Abstract. The ionic liquid [MMIM][DMP] was synthesized from the reactants methyl imidazole [MIM] and trimethylphosphate [TMP] and verified using 1 HNMR and FTIR. Coconut coir dust was pretreated with a 1% alkaline solution. Its crystalline structure increased significantly due to the dissolution of lignin and hemicelluloses under alkaline conditions, exposing the cellulose. After NaOH and IL were employed, the XRD showed that peak (002) decreased significantly and peak (101) almost vanished. This significant decrease in crystallinity was related to the alteration of the substrate from the cellulose I structure to the cellulose II structure. The pretreated substrates were hydrolyzed to convert them to reducing sugars by pure cellulase and xylanase, and the reaction was conducted at 60°C, pH 3, for 12 or 48 hours. The yields of sugar hydrolyzed from untreated and NaOH-pretreated substrates were 0.07 and 0.12 g sugar/g lignocellulose, respectively. Pretreatment with IL or the combination of NaOH+IL resulted in yields of reducing sugars of 0.11 and 0.13 g/g, respectively. These findings showed that IL pretreatment of the high-lignin lignocellulose is a new prospect for the economical manufacture of reducing sugars and bioethanol in the coming years.

This study aims to produce reducing sugar hydrolyzed from substrate, coconut coir dust pretreated by recycled ionic liquid and its combination with alkaline. The 1H NMR and FTIR were performed to ver-ify the synthesized ionic liquid methylmethylimidazolium dimethyl phosphate ([mmim][dmp]). The structure of pretreated substrates was analyzed by XRD measurement. The used ionic liquid was recy-cled twice to re-employ for substrate pretreatment. The treated- and untreated-coconut coir dust were hydrolyzed into sugars using pure cellulase. The reaction, which called an enzymatic hydrolysis, was conducted at 60 °C, pH 3, for 48 h. The yields of sugar hydrolyzed from fresh IL-pretreated, 1R*IL-pretreated and 2R*IL-pretreated substrates were of 0.19, 0.15 and 0.15 g sugar / g cellu-lose+hemicellulose, respectively. Pretreatment with NaOH or the combination of NaOH+IL resulted in yields of reducing sugars of 0.25, 0.28 g/g, respectively. When alkaline combined with the recycled ionic liquids, NaOH+1R*IL, NaOH+2R*IL in the pretreatment, the yields of sugar were relatively similar to those obtained using alkaline followed by fresh ionic liquid. If the mixture enzymes, cellu-lase+xylanase, used to liberate sugars from fresh IL-pretreated, or recycled IL-pretreated substrates, the amount of sugar (concentration or yield) increased slightly compared to that employing a single cel-lulase. These findings showed that recycled IL pretreatment of the high-lignin lignocellulose, coconut coir dust, is a new prospect for the economical manufacture of fermentable sugars and biofuel in the coming years. © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

Sugarcane bagasse is one of lignocellulose materials that can be converted to biofuel. This work was aimed to develop new pretreatment combination methods to process sugarcane bagasse lignocellulose into biofuel (bio-hydrogen). Pretreatment of sugarcane bagasse using NaOH solution in combination with ionic liquid [DMIM]DMP enhanced the enzymatic hydrolysis significantly. After the pretreatment, the content of cellulose and hemicellulose increased by 29.31% compared to the untreated one. Cellulose and hemicelluloses were used as raw materials to produce reducing sugars, that can be converted to bio-hydrogen via fermentation. After being subjected to combined pretreatment processes, the crystalline index of sugarcane bagasse decreased significantly compared to solely NaOH pretratment. This indicates a more amorphous structure of the sugarcane bagasse, which makes it is easier to be hydrolyzed into reducing sugars. The recovery of cellulose + hemicellulose after pretreatment for 20 min and 120 °C was 92%, and the yield obtained was 0.556 g sugars/g (cellulose + hemicellulose) after 12 h and the bio-hydrogen yield was 0.46 mol H2/mol sugars consumed after 48 h fermentation. The use of recycled of ionic liquid showed similar performance compared to the use of fresh ionic liquid.

The main goal of this work is optimize low temperature shift converter (LTS) of Carbon Monoxide (CO) in an Industrial Ammonia Plant considering life time of the catalyst in that converter. Shift converter is a reactor to convert CO into carbon dioxide. CO in ammonia plant comes from steam reforming process that convert natural gas into hydrogen gas. This process will also produce CO gas, where CO gas is toxic to the catalyst in ammonia syntesis reactor and also able to oxidize Fe in ammonia synthesis that is the reason why CO is one of component that can interfere the ammonia gas manufacturing process. To prevent this, the CO gas purification process needs to be done, one of the method is using shift converter process. From the optimization of several operating conditions in low temperature shift converter, a relatively strong correlation is found between flow rate feed and average temperature bed catalyst with the lifetime of the catalyst. The optimization result show that the optimum flow rate feed in LTS is 2754.49 m3/day and average temperature bed catalyst is 224°C. Operating at the proposed optimal condition increases life time of the catalyst about 8.02% per year.

