THE SOURCE - Spring 2016 - (Page 22)

feature Natural Gas Power Plant Opportunities C By Alex Fassbender, P.E., CEO, EcoVia Corporation urrently, many communities' wastewater treatment plants face tighter National Pollution Discharge Elimination System (NPDES) standards based on a recent Total Maximum Daily Limit (TMDL) determination or the Waters of the United States (WOTUS) regulatory drivers. Pair this with the Clean Power Plan (CPP), the Mercury and Air Toxics Standards (MATS) and the many announced power plant closings, natural gas utilities around the country are concerned about the reliability of electricity supply. However, there may be an opportunity for your community if it anticipates the need for an upgrade to their wastewater treatment plant. If so, your community might be a candidate for a "free" natural gas power plant. A natural gas power plant can be free because its essential duties-electricity and wastewater treatment-cover its costs. The natural gas power plant produces electricity and low-grade heat. Rather than go to waste, the low-grade heat is used to supercharge wastewater treatment. Bacteria that treat wastewater grow exponentially faster with increasing temperature. Harnessing this well-known supercharging effect is made possible by a new way to perform "utility grade" heat transfer to sewage. Utility grade means it is designed to work 24/7/365 for decades without shutdown or complex maintenance, and this sets it apart from previous practice. Until now, sewage has been a challenge because it is loaded with bacteria that stick to any surface to form biofilm. Rapidly forming biofilm quickly degrades the performance of traditional heat exchangers and makes them unsuitable for this service. EcoVia's CARMON FBX™ uses a fluidized bed of plastic media to continuously clean heat exchanger surfaces. The plastic Process Inputs Process Steps and Flows Wastewater Treatment Plant Wastewater Each 10ºC increase in temperature doubles the rate of biological activity in the wastewater treatment plant 22 THE SOURCE | THE vOiCE and CHOiCE Of pUbliC gaS Natural Gas media is designed for this service and it simultaneously cleans the heat exchanger and wastewater. Most wastewater treatment upgrades at this time involve the addition of nutrient removal. Nutrient removal means taking the nitrogen and phosphorus out of the wastewater. The bacteria that treat nitrogen by oxidizing ammonia (nitrification) pose a challenge. The ammonia oxidizing bacteria (AOB) that oxidize ammonia into nitrite are strongly affected by temperature. When they are warm, they work fast. When they are cold, they slow down significantly. Traditional wastewater engineers prepare upgrade designs that they believe will work during the largest flows and coldest sewage temperatures of the year. They accomplish this by designing very large reactors that can provide the slow and cold bacteria time to do their job. That translates into high costs because these slow and cold designs often double or triple the size of the aerobic reactors at the wastewater treatment plant. Not only Low Grade Heat From Power Plant Electric Power Power Plant with Heat Capture Process Outputs Clean Water Biogas (option) Electricity (option)

Table of Contents for the Digital Edition of THE SOURCE - Spring 2016

First Person
APGA Events
A Friendly Business Partnership of Two of the Nation’s Largest Utilities Can Benefit the Natural Gas Industry
Natural Gas Direct-Use in Net Zero Energy Buildings
Henry Hub and Changing Liquidity in the North American Gas Market
Cold Season Planning Preparedness: From Supply to Delivery
Natural Gas Power Plant Opportunities
Legislative Outlook
The Pipeline
Marketing Matters
Advertisers’ Index/
At Last

THE SOURCE - Spring 2016