Kraft Lignin as an Additive in Pine and Eucalyptus Particle Composition for Briquette Production

Abstract

The objective of this study was to evaluate the properties of briquettes produced with different proportions of pine and eucalyptus wood, as well as to characterize the potential of kraft lignin as an additive in the composition of briquettes for energy generation. The treatments differed from one another in the pine and eucalyptus wood particle ratios (0, 25, 50, 75 and 100%), as well as for the kraft lignin content (0, 2, 4, 6, 8, 10, and 12%). The biomasses were characterized by their physical and chemical properties, and briquette properties were evaluated according to apparent density, lower calorific value (LCV), energy density, and maximum burst load. The results showed an increase in the apparent density as the proportion of lignin and eucalyptus in the briquettes increased. The particle composition of the briquettes had a higher influence on the energy density increase compared to the addition of kraft lignin, being more significant in briquettes produced with higher proportions of eucalyptus. It was also observed that the addition of lignin increased the resistance to the rupture load, and that there was a specific value at which this resistance was higher (at 7% or 11% of lignin, depending on the proportion of particles). Additionally, the briquettes made with 100% pine achieved greater mechanical resistance. In general, kraft lignin presented good potential for use as a briquette additive, contributing to improved energy and mechanical properties.

Recovering Wood Waste to Produce Briquettes Enriched with Commercial Kraft Lignin

“…Regarding to the kraft lignin composition, it is possible to verify that the studied lignin in this research has similar percentage of carbon (49.8% -61.8%), hydrogen (5.0% -6.5%), nitrogen (0.1% -1.3%), but lower oxygen content (29.2% -37.9%) and significantly higher content of sulfur (0.8% -2.5%) [29] [85] [86] [87]. This information and the higher ash content directly influence in the lignin purity and energy generation.…”

“…The purity is also related to the acid insoluble (Klason lignin) and soluble lignin presented in the binder material. Compared to Zhou and Lu [86] and Boschetti et al [29] the studied kraft lignin used in this research is more impure, presenting lower contents of total lignin on its composition. However, the carbohydrates content presented is lower than other studies [85] [86] [87].…”

“…Boschetti et al [29] studying Hymenolobium petraeum Ducke, Eucalyptus spp., and Pinus spp. briquettes also found similar results, proving that 6% of impregnated Kraft lignin gives better bulk density and rupture modulus properties.…”

“…The worldwide lignin production is approximately 50 million tons [31] by-product have distinct adhesive characteristics and may be used as a densification binder [29]. The use of lignin as binder is relatively new and studies of this application as a binder have been done recently [28] [29] [32]- [38].…”

Binderless, All-Lignin Briquette from Black Liquor Waste: Isolation, Purification, and Characterization

“…Lignin is reported to be used as a binder in briquette application [ 1 , 2 , 19 , 20 , 21 , 22 ]. Previous research studies utilized lignin as a binder for anthracite-based briquette [ 23 ], organic municipal solid waste [ 24 ], and wood [ 4 , 25 ]. It was also reported that lignin can serve both as a binder and fuel, improving both the physical and heat properties of the briquette.…”