Fast Pyrolysis of Biomass Residues in a Twin-screw Mixing Reactor

Abstract

Fast pyrolysis is being increasingly applied in commercial plants worldwide. They run exclusively on woody biomass, which has favorable properties for conversion with fast pyrolysis. In order to increase the synergies of food production and the energetic and/or material use of biomass, it is desirable to utilize residues from agricultural production, e.g., straw. The presented method is suitable for converting such a material on an industrial scale. The main features are presented and an example of mass balances from the conversion of several biomass residues is given. After conversion, fractionated condensation is applied in order to retrieve two condensates -an organic-rich and an aqueousrich one. This design prevents the production of fast pyrolysis bio-oil that exhibits phase separation. A two phase bio-oil is to be expected because of the typically high ash content of straw biomass, which promotes the production of water of reaction during conversion.Both fractionated condensation and the use of biomass with high ash content demand a careful approach for establishing balances. Not all kind of balances are both meaningful and comparable to other results from the literature. Different balancing methods are presented, and the information that can be derived from them is discussed.

Managing Non-Sewered Human Waste Using Thermochemical Waste Treatment Technologies: A Review

“…The chemical reactions taking place during pyrolysis are endothermic and are pursued in an inert (non-ignition) environment by means of external heat source. Hence, to address the energy intensity of pyrolysis, research on the partial/complete combustion of syngas and pyrolytic oil for the self-sustainability of this process has been carried out [44,45]. Since the desirable product from pyrolysis (mainly fast and flash modes) is the bio-oil, <10% moisture content [18] in the feedstock has been considered suitable for fast pyrolysis, which implies greater energy consumption for pre-drying in comparison to combustion.…”

Moisture content as a design and operational parameter for fast pyrolysis

“…The pyrolysis trials were conducted in the process development unit 'Python' with a feed capacity of 10 kg•h -1 [35]. At the beginning of an experiment pre-conditioned biomass is fed to a buffer silo, which feeds a screw that controls the feed rate to the reactor of about 7 kg•h -1 .…”

Hydrotreatment of Fast Pyrolysis Bio-oil Fractions Over Nickel-Based Catalyst

“…There are two principle ways: gasification of pyrolysis products to generate synthesis gas and subsequent production of synthetic fuels as e.g. targeted in KIT's bioliq® process [9]. Alternatively, hydrotreatment has intensively been investigated as a promising method of bio-oil upgrading to directly produce drop-in fuels or fractions to be applied in crude oil refineries [10].…”