The performance and biomass yield of the perennial energy plant Sida hermaphrodita (hereafter referred to as Sida) as a feedstock for biogas and solid fuel was evaluated throughout one entire growing period at agricultural field conditions. A Sida plant development code was established to allow comparison of the plant growth stages and biomass composition. Four scenarios were evaluated to determine the use of Sida biomass with regard to plant development and harvest time: (i) one harvest for solid fuel only; (ii) one harvest for biogas production only; (iii) one harvest for biogas production, followed by a harvest of the regrown biomass for solid fuel; and (iv) two consecutive harvests for biogas production. To determine Sida's value as a feedstock for combustion, we assessed the caloric value, the ash quality, and melting point with regard to DIN EN ISO norms. The results showed highest total dry biomass yields of max. 25 t ha À1, whereas the highest dry matter of 70% to 80% was obtained at the end of the growing period. Scenario (i) clearly indicated the highest energy recovery, accounting for 439 288 MJ ha À1 ; the energy recovery of the four scenarios from highest to lowest followed this order: (i) ≫ (iii) ≫ (iv) > (ii). Analysis of the Sida ashes showed a high melting point of >1500°C, associated with a net calorific value of 16.5-17.2 MJ kg À1 . All prerequisites for DIN EN ISO norms were achieved, indicating Sida's advantage as a solid energy carrier without any post-treatment after harvesting. Cell wall analysis of the stems showed a constant lignin content after sampling week 16 (July), whereas cellulose had already reached a plateau in sampling week 4 (April). The results highlight Sida as a promising woody, perennial plant, providing biomass for flexible and multipurpose energy applications.

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The objective of this work was to investigate the influence of feedstock on the release of trace elements during gasification. Therefore, different types of woody biomass and biomass residues (shells) were thermochemically converted in an atmospheric flow channel reactor furnace at different temperatures (900, 1200, and 1400 °C) under gasification-like conditions. For the determination of the composition of the hot gas, the flow channel reactor was coupled to a molecular beam mass spectrometer. The focus was set on the release of alkali metals (K and Na) and non-metals (S, Cl, and P), which are known for their high volatility and influence on the solid-and gas-phase chemistries, as well as the volatility of the other elements. The main gaseous species were 36 HCl + , 58 NaCl + , 74 KCl + , 64 SO 2 + , 60 COS + , and 63 PO 2 + . After quantification, the data set was correlated with the elemental composition of the biomass and likely release mechanisms are discussed.

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