Condenser Column Research Articles

Evaluasi Kebutuhan Energi dari Teknologi Distilasi Spray sebagai Alternatif Hijau Proses Hilirisasi Bioetanol

Bioethanol downstream processing is consuming 40-60% of total energy requirement in production of bioethanol as fuel, with highest consumption being the evaporation and distillation process. One of the technologies currently in development stage is spray distillation. In spray distillation, ethanol-water mixture feed is dispersed as micro droplets into a heated column at 40oC, while counter current air is flown upward to collect the vapor and discharged into condensation column. Since the spray distillation principles has been tested in controlled laboratory scale, this research objective is to evaluate the energy requirement for such process and comparison to conventional distillation. Testing was conducted on 20 L batch stainless steel column distillation and spray distillation of the same capacity. The ethanol concentration in feed was set to 15%-v to simulate fermentation broth, and operating parameters were sets to obtain 80%-v product. Batch distillation was heated using LPG gas and calculation shows that heat requirement 3.34 MJ/L pure ethanol equivalent. Alternatively, spray distillation running with feed rate of 5.05 ml/s at 40oC only requires 2.2-2.6 MJ/L pure ethanol equivalent. The study shows potential of spray distillation technology in reducing the energy requirement in downstream processing of bioethanol to 62-79% of conventional distillation.

Separation of volatile organic contaminants from water using a direct-contact dehumidifier: An experimental study and modeling

A packed-bed, direct-contact dehumidifier (PB-DCD) has been developed to selectively condense water from a gaseous mixture of organic contaminants. In this process, hot air is humidified by mixing with wastewater vapor in a static mixer and is dehumidified by subcooled fresh water passing through the PB-DCD in a counter-current configuration. The goal of this study is to understand the relationship between various operating parameters and how they affect separation of isopropyl alcohol (IPA) from the gaseous mixture with the purpose of expanding the investigation to other contaminants in the future. The process has been successfully used to separate IPA from wastewater. Different parameters including the concentration of IPA in water, feed temperature, air-to-vapor ratio, and cooling-water-to-vapor mass ratio, as well as residence time were examined to determine their influence on contaminant separation and clean water recovery rate. The Buckingham Pi theorem was applied to reduce the number of studying variables by generating non-dimensional groups. Experiments were performed to determine the relationship between the non-dimensional parameters and model mass transfer in the system. Mass transfer coefficients for multicomponent gaseous mixture condensation in a packed-bed direct contact condenser column are calculated and a modified correlation of mass transfer is developed. The parameters of the mass transfer model are obtained from operating conditions of the PB-DCD, stream conditions and thermodynamic properties. A modified Sherwood correlation is developed to predict IPA separation from a gaseous mixture consisting of air, water, and IPA. The modified Sherwood correlation is applied to successfully predict the Sherwood number with a mean absolute error equal to 6.6 %. According to the experimental results, the maximum IPA separation achieved was 76.3 %, which corresponds to a water recovery rate of 58.7 %.

Exploiting Virgin Olive Oil By-products Using Hydrodistillation

Virgin olive oil processing results in a large amount of biomass (leaves, pomace, stones and wastewater) during harvesting, pruning and production. In recent years, these by-products have been studied as possible sources of bioactive compounds, and several techniques have been developed, including microwave, ultrasound, subcritical extraction, high hydrostatic pressure, a pulsed electric field, and high-voltage electrical discharge. However, these techniques can be expensive, and may require specialized staff to implement them. Therefore, this study proposes a novel method. Hydrodistillation is a simple and fast technique that can recover valuable compounds from olive oil biomasses. As it uses water as a solvent, it is sustainable, does not harm the environment, and is compatible with industrial practice. This paper presents the results of a hydrodistillation experiment on olive leaves, olive pomace and olive stones. Two fractions were obtained: a “phytocomplex” fraction from inside the boiler, and a “hydrolate” fraction from inside the condenser column. HPLC–DAD–MS and GC–MS analyses characterized and differentiated these two fractions. In general, more bioactive compounds, notably phenolic, were recovered from the phytocomplex fraction than the hydrolate fraction. Total phenolic compounds (mgtyr/kgoil) in the phytocomplex fraction were 11903.51, 4007.33, and 2469.42 mgtyr/kgoil for olive leaves, olive pomace and olive stone, while in the hydrolate fraction they were 67.67, 1.98, and 29.05 mgtyr/kgoil, respectively. Furthermore, interesting phenolic compounds typical of Olea europaea L. were found for both matrices. The main families were phenolic alcohols, secoiridoids and flavonoids. In particular, oleuropein, hydroxytyrosol, and tyrosol were recovered from the phytocomplex fraction of leaves and pomace. Finally, the analysis revealed higher amounts of volatile compounds in the hydrolate fraction than the phytocomplex fraction for leaves, stone and pomace. The main class of compounds were esters, ketones, aldehydes, alcohols, terpenes, phenols and their derivatives.Graphical

