demand inquiry with Lux
Research analysts.