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The efficient use of renewable resources has become a driving force for the worldwide industry aiming to improve the competitiveness. Considering the available natural raw materials, the lignin present in the lignocellulosic biomass such as trees, is the unique natural polymer that presents aromatic rings in its constitution. In this way, this review details the structure of native lignin as well as the technical lignin, including information on the characteristics that this polymer must have for the most promissory applications as feedstock for bioproducts. Approximately 50 million tons of lignin are produced worldwide annually, of which 98% to 99% is incinerated to produce energy and steam in the pulp mills. Only a small fraction of the lignin, derived mainly from the sulfite pulp mill is recovered commercially in a biorefinery concept. There are many opportunities for producing high value-added products from technical lignin, mainly considering the pulp mills growing, and environmental restrictions using non-renewable raw materials. The currently trend have shown that technical lignin sources may also be used as feedstock for phenol derived products, technical carbons, fuels, and adhesives. On the other hand, there are some technological hurdles must be overcome to make these uses feasible.

Biorefinery is a new term to designate two main subjects, bioproducts and bioenergy, which play important roles towards a more bio-based society. This paper reviews the current biorefineries model as well as its future importance focusing on pulp mill opportunities. There are currently several different levels of integration in biorefineries which add to their sustainability, both economically and environmentally. Enzymatic pretreatment for biomass deconstruction aiming to release the polysaccharides is a key technology in the future biorefineries and it is currently the subject of intensive research.

Brazil has 8.51 million km 2 of territorial area and a tropical climate. In 2010, the occupation of the Brazilian soil consists of 20.8% pasture, 6.8% agriculture, 0.8% forested areas, 61.0% natural forests, and 9.7% other areas. In 2012, of the total area of the country 3.25% (27.65 million ha) is occupied by soy bean cultivation and 1% (8.5 million ha) by sugar cane cultivation. In 2012, the main cultivated species in the country were Eucalyptus spp. (71.0%), Pinus spp. (21.75%), Acacia mearnsii and Acacia mangium (2.12%), Hevea brasiliensis (2.36%), and Schizolobium amazonicum (1.22%). From 2004 to 2012, the planted forest area growth was 50.4%. The main factor that boosted this growth was the demand of the pulp and paper, followed by wood-based panels sector. It is also notable the development of new planted forests in Brazil for energy purposes. In recent decades, scientific and technological advance shave resulted in significant improvements in productivity, resistance to diseases, uniform degree of the forest plantations, wood quality etc. Among the most researched species are the ones belonging to Eucalyptus gender for having excellent adaptability to the edaphoclimatic conditions in the country. The current average productivity of Eucalyptus is of 40.7 m 3 /ha·year. In some regions of the country the average productivity of Eucalyptus has reached 100 m 3 /ha·year. The Brazilian forestry industry uses mainly planted forests, and the pulp and paper industry consumes only this type of wood. The pulp and wood panel sectors are more technologically advanced in relation to the other wood products sectors.