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The biochar is characterized by low surface area and, in order to their use as adsorbent it is possible to use the activation process that allows to liberate and to increase the pores of the surface, increasing its sorption capacity. In the present work the activation of the biochar produced in the pyrolysis of agroindustrial residue (fiber) of the green coconut was studied, being done with sodium carbonate (Na 2 CO 3 ) at high temperature. Biochar (BC) and activated biochar (ABC) were characterized and ABC was tested for use in the extraction of organic compounds present in the phenolic liquor, produced during the same pyrolysis process. The determination of the textural characteristics was done by N 2 adsorption-desorption isotherms, obtaining an area of 1130 m 2  g −1 for the ABC, being superior to the area of commercial activated coals, with a total volume of pores of 0.55 cm 3  g −1 . For the solid phase extraction (SPE) test, 500 mg of ABC were used in cartridges (equal to the commercial ones) obtaining a retention of about 100% of the organic compounds pre-existing in the sample, demonstrating the high adsorptive capacity of the activated biochar produced in this work. Desorption, as expected, had a lower performance than adsorption, being improved using ultrasonic bath, reaching values of the order of 40% recovery. [ABSTRACT FROM AUTHOR]

• Optimization of the pyrolysis of coconut fiber. • Characterization of the solid product generated by pyrolysis. • Qualitative and semi-quantitative analysis of the bio-oil sample. • Bio-oil evaluation as a source of chemical products with high added value. Pyrolysis of agroindustrial waste is an important way to add value to this material avoiding its discard in the environment. However, when residues are derived from oilseeds or similar, it is possible to find a large amount of fatty acid derivatives in the biomass and later in bio-oil composition. These compounds are not adequately thermo-degraded in pyrolysis processes, reducing the quality. Another common compound class and with a high added value present in bio-oils are phenols. In this work two forms of upgrading processes were performed in coconut fiber pyrolysis process. One of them is the alkaline extraction of coconut fiber bio-oil in order to produce a high acidic and a neutral fraction. The other upgrading process is a biomass pretreatment before the pyrolysis, using two different extraction techniques (Soxhlet and ultrasound). The two processes proved to be efficient and complimentary: in the first case, there was the pre-concentration of the phenols in a single fraction and in the second one, a great part of the fatty acids derivatives were removed from the bi-oil. These results indicate that the two techniques can be used to improve the quality of bio-oil produced by removing the free fatty acids from biomass and isolating compounds with high added value (in the case of phenols). [ABSTRACT FROM AUTHOR]