Non-catalytic and Catalytic Pyrolysis of Low Density Polyethylene LDPE Plastic Waste Into Fuel Ranged Hydrocarbons Using Nigerian Local Clay Composites

Plastic utilisation and plastic waste accumulation is rising in recent times mostly in developing countries. The utilization of modified and unmodified Nigerian bentonite clay as catalyst for preparation of fuel-ranged hydrocarbons from low-density polyethylene (LDPE) sachet wastes by pyrolysis was investigated. Pyrolysis of LDPE was done using locally fabricated semi-batch reactor condenser column. The products were characterized using Fourier transform infra-red spectroscopy (FTIR) and gas chromatograph with a flame ionisation detector (GC-FID). Physicochemical properties of the products were determined using standard analytical methods. The products from non-catalysed contained mostly saturated hydrocarbons compared to that of the catalytic process which contained more branched-chain hydrocarbons and mono-substituted aromatics. Physicochemical properties of the product from non-catalytic process showed resemblance to those of kerosene and diesel fuel while the properties of products from catalytic pyrolysis closely approximates those of commercial gasoline. This implies that the catalytic process gave products that were more suitable as fuels for auto engine which require higher octane number based on their naphthenic and aromatic content.

Hydrodistillation of Coffee By-products to Recover of Bioactive Compounds: the Spent Coffee Ground and Coffee Silvers Skin Case-study

Coffee industry produces large amounts of residues, mainly associated with roasting and consumption. Among these residues, coffee silver skin (CSS) and spent coffee grounds (SCG) are the most generated. In recent years, CSS and SCG have been object of increasing attention by researchers to study their possible reuses. The growing interest in the use of natural compounds has made it possible to study these residues as a source of bioactive compounds such as caffeine (CAF) and chlorogenic acids (CGAs). Nowadays, a great variety of techniques can be used for recovering of bioactive compounds from biomasses as raw materials. However, we need to evaluate more sustainable methodologies that, for instance, do not require the use of organic solvents. Accordingly, water is often accounted as the greenest solvent because of the its non-harmful character for both environment and human health. In our study, hydrodistillation (HD) process has been tested as a green method to recover and differentiate valuable compounds from SCG and CSS. HD is a variant of steam distillation in which the matrix is in direct contact with the solvent. In the present experiment, water has been chosen as a green solvent. Basically, the HD process allows merging the autohydrolysis extraction in mild temperature conditions (about 100°C), inside the boiler, with the continuous recovery of a condensate fraction with potentially different composition than the water-extract inside the boiler. In our experiment three matrices have been used, SCG, CSS and coffee powder as benchmark. Two fractions have been obtained, the condensate fraction, recovered in condenser column, and the water-extract, i.e. a phytocomplex recovered inside boiler. The two fractions of each processed matrix were characterized and then differentiated by chemical and physical analyses (total dissolved solids, electrical conductivity, oxidation-reduction potential and pH). Furthermore, compositional profiles were analyzed with HPLC technique, confirming the presence of compounds of interest such as caffeine and chlorogenic acids. In conclusion, the HD process allowed us to obtain two different fractions with different chemical and physical features, depending on the coffee residues (SCG and CSS). This could allow for a wider spectrum of possible uses of coffee residues available to the interested industry.

The Birgitta Field, Block 22/19a, UK North Sea

Abstract Birgitta Field was discovered by well 22/19-1 which encountered a 230 ft gas–condensate column in Triassic Skagerrak Formation and tested at a combined rate of 38.3 MMscfgd and 3750 bcpd. The tilted-fault block trap forms the crest of a Triassic ‘pod’ or mini-basin formed by salt withdrawal during Triassic extension, further rotated and eroded during Jurassic extension. Field extent is supported by apparent seismic hydrocarbon indications. An early oil charge was likely converted to condensate by Plio-Pleistocene gas influx and rapid burial, whilst an underlying palaeoresidual gas column reflects some trap leakage. Birgitta typifies certain Triassic reservoir characteristics in this part of the Central North Sea. The thick, relatively high net:gross reservoir comprises moderate to poorly sorted, sub-lithic to sub-arkosic sandstones deposited in a dryland braided fluvial system. Pore-lining chlorite overgrowths dominate the pore fabric, reducing pore throat sizes and contributing to appreciable levels of non-effective micro-porosity and hence elevated water saturation. Key petrophysical challenges are the accurate determination of effective porosity and water saturation. Birgitta approaches high pressure–high temperature conditions and illustrates some of the challenges of progressing small, unappraised field tie-backs. These include resource uncertainty, compartmentalization risk, infrastructure access and marginal economics. Evaluated for development several times, Birgitta presently remains undeveloped.

Research on the refrigerant column height in the downcomer of a two-phase loop thermosyphon

A two-phase loop thermosyphon (TPLT) is a highly efficient heat transfer device. It is a type of gravity-assisted heat pipe system. Therefore, there is a high refrigerant column height in the downcomer that supplies the driving force for the TPLT system. This study focused on the investigation of factors that influence the refrigerant column height in the downcomer of a TPLT system through an experiment and a numerical simulation. These factors were