Project Background

In 2005, the Indiana Department of Agriculture selected the Town of Reynolds, Indiana to serve as the location of Bio Town USA. The purpose of Bio Town is to create a model community that is energy selfsufficient. Bio Town will create a cleaner environment, develop new markets and enhance value for Indiana waste products while producing its own energy. This opportunity required the Town to address its existing wastewater treatment plant deficiencies.

The Town of Reynolds, Indiana currently operates a 0.08 million gallons per day (MGD) controlleddischarge waste stabilization lagoon facility. It was constructed in the early 1970's. No major improvements have been made to the facility since that time. Much of the mechanical equipment is beyond its useful life, and in need of replacement. The lagoons have built up sludge over the years which now needs to be removed if the lagoons are to remain in service. Lastly, lagoon facilities, like Reynolds', are not capable of meeting stricter regulatory discharge limits which will soon be placed on the Town. The Town hired a professional engineering firm to prepare a Preliminary Engineering Report to recommend a solution to their wastewater treatment needs. The report recommended abandoning the lagoon system and installing a conventional wastewater treatment facility.

Conventional wastewater treatment plants account for 3% of the entire U.S. electrical consumption, generate 3.4% of all the greenhouse gases (GHG) emitted in the U.S., and consume more than half of all the electricity used by most Cities and Towns. This obviously is counterintuitive to the Town's primary goal of being energy self-sufficient and creating a cleaner environment. In addition, the conventional plant would not have created any usable end products from the Town's wastewater.

As an alternative to a conventional treatment plant, the Town Council of Reynolds decided to construct an algae-based system to address their wastewater treatment needs and fulfill the primary objectives of Bio Town. The Town of Reynolds selected Algaewheel Technologies, LLC and Thieneman Construction, Inc. to build an Algaewheel Wastewater to Energy Process for the Town. Construction of the new algaewheel waste to energy plant began on June 1, 2009 with facility startup scheduled to be January 2010.

Project Description

The Town's existing wastewater treatment plant (WWTP) influent raw sewage force main will be diverted to the new Algaewheel Renewable Energy Center for wastewater treatment and algae biomass production. The new Algaewheel Facility will be sized to treat 90,000 gallons per day (GPD) of raw sewage from the Town and will consist of: a new influent flow meter, a mechanically cleaned fine screen, primary clarifiers, primary algaewheel algae production system (APS), secondary clarifiers, secondary algaewheel APS, and tertiary clarifiers. Clean effluent from the algaewheel facility will be discharged to the existing lagoon system where it will be stored and discharged through the existing facilities. The existing lagoons will be used for wet weather inflow events exceeding a 4:1 peaking factor to the & algaewheel facility and for additional algae biomass production. Sludge and algae biomass from the algaewheel system will be dewatered through a centrifuge and thermally processed for generation of heat, bio-oil, bio-gas, bio-char, electricity, and CO2. The CO2 emissions will be recycled back to the algaewheels for increased algae production.

Redirecting the Town's sewage to the new algaewheel treatment facility will also prevent further sewage disposal into the existing lagoons. This will allow the lagoons to digest the existing sludge without further buildup and eliminate the need for an expensive lagoon cleaning project. The Preliminary Engineering Report estimated the lagoon cleaning costs to be $250,000 which did not include non-construction costs. This will also provide the Town with additional capacity to help address future wastewater needs from energy companies locating their facilities in the area.

Benefits to the Town of Reynolds

1. Clean Water: The algaewheel system will treat the incoming sewage to a level equal to or superior to that of a conventional activated sludge process and will allow direct discharge of the effluent or water re-use. The Town will no longer rely on their lagoon system for treatment and can use the lagoons for future wastewater flows and additional bio-fuels production. The biomass created at the facility will be thermally processed or sold, eliminating the need to land apply sludge on food crops and/or haul the sludge to a landfill.
2. Clean Air: The algaewheel system will abate greenhouse gases associated with bacteria based treatment processes and capture additional CO2 from processes within or outside the facility. Conventional bacteria based treatment processes, such as the Town's existing lagoons, create methane gas (CH4) which is 21 times more destructive to the atmosphere than CO2 (Kyoto). An activated sludge plant generates nitrous oxide (N2O) which is 310 times more destructive than CO2 (Kyoto). The algaewheel facility will qualify for carbon credits and/or renewable energy certificates (REC's).
3. Clean Energy: The algaewheel facility will create a feedstock that can be used for the production of many types of bio-fuels and will thus attract a variety of bio-fuels companies to the Town of Reynolds. Algae can be used to create liquid fuels, bio-gas, and/or electricity. The algaewheel system is 100% energy self-sustaining and will run completely off-the-grid.
4. Waste to Energy Facility for White County, Indiana: The algaewheel facility will also receive sludge, septage, recycled plastics, and trash from the surrounding communities for conversion into biofuels and other valuable byproducts.

Project Background

The City of Hopewell, Virginia operates a 27 million gallon per day (mgd) wastewater treatment facility that consists of 5 mgd of domestic wastewater and 22 mgd of industrial wastewater. Total average flows to the treatment facility are expected to increase to 32 mgd or more over the next several years due to additional domestic wastewater flows. Like many wastewater treatment facilities across the United States, the City is faced with pending nitrogen regulations and is evaluating a number of approaches for reducing effluent ammonia and total nitrogen from their facility. As part of their evaluation, the City is executing a pilot testing program to establish the technical and financial feasibility of implementing an algaewheel wastewater treatment process for tertiary nitrogen removal at their facility at a full-plant scale.

An algaewheel wastewater system for nitrogen reduction in the plant's effluent also offers the City a way to capitalize on their existing nitrogen rich effluent. As a result of the algae's nitrogen uptake and removal from the effluent water, the City benefits from growing a high value byproduct (algae) that can used for the production of biofuels, biogas, "green coal", electricity, and organic fertilizer. Based on the nitrogen levels found in the City's effluent, enough algae can be produced to power the algaewheel system and provide surplus power to the main treatment process and biosolids processing utilizing pyrolysis or gasification. The City can also re-direct emissions from biomass (sludge) thermal processes to the algaewheel facility to enhance algae growth and capture carbon dioxide. This will allow the City to sell carbon credits and/or offset their current carbon footprint.

Another significant advantage to using an algaewheel system for nitrogen removal is the abatement of the greenhouse gas nitrous oxide (N2O). Algae remove ammonia directly from the wastewater and convert it to protein. Bacteria, however, convert ammonia to other forms of nitrogen through nitrification and eventually greenhouse gases if denitrification is utilized. If the City chose a bacteria based nitrogen removal process their production of N2O gas would increase significantly. Under the Kyoto protocol, N2O gas is estimated to be 310 times more damaging to the earth's atmosphere than CO2. A bacteria based system would essentially be creating another form of air pollution that is likely to be regulated by the EPA this year.

Project Goals

The goals and design of the algaewheel facility are:
1. Demonstration of a cost effective and sustainable tertiary nitrogen removal process to enable the City to meet pending Chesapeake Bay nutrient reduction regulations.
2. Demonstration of effective harvesting and dewatering of the algae biomass.
3. Development of design parameters for a full-scale facility at the City's wastewater plant based on using the effluent from the existing wastewater treatment process.
4. Determination of the quantities and values of biofuels and other forms of renewable energy derived from the algae biomass produced in the algaewheel nitrogen removal process.