This work evaluated the use of protic ionic liquids (PILs) for the valorization of biomass at cost effective conditions; use of larger particle sizes, elevated biomass loadings and the reuse of PILs for pretreatment. PILs, triethylammonium hydrogen sulfate (TEAHSO₄), 1-butylimidazolium hydrogen sulfate (HBIMHSO₄) and 4-methylmorpholinium hydrogen sulfate (HMMorpHSO₄) were used to pretreat the hardwood species, hornbeam. Hornbeam (Carpinus betulus L.) is regarded as an important forest residue since it is found among common hardwoods in Turkey and possess great potential to be valorized in the biorefinery context. Each PIL showed similar impacts on biomass structure; they enriched the cellulose content by lignin removal and increased the crystallinity of biomass. Notably, HBIMHSO₄ removed 91 % lignin and the cellulose content of biomass increased to 81 % which was attributed to the lower hydrogen bond donor capacity of imidazolium cation in HBIMHSO₄. The cellulose in the untreated biomass was hydrolyzed into glucose with 95 % yield. The results were also verified with FTIR and XRD findings; the intensities of the peaks associated with the presence of lignin got lower and higher crystallinity indices were obtained upon HBIMSO₄ pretreatment. The best results in terms of biomass composition were achieved when hornbeam with particle size, 0.15–1.18 mm was used. Pretreatment of biomass correlated inversely with an increase in biomass loading. Nevertheless, TEAHSO₄ and HBIMHSO₄ were able to extract lignin as high as 70 % at 30 % biomass loading. Recycled HBIMHSO₄ at 20 % biomass loading performed very stably regarding the changes in the biomass structure and saccharification. Besides, no changes were observed between the chemical shifts of pristine PILs and recycled PILs analyzed with ¹H-NMR after their 6th reuse in pretreatment. The findings addressed the potential of HBIMHSO₄, for its use at larger volumes of biomass-PIL interactions.

这项工作评估了质子离子液体（PIL）在成本有效条件下对生物质进行增值的能力；使用更大的粒径，增加的生物量负荷以及将PIL重复用于预处理。PIL，三乙基硫酸氢铵（TEAHSO ₄），1-丁基咪唑硫酸氢盐（HBIMHSO ₄）和4-甲基吗啉硫酸氢盐（HMMorpHSO ₄）用于预处理硬木树种角树。角树（Carpinus betulusL.）被认为是重要的森林残留物，因为它在土耳其的普通硬木中发现并且具有在生物精炼厂中进行增值的巨大潜力。每个PIL对生物量结构显示出相似的影响。他们通过去除木质素来丰富纤维素含量，并增加了生物质的结晶度。值得注意的是，HBIMHSO ₄去除了91％的木质素，而生物质中的纤维素含量增加至81％，这归因于HBIMHSO ₄中咪唑鎓阳离子的氢键供体容量较低。未经处理的生物质中的纤维素以95％的产率水解为葡萄糖。FTIR和XRD结果也验证了结果；通过HBIMSO获得与木质素存在相关的峰强度越来越低的结晶度指数_4．预处理。当使用角尺寸为0.15–1.18 mm的角树时，就生物质组成而言，可获得最佳结果。生物量的预处理与生物量负荷的增加成反比。然而，TEAHSO ₄和HBIMHSO ₄能够在30％的生物量负载下提取高达70％的木质素。考虑到生物质结构和糖化的变化，回收的HBIMHSO ₄在生物质负载量为20％时非常稳定。此外，在预处理中第6次重复使用后，通过¹ H-NMR分析的原始PIL和回收的PIL的化学位移之间没有观察到变化。研究结果探讨了HBIMHSO ₄的潜力，用于更大数量的生物质-PIL相互作用。