Sludge Watch ==> BioCycle - Closing the Loop - what to do with waste sludges manures

[maureen.reilly at sympatico.ca]

BioCycle

Apr 2006
Pg. 66 Vol. 47 No. 4


CLOSING THE LOOP ON ANAEROBIC DIGESTION
Rovins, Cindy

Organic energetics is an environmentally closed looped, self-sustaining 
waste to energy process developed at Rutgers University and marketed by 
Bioscan A/S, Denmark and US. The system uses a series of processes to 
degrade products into their primary components: anaerobic digestion, 
membrane filtration, reverse osmosis, gasification, and membrane gas 
separation. The patent pending technology was developed by Paula Marie Ward, 
Assistant Research Professor in the Department of Biochemistry and 
Microbiology at Rutgers University's Cook College. Bioscan looked at 
mechanically converting animal waste via containerized anaerobic digestion 
into products that can be harvested and reused. Its patented Biorek process 
uses several digestion and separation technologies which result in a cleaned 
up methane/CO2 stream, the harvesting of ammonia, the stripping of potassium 
and phosphorus salts from the liquid digestate, and purification to provide 
potable water. Biorek facilities already in operation span the globe. 
Projects in Denmark, Germany, Japan, Australia and Holland all deal with 
animal waste feedstocks.

GASIFICATION AND COMPOSTING

Developed at Rutgers University with Bioscan, a Danish firm, the technology 
separates organics into usable components. A 10 megawatt facility is being 
constructed in Belmont, Wisconsin.
A Biorek process in operation at a swine farm in Denmark uses several 
anaerobic digestion and separation technologies to clean up the methane/CO2 
stream and strip salts from liquid digestate.


ORGANIC ENERGETICS is an environmentally closed looped, self-sustaining 
waste to energy process developed at Rutgers University and marketed by 
Bioscan A/S, Denmark and U.S. The system uses a series of processes to 
degrade products into their primary components: anaerobic digestion, 
membrane filtration, reverse osmosis, gasification, and membrane gas 
separation. The patent pending technology was developed by Dr. Paula Marie 
Ward, Assistant Research Professor in the Department of Biochemistry and 
Microbiology at Rutgers University's Cook College.

Ward's Ph.D. is in Animal Sciences and she teaches and researches antibiotic 
resistance in food and water systems. It was through her interest in 
disabling antibiotics entering the environment from animal wastes that she 
developed the organic energetics process. Antibiotics are used as growth 
promotants in animals. When agricultural pesticides, hormones and 
antibiotics from plants and animals get into the surface water, the 
biological impact of those residues can create antibiotic-resistant 
organisms. When exposed to humans, animals and plants, these 
antibioticresistant organisms can create diseases that are very difficult or 
impossible to suppress.

As a researcher studying the land application of animal waste and its 
microbiology and looking at where resistant organisms could come from in 
surface water and soils, she realized the amount of antibiotics we use to 
raise animals in this country could contribute greatly. "According to the 
Union of Concerned Scientists, approximately 70 percent of the 
pharmaceuticals we produce in this country are used to increase the growth 
rate of animals, with less than 30 percent used for humans and the rest for 
plants," says Ward. "With that kind of number and the way we handle animal 
waste, it is evident where some of the resistance could be coming from, and 
that is why I wanted to stop it - it is something we can control. If we are 
not going to stop using the antibiotics, then let's at least contain them."

Creating the system mainly as a solution for lagooned animal waste in 
Concentrated Animal Feeding Operations (CAFOs), Ward was introduced to 
Bioscan of Denmark, a company with a patented state-of-the-art anaerobic 
digestion system that met her criteria in terms of an environmentally 
closed-loop operation.

DIGESTION, GASIFICATION AND COMPOST

Denmark requires concrete lagoons to prevent fugitive seepages. However, 
after noticing that land application of the digestate was excessive - the 
ratios of available nutrients to what was required for plant uptake were too 
high - Denmark put restrictions on land application. Bioscan looked at 
mechanically converting animal waste via containerized anaerobic digestion 
into products that can be harvested and reused. Its patented Biorek process 
uses several digestion and separation technologies which result in a cleaned 
up methane/CO2 stream, the harvesting of ammonia, the stripping of potassium 
and phosphorus salts from the liquid digestate, and purification to provide 
potable water. The cleaned methane can be used for energy and the salts can 
be land applied in proportions that plants can use. They are also left with 
a solid "compost".

Although the Biorek technology had highly refined the anaerobic digestion 
process, it still could not disable the U.S. pharmaceutical products, either 
in whole or their metabolites, which sometimes can be as effective as the 
original drug. Ward collaborated with Bioscan and added another technology 
to its AD system - gasification, which would take the solids from the 
digestate and crack the hydrocarbons, but not destroy them, so that producer 
gases can be harvested. The producer gases can be reformed into Syngas and 
other beneficial uses. The gasifier phase also results in an ash product, 
which contains the remaining carbon and trace metals including potassium and 
phosphorus. And most importantly for Ward, along with adsorbents used to 
filter pharmaceuticals from the liquid phase, the higher temperature of 
gasification in comparison with anaerobic digestion disables the 
pharmaceuticals in the solid residual.

The gasification phase also achieved another one of Ward's goals - to 
completely close the loop on anaerobic digestion. While deriving energy, 
purified gases, salts and water from the Biorek process, a solid compost is 
an additional end product. Through gasification, the components are further 
separated, so that all by-products of the system are useful, marketable 
products.

