Moving Bioenergy Technologies From Disposal to Green Energy

Abstract

The push to conserve fossil fuels and other natural resources in the United States intensified in the late 2000s as global warming, sustainability, carbon credits, and related issues became subjects of public awareness. As a result, the energy environment for wastewater management professionals has changed. New treatment facility designs and operations have begun to focus on green energy use, process efficiency, and economic accountability.The success of efforts to reduce a treatment facility's carbon footprint will significantly depend on both creative problem solving, and enhancements to existing technologies. Biosolids, FOG (fats, oil, grease), and local green waste are the major energy source at wastewater facilities, and the bioenergy technologies include thermal oxidation (modern incineration), drying, and the emerging technology of gasification. This paper addresses thermal oxidation (modern incineration).The primary author has the following career background • Employment at Texaco advising large industrial customers on fuel and lubrication oil technologies. • Started a company for recycling waste to sell as fuel to the tomato growing industry. • Started a company manufacturing dewatering and polymer makeup equipment.(http://www.solidstechnology.com/Images/webrefs.pdf) • Was employed by a company offering fluid bed reactors, MHFs, dryers, and energy recovery systems. For example, in the early 1990s this company supplied a fluid bed furnace, an energy recovery boiler, and a steam turbine generator to the wastewater facility at Asheville, NC.Hence, the author and his bioenergy partners were well positioned to see the emerging green energy market, and they took a proactive approach to customizing their products for this new energy environment. These companies included -A market leader in heat exchangers and boilers. This company identified one of their products (in bed coils), already in industrial use since the 1980s, as an add-on to improve the thermal efficiency of biosolids fluid bed reactors. -The same company was able to significantly improve the life and efficiency of their heat exchangers by employing improved process control.-To cater for different size facilities, and different needs, the same company now offers three types of boilers for biosolids centered applications. -Another market leader providing solids sensors to the Pulp and Paper industry adapted their equipment for reading percent cake solids in line. -In response to EPA encouragement in the late 1990s, the author's company developed an advanced Mass Flow Control System for use with fluid bed reactors, and multiple hearth furnaces, expanding the traditional control boundary to include dewatering. This system provides several benefits; including multi fuel feed capability, higher throughput, more stable performance, and the capability of capturing extra energy.All of the above technologies are full scale proven, mostly in wastewater, and the components are in operation at multiple facilities. In summary, they -Improve the thermal efficienc...