Generating Power From Wood Waste With Solid Process Automation

Thirteen years. Throw out that used wooden furniture and it will sit in a landfill for thirteen years as it decomposes. Or, how about using it to power businesses’ energy needs? A wood waste gasification facility in England uses household wood waste— chipboard, broken furniture, building materials—to generate upwards of four megawatts of power. Throughout the generation process, Siemens process instrumentation helps monitor and control operations, increasing efficiency and reducing waste. Moving bedknobs to buckets Trucks arrive regularly at the facility, first driving over a weighbridge to get material totals and then unloading wood into stockpiles. An operator maneuvers a bucket loader to carry wood from the piles onto a conveyor entering the plant. Massive magnets remove any metals mixed in with the wood, followed by removal of rocks or other heavier debris using large fans, which blow the pieces or wood away from heavier materials. The ideal material size for optimal burning is 150 millimeters in any dimension, so wood must be sorted and pieces that are too large are sent to the reject woodpile.

Instrumentation precision The facility has 18 gassifiers, each monitored by a SITRANS TS temperature sensor and a SITRANS TH400 head mount temperature transmitter to ensure these high temperatures. Setup and programming of these devices was simple, and technicians had no trouble installing them and connecting each to the facility’s control system using Profibus PA industrial communications. SITRANS P DSIII digital pressure transmitters measure the amount of pressure in the main combustion area of the gassifiers. Measurement accuracy is crucial here, as too much pressure could be dangerous, while pressure that is too low is not suitable for the gassification process. These transmitters offer extreme reliability in this application, maintaining the process at its optimum level and keeping operators informed of exact pressure levels. With 140 tons of waste burned each day once the facility is operating at full capacity, operators need to remove the waste products left over after gasification. To do so, the resulting gas is cooled quickly to 25 °C (77 °F) and then moves through scrubbers. These scrubbers contain water that catches any tar particulates in the gas. Siemens guided wave radar transmitters continuously measure the level of water in the scrubbers. As well, in the scrubber condensate vessels, Siemens Pointek CLS200 capacitance level switches provide high level alarming, sending an alert if condensate levels get too high.

Download Tech-Spec for full application details.

Products used in solution https://www.finecontrols.co.uk/level-control/level-transmitters/siemens-milltronics-sitrans-lr560-radar-level-transmitter-7ml5440-

https://www.finecontrols.co.uk/pressure-control/pressure-transmitters/siemens-sitrans-p-ds-iii-pressure-transmitter

https://www.finecontrols.co.uk/level-control/level-switches/siemens-milltronics-pointek-cls-200-capacitance-level-switch