Benefits of Implementing Biogas Plant Technology for Application Level and Flow Control
Biogas is produced at many industrial and municipal facilities and there are many opportunities to measure and improve the processes. Biogas in this post can refer to biogas plants, landfill gas and digester gas, all of which typically consist of 60-70% methane and 30-40% carbon dioxide. These gases are used to fuel boilers that produce heat or steam and to fuel generators or gas turbines to produce electricity.
Responsible energy management through level and flow instrumentation reduces environmental impact, maintains safe operations and reduces energy costs. Here are a few applications where biogas plant technology can help you achieve these goals.
Biogas is primarily produced by the biological breakdown of organic matter in the absence of oxygen – a process known as anaerobic digestion. Feed materials include biomass, manure, sewage, plants and plant waste, grease trap contents and the organic fraction of municipal solid waste.
在所有形式的沼氣生產中，安全可靠的氣體流量測量對於沼氣的收集，處置或重複使用至關重要。沼氣流量測量可能尤其具有挑戰性，因為所選擇的儀器必須提供低流量靈敏度，低壓下降和耐受溫度和壓力變化。
A few example applications are measuring digester gas flow and landfill gas. Measuring digester gas at wastewater treatment plants has allowed users to size generators needed to produce electricity or provide fuel flow to boilers to create heat or steam. Excess digester gas must be measured before it is flared. This gas reuse greatly reduces energy costs for the plant and reduces greenhouse gas emissions to the environment. Similarly, landfills need flow meters to measure flare gas or assist in creating their own electricity to feed back to the grid. These facilities may also participate in carbon credit programs that are verified by the flow measurement.
Scrubbers are essential in gasification processes, because they remove odors, pollutants, acid gases and chemical wastes from biogas. Accurate level monitoring of the scrubbing water calls for a control that can automatically feed the correct amount of make-up water to the recycle reservoir either continuously or on a periodic basis. The level monitoring device for water-out control should be equipped with a level alarm.
Guided wave radar (GWR), such as the Eclipse® Model 706, or an ultrasonic transmitter can provide a reliable continuous level control solution. A float level switch, such as the Tuffy® II, or an ultrasonic level switch is recommended when point level control is required.
In the U.S., hundreds of landfills recover methane, which forms when waste decomposes in low-oxygen conditions. A landfill gas-to-energy system consists of a series of wells drilled into the landfill. A piping system connects the wells and collects the biogas.
As biogas emerges from a digester or a landfill, it is saturated with water that causes corrosion problems upon condensation. Dehydration systems using air, vacuum and desiccant processes to remove water typically include a holding tank for water drawn off the gas with a level control actuating a valve to vacate the tank at high level. Biogas is dehydrated according to the user’s specifications for maximum water content. Some uses, such as boiler fuel, require an extremely dry gas.
置換器發射器（例如E3Modulevel®或GWR技術）是本申請中最合適的連續電平控製，而置換器開關（例如A15頂部安裝的置換器開關）可以提供該應用所需的點電平控製。乐动体育下载
To learn more about how level and flow instruments are used in the renewable energy industry, check out next week’s post, or下載可再生能源技術公告的Magnetrol®儀器。
