Pelletization of biomass reduces its handling costs, and results in a fuel

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The Two-Stage Gasifier was operated for several weeks (465 hours) and of these 190 hours continuously. The gasifier is operated automatically unattended day and night, and only small adjustments of the feeding rate were necessary once or twice a day. The operation was successful, and the output as expected. The engine operated well on the produced gas, and no deposits were observed in the engine afterwards. The bag house filter was an excellent and well operating gas cleaning system. Small amounts of deposits consisting of salts and carbonates were observed in the hot gas heat exchangers. The top of the reactor had to be constructed in some other material.

Torrefaction is a thermo-chemical conversion process improving the handling, storage and combustion properties of wood. To save storage space and transportation costs, it can be compressed into fuel pellets of high physical and energetic density. The resulting pellets are relatively resistant to moisture uptake, microbiological decay and easy to comminute into small particles. The present study focused on the pelletizing properties of spruce torrefied at 250, 275 and 300 °C. The changes in composition were characterized by infrared spectroscopy and chemical analysis. The pelletizing properties were determined using a single pellet press and pellet stability was determined by compression testing. The bonding mechanism in the pellets was studied by fracture surface analysis using scanning electron microscopy. The composition of the wood changed drastically under torrefaction, with hemicelluloses being most sensitive to thermal degradation. The chemical changes had a negative impact, both on the pelletizing process and the pellet properties. Torrefaction resulted in higher friction in the press channel of the pellet press and low compression strength of the pellets. Fracture surface analysis revealed a cohesive failure mechanism due to strong inter-particle bonding in spruce pellets as a resulting from a plastic flow of the amorphous wood polymers, forming solid polymer bridges between adjacent particles. Fracture surfaces of pellets made from torrefied spruce possessed gaps and voids between adjacent particles due to a spring back effect after pelletization. They showed no signs of inter-particle polymer bridges indicating that bonding is likely limited to Van der Waals forces and mechanical fiber interlocking.

In this work, we provide detailed information on the change in product distribution and bio-oil 12 quality during extended feeding of biomass derived fast pyrolysis vapors over ZSM-5. The effect 13 of catalyst deactivation by coking on the resulting oil product characteristics was clarified in order 14 to determine when the vapor upgrading should be stopped and the regeneration initiated. Obtaining 15 a stable catalytic fast pyrolysis (CFP) oil while maintaining good energy recovery is important 16 within the context of potential co-processing these oils with petroleum feedstocks via FCC or 17 hydrotreatment of the whole CFP oil. 18 Wheat straw derived fast pyrolysis vapors were upgraded in an ex-situ fixed bed reactor containing 19 a steamed ZSM-5 catalyst at 500 °C. Oils were collected both for runs starting the upgrading over 20

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.

13The purpose of the study was to investigate the influence of torrefaction on the grindability of wheat straw. 14 Straw samples were torrefied at temperatures between 200 ˚C to 300 ˚C and with residence times between 0.5 to 15 3 hours. Spectroscopic information obtained from ATR-FTIR indicated that below 200 ˚C there was no obvious 16 structural change of the wheat straw. At 200-250 ˚C hemicelluloses started to decompose and were totally 17 degraded when torrefied at 300 ˚C for 2 hours, while cellulose and lignin began to decompose at about 270-300 18 ˚C. Tensile failure strength and strain energy of oven dried wheat straw and torrefied wheat straw showed a clear 19 reduction with increasing torrefaction temperature. In addition, Hardgrove Grindability Index (HGI) of wheat 20Page 2 of 23 straw torrefied at different conditions was determined on a standard Hardgrove grinder. Both results showed an 21 improvement of grindability in the torrefaction temperature range 250-300 ˚C, which can be well explained by 22 the findings from FTIR analysis. At a torrefaction temperature of 260 ˚C and with a residence time of 2 hours, 23 wheat straw samples produced similar HGI values as coal (RUKUZN) with 0% moisture content. Under this 24 condition, the Anhydrous Weight Loss (AWL%) of the wheat straw sample was 30% on dry and ash free basis 25 (daf), and the higher heating value of the torrefied wheat straw was 24.2 MJ kg -1 (daf). The energy loss 26 compared to the original material was 15% (daf). 27