Advancing Utilization of Manure Methane Digester

Funding for this project was recommended by the Legislative Commission on Minnesota Resources

from the Minnesota Environment and Natural Resources Trust Fund ($204, 375)

Haubenschild Dairy Farm Energy Production

Princeton, Minnesota

Milk Production + Crop Production + Electrical Production + Future

Hydrogen Production

= Farm Income Diversification

Plug-Flow Digester - A small “plug” of slurry is pumped into one end each day, causing a comparable amount to flow out of the other end into the storage basin in the background.

Methane Digester: To breakdown organic matter in the absence of oxygen to biogas, which is primarily CH4/methane, CO2/carbon dioxide, H2S/hydrogen sulfide, and water vapor.

View of digester, barn and engine generator building at time of installation in 1999.

Engine Generator set:

Internal combustion

engine with 135 kW 240 VAC

electrical generator.

Biogas Production Used in Generator

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

09/17/99 09/16/00 09/16/01 09/17/02 09/17/03 09/17/04

Date

Biogas Produced

(ft3/day)

Comparison of Fuel Cell and a Genset Utilizing Biogas

Philip R. Goodrich PE, David Nelson PE, Richard Huelskamp, David Schmidt PE*, R. Vance Morey from Department of Biosystems and Agricultural Engineering, University of Minnesota.

Dennis Haubenschild from Haubenschild Farms, Princeton MN

Matthew Drewitz, Paul Burns, fromMinnesota Department of Agriculture

Other participants in this project include:

• Amanda Bilik, The Minnesota Project, • Verlyn Johnson and Blanca Martinez, BAE • Henry Fischer, East Central Energy. • Rob Lowen, Plug Power, Inc. • Jamie Tooley, CES-Landtec Engineering• Don White, Donaldson Corp.

Objective:

To demonstrate the feasibility

of converting biogas to electrical energy

using a commercially

available fuel cell.

Challenges to using biogas

for a fuel cellHydrogen sulfide removal

Initial concentration 3000-5000 ppmNeed concentration < 25 ppb

Moisture removalNeed dry gasDewpoint < -30 degrees Celsius

Carbon dioxide removalNeed concentration < 5 ppm

The building at the left houses the 135 kW engine generator and the building on the right houses the fuel cell and instrumentation. One barn is to the right rear of the picture

Fuel Cell: Uses hydrogen to

generate electricity without

combustion. Output is 5 kW at 120 VAC

A fuel cell is similar to a car battery in that it produces electricity

through electrochemical reactions. A fuel cell produces electricity as long as

the hydrogen fuel source and oxygen passes

through it.

Heat is also produced and can be utilized for space heating and hot water needs.

Electricity conversion efficiency is around 25%

The energy resources for hydrogen can be biogas, natural gas, propane, methanol, ethanol, and other hydrogen based liquids or gases.

From Plug Power Fuel Cell Software Screen

Cost per kilowatt is very high.$10,000 -->20,000 per

kW

Biogas must be cleaned up to strict specifications. Adds cost and complexity while consuming energy.

Fuel cell is an emerging technology.

Comparing Electrical Generator Technologies

Engine Generator System

Cost per kilowatt is low. $50 -->100 per kW

Biogas can be used directly from the digester with no cleanup.

ICE is mature technology.

Fuel Cell System

Greenhouse emissions and particulates are very low.

System is very quiet.

Few moving parts.

Cost of maintenance is unknown.

Fuel cell technology is continuously improving at a rapid rate.

Comparing Electrical Generator Technologies

Engine Generator System

Greenhouse emissions of CO2, SO2, CO and particulates are significant.

Noise level is very high and sound mitigation is necessary.

Many moving parts, most moving in a hot environment needing oil and cooling.

Maintenance is well known.

Technology is mature and changing slowly.

Fuel Cell System

Biogas Clean Up

Emissions from Haubenschild Generator Compared to Plug Power™

Proton Exchange Membrane (PEM) Fuel Cell

( 799ppmv) 4.18 g/kWh

(2963 ppmv) 25.5 g/kWh

(277 ppmv) 3.34 g/kWh

(2.46 ppmv) 53 g/kWh

( <1 ppmv) 0.014 g/kWh

(<1 ppmv) <.0023 g/kWh

(<1 ppmv) <0.030 g/kWh

(1790 ppmv) 14.5 g/kWh

Fuel CellEngine Generator

CO

NOx

SOX

CX HY

Energy Production +

Organic Fertilizer +

Net Air Emissions

=

$nergy Income +

$avings +

Environment Impact Reduction

Thank you

Rich Huelskamp

Advancing Utilization of Manure Methane Digester

Funding for this project was recommended by the Legislative Commission on Minnesota Resources from the Minnesota Environment

and Natural Resources Trust Fund