Densification techniques, such as baling, pelleting, and pyrolysis, help mitigate logistics costs associated with biomass transportation, storage, and handling, but the role of densification within the overall biomass-to-biofuel supply chain context is not yet well understood. This paper reviews the literature for modeling and optimization studies of lignocellulosic biomass supply chains with densification processes. Research studies in academic journals, books, and trade publications are classified based on four criteria: biomass type, densification form, analytical methodology, and densification machines’ mobility. We find that baling is the most-studied densification technique, while optimization modeling is the most common analysis method. Although pelleting and pyrolysis achieve a higher density than baling, comparatively few studies have examined their role in the overall supply chain. We identify future research opportunities, the most significant of which are integrating mobile densification and introducing comprehensive biomass-to-biofuel supply chain optimization models.

致密化技术（例如打包，制粒和热解）有助于降低与生物质运输，存储和处理相关的物流成本，但是致密化在整个生物质到生物燃料供应链环境中的作用还没有被很好地理解。本文综述了利用致密化工艺对木质纤维素生物质供应链进行建模和优化研究的文献。学术期刊，书籍和贸易出版物中的研究依据以下四个标准进行分类：生物质类型，致密化形式，分析方法和致密化机器的移动性。我们发现打包是研究最多的致密化技术，而优化建模是最常用的分析方法。尽管制粒和热解的密度高于打包的密度，很少有研究检查它们在整个供应链中的作用。我们确定了未来的研究机会，其中最重要的是整合移动致密化并引入全面的生物质到生物燃料供应链优化模型。