New model for ecological assessment of comminution process in energy biomass processing chain

Abstract

Acquiring energy contained in the biomass structure requires its prior appropriate preparation. These treatments require some energy inputs, which significantly affects the reduction of the energy and environmental balance in the entire life cycle of energy biomass processing chain. In connection with the above, the aim of the work was to develop a methodology for ecological assessment of biomass grinding in the processing chain for energy purposes. The research problem was formulated as follows: is it possible to create an assessment model that takes into account the environmental inputs and benefits of the grinding process of biomass intended for further energy use (combustion); how the control variables of the grinding machine affect the ecological evaluation of the process. In response to the research problem, the original index of ecological assessment of the biomass grinding process was developed. The model was verified by assessing the process of rice and maize grinding on a real object - a five-disc mill, for various settings of grinding discs speed. It was found that the developed ecological assessment model allows comparison of grinding processes and indication of the process with a more favorable CO2 emission balance and its values depend on the control parameters of the mill.

A New Model for Environmental Assessment of the Comminution Process in the Chain of Biomass Energy Processing †

“…Equivalent CO 2 emissions in the grinding process are closely related to its energy consumption [45][46][47][48][49]. Considering a system whose aim is to reduce the process, product, machine, and environmental impacts (e.g., by eliminating CO 2 ) while maintaining its higher efficiency and providing a high-quality product as well as energy efficiency, the integrated energy purpose of product (for example, combustion) sustainable CO 2 emissions index can be expressed as [54,55]…”

“…Additionally, in industrial emission monitoring systems, CO 2 emission indexes from biomass are treated as zero [57]. These should be reduced by equivalent CO 2 emissions related to energy consumption in the grinding process X RCO 2 in accordance with the equation on environmental benefits [54]:…”

“…The results of previous research show that the energy properties of biomass (especially its digestibility, exergy) change depending on the degree of fineness (post-grinding particle size) [46,55,58]; therefore, it was accepted that emissions from the combustion of ground biomass X BCO 2 are expressed as the sum of emissions from the combustion of biomass divided into size classes, according to the equation [54]:…”

“…where The emissions involved in electricity consumption during grinding are described as follows [54]:…”

“…The research problem is formulated as follows: Is it possible to create an assessment model that takes into account the environmental inputs and benefits of the grinding process of biomass intended for further energy use (for example combustion)? How do the control variables (the angular velocity of the cutting edges of working elements) of the grinding machine affect the carbon dioxide emissions of the process [54]?…”