Because of its wide use in industrial chemicals, acetic acid has become a high-value chemical. Acetic acid can be obtained from bio-oil obtained from various biomasses such as agricultural waste. In this study, the extraction of acetic acid from bio-oil is investigated based on the composition of acetic acid in an empty fruit cluster.
It was found that effective phase separation of bio-oil can be successfully performed by adding an aqueous salt solution. In this study, aqueous ammonium sulfate, (NH4)2 SO4, is used to perform phase separation, and the effect of salt concentration on the recovery of acetic acid from bio-oil is investigated. Research has shown that the upper layer contains mainly acetic acid and water-soluble compounds, while the lower layer consists of water-insoluble, non-polar compounds.
The composition of acetic acid in the upper and lower phases depends on the type and dosage of added salt. Based on the result, it is found that the maximum amount of extracted acetic acid in the upper phase is achieved using 15% (NH4)2 SO4 in bio-oil with a yield of 25.27.
INTRODUCTION
- Global Demand on Acetic Acid
- Bio-oil as a Resource
- Recovery Technology of Acetic Acid .................................................... 3-4
- Objectives
- Scope of Study
- Significant of the Project
- Feasibility of the Project
The future growth of the acetic acid market will continue to be driven by China (IHS, 2010). Various recovery techniques have been introduced to extract acetic acid from bio-oil, such as catalytic distillation. Zu et al. 1999), anion exchange resin method Sukhbaatar et al., 2009) and microemulsion liquid membrane separation (Wiencek and Qutubuddin, 1992). As reported by Zu et al., (1999), catalytic distillation experiments were performed using a 100 mm diameter column for the removal of acetic acid from water.
Study was conducted by Sukhbaatar et al., (2009) using anion exchange resin method to remove acetic acid from bio-oil. The successful extraction of acetic acid from bio-oil with common salt is influenced by factors such as salt concentration. The general aim of this research work is to study the feasibility of recovering acetic acid from bio-oil using liquid-liquid extraction method.
To study the potential of obtaining acetic acid from bio-oil using ammonium sulfate (NH4)2SO4. The extraction of this acetic acid from pyrolysis oil is a potentially attractive area of research.
LITERATURE REVIEW
Bio-oil as Potential Resource for Acetic Acid
Literature research reveals that bio-oil has potential as a source for acetic acid. The volume percentage resulting from the phase separation of the upper and lower bio-oil layer was calculated. The concentration of acetic acid in the upper and lower layer of the bio-oil is measured.
Extraction of acetic acid from bio-oil. Measurement of the mass fraction on the top and bottom layers. This curve is used as a reference to determine the concentration of acetic acid in the upper and lower phases of the bio-oil. The addition of 1 ml of an aqueous solution of (NH4)2SO4 at a concentration of 5 to 20% w/v resulted in phase separation of the bio-oil.
Yield is calculated to determine the amount of acetic acid recovered based on the original bio-oil. Similar study is also done by Sukhbaatar et al. 2009) on the removal of acetic acid from bio-oil using calcium oxide. In conclusion, the extraction of acetic acid from bio-oil can be carried out using aqueous salt system.
Reported Studies on Bio-oil Composition ............................................. 8-9
METHODOLOGY
Research Flow
Bio-oil was characterized based on viscosity, water content, density, chemical composition, elemental composition, pH and calorific value. Research was conducted on the effect of salt concentration on the liquid-liquid extraction method.
Experimental Section ......................................................................... 17-24
The composition was chosen based on the study carried out by (Sukhbaatar et al., 2009) on typical pyrolysis oil derived from different biomasses, and the acetic acid composition is chosen to reflect the composition in biomass (Misson et al., 2009; Ani, 2001). 100 ml of synthetic bio-oil is produced by mixing the chemicals completely with their respective volumes. Synthetic bio-oil produced is stored in glassware with lids (150 ml) and refrigerated to avoid volatility of this product.
100 ml of prepared synthetic bio-oil is stirred using a magnetic stirrer at 400 rpm for 2 hours to form a homogeneous mixture. Bio-oil phase separation is performed by adding 1 ml of aqueous (NH4)2SO4 in different concentrations to 10 ml of bio-oil. 8 samples, each containing 10 ml of bio-oil, were placed in a glass tube (content 15 ml and diameter 15 mm).
The procedures performed follow the same procedure performed by Vitasari et al., (2011) on water extraction of pyrolysis oil. The upper, middle and lower layers formed by adding aqueous (NH 4 ) 2 SO 4 at a concentration of 5 to 20% w/v were extracted using a syringe. Then, samples in each phase are analyzed using GC-FID to obtain the concentration of acetic acid.
The partition coefficient is defined as the ratio between the amount of acetic acid in the aqueous extract phase and the amount of acetic acid in the organic phase. Preparation of the calibration curve for acetic acid using GC-FID (peak area versus concentration, volume.
Calibration curve of acetic acid
Physicochemical characterization of bio-oil
Phase separation of bio-oil using aqueous salt ................................... 31-32
Based on the result, it is found that the peak area of acetic acid in the upper layer is 24% and the lower layer mainly contains phenol with a maximum area of 60%. In the upper layer, it shows that the concentration of acetic acid at the retention time of 2.463 is by 9.68. A further study was carried out to determine the optimum concentration of aqueous (NH4)2 SO4 which gives the highest amount of acetic acid in the upper phase.
As the salt concentration increased, a slight increase in the amount of acetic acid was extracted in the upper phase. Water-soluble compounds such as acetic acid go to the top and water-insoluble compounds such as phenol go to the bottom. The highest amount of acetic acid extracted is obtained at 15 % w/v with 0.28 ml compared to 1 ml of acetic acid in the crude bio-oil.
However, a further increase in the salt concentration above 15% w/v causes the amount of acetic acid in the upper layer to decrease. Based on the result, as the salt concentration increases, the recovered yield of acetic acid is also increased. This clearly shows that the amount of acetic acid recovered depends on the dose of added salt.
Comparing the obtained results with other studies done, there is a need to improve this study in order to increase the yield of acetic acid from bio-oil. The ratio is obtained by dividing the amount of acetic acid extracted in the upper layer by the lower layer. It means that the amount of acetic acid is less in the upper phase compared to the lower phase.
This is because only a small amount of acetic acid managed to be extracted through the addition of salt. This indicates that lower concentration of (NH4)2SO4 leads to a low amount of acetic acid extracted in the upper phase. Several procedures must first be performed, such as preparing the synthetic bio-oil and characterizing the amount of acetic acid in the bio-oil.
The compound contained in both layers can be converted into value added chemical such as acetic acid and phenol. Recovery of acetic acid from an aqueous pyrolysis oil phase by reactive extraction with tri-n-octylamine.
