Choosing Physical, Physicochemical and Chemical Methods of Pre-Treating Lignocellulosic Wastes to Repurpose into Solid Fuels

Abstract

Various methods of physical, chemical and combined physicochemical pre-treatments for lignocellulosic biomass waste valorisation to value-added feedstock/solid fuels for downstream processes in chemical industries have been reviewed. The relevant literature was scrutinized for lignocellulosic waste applicability in advanced thermochemical treatments for either energy or liquid fuels. By altering the overall naturally occurring bio-polymeric matrix of lignocellulosic biomass waste, individual components such as cellulose, hemicellulose and lignin can be accessed for numerous downstream processes such as pyrolysis, gasification and catalytic upgrading to value-added products such as low carbon energy. Assessing the appropriate lignocellulosic pre-treatment technology is critical to suit the downstream process of both small- and large-scale operations. The cost to operate the process (temperature, pressure or energy constraints), the physical and chemical structure of the feedstock after pre-treatment (decomposition/degradation, removal of inorganic components or organic solubilization) or the ability to scale up the pre-treating process must be considered so that the true value in the use of bio-renewable waste can be revealed.

Towards Circular Economy Solutions for The Management of Rice Processing Residues to Bioenergy via Gasification

“…When it comes to utilization of lignocellulosic biomass residues in FB gasification, in order to align well with the EU policies related to climate change, resource efficiency, environmental protection, and biomass residues need to be upgraded in terms of both energy and material content closed loops [13].…”

“…When it comes to utilization of lignocellulosic biomass residues in FB gasification, in order to align well with the EU policies related to climate change, resource efficiency, environmental protection, and biomass residues need to be upgraded in terms of both energy and material content closed loops [13]. Existing technologies for the exploitation of the energy content of gaseous fuels are the internal combustion engines (ICEs), gas turbines (GT) while some are in the development stage (fuel cells).…”

“…Some of the advantages of microwave over conventional heating include better process control and reproducibility, flexibility for different applications, short extraction times (minutes instead of hours), higher analyte recovery levels (between 80 and 98%), lower volume of solvents used, [42], and considerably shorter heavy metal extraction time [43][44][45][46]. However, microwave technologies are currently not scalable for industrial use [13].…”

“…Agricultural and agro-industrial wastes can be effectively used as alternative energy sources, usually after appropriate pretreatments [13] to make them or problematic solid fuels when valorized towards energy production. Using wastes from agriculture for energy generation to satisfy local energy needs help in protecting the environment, while providing a solution for the energy crisis peaks in energy demand of rural areas and resilience of rural areas of countries under development, which are heavily relying on agriculture.…”

Big problem, little answer: overcoming bed agglomeration and reactor slagging during the gasification of barley straw under continuous operation

“…This is important especially as when waste-toenergy production technologies are coupled with Carbon Capture and Storage (CCS) or Utilisation (CCSU) technologies, leading to net CO 2 emissions being negated. 3,4 Repurposing such wastes as alternative and 'green' solid fuels are further benecial to the environment by releasing far lower emissions (CO 2 , NO x , SO x and heavy metals) and various other pollutants when compared to traditional fossil based fuels such as coal. 1,3,[5][6][7] Currently, woody biomass is the dominant variant used for generating energy via combustion, as a result the demand and the cost has increased over recent years.…”