Full Text Available

Note: Clicking the button above will open the full text document at the original institutional repository in a new window.

Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis

Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2022.

Saved in:
Bibliographic Details
Other Authors: Heydenrych, Mike
Format: Thesis
Language:English
Published: University of Pretoria 2022
Subjects:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1867613487282257920
access_status_str Open Access
author2 Heydenrych, Mike
author_browse Heydenrych, Mike
author_facet Heydenrych, Mike
collection Thesis
dc_rights_str_mv © 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.
description Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2022.
format Thesis
id oai:repository.up.ac.za:2263/83879
institution University of Pretoria (South Africa)
language English
last_indexed 2026-06-10T12:36:55.772Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository
publishDate 2022
publishDateRange 2022
publishDateSort 2022
publisher University of Pretoria
publisherStr University of Pretoria
record_format dspace
source_str UPSpace — University of Pretoria Institutional Repository
spelling oai:repository.up.ac.za:2263/83879 Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis Heydenrych, Mike reynders.jonathan@tuks.co.za Merckel, Ryan David Reynders, Jonathan UCTD Fast pyrolysis Dual fluidised bed Commissioning Performance analysis Engineering, built environment and information technology theses SDG-07 Engineering, built environment and information technology theses SDG-09 Engineering, built environment and information technology theses SDG-12 Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2022. The CRIPS 2 dual fluidised bed pyrolysis unit at the University of Pretoria was successfully constructed and subsequently commissioned through eight experimental runs. The scope of the investigation involved determining the mass and energy balances around the unit, the thermal efficiency during operation, and the pyrolysis capabilities. The lignocellulosic biomass chosen for the experimental runs was Eucalyptus grandis wood chips with an average diameter of 448 to 489 μm. The products generated from the pyrolysis of lignocellulosic biomass are bio-oil, biochar, and non-condensable gases (NCG). The optimal experimental run involved the highest feed rate of biomass (5 kg/h) with a reduced NCG recycle flow-rate (140 l/ min) to produce a bio-oil with an HHV of 7.29 MJ/kg. The lower HHV and higher water content in the bio-oil was caused by oxygen transfer between the combustion bed and the pyrolysis unit. Nevertheless, the unit is very capable of processing higher biomass throughputs than the previous generation CRIPS unit. Residues found in the condensation unit and the bio-oil collection container were found to have an HHV of 22.11 MJ/kg, therefore confirming the pyrolysis potential of the unit. The biochar produced from the optimal run conditions had an HHV of 26.54 MJ/kg which can find a use in various heating applications. The BET surface area results for the collected biochar were very low. However, the wood feedstock was oversized to allow it to remain in the unit to produce additional combustion energy. As a result, the surface areas are not representative of the total biochar produced. Mass balances were performed with an error of under one percent and confirmed that pyrolysis was taking place. However, energy balances indicated that 35 % of the heat was unaccounted for. This discrepancy was discovered due to thermal soaking of the unit, whereby the large thermal mass was still consuming the heat during operations and was not at a thermal-steady state. Nevertheless, analysis of the thermal conservation abilities could still be calculated, indicating that the operation of the unit was very close to its design values. The insulation and integrated combustion unit reduced the radial heat losses by 82 % during the experimental runs and by 40 % (theoretical) at full design capacity compared to the CRIPS 1 unit. The integrated APH (air preheater) also reduced the LPG flow rate requirements by 49 % and operated very close to the design values. The recommendations for future work include various operational changes and unit modifications: • Reduce the oxygen transfer through operation and unit modifications. • Change the biomass screw conveyor delivery arrangement. • Add cyclones in series for better biochar recovery. • Increase the cyclone capacity. • Add pilot burner and flame detection unit. • Add a separate distribution manifold for recycled NCG. • Provide additional insulation for the top of the unit. mi2026 Chemical Engineering MEng (Chemical Engineering) Unrestricted SDG-07: Affordable and clean energy SDG-09: Industry, innovation and infrastructure SDG-12: Responsible consumption and production 2022-02-14T11:26:02Z 2022-02-14T11:26:02Z 2022-05-10 2022 Thesis * A2022 http://hdl.handle.net/2263/83879 en © 2022 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria
spellingShingle UCTD
Fast pyrolysis
Dual fluidised bed
Commissioning
Performance analysis
Engineering, built environment and information technology theses SDG-07
Engineering, built environment and information technology theses SDG-09
Engineering, built environment and information technology theses SDG-12
Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis
title Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis
title_full Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis
title_fullStr Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis
title_full_unstemmed Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis
title_short Construction and Commissioning of a Novel Dual Fluidised Bed Reactor for Biomass Fast Pyrolysis
title_sort construction and commissioning of a novel dual fluidised bed reactor for biomass fast pyrolysis
topic UCTD
Fast pyrolysis
Dual fluidised bed
Commissioning
Performance analysis
Engineering, built environment and information technology theses SDG-07
Engineering, built environment and information technology theses SDG-09
Engineering, built environment and information technology theses SDG-12
url http://hdl.handle.net/2263/83879