When biomass is heated in the absence of oxygen, it decomposes into a mixture of hydrogen and carbon monoxide gases known as synthesis gas or “syngas.” Like natural gas, syngas is a valuable energy asset that can fuel boilers, generators, and furnaces, or serve as a feedstock.
This blog post, part of the Magnetrol® series on modular skid systems, explores the way biomass can be converted to gas using biomass gasifier skids and the level measurement solutions to monitor them.
Skid Configurations
Biomass is frequently processed using a biomass-to-syngas skid. In this entrained-flow type of gasifier, the steam and oxygen reactants flow uni-directionally upwards through the gasifier until high temperature finished syngas exits the reactor. The biomass feedstock enters the gasifier for conversion into synthesis gas. The syngas exits the biomass gasifier and is then routed to a gas cooler to recover any useable thermal energy. The gas is then cleaned and routed to an application or to storage.
Level Measurement Solutions
Below are common level measurement solutions for biomass gasifier skids and level measurement solutions for these applications:
- Hopper Level: Solid biomass feedstock is ground into small particles and fed into a biomass hopper from where it is conveyed to the gasifier. High and low level detection in the hopper maintains correct hopper level. For continuous level, the Eclipse® Model 706 guided wave radar transmitter is recommended. For point level, the Solitel® vibrating rod level transmitter is recommended.
- Gas Cooler: The raw syngas leaving the gasifier enters a gas cooling unit to reduce the temperature. Level controls monitoring the coolant within the cooler body serve as a leak detection system for the gas cooler. For continuous level, the ECLIPSE Model 706 guided wave radar transmitter is recommended. For point level, the Model B35 external cage float level switch or the Echotel® 961/962 ultrasonic level switch are recommended.
- Scrubbers: Impurities in the syngas—including trace minerals, particulates, sulfur, mercury, and unconverted carbon—are reduced to very low levels by using gas scrubbers. Accurate level monitoring maintains correct amounts of scrubber make-up water. For continuous level, the ECLIPSE Model 706 guided wave radar transmitter is recommended. For point level, the Model B35 external cage float level switch or the ECHOTEL 961/962 ultrasonic level switch are recommended.
