Gasification biochar as a valuable by-product for carbon sequestration and soil amendment

Abstract

Soil quality improvement a b s t r a c tThermal gasification of various biomass residues is a promising technology for combining bioenergy production with soil fertility management through the application of the resulting biochar as soil amendment. In this study, we investigated gasification biochar (GB) materials originating from two major global biomass fuels: straw gasification biochar (SGB) and wood gasification biochar (WGB), produced by a Low Temperature Circulating Fluidized Bed gasifier (LT-CFB) and a TwoStage gasifier, respectively, optimized for energy conversion. Stability of carbon in GB against microbial degradation was assessed in a shortterm soil incubation study and compared to the traditional practice of direct incorporation of cereal straw. The GBs were chemically and physically characterized to evaluate their potential to improve soil quality parameters. After 110 days of incubation, about 3% of the added GB carbon was respired as CO 2 , compared to 80% of the straw carbon added. The stability of GB was also confirmed by low H/C and O/C atomic ratios with lowest values for WGB (H/C 0.12 and O/C 0.10). The soil application of GBs exhibited a liming effect increasing the soil pH from ca 8 to 9. Results from scanning electron microscopy and BET analyses showed high porosity and specific surface area of both GBs, indicating a high potential to increase important soil quality parameters such as soil structure, nutrient and water retention, especially for WGB. These results seem promising regarding the possibility to combine an efficient bioenergy production with various soil aspects such as carbon sequestration and soil quality improvements.

Climate effect of an integrated wheat production and bioenergy system with Low Temperature Circulating Fluidized Bed gasifier

“…Moreover, in addition to the recycling of valuable nutrients, the use of ash containing recalcitrant carbon fractions could maintain or even increase soil organic carbon stocks and thus contribute to carbon sequestration as suggested by Brandao et al [13]. Recently Veronika et al [14] contributed to this discussion by experimental results indicate that gasification biochar is very stable in soil and has good potential for a longterm carbon sequestration in soil.…”

Biochar for Soil Improvement: Evaluation of Biochar from Gasification and Slow Pyrolysis

“…Some literature exists on the use of biochar as a co-product from biomass gasifiers [58,59]. The results from these studies seem promising regarding the possibility to combine an efficient bioenergy production with carbon sequestration and soil quality improvements.…”

“…The results from these studies seem promising regarding the possibility to combine an efficient bioenergy production with carbon sequestration and soil quality improvements. Low temperature gasification offers an option to use novel residual biomass streams from agriculture activities with low ash melting temperatures, compared with conventional combustion processes [59]. However, more information is needed for a thorough evaluation.…”

Evaluacion del uso de residuos organicos para la produccion de biochar y su aplicacion como enmienda organica

“…De igual forma, diversos estudios han reportado altas concentraciones de HAP's en biochars producidos a partir de madera y mediante procesos de gasificación (Hansen et al, 2015).…”

“…Las altas concentraciones de HAP's en el Hollín HM se corresponden con la elevada temperatura con la que este material fue producido y con las investigaciones previas en las que se han observado altas concentraciones de HAP's en biochars producidos a partir de madera mediante procesos de gasificación (Hansen et al, 2015).…”