The present work is aimed at analysing the compositions of the water, ethanol, and gasoline which has Research Octane Number/RON was 88 forming a stable emulsion (one phase) employing a ternary graph. When the mixture process, the blended fuels consisted of water-ethanol-gasoline were successfully prepared in which they were formed in one phase. Ethanol was derived from Arenga pinnata liquor which is locally called cap tikus using a home-made reflux distillation filled by packing materials. Ethanol obtained were differing their concentration that depended on the column temperature set. It was found that the purities were ranged from 80 to 96% and the higher column temperature was chosen the lower concentration was obtained. Each aqueous ethanol was blended with gasoline to obtain a homogenous solution. For ethanol 80%, compositions of water, pure ethanol, and gasoline were observed at 18, 74, and 8 (%v/v), and 22, 70, and 7 (%w/w). While ethanol 96%, the compositions ratios were 1:22:77 (%v/v) and 1:23:76 (%w/w). The ranges of pure ethanol, gasoline, and water in which they formed one phase solution were recorded at 23-70%, 7-76%, and 1-22%. The work found that substance was in one phase if the wet ethanol keeps being added. When the ethanol composition has decreased the substance was separated into wet ethanol and gasoline. The minimum ethanol dissolved completely into gasoline was of 80%.

This study investigates the composition and fuel parameters of a fuel blend of aqueous ethanol and gasoline, with RONs (Research Octane Numbers) of 90 and 92, called pertalite and pertamax in Indonesia, respectively. The emulsion fuel blend of gasoline and ethanol was prepared successfully, and the concentrations ranged from 80 to 98% (v/v). The steps employed in this work are as follows: first, the fermentation of sugar tapped from a palm tree (Arenga pinnata). The obtained liquor containing ethanol was distilled using a reflux still to separate ethanol and water. The purity of the ethanol obtained from the reflux process ranged from 80 to 96%, depending on the column temperature set. Ethanol solutions of 97 and 98% purities were obtained through an absorption method employing lime particles. Subsequently, aqueous ethanol was blended with gasoline manually inside a flask. It was discovered that the minimum ethanol concentration, which could be blended with pertalite to form a single-phase substance, was 80%. By using 80% ethanol in the blending process, the composition ratio of pertalite, pure ethanol, and water was recorded as 1:11.65:2.91 (in volume unit), while this was not the case with pertamax. The minimum ethanol concentration that could be blended with pertamax to form a single-phase emulsion was 88%, with a composition ratio of 1:5.91:0.81. The composition proportions of the three components with 96% ethanol were 1:0.27:0.01 (RON 90) and 1:0.41:0.02 (RON 92). It was observed that the higher the ethanol concentration, the less the amount of ethanol required for the blending process with gasoline to form a single-phase emulsion.

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Many countries worldwide encounter the greatest difficulties in improving people's life quality since fossil fuel reserves are decreasing, causing fuel prices to rise drastically. This problem has made many countries, including Indonesia, struggle to import them from producers in the Middle East. Adding a small part of ethanol to gasoline is one of the solutions that has been investigated and developed. The previous works relating to blended fuels, gasoline and ethanol, generally employed absolute alcohol, which was expensive. A small surfactant was added to the mixture to stabilize the emulsion, and the blending was conducted in normal conditions (room temperature). If the composition of gasoline and aqueous ethanol is not precise, the components can be separated at a specific temperature. The present study is aimed to report the analysis of compositions and fuel specifications of aqueous emulsions of gasoline (RON 90)-ethanol-water in a single phase without using a synthetic surfactant in the temperature range of 0–25 °C. The procedures were as follows: fermentation, ethanol distillation and purification, cooling, blending, and characterization of fuel specifications. Components of gasoline (RON 90)-ethanol-water formed a stable emulsion in the composition range of 28.00‒99.79 %, 0.20‒67.97 %, and 0.01‒3.58 %. The observation found that continually increasing the amount of aqueous ethanol and temperature after one phase was attained would not lead to the separation of components. Therefore, gasoline and aqueous ethanol can form a single phase functioning as a surfactant binding water and fossil fuel. The decrease in temperature after the emulsion is stabilized can separate the components whereby it is caused by the faster density change of aqueous ethanol than gasoline