JANESVILLE’S ROAD TO CNG

Presented by:

Joe Zakovec

BIOGAS TO ENERGY SYSTEM

Digester upgrades

High Strength Waste unloading place

Gas Storage System

Gas conditioning and compressor system

(4) 65 kW microturbines with integral heat

recovery

(1) 200 kW microturbine with heat exchanger

Bio CNG Option

HIGH STRENGTH WASTE

GAS STORAGE SYSTEM

• Capacity is 107,000

cubic feet of gas

• Allows for

maximizing on peak

power production

• Delays or prevents

flaring of gas

GAS CONDITIONING SYSTEM

• Began operation

November 2010

• Removes moisture,

particulates, and

siloxane from digester

gas

• Compresses gas to

pressure required by

the turbines

(4) 65 KW MICROTURBINES

• Recovered

thermal energy

heats water that

is used to heat

the digesters

• Electricity is sold

to Alliant Energy

• Low maintenance

due to one

moving part

200 KW MICROTURBINE AND HEAT

EXCHANGER

• Microturbine started

up in January 2012

• Heat exchanger was

added in December

2013

CO2 REMOVAL SYSTEM

• Required to make

digester gas

suitable for

vehicle fuel

• Concentrates

methane from

60% to 90% by

removing Carbon

Dioxide and other

gases

CNG STORAGE AND FUELING STATION

• 100 gallons gasoline

equivalent storage

spheres

• Includes further

drying and

compression of the

gas before the

entering the storage

spheres

• Fast-fill system

CNG VEHICLE

• Handles the same as a conventional vehicle

• Uses the same engine with a few modifications

• Can switch from gasoline to CNG on the move

CNG LAWNMOWER

METHANE PRODUCED

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

160,000

180,000

200,000

C

U

B

I

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F

E

E

T

/

D

A

Y

Last 6 months daily average

CNG PRODUCED AND USED

0

50

100

150

200

250

G

a

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l

o

n

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Last 6 months

COST TO PRODUCE BIO-CNG

Cost to produce Bio-CNG $0.88/gallon

Current cost of Gasoline $3.15/gallon

On vehicles that use the roads the City pays

$0.247/gallon in road tax.

Savings is $2.02/gallon

Exploring options to add more CNG vehicles to

fleet.

THANK YOU!

Joe Zakovec

zakovecj@ci.janesville.wi.us