Kiky C. Sembiring

Bioethanol G2: Production Process and Recent Studies

The demand for ethanol as a substitute of gasoline is rapidly increasing due to the recent increase of imbalance in oil market and interest in environmental issues. First-generation (G1) bioethanol which is currently derived mainly from food crops generate many problems such as net energy losses, greenhouse gas emission, and increased food price. On the other hand, biofuel produced from lignocellulosic materials, so-called second-generation (G2) bioethanol, shows environmental advantages in comparison to G1. The development of bioethanol G2 from lignocellulosic materials possesses many advantages from energy and environmental aspects. Efficient conversion of lignocellulosic biomass to ethanol and value-added biochemicals is still today a challenging proposition. Basically, four steps are included in the production process of bioethanol G2, composed of pretreatment, saccharification, fermentation, and product separation/purification. In each step, there are several ideas to improve its productivity and benefitability. In this chapter, we describe some details about the production process selection or ideas. New studies such as catalytic conversion of lignocellulosic biomass are also rapidly developing, although they are not yet mature to be utilized for industrial purposes.

Preparation of Sulfated Zirconia Using Modified Sol Gel Method

A series of sulfated zirconia was prepared through sol gel method in alcohol medium. Porosity of the catalyst was developed in two different methods, which were immersion of cetyltrimethyl ammonium chloride (CTAC) surfactant as templating agent and Supercritical Fluid Extraction (SFE). The physico-chemical properties of the catalysts were characterized by Thermal Gravimetric-Differential Thermal Analysis (TG-DTA), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) and gravimetry method for acidity measurement following by the adsorption of organic bases. The characterization results show that different method of immersing CTAC surfactant and SFE affecting physical and chemical properties, i.e. crystalinity, surface area, pore size, pore volume and acidity.

Carbonization of Palm Oil Empty Fruit Bunch (EFB) in Hydrothermal Processes to Produce Biochar

Empty fruit bunch (EFB) of palm oil is a waste from the palm oil industries which in a large amount, those waste is not properly utilized yet. EFB is a lignocelluloses waste as a polymer with big molecule such as cellulose, lignin, and hemicelluloses that can be degraded into smaller molecules in hydrothermal carbonization (HTC) process. The HTC process of EFB will result three fractions such as gas, organic water soluble and biochar as solid residue or bio-char-water-slurry. EFB degradation is influenced by the operation conditions such as temperature, pressure, catalysts, reaction time, stirring and ratio liquid and solid. The HTC process involved many routes of reaction such as liquefaction, hydrolysis, dehydration, decarboxylation, condensation, aromatization, and polymerization. In this experiment 60 ml closed vessel was used as the HTC reactor to degrade of EFB. EFB concentration of 6.44% resulted 62% of conversion. Reaction time of 6 hours resulted 62 % of conversion. Increasing the reaction time and temperature increase the conversion of EFB. Liquid products of organic water soluble has cleared yellow color, after several hours the color become darkness that is further reaction still occurs in that solution. Solid products is biochar as brown coal, that can be easily separated and processed into powder, pellet or briquette form with outstanding storage and transport characteristics. For further economic development, biochar with excellent transport characteristics, the possibility of exporting this commodity to the worlds energy market is possible.