Although wastewater sewage sludge is usually considered an expensive nuisance to be disposed of, it can actually be a source of energy, phosphorus and other products. Water treatment facilities are currently exploring technologies to extract this value. Research shows that the potential of recovery grows from USD25 billion today to USD45 billion in 2020.
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.