Tools for estimating uncertainty in the sucrose balance
Cenicaña developed a methodology that allows establishing the reliability of the sucrose balance carried out in the mills and identifying the sources of errors that impact the manufacturing indicators, which contributes to an adequate quality management of the data used for management decision making.
The losses of sucrose in the sugarcane agribusiness can be attributed to three possible sources: those from pre-harvest practices, those that occur after cutting and / or harvest, and those that occur in the manufacturing process.
The latter are classified into certain or quantifiable (bagasse, cachaza and final honey) and indeterminate or non-quantifiable. All are subject to different analyzes that seek their reduction and control.
The four possible sources of indeterminate losses are:
- Apparent: caused by deviations in analytical metrics, errors in weighing and analytical equipment, sampling systems, existing materials and calculations.
- Investment: Chemical, microbiological and enzymatic.
- Physical: mechanical (leaks), trawls (in evaporation condensates and plugs) and effluents (by equipment washes).
- Thermal decomposition: heating and evaporation systems of juices.
Since 2012 Cenicaña works on the development of a tool with which the impact of apparent sources on undetermined losses can be quantified. This tends to demonstrate with objective evidence the reliability of the sucrose balance.
“It is a diagnostic and control tool, since once the deviations in the quantification metric of sucrose have been identified, they are corrected during the methodology implementation process and additional elements are given to the mill to focus its resources and make decisions towards the sources that produce them, ”says Sara Pereddo, a chemist at the Research Center.
The tool is called Estimation of the uncertainty of the sucrose balance and is composed of:
- Protocol to validate the methodologies used in the physicochemical analysis of the balance materials. Allow to evaluate the performance of the analysts in the daily routine in terms of repeatability and reproducibility, in turns and in the environmental conditions of the laboratory.
- Protocol to validate material sampling systems of the balance sheet in order to establish whether there is representativeness in the collected sample with respect to the variable composition of the material entering the process.
- Spreadsheets to estimate the validation attributes of the analytical methods, the uncertainty of the measurement of methods, instruments and manufacturing indicators of the sucrose balance.
The results obtained in a pilot mill allowed us to identify that the indeterminate losses from apparent sources represented between 33% and 51% of their indeterminate losses (% cane). The sources of greatest contribution were analytical methodologies and sampling systems.
Likewise, more recent analyzes using the tool in another pilot mill revealed a deficiency in representativeness of sampling systems and deviations in analytical methods, which transfer uncertainty to undetermined losses.
Both mills technologically updated their samplers and implemented corrective analytical practices to improve their performance. One of them managed to reduce its indeterminate losses by 0.2 percentage units of sucrose, with the minimization of those associated with apparent sources and thermal decomposition.
KEEP IN MIND
Cenicaña works in a complementary manner in the search for new tools for the diagnosis and quantification of other sources of indeterminate losses, such as those generated by thermal decomposition and evaporation drag. For this, a protocol was developed that allows quantifying and monitoring these losses and their relationship with process variables.
In Library Catalog: Job: Identification of sources of variation that contribute to indeterminate losses.