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Title: Data-driven acoustic measurement of moisture content in flowing biomass

Journal Article · · Machine Learning with Applications

Measuring the moisture content in flowing biomass is critical to processes such as liquid biofuel conversion, such as biogasoline, biodiesel, bio jet kerosene, etc. However, biomass tends to flow in aggregates, which results in significant inhomogeneities in the amount of biomass flowing in front of a sensor at a given time, and there can be significant overlap in the material properties of dry vs wet biomass, leading to poor signal-to-noise ratio. We present a technique for identifying biomass moisture content using a series of acoustic pitch-catch measurements to quantify the sound speed and acoustic amplitude through the biomass, in conjunction with classical machine learning techniques, including Naive Bayes, Random Forest, and K-Nearest Neighbors classification. We amplify the differences between the acoustic measurements in different moisture levels by collecting a series of pulse-echo measurements, which we sort in order of ascending sound speed. We test the accuracy of the technique on experimentally-prepared batches of corn stover biomass with specified moisture levels and measure the average error in the estimated moisture level as a function of the number of pitch-catch measurements used. We observe average estimation errors as low as 6.7% by increasing the number of measurements and optimizing the hyperparameters. This work presents a novel method determining moisture content in flowing biomass with inhomogeneous flow. Additionally, this technique has application in optimizing biomass conversion processes, as well as other fields including, paper production, natural fiber processing, and mineral extraction.

Research Organization:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Office of Sustainable Transportation. Bioenergy Technologies Office (BETO); USDOE National Nuclear Security Administration (NNSA)
Grant/Contract Number:
89233218CNA000001; EE0034978
OSTI ID:
2005842
Report Number(s):
LA-UR-23-21176
Journal Information:
Machine Learning with Applications, Vol. 13; ISSN 2666-8270
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English

References (16)

High dielectric constant microwave probes for sensing soil moisture journal January 1974
Predicting moisture content and density distribution of Scots pine by microwave scanning of sawn timber II: evaluation of models generated on a pixel level journal February 2006
In-line microwave reflection measurement technique for determining moisture content of biomass material journal December 2019
A resistive probe moisture sensor for tropical root crops and vegetables journal May 1987
Sustainable acoustic absorbers from the biomass journal May 2011
Measurement of Cereal Moisture Content with an Experimental Acoustic Device journal January 2012
An Acoustic Method for Soil Moisture Measurement journal August 2004
Moisture effects on the dielectric properties of soils journal January 2001
Using cereal grain permittivity for sensing moisture content journal June 2000
Machine learning in acoustics: Theory and applications journal November 2019
Acoustic on-line grain moisture meter journal June 2006
Microwave sensing of moisture in flowing biomass pellets journal March 2017
Random Forests journal January 2001
Fractional yield and moisture of corn stover biomass produced in the Northern US Corn Belt journal August 2007
Low frequency microwave technique for on-line measurement of moisture journal December 2000
Acoustic Measurements of Soil Pipeflow and Internal Erosion journal May 2012

Figures / Tables (7)