This study aims to utilize benzotriazolium salt-ionic liquids (ILs) as solvents in the oil palm empty fruit bunch (EFB) waste pretreatment along with bibliometric analysis using VOSviewer. Three ILs have been synthesized and tested as EFB solvents by a microwave-heating method. Those are organic salts of 1,3-methyl-octyl-1,2,3-benzotriazolium ([MOBzt]+) cation with three kinds of anions such as bromide ([Br]-), acetate ([CH3COO]-), and thiocyanate ([SCN]-). The bibliometric analysis showed that new research needs to be conducted to improve the development of research relating to biomass pretreatment. The highest solubility of EFB is in [MOBzt]CH3COO is about 7,5% w/w. The effect of anions on the ability to dissolve EFB is CH3COO-SCN-Br-. When subject to ILs pretreatment, EFB exhibited increased cellulose crystallinity, changed in the structure of cellulose I to cellulose II, reduced particle size, and decreased lignin content compared to untreated one, improving the glucose yield from enzymatic hydrolysis. The highest glucose yield (1,237 mg/mL) was obtained when the EFB was pretreated by [MOBzt]CH3COO with enzymatic hydrolysis for 24 hours. This research is expected to contribute to the development of new biomass pretreatment methods.

Fatty-imidazolinium electrolytes, waste graphite dispersed composite electrolytes like cocktails (1,3-methyl octyl-1,2,3benzotiazolium acetate-cis-oleyl-imidazolinium iodide), and graphite exfoliation using cis-oleyl-imidazolinium acetate have been studied to enhance the efficiency of a newly developing dye-sensitized solar cells (DSSCs). The DSSCs were fabricated in a sandwich structure and characterized using Solar Simulator. The graphite exfoliation was conducted by sonication and microwave energy, as well as the electrochemical method. Cis-oleyl-imidazolinium iodide efficiency (0.53%) was highest than stearyl-imidazolinium iodide and palmityl-imidazolinium iodide because cis-oleyl-imidazolinium iodide has a double bond and the longest alkyl chain which triggered a self-assembly structure formation and increased the rate of I -/I 3transport in cells. Then, the efficiency of DSSCs-based composite electrolytes was in the range of 0.020-0.203%. Dispersion of 0.05% of the graphite results in efficiency enhancement of about 100%, but the greater fraction (0.10%) of the graphite causes a poor performance (lower efficiency), possibly due to interference of the internal electron transportation routes in the DSSC by insoluble graphite. After exfoliation, the conductivity of synthetic graphite (11.58 x 10 -1 S/cm), new battery graphite (9.32 x 10 -1 S/cm), and battery waste graphite (7.96 x 10 -1 S/cm) were increased respectively 10 times, 2 times, and 4 times from the graphite before exfoliation due to changes in crystallinity, the distance between layers, crystal size, formation of multilayer graphene, and the occurrence of π to π* transition. This enhancement of solar conversion efficiency can give a new contribution to the development of DSSC.

This study aims to evaluate the feasibility of the yttrium recovery from compact fluorescent lamp waste using methyltrioctylammonium peanut oil ([N1,8,8,8][PO]) compared to methyltrioctylammonium naphthenic acid ([N1,8,8,8][NA]) and tetraoctylphosphonium oleate ([P8,8,8,8][Oleate]) on a large scale. Based on the techno-economic analysis, the process was feasible on a large scale commercially due to changes in economic parameters such as gross profit margin (GPM), payback period (PBP), break-even point (BEP), break even capacity (BEC), cumulative net present value (CNPV), profitability index (PI), internal rate return (IRR), and return on investment (ROI) tend to be positive with the greatest profit when using [P8,8,8,8][Oleate] compared to [N1,8,8,8][NA] and [N1,8,8,8][PO] under ideal conditions and the use of [N1,8,8,8][PO] can still be profitable under non-ideal conditions with certain fluctuation limits.