"We need not look farther than ordinary, everyday organic materials for 
production of the thermal and mechanical power we have come to expect to 
accommodate our daily lives," explains Ward. "Viewing waste resources as 
valuable could start directing society to understand the value of the 
two-way transformation of organic matter into and out of free, gaseous 
energy. Power generation from subterrestrial organic fuel sources such as 
oil, natural gas, and coal is essentially no different from surface forms, 
providing that the mechanical technologies exist to complete the 
transformation. In addition, products manufactured from subterrestrial 
energy sources can also be synthesized from the breakdown products of 
surface organic sources."

How best to mine our wastes for valuable resources? Ward shares the 
philosophy that she, along with other key players in New Jersey and 
elsewhere are working to implement. "It's more about a philosophy of 
integrating a wider variety of technologies that are appropriate to a region 
or facility or a feedstock stream that makes better use of what has been 
previously considered waste and turn it back into useful products, including 
energy and clean water. This big picture thinking is where we need to go in 
handling our waste." Ward adds one caveat to this theory: "The focus is not 
about the renewable energy that can be derived from conversion, but rather 
how we need to be smarter about how we sustainably handle and terminate our 
ever-increasing waste stream." (See sidebar on Integrated Waste 
Technologies.)

In addition to animal waste processing, the Organic Energetics technology 
can be applied to wastewater processing, grease trap wastes, organic 
industrial wastes, food processing plants or colocated with landfills. By 
using an anaerobic digester with a gasifier, presorted commercial and 
household food waste, and nonrecyclable paper, plastics and packaging can be 
converted into usable fuel. The gasifier can further harvest residual power 
out of plastics that can't be degraded in the digester. Down the road, 
colocating a digester and gasifier next to landfills also lends itself to 
the mining of old, dead capped landfills.

A key factor for sewage treatment plants is an issue not yet on the public 
health and environmental sector's radar screen - pharmaceutical products in 
the human waste stream. Just like the presence of pharmaceuticals in animal 
waste, in human sewage sludge, the pharmaceuticals end up in the biosolids. 
Explains Ward, "Many drug compounds go right through human and animal 
systems, virtually unchanged." Anticipating that these will be the next 
compounds to be regulated in wastewater treatment effluent, Ward emphasizes 
that there are patented ways to treat them: different kinds of filtration 
systems disable and filter the compounds from aqueous systems, and high 
temperatures from processes such as gasification disables them in the 
solids.

ADDITIONAL APPLICATION

Another innovative application of this technology is for residential 
housing. Economy of scale predicates using the system in a cluster facility, 
rather than an individual home. Residential systems would entail pumping and 
piping. They can use the products themselves, water and biogas for heat and 
electricity, and depending if they have land, they can use the trace 
nutrients as fertilizers. The system can be applied to new construction, or 
retrofitted to existing construction. The exterior of a neighborhood 
conversion facility can look architecturally like a house, so it doesn't 
detract from the aesthetics of the neighborhood.

Under consideration for U.S. military use, the Organic Energetics system is 
seen as a production source for key materials as well as a solution for 
disposal problems. The production of water, fuel, hydrogen and other viable 
products such as ammonia, phosphorus and potassium entails a cost savings on 
purchasing and shipping from outside sources. Cost avoidance also results 
from reduced and eliminated transportation for waste disposal.

Table 1 lists wastes that are suitable to be processed using the Organic 
Energetics technology. Materials that are not suitable include aluminum, and 
halogenated products such as polyvinyl chloride, chlorine, fluorine and 
bromine. These pose a disposal issue and require separation. End products 
from the Organic Energetics processes include: Anaerobic Digestion Phase: 
Ammonia, biogas (methane), CO2, sulfur; Liquid/Solid Separator Phase: 
Potable water, potassium and phosphorus salts; Gasifier Phase (depending on 
feedstock profile): Hydrogen, carbon monoxide, CO2, nitrogen, ash, and 
traces of water, ammonia, methane, ethane, ethane and hydrogen sulfide gas.

EXISTING/PLANNED FACILITIES USING BIOREK

The Biorek facilities already in operation span the globe. Projects in 
Denmark, Germany, Japan, Australia and Holland all deal with animal waste 
feedstocks. A facility being built in Canada will handle the distiller's 
grains in an old whiskey plant to produce ethanol. Another plant is planned 
for Denmark, which will take a mix of industrial organics, including fish 
and slaughter-house wastes.
Table 1. Wastes suitable for Organic Energetics Process

Says Poul Ejner Rasmussen, Bioscan's Director of Business Development: "We 
started with animal wastes because that was the biggest volume problem in 
Europe." The current Denmark plant is a 2 megawatt facility that processes 
600 metric tons/day of organic feedstock.

The first facility to implement the Organic Energetics technology will be 
Belmont BioAg, in Belmont, Wisconsin. A fluidized bed reactor will be used 
to produce steam. Belmont BioAg is an environmentally inspired agricultural 
campus design integrating various processes. "Their main purpose is to 
produce ethanol, but they've colocated their site at an access point for 
corn for ethanol as feedstock, as well as CAFO or feedlot waste so they can 
take the animal waste as well as the ethanol production waste," says Ward. 
"The various liquors and grain wastes from the ethanol process go into a 
digester to produce power to heat and run the ethanol plant. They are also 
moving spent heat to greenhouses." Bioscan's Biorek system will be used as 
the anaerobic digester and will be a 10 megawatt facility.

The Belmont project, which is in the development stage, can be read about at
http:// www.belmontbioag.com/

'The focus is on how we need to be smarter about how we sustainably handle 
and terminate our ever-increasing waste stream."

Cindy Rovins is an Agricultural Communications Editor for Rutgers 
Cooperative Research & Extension.