Acoustic chemometric prediction of total solids in bioslurry: A full-scale feasibility study for on-line biogas process monitoring

Abstract

Dry matter is an important process control parameter in the bioconversion application field. Acoustic chemometrics, as a Process Analytical Technology (PAT) modality for quantitative characterisation of dry matter in complex bioslurry systems (biogas fermentation), has not been successful despite several earlier dedicated attempts. A fullscale feasibility study based on standard addition experiments involving natural plant biomass was conducted using multivariate calibration (Partial Least Squares Regression, PLS-R) of acoustic signatures against dry matter content (total solids, TS). Prediction performance of the optimised process implementation was evaluated using independent test set validation, with estimates of accuracy (slope of predicted vs. reference values) and precision (squared correlation coefficient, r 2 ) of 0.94 and 0.97 respectively, with RMSEP of 0.32 % w/w (RMSEP rel = 3.86 %) in the range of 5.8 -10.8 % w/w dry matter. Based on these excellent prediction performance measures, it is concluded that acoustic chemometrics has come of age as a full grown PAT approach for on-line monitoring of dry matter (TS) in complex bioslurry, with a promising application potential in other biomass processing industries as well.

Online acoustic chemometric monitoring of fish feed pellet velocity in a pneumatic conveying system

“…The acoustic response to varying pellet velocities is shown in Figure 3 where acoustic frequency spectra from experiments with three different pellet velocities (17,25 and 36 m/s) show the direct relationship between acoustic frequency response and the pellet velocities. The acoustic frequency distribution is different in the three spectra.…”

“…The publications span a broad variety of industrial applications demonstrating the potential of the method [21][22][23][24][25][26][27]29]. These applications include studies on liquids, particulate materials, and slurries.…”

“…Acoustic chemometrics is a non-invasive on-line PAT technique which has entered a new phase in recent years. The recent advances offer vast opportunities for research and development in areas of technological applications which are documented in the literature [21][22][23][24][25]. Mass flow rates of material transported in pneumatic conveying lines in dilute phase [21] and dense phase [26] systems have previously been investigated.…”

Acoustic Chemometric At-Line Characterization for Monitoring Particle Size Fractions in Pneumatically Conveyed Biomass

“…In recent years, the applications of acoustic chemometrics (a.c.) and acoustic measurement span many research and industrial sectors and process monitoring implementation scenarios Halstensen and Esbensen 2000;Tallon and Davies 2001;Huang et al 2003;Halstensen et al 2006;Albion et al 2007a;Albion et al 2007b;Albion et al 2008;Halstensen and Esbensen 2010;Ihunegbo et al 2012). The basis for the acoustic measurement concept is the use of process noise (passive acoustic emission), which is an indirect representation of numerous industrial product characteristics and processes states Halstensen et al 1998;Halstensen and Esbensen 2000;Tallon and Davies 2001;Huang et al 2003;Halstensen et al 2006;Albion et al 2007a;Albion et al 2007b;Albion et al 2008;Halstensen and Esbensen 2010;Ihunegbo et al 2012).…”

Acoustic chemometrics for on-line monitoring and end-point determination of fluidised bed drying

“…In this regard, the calculated frequency spectra are thus related to the physical/chemical properties of the investigated materials/test system. In recent years, application of acoustic chemometric for various research and industrial process studies has increased [7,[12][13][14][15][16][17]24]. The advantages of acoustic chemometrics as compared to other on-line methods are numerous and some of them can be summarised as follows:…”