Search

A process development unit (PDU) with 10 kg/h biomass capacity was designed, built and operated for fast pyrolysis of biomass. A twin-screw type reactor, in earlier applications used for treatment of coal, oil shale, oil sand and oil refinery residues, was used. Test campaigns with a variety of biomass types were performed. The results with hard-wood, softwood, wheat straw and wheat bran are reported and discussed in this paper, verifying the suitability of the twin screw reactor along with a new product recovery procedure. Liquid pyrolysis condensate, termed bio-oil, is the main product of FP and the yields are about 65 ± 10 wt.% for wood but only about 50 ± 10 wt.% for cereal straw, which is a typical result for all fast growing types of biomass with higher ash content. These product yields and properties are similar to those found for other FP reactor types and recovery procedures. [ABSTRACT FROM AUTHOR]

The feasibility of applying char obtained from wheat straw fast pyrolysis as charge carbon in an electric arc furnace (EAF) for the production of steel was investigated. Fast pyrolysis char represents a by-product which could be made available at reasonable cost. It is characterized by higher volatile content than slow pyrolysis char. Prior to application in the EAF, agglomerates with good strength characteristics were formed from the char by adding water and molasses as binder material. Minerals content, specifically potassium, was increased by this procedure which possibly limits the use in an EAF. The burn-off characteristics of these agglomerates in the EAF proved to be feasible. Further experiments in industrial scale can be recommended based on the results of this pilot study with special focus on balancing the minerals in the process. [ABSTRACT FROM AUTHOR]

Experiments with a process development unit for fast pyrolysis of biomass residues of 10 kg h −1 have been performed to quantify the impact of two different product recovery options. Wheat straw, miscanthus and scrap wood have been used as feedstock. A separate recovery of char increases the organic oil yield as compared to a combined recovery of char and organic condensate (OC). Furthermore, it allows for an alternative use of the byproduct char which represents an important product fraction for the high ash biomass residues under consideration. The char produced shows little advantage over its biomass precursor when considered as energy carrier due to its high ash content. Significant value can be added by demineralizing and activating the char. The potential to increase the economic feasibility of fast pyrolysis is shown by an assessment of the bioliq® process chain. [ABSTRACT FROM AUTHOR]

With the rapid growth in population and urbanization, a development in sustainable treatment of sewage sludge has become an urgent environmental concern globally. Lipid extraction has been investigated in order to valorize waste sewage sludge treatment through a pathway that leads to biodiesel. In this work, an integrated approach that combines lipid extraction of sewage sludge with hydrothermal liquefaction of the lipid-extracted sludge was studied in order to maximize valorization. The hydrothermal process was performed at temperatures ranging from 250 to 350 °C with 20 min. Regarding the bio-crude: below 300 °C, similar values are found with and without lipid-extraction, with the former variant containing more nitrogenated compounds stemming from Maillard reactions, while the latter more hydrocarbons; at 350 °C, higher bio-crude is obtained from raw sewage sludge owning to the conversion of lipids. Palmitic acid was selected as a model lipid to elucidate the role of lipids during the process, as well as to provide an improved understanding of the reaction network. Energy recovery reached values of 85.4% for hydrothermal liquefaction of sewage sludge and 98.3% for integrated approach considering the whole range of biofuel products. The energy consumption ratio was applied to estimate energetic efficiency for the combined process, making it possible to estimate the breakeven point of the process, plus the efficiency of both the hydrothermal process on its own in comparison with the combined option. Image 1 • Raw sewage sludge was submitted to lipid extraction. • Raw and lipid-extracted sewage sludge, and a model lipid were subjected to HTL. • Combined process (HTL + extraction) yielded 29.3 wt% liquid fuel-like products. • Combined process showed an energy recovery up to 98% based on HHV comparison. • Energy consumption ratio shows a significant temperature dependency. [ABSTRACT FROM AUTHOR]