The N-VIRO Fuel™

Technology

Terry J. Logan, Ph.D.

Organic Wastes as Biomass Fuel

There are ~ 40 million tons of sewage sludge produced in the U.S. annually.

There are ~ 600 million tons of collectable manure.

There are ~ 150 million tons of organic municipal solid wastes (garbage).

There are high tip fees for sewage sludge (> $100/ton in the NE, ~ $25-40/ton nationally)

There are federal grants for treatment of manure.

There is increased interest in using organic wastes as biomass fuels.

Fuel and Ash Content of

Organic Wastes

Organic waste Energy value

(kJ/kg)

Ash content

(% dry

weight)

Wood 19,000 0.5-1.5

Manure 15,000 10-25

Food waste 16,000 – 21,000 1-20

Sewage sludge 16,000 – 28,000 20-40

Municipal solid waste 3,000 – 14,000 20

The N-VIRO Organic Waste

Stabilization Process Alkaline mineral by-products (fly ash,

cement kiln dust, lime kiln dust) are mixed with dewatered sludge or manure.

Stabilization is achieved by a combination of high pH, heat and drying.

USEPA approved parameters for Class A disinfection of sewage sludge are pH 12 for 72 hours, 52 0C for 12 hours, and solids > 50 %.

The N-VIRO Stabilization

Process

The N-VIRO Soil Product The product of the N-Viro stabilization process is a dry,

granular material with soil-like physical properties.

It is used as an agricultural soil amendment as a liming

material, low analysis fertilizer and source of organic

matter.

It is also used for land reclamation, and as a blend with

compost to make horticultural topsoil.

Properties of N-VIRO Soil

Characteristic Value

Organic matter content (% dry weight) 30

Liming value (% dry weight) 25

Total nitrogen (% dry weight) 1

Total phosphorus (% dry weight) 0.5

Total potassium (% dry weight) 0.1

Total sulfur (% dry weight) 5

Total calcium (% dry weight) 12

Total magne sium (% dry weight) 2

Total boron (mg/kg d ry weight) 500

Total mangane se (mg/kg) 200

Total zinc (mg/kg) 200

pH 12

Solids content (% by weight) 60

The N-VIRO BioDry™ Process

Heated air is used to dry the sludge or manure

mixed with alkaline by-products.

Drying is done in a rotary drum dryer.

Less by-product is used compared to the

conventional process since part of the required

heat for disinfection comes from the dryer.

Final solids content of the final product can be

better controlled.

Final product is more uniform in particle size.

The N-Viro BioDry™ Process

Sludge/fly ash leaving the mixer and entering the rotary drum dryer

Lessons Learned from the

BioDry™ Process Traditional sludge dryers are prone to fires

and explosions because of the volatile nature of sludge.

Operational BioDryers have had not experienced these problems.

Research showed that the addition of mineral by-products to sludge raised ignition temperatures above air-drying temperatures.

The N-VIRO Fuel™ Process

The N-Viro Fuel process is a modification of the BioDry process.

The process uses less mineral by-products than the BioDry process, and recycles some of the dried material to further reduce the mineral component and increase the organic content and fuel value.

The process can be optimized for higher solids than produced for an agricultural product.

The N-Viro Fuel process still meets EPA requirements for Class A disinfection.

The N-VIRO Fuel™ Process

Sludge cake

Alkaline

additives

Recycle

Mixer Dryer

Odor

control

Heat pulse N-Viro

Fuel®

Coal blend

14-30 % solids

10 % dose35 % solids

70-90 % solids

Characteristics of N-VIRO Fuel™

Has physical characteristics similar to coal.

Solids content is 70-90 % and can be controlled.

BTU value is 4,000-7,500/lb.

Ash content is 20-40 %.

Sulfur content is ~ 1 %.

Heavy metals are similar in concentration to that of coal; coal is higher in arsenic and sludges are higher in copper and zinc.

Biologically stable, low odor potential, and fully disinfected.

Synergy with Coal Fired Power Plants

Sludge production and power plant operations are both 24/7.

If the N-Viro Fuel® facility is co-located at the power plant, waste

heat from the power plant can be used to run the dryer.

The N-Viro Fuel® process will utilize the power plant’s fly ash as

additive.

N-Viro Fuel® contains lime which can offset limestone addition for

SOx reduction.

The exhaust gases from the BioDryer contains ammonia which

might be utilized for NOx reduction.

Sewage sludge and other waste organics are low in sulfur compared

to most coals.

There should be opportunities to earn CO2, NOx and SOx credits.