CFD-based optimization of Tar destruction in downdraft biomass gasifiers via advanced injection strategies

IF 5.8 2区生物学 Q1 AGRICULTURAL ENGINEERING

Biomass & Bioenergy Pub Date : 2025-09-24 DOI:10.1016/j.biombioe.2025.108415

Ahmed M. Salem, Ahmed Abdo, H.A. Nasef, Ayman Refat Abd Elbar

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引用次数: 0

Abstract

The gasification technology still restricted by the generation of tar compounds during the gasification process, which restricts the direct utilization of the resulting syngas. To tackle this challenge, the present study introduces a two-dimensional CFD model of rubberwood downdraft gasification to investigate the formation and destruction of key tar compounds – benzene, toluene, naphthalene, and phenol (representing primary, secondary, and tertiary tars) – and to evaluate the impact of side-nozzle injections attached to the reduction zone. Steam, oxygen, and CO₂ were each injected downstream to assess their combined effects on syngas composition and tar species yields.

Oxygen and CO₂ downstream injections effectively reduced tar, but caused a significant drop in syngas heating value, limiting their practical application. In contrast, steam injection (at reduction zone) achieved a notable reduction of total tar content by 15–35 wt %, boosted hydrogen production, lowered CO₂ emissions, and preserved high heating values without the need for additional tar separation.

These findings demonstrate that steam injection in the reduction zone offers a practical, scalable strategy for tar mitigation in biomass gasification. This approach enhances syngas quality and supports possible broader adoption of sustainable gasification technologies.

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基于cfd的下吸式生物质气化炉焦油破坏优化研究

气化技术仍然受到气化过程中焦油化合物的产生的限制，这限制了所产生的合成气的直接利用。为了应对这一挑战，本研究引入了橡胶木下气流气化的二维CFD模型，以研究主要焦油化合物——苯、甲苯、萘和苯酚（代表初级、二级和三级焦油）的形成和破坏，并评估附加在还原区的侧喷嘴注入的影响。蒸汽、氧气和二氧化碳分别注入下游，以评估它们对合成气成分和焦油种类产量的综合影响。下游注入氧气和二氧化碳可以有效降低焦油含量，但导致合成气热值显著下降，限制了合成气的实际应用。相比之下，蒸汽注入（在还原区）使总焦油含量显著降低了15-35 wt %，提高了氢气产量，降低了二氧化碳排放，并且在不需要额外分离焦油的情况下保持了较高的热值。这些发现表明，在还原区注入蒸汽为减少生物质气化中的焦油提供了一种实用的、可扩展的策略。这种方法提高了合成气的质量，并支持可持续气化技术的广泛采用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Biomass & Bioenergy 工程技术-能源与燃料

CiteScore

11.50

自引率

3.30%

发文量

258

审稿时长

60 days

期刊介绍： Biomass & Bioenergy is an international journal publishing original research papers and short communications, review articles and case studies on biological resources, chemical and biological processes, and biomass products for new renewable sources of energy and materials. The scope of the journal extends to the environmental, management and economic aspects of biomass and bioenergy. Key areas covered by the journal: • Biomass: sources, energy crop production processes, genetic improvements, composition. Please note that research on these biomass subjects must be linked directly to bioenergy generation. • Biological Residues: residues/rests from agricultural production, forestry and plantations (palm, sugar etc), processing industries, and municipal sources (MSW). Papers on the use of biomass residues through innovative processes/technological novelty and/or consideration of feedstock/system sustainability (or unsustainability) are welcomed. However waste treatment processes and pollution control or mitigation which are only tangentially related to bioenergy are not in the scope of the journal, as they are more suited to publications in the environmental arena. Papers that describe conventional waste streams (ie well described in existing literature) that do not empirically address ''new'' added value from the process are not suitable for submission to the journal. • Bioenergy Processes: fermentations, thermochemical conversions, liquid and gaseous fuels, and petrochemical substitutes • Bioenergy Utilization: direct combustion, gasification, electricity production, chemical processes, and by-product remediation • Biomass and the Environment: carbon cycle, the net energy efficiency of bioenergy systems, assessment of sustainability, and biodiversity issues.