Waste from age-old paper industry becomes new source of solid fuel

Feb 12, 2014

In today's search for renewable energy sources, researchers are turning to the hi-tech, from solar and hydrogen fuel cells, and the very low-tech. The latest example of a low-tech alternative comes from an age-old industry: paper. A new study, appearing in ACS' journal Energy & Fuels, reveals a sustainable way to turn the huge amounts of waste from paper production into solid fuel with the added bonus of diverting the sludge from overflowing landfills.

Chinnathan Areeprasert, Peitao Zhao and colleagues note that making paper, from debarking and chipping wood to the final steps of pulping and refining, creates a tremendous amount of wood fibers and other wastes. Sending this sludge to landfills can be problematic, because substances can leach out and pollute groundwater. But recently, researchers have been exploring ways to turn the planet's growing waste streams into useful products, such as fuel and fertilizer. One such process is called subcritical hydrothermal treatment (HTT), and it uses heat and pressure to break down and remove various components of a mixture. In one case, researchers used HTT to turn sewage into a clean, . Early studies show it can transform paper sludge into fuel as well. Areeprasert's team decided to figure out the best HTT conditions for this process, and to test them in a pilot plant.

They tried different temperatures and defined the optimal conditions for converting paper waste into fuel using HTT. The resulting product had a composition similar to coal. Importantly, the amount of energy that can be recovered from the fuel is higher than the energy required to make it. The researchers conclude that this method for making is both sustainable and lends itself to commercialization.

Explore further: Ask a scientist: Ethanol & car performance

More information: "Alternative Solid Fuel Production from Paper Sludge Employing Hydrothermal Treatment" Energy Fuels, Article ASAP. DOI: 10.1021/ef402371h

Abstract
This paper aims to investigate the alternative solid fuel production from paper sludge employing hydrothermal treatment (HTT) in a lab-scale facility for implementation of the pilot-scale plant. The paper sludge was subjected to the HTT under subcritical hydrothermal conditions. In the lab-scale experiment, the temperature conditions were 180 °C, 200 °C, 220 °C, and 240 °C, respectively, while it was 197 °C in the pilot plant as the optimum condition. The holding time was 30 min in both cases. The hydrothermally produced solid fuel was evaluated for the fuel property, the water removal performance, and the mass distribution. Furthermore, the energy balance of the process was studied. The higher heating value of the HT pretreated paper sludge was slightly improved. In addition, the produced solid fuel had comparable H/C and O/C atomic ratios with that of coal, indicating the presence of carbonization during the HTT process. Using the mechanical dewatering, only 4.1% of moisture in the raw paper sludge can be removed while the solid fuel production from paper sludge by HTT at 200 °C showed 19.5% moisture reduction. According to the energy balance of the pilot plant, the recovered energy was significantly higher than the energy input, showing the feasibility of employing the HTT to produce alternative solid fuel from paper sludge.

add to favorites email to friend print save as pdf

Related Stories

Energy from microbes for drying sewage sludge

Aug 13, 2012

A new biodrying process from Siemens quickly converts sewage sludge into a usable form while saving energy. When dried with the new process, sludge from wastewater treatment can be used as fertilizer, dumped ...

Paper waste used to make bricks

Dec 19, 2012

Researchers at the University of Jaen (Spain) have mixed waste from the paper industry with ceramic material used in the construction industry. The result is a brick that has low thermal conductivity meaning ...

New tech could be "Mr. Fusion" for biofuel

Nov 20, 2013

A new technology from Argonne may remind viewers of Mr. Fusion of Back to the Future fame, only with a biofuel twist: put in your waste and out comes diesel fuel.

Microbes strip power from poo

Sep 17, 2013

EPSRC-funded scientists have developed a process using microbes which removes the need to use electricity to process sewage at treatment plants. The microbes can also be used to produce large quantities of ...

Recommended for you

Environmentally compatible organic solar cells

16 hours ago

Environmentally compatible production methods for organic solar cells from novel materials are in the focus of "MatHero". The new project coordinated by Karlsruhe Institute of Technology (KIT) aims at making ...

Floating nuclear plants could ride out tsunamis

18 hours ago

When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects—specifically, ...

Unlocking secrets of new solar material

18 hours ago

(Phys.org) —A new solar material that has the same crystal structure as a mineral first found in the Ural Mountains in 1839 is shooting up the efficiency charts faster than almost anything researchers have ...

Ikea buys wind farm in Illinois

Apr 15, 2014

These days, Ikea is assembling more than just furniture. About 150 miles south of Chicago in Vermilion County, Ill., the home goods giant is building a wind farm large enough to ensure that its stores will never have to buy ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

vincent-pawlowski
not rated yet Feb 12, 2014
Sometimes I wonder why we do not get more power from the Sun. Could it be that sunshine cannot be privatized?
Doesn't it make more sense to keep all the complex hydrocarbons, and even cellulose, whole?
Paper waste makes excellent building material. I have been using it for years. Recently, a process was patented to reunite cellulose fibers and lignin full resin into - wood? No, building blocks. For more information, see http://masongreenstar.com/

More news stories

Simplicity is key to co-operative robots

A way of making hundreds—or even thousands—of tiny robots cluster to carry out tasks without using any memory or processing power has been developed by engineers at the University of Sheffield, UK.

Microsoft CEO is driving data-culture mindset

(Phys.org) —Microsoft's future strategy: is all about leveraging data, from different sources, coming together using one cohesive Microsoft architecture. Microsoft CEO Satya Nadella on Tuesday, both in ...

Floating nuclear plants could ride out tsunamis

When an earthquake and tsunami struck the Fukushima Daiichi nuclear plant complex in 2011, neither the quake nor the inundation caused the ensuing contamination. Rather, it was the aftereffects—specifically, ...

New clinical trial launched for advance lung cancer

Cancer Research UK is partnering with pharmaceutical companies AstraZeneca and Pfizer to create a pioneering clinical trial for patients with advanced lung cancer – marking a new era of research into personalised medicines ...

More vets turn to prosthetics to help legless pets

A 9-month-old boxer pup named Duncan barreled down a beach in Oregon, running full tilt on soft sand into YouTube history and showing more than 4 million viewers that he can revel in a good romp despite lacking ...