Torrefaction as a Pretreatment Technology for Chlorine Elimination from Biomass: A Case Study Using Eucalyptus globulus Labill

Abstract

The recognition of the effects of fossil fuel consumption resulted in several agreements, legislation, and projects focusing on the minimization of impacts caused. Biomass is a versatile energy source. Eucalyptus is a fast-growing crop, mainly used by the pulp and paper industry. Torrefaction is a thermochemical conversion process that can improve biomass fuel properties, enabling its use in the energy sector. However, correct management of biomass is crucial for the sustainability of this process. Torrefaction can also be used to eliminate some elements that can hinder subsequent conversion processes. One example is chlorine, which, during combustion or gasification processes, can form hydrochloric acid that leads to corrosion of metal surfaces. In this context, this research aimed to determine the temperature at which chlorine is eliminated during torrefaction process. For this purpose, several tests were performed at different temperatures and residence times. All samples were analyzed before and after the process, and were characterized by proximate and elemental analysis, calorimetry, and chlorine titration. The analysis showed that, even for the lowest torrefaction temperature used, chlorine content was already below the detection value, showing that, even at lower temperatures, thermal treatment is an efficient technique for the elimination of chlorine from biomass.

An Assessment of Potential Resources for Biomass Energy in Nigeria

“…The end products of pyrolysis are biochar, bio-oil, and gases. The products obtained from pyrolysis will depend on the operating temperature, solid residence time, reactor type, and heating rates of the process [268]. Torrefaction and carbonization are also thermochemical processes linked with pyrolysis.…”

Characterization of Cytisus striatus (Hill) Rothm.: Waste Biomass Energy Recovery as a Measure to Reduce the Risk of Rural Fires

“…For this reason, the creation of value chains that can add some value to the residual materials resulting from the cleaning operations of the C. striatus stands presents itself as a possibility that could contribute for the reduction of costs associated with the control operations [23][24][25]-for example, by incorporating these waste materials as raw materials in the production of biomass pellets or in the production of torrefied biomass [26][27][28]. These possibilities, in addition to the introduction of a circular economy component to the rural fire prevention process, would counterbalance the fact that currently these targets are no longer used for traditional practices, such as accommodation of livestock or in the production of rudimentary brooms, or even used as firewood [29][30][31].…”

Carbon Sequestration Potential of Forest Invasive Species: A Case Study with Acacia dealbata Link

“…The physico-chemical properties of A. dealbata wood, as well as other invasive forest species, such as A. melanoxylon, Robinia pseudoacacia L., and E. globulus, with non-acceptable parameters for the pulp industry, are already well-known. There are several reporting the possibility of using this residual biomass for energy recovery, such as those presented by Sá [32][33][34], especially if this recovery is associated to energy densification processes, such as torrefaction or pyrolysis. This seems to be an interesting perspective since even when there is no possibility to use the charcoals for energy purposes, those can be stored in the soil, sequestrating CO 2 [35][36][37].…”