Understanding the suitability of different conversion technologies for different types of biomass feedstocks is crucial in delivering the full valorisation of different types of biomasses. This is novel research which presents an extensive comparative study on how three different thermal conversion technologies (torrefaction, pyrolysis, and semi-continuous hydrothermal conversion) and process interdependencies are influenced by different feedstocks (Rapeseed (RS), Whitewood (WW), Seaweed Laminaria digitata (LD))) for the optimisation of char (hydrochar/biochar) formation and their associated bioenergy applications. A wide range of processing conditions was analysed to optimise char formation and potential applications of these chars in energy production were extensively investigated. Based on the evaluation of char structures, hydrothermal conversion could be an applicable method for char production from WW and RS. The char yield of WW is in the range of 30–50 wt% at the early stage of hydrothermal carbonisation (HTC, 235 °C). Increasing temperature (>265 °C) decreased char yield but produced a higher HHV char (∼30 kJ/g). Approximately 90 wt% of LD dissolved into the water at low temperatures (<200 °C) during hydrothermal conversion, leaving small amounts of char with a significant ash content (∼50 wt%). During pyrolysis, RS and WW gradually decomposed and produced char with yield of ∼ 35–40 wt% at 400 °C consisting of a high lignin content with a HHV of > 34 kJ/g. Similarly, LD decomposed gradually with a char yield of 45 wt% at 400 °C, but with a low HHV (∼15 kJ/g) and high ash content (20 wt%). WW had relatively high char yield of ∼ 60 wt% during pyrolysis at 250 °C, with a HHV of 25 kJ/g. Although RS had a high char yield (∼75 wt%) with a high HHV (>30 kJ/g), the chars still contained a significant amount of volatiles. The WW char from these three thermal conversion technologies, and RS chars produced by pyrolysis and hydrothermal conversion, could have a potential application in bioenergy production. However, the ash content and low HHV make LD unsuitable for bioenergy applications.

了解不同转化技术对不同类型生物质原料的适用性对于实现不同类型生物质的全面增值至关重要。这是一项新颖的研究，它对三种不同的热转化技术（烘焙、热解和半连续水热转化）和工艺相互依赖性如何受到不同原料（油菜籽 (RS)、白木 (WW)、海藻海带的影响）进行了广泛的比较研究数位 (LD))) 用于优化炭（水炭/生物炭）的形成及其相关的生物能源应用。分析了广泛的加工条件以优化炭的形成，并广泛研究了这些炭在能源生产中的潜在应用。基于对焦炭结构的评估，水热转化可能是 WW 和 RS 生产焦炭的一种适用方法。在水热碳化的早期（HTC，235°C），WW 的焦炭产量在 30-50 wt% 的范围内。升高温度（>265 °C）会降低焦炭产量，但会产生更高的 HHV 焦炭（~30 kJ/g）。在水热转化过程中，大约 90 wt% 的 LD 在低温（<200 °C）下溶解到水中，留下少量具有显着灰分含量的炭（~50 wt%）。在热解过程中，RS 和 WW 逐渐分解并产生炭，在 400 °C 下产率为 35-40 wt%，其中木质素含量高，HHV > 34 kJ/g。类似地，LD 在 400 °C 下逐渐分解，炭产量为 45 wt%，但 HHV 低（~15 kJ/g）和灰分含量高（20 wt%）。WW 在 250 °C 热解过程中具有相对较高的焦炭产率，约为 60 wt%，HHV 为 25 kJ/g。尽管 RS 具有高 HHV（>30 kJ/g）的高焦炭产率（~75 wt%），但焦炭仍然含有大量的挥发物。这三种热转化技术产生的 WW 炭，以及通过热解和水热转化产生的 RS 炭，可能在生物能源生产中具有潜在的应用。然而，灰分含量和低 HHV 使 LD 不适用于生物能源应用。