Hydrothermal carbonization of coniferous biomass: Effect of process parameters on mass and energy yields

Influence of reaction conditions and feedstock on hydrochar properties

“…In recent years, different types of complex biomass feedstock [5], including woody biomass [6][7][8][9][10], herbaceous biomass [11][12][13][14][15] and fruit biomass [16][17][18][19], have been used for hydrothermal carbonization. These studies help to understand the HTC process and the hydrochar properties.…”

“…It has shown that the hydrochar properties highly depend on reaction temperature, residence time and feedstock type [3,20]. At the same time, there is a certain effect of water to biomass ratio on the hydrochar yield, which was discussed in some references only [10,11,16]. These studies also have revealed that different lignocellulose materials are mainly composed of hemicellulose, cellulose, lignin and some extractives, which may experience similar reactions, including hydrolysis, dehydration, decarboxylation, polymerization, aromatization, and solid-solid reaction [3,4,13].…”

Hydrothermal Carbonization of Deciduous Biomass (<i>Alnus incana</i>) and Pelletization Prospects

“…(2017) Hydrothermal Carbonization of Journal of Sustainable Bioenergy Systems such as lack of uniformity, high moisture content and low mass density, hinder its wider applicability. However, pre-treatment and/or modification such as dry and wet torrefaction of biomass are promising solutions to the aforementioned difficulties [1].…”

“…Hydrothermal carbonization (HTC), also known as wet pyrolysis, is a thermochemical treatment of biomass based materials taking place in the presence of water at moderate temperature ranging from 180˚C to 260˚C [1] [2] [3]. HTC may be more suitable for raw materials with varying moisture percentage because reaction takes place in a wet environment and eliminates the pre-drying phase which could potentially eliminate the energy intensive phase [4].…”

“…As the HTC involves a pressurized reaction environment in saturated water, it is significantly different than traditional dry torrefaction where biomass is pre-dried and then torrefied in the dry and oxygen deficient environment. However, the final product, hydrochar, is found to be homogeneous compared to raw material and similar to torrefied biomass [1] [5]. According to the study by [6], −OH groups in biomass are partly removed by dehydration reaction during wet pyrolysis, which reduces its capacity to absorb water, thus, making the final product more hydrophobic than the raw material is.…”