Ethylene glycol injection for hydrate formation prevention in deepwater gas pipelines

The presence of hydrates in deepwater oil-gas-field operations is a fairly frequent issue. It is very important to have a hydrate management strategy for normal operation and while shutdown. The objectives of the work were to mitigate the hydrate formation in the deepwater operation conditions. This study analyzed the sensitivity of the hydrate compound formation process in flow line system with diameter 9.5" with a length of about 22 Km in deep water gas-field, based on actual condition and production rate assumption. Based on the simulation results for the actual production flow rate, hydrate is formed at a distance of about 17991 ft from the wellhead that is in the first segment of the well head to the Pipeline End Manifold (PLEM). For a higher production flow rate, hydrate formation occurs at a distance approaching the wellhead which is part of the first segment. This is because the temperature at the bottom of the deep-water is as low as 40 °F. The addition of MEG to prevent the formation of hydrate compounds was further investigated. Fluid flow modeling was performed under steady state with CH4 levels of about 87%, pressure of 1900 psia, 125 °F temperature and 85 MMSCFD production flow rate as the basic conditions. The data used in this research is taken from one of the deepsea gas field in Makassar Strait. Adding MEG dose of 0.175% mole, lowering the hydrate-forming temperature from 67.8 °F to 3.2 °F. Similarly, for increasing MEG doses, the greater the decrease in hydrate formation temperature. The addition of MEG dose of 0.175% mole at each production flow rate gives different working fluid temperature with hydrate formation temperature of 5.5 °F to 18 °F, so it is safe from the risk of hydrate formation

Utilization of Tamarind Seeds Extract as a Natural and Sustainable Fabric Dye

This research focuses on the use of tannin components in tamarind seed coats as a mordant and natural dye in cotton fabrics. Tannins were extracted from the tamarind seed coat by boiling method and then the tannin content was determined. The tannin extract was then used as a natural mordant with the addition of metallic copper sulfate (CuSO4) mordant. Tannin extract is also used as a dye on fabrics with the addition of sodium sulfate (NaSO4). The color strength of the tannins in the fabric was analyzed using a spectrophotometer from the rinse water. The results showed that the cloth that had been given the mordant had a stronger color strength than the cloth without the mordant. The use of mordant was varied at concentrations of 5, 10, 15, 20, and 25%-owf. The results of the analysis showed the most optimum tannin concentration at 15%-owf. The concentration of tannin used in the coloring process was also varied at concentrations of 5, 10, 15, 20, and 25%-owf. The results of the analysis show that the concentration of tannin used in the dye does not affect the strength of the color, but only affects the brightness of this color

Ethylene glycol injection for hydrate formation prevention in deepwater gas pipelines

The presence of hydrates in deepwater oil-gas-field operations is a fairly frequent issue. It is very important to have a hydrate management strategy for normal operation and while shutdown. The objectives of the work were to mitigate the hydrate formation in the deepwater operation conditions. This study analyzed the sensitivity of the hydrate compound formation process in flow line system with diameter 9.5" with a length of about 22 Km in deep water gas-field, based on actual condition and production rate assumption. Based on the simulation results for the actual production flow rate, hydrate is formed at a distance of about 17991 ft from the wellhead that is in the first segment of the well head to the Pipeline End Manifold (PLEM). For a higher production flow rate, hydrate formation occurs at a distance approaching the wellhead which is part of the first segment. This is because the temperature at the bottom of the deep-water is as low as 40 °F. The addition of MEG to prevent the formation of hydrate compounds was further investigated. Fluid flow modeling was performed under steady state with CH4 levels of about 87%, pressure of 1900 psia, 125 °F temperature and 85 MMSCFD production flow rate as the basic conditions. The data used in this research is taken from one of the deepsea gas field in Makassar Strait. Adding MEG dose of 0.175% mole, lowering the hydrate-forming temperature from 67.8 °F to 3.2 °F. Similarly, for increasing MEG doses, the greater the decrease in hydrate formation temperature. The addition of MEG dose of 0.175% mole at each production flow rate gives different working fluid temperature with hydrate formation temperature of 5.5 °F to 18 °F, so it is safe from the risk of hydrate formation

Determination of the Optimum Operating Conditions for Integrated Methanol and Ethanol Plant from Natural Gas Reactors

Methanol and ethanol can be produced from many kinds of feedstock. One of the most preferred methods to synthesize methanol is from natural gas, which is reformed to form synthesis gas (syngas) and converted by a catalyst to form methanol. Conversely, ethanol production mostly comes from biomass, which competes with human food fulfilment. Several pieces of literature conduct syngas transformation to ethanol to solve this problem. However, the experiment is conducted on a lab scale or pilot scale. Before the technology can be mass-produced on a plant scale, we must determine the most suitable operating condition for the reactor to escalate the reactor's productivity. This study is aimed to determine the optimal operating condition for the integrated methanol and ethanol plant, which is the reactors. The software used for the study is Aspen Plus V12.1. The independent variables for all the reactors in this study are the pressure (P) and the temperature (T). We add the feed molar flow ratio as the independent variable for the Steam Methane Reforming (SMR) and the ethanol synthesis reactor. The dependent variable that will be used for the determination of the optimal operating condition of the reactors is the reactant conversion and the product yield. The data validation between the experimental data conducted by other authors and the process modeling result is in good agreement with less than 6% of error for all three reactors. After performing the process simulation and sensitivity analysis to determine the optimal operating condition for the reactors, it is found that the optimal operating condition for the reactors is as follows: (1) SMR reactor: 25 bar pressure, 1,223 K temperature, feed molar flow ratio (H2O/CH4 ratio) of 3, (2) methanol synthesis reactor: 100 bar pressure and 503 K temperature, and (3) ethanol synthesis reactor:110 bar pressure, 583 K temperature, and feed molar flow ratio (H2/CO ratio) of 0.75

Effect of Pre-treatments on Shelf Life and Quality of Dried Pineapples (Ananas comosus)

This study aims to determine the effect of different pre-treatment and freezing on the quality of dehydrated pineapple using a food dehydrator with a convective drying method. The variations of pre-treatment conducted include control variation (K), immersion in sucrose solution (G), sucrose-citric acid mixture (GS), citric acid (S), thermal blanching (B), and kapur sirih or betel lime solution (KS), with and without freezing process before drying. The S variation resulted in the best shelf life of dried pineapple, lasting 106 days under room conditions using 0.75% citric acid solution. The shelf life of dried pineapple with pre-treatments K, G, GS, B, and K, respectively, were 61, 49, 33, 72, and 20 days. Drying and all types of pre-treatments resulted in a darker colour compared to fresh pineapple. Drying and all types of pre-treatments also yielded higher firmness values compared to fresh pineapple. Freezing prior to drying resulted in a darker colour for dried pineapple compared to unfrozen dried pineapple. Freezing prior to drying also yielded a softer texture compared to unfrozen dried pineapples. According to a group of 32 untrained panellists in the age group of 20-24 years old, the G variation was the most preferred variation of dried pineapple

Improved Joule Thomson equation of supercritical CO2-rich natural gas in separation system

The rapid expansion of supercritical gas technology for high-content CO2 separation from natural gas is a promising avenue of research. However, CO2-rich natural gas cools immediately after being separated and expands when the CO2 dew point is reached in the absence of a refrigerant system. In our previous study, supercritical expansion experiments using various CO2 compositions revealed that the Joule–Thomson equation gives a significant absolute average error value of 16.28%. This paper describes corrections to the Joule–Thomson expansion equation under supercritical conditions with various CO2 concentrations. The results show that the trend of the expansion coefficient is highly dependent on the CO2 composition. Using an improved Joule–Thomson equation of state over a CO2 range of 25%–45% mol, the expansion coefficient tends to fall immediately when a rapid expansion occurs. For a supercritical fluid, the specific heat Cp depends on temperature, pressure, and density changes. The Van der Waals expansion coefficient profile is simulated using MATLAB, resulting in a correction factor of 1.17–1.32 being applied to the Cp value for CO2 concentrations of 25%–40% mol, whereby the absolute average error tends to zero. For CO2 concentrations of more than 40%, the Joule–Thomson equation cannot be applied because the expansion coefficient exhibits significant errors compared with the experimental data. The expansion coefficient does not directly determine the performance of supercritical expansion, but does affect the vapor fraction. Integrated production systems based on supercritical expansion are expected to produce an annual profit of around US$18 million from turbine expansion and US$489 million from the production of sweet gas with a purity of 96.6% and less than 2% mol CO2