Pyrolysis bio-oils have great potential for the future use as biofuels and source of oxygenated chemicals. To optimize a pyrolysis process, detailed knowledge about the chemical composition of bio-oils is necessary. In recent years, high-resolution mass spectrometry (HRMS) has successfully been used to the characterization of pyrolysis bio-oils from lignocellulosic biomass. This method enabled to detect thousands of semivolatile and nonvolatile, high-molecular-weight bio-oil compounds and provided partial information about their structure. In this work, we used high-resolution orbitrap mass spectrometry to characterize semivolatile and nonvolatile, high-molecular-weight compounds of four bio-oils obtained from the ablative flash pyrolysis of different biomass sources. Before the analyses of these bio-oils, we analyzed model bio-oil compounds and commercially available bio-oil from fast pyrolysis of wood using positive-ion and negative-ion electrospray (ESI) and positive-ion and negative-ion atmospheric pressure chemical ionization (APCI) orbitrap mass spectrometry and compared the results. Based on this comparison, a combination of negative-ion ESI and APCI was found to be well suited for the characterization of pyrolysis bio-oils; these techniques were thus used for the study of bio-oils from different biomass sources and the obtained results were compared. In the studied bio-oils, mostly compounds with 1–8 oxygen atoms per molecule were detected and their degree of unsaturation (DBE) was about 1–10 (negative-ion ESI) and 1–17 (negative-ion APCI), respectively. Among the studied bio-oils, the differences were observed mostly in abundances of their major compounds (compound classes). The analyses of model bio-oil compounds brought valuable information about their behavior during the HRMS characterization of bio-oils. The presented results could help to improve the understanding of bio-oil composition and HRMS characterization of bio-oils and facilitate their further utilization

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In the field of soft robotics, pneumatic elements play an important role due to their sensitive and adaptive behavior. Nevertheless, the rapid prototyping of such actuators is still challenging since conventional 3D printers are not designed to fabricate airtight objects or to specify their bending behavior by combining materials of different stiffness. In order to address this challenge, a tool changing multi-material 3D printer has been constructed, which can be equipped with various print-heads fitted to the specific application. By alternately processing filaments with varying mechanical properties, a series of pneumatic elements was produced. The actuators were printed in thermoplastic polyurethane with shore hardness A70 for flexible parts and D65 for stiff parts. A novel procedure for the feature adaptation of the flow rate allowed the fabrication of vertically printed flexible membranes with a thickness of just 500 μm. This way the bending and expanding printed structures can all be actuated with a pressure of 100 kPa or less. Furthermore, a new kind of generic actuator that is customizable to specific tasks and can perform complex motion behavior was designed. All together, these actuators demonstrate the high potential of the developed platform for further research on and production of soft robotic elements and complex pressurized systems.

Fast pyrolysis is one of the most promising conversion processes for producing advanced biofuels, which can be used as substitute for fuel oils or chemicals. This article investigates the fast pyrolysis of two common types of biomass: a mixture of wheat/barley straw as typical agriculture residue and miscanthus as fast‐growing energy plant. All experiments were performed using an ablative hot surface reactor. It was observed that the product yields using wheat/barley straw and miscanthus are almost similar on mass basis. Noteworthy were the higher share on reaction water and a lower content of organics in the wheat/barley straw based pyrolysis bio‐oil. As a result of the high total water content (about 48 wt%), the bio‐oil separated into two phases: an upper aqueous phase and a bottom tarry phase. The amount of water‐soluble organic compounds contained in the aqueous phase of bio‐oil derived from miscanthus pyrolysis can be attributed to the higher amount of hemicellulose present in miscanthus compared to straw. The phase separation by decantation is not an efficient method to reduce the water content and total acid number because a part of valuable components will be lost to the aqueous phase. Significance The production of bio‐oils through fast pyrolysis technologies (mainly small scale and fluidized bed reactor systems) is widely described in literature. Therefore, the main objective of this work lies in the comparison of yield and quality of bio‐oils from different biomasses (straw as example for agricultural residues and miscanthus representing dedicated energy crops) in the same ablative hot surface reactor with a capacity of about 5 kg/hr.