Preparation and Characterization of Physicochemical Properties of Spruce Cone Biochars Activated by CO2

Abstract

In this study the pyrolysis of Norway spruce cones, a lignocellulosic biomass was made. The biochar product was obtained by means of the physical activation method. CO2 was used as the activating gas. The surface properties of biochars were characterized by the nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM/EDS), X-ray fluorescence energy dispersion spectroscopy (ED-XRF), thermal analysis (TGA/DTA), infrared spectroscopy (ATR FT-IR), Raman spectroscopy and the Boehm’s titration method as well as the point of zero charge (pHpzc). The adsorption capacity and the possibility of ammonia desorption (TPD) were also examined. It has been shown that spruce cones can be successfully used as a cheap precursor of well-developed surface biochars, characterized by a large pore volume and good sorption properties. All obtained activated biochars exhibit a largely microporous structure and an acidic character surface. The investigated activated materials have the specific surface areas from 112 to 1181 m2 g−1. The maximum NH3 adsorption capacity of the activated biochar was determined to be 5.18 mg g−1 (88.22 mmol g−1) at 0 °C. These results indicate the applicability of spruce cones as a cheap precursor for the sustainable production of the cost-effective and environmentally friendly biochar adsorbent.

Effect of pyrolysis temperature and hydrothermal activation on structure, physicochemical, thermal and dye adsorption characteristics of the biocarbons

“…One of the main problems of wastewater treatment is dyes and heavy metals removal. [14,15] Dyes are synthetic or natural compounds characterized by complex, aromatic structures of the molecules. They are considered toxic, carcinogenic, non-biodegradable, and environmentally dangerous substances, therefore, their removal from wastewater and water is a very important undertaking.…”

“…[17,18] Properties of biocarbons depend on the type of initial material, type of activating factor and conditions of the pyrolysis process. [1,2,5,14,19] It should be noted that biomass, being a common and readily available waste material, is an excellent source of carbon that can be efficiently converted into biocarbon. However, it should be also remembered that the properties of biochars depend on the characteristics of the starting material, and, as biomass is waste, they vary.…”

“…Wastewater from the textile, chemical and tanning industries as well as artificial fertilizers and pesticides pose a serious threat to the aquatic environment. One of the main problems of wastewater treatment is dyes and heavy metals removal [14,15] . Dyes are synthetic or natural compounds characterized by complex, aromatic structures of the molecules.…”

“…Properties of biocarbons depend on the type of initial material, type of activating factor and conditions of the pyrolysis process [1,2,5,14,19] . It should be noted that biomass, being a common and readily available waste material, is an excellent source of carbon that can be efficiently converted into biocarbon.…”

Preparation of Activated Biocarbons from Cones and their Potential Application for Adsorption of Antibiotics (Tetracycline)

“…[23,24] Adsorption has become a common method because it can remove both organic and inorganic contaminants. [24][25][26][27][28] However, for efficient and costeffective removal of contaminants using this technique, it is important to select appropriate adsorbents. Such materials can be biocarbons with developed porosity.…”