Hog fuel is a made up of scrap wood, shavings, sawdust, bark, needles and contaminants such as rocks, dirt, ice and other materials that lower BTU content. It is used as fuel in modern energy plants where it supplements fossil fuels like oil and natural gas.
The moisture content of hog fuel can vary widely, affecting its burning efficiency. It is very important that the operator is aware of the moisture content of the feedstock at all times so that the air/fuel ratio of the boiler can be controlled with real time information. Hog fuel moisture content typically varies from 30 to 65 percent. The average pound of dry wood has a BTU content of between 8600 to 9050. The average hog fuel content is approximately 5500 BTU per pound.
A QuikCheck (NIR) bench-top analyzer may be used to evaluate moisture content of hog fuel at delivery.
In storage, piles of hog fuels can spontaneously combust if stored in warm environments for extended periods of time. Continuous temperature monitoring is essential to prevent incidents of spontaneous combustion. Thermal imaging cameras from Process Sensors Corporation are employed as an “active” safety system to alert operators if heat production from oxidation is higher than heat dissipation.
Prior to the furnace or boiler, an MCT460-WP (NIR) transmitter is typically mounted on the infeed conveyor, at a location shortly after the hog fuel has been turned over (for example, after the product has transferred from one belt to another). This helps to ensure that the moisture measurement is representative of the bulk hog fuel. The MCT460-WP transmits real-time moisture measurements to the control room, allowing the user to monitor the moisture content going into the boiler, adjust boiler parameters and log historical data.
Hog fuel is purchased by weight; however, the moisture content of hog fuel reduces its value. At 65% moisture, hog fuel is about 60% more valuable than hog fuel at 30% moisture.
For many hog fuel users, it is a byproduct of their operations, so hog fuel cost may not be important, but furnace control is. Without good moisture measurement of incoming hog fuel, air flow, temperature and throughput cannot be optimized. This requires excess fuel usage and drives up operating costs.
To learn more about how we can optimize your hog fuel production, please fill out the contact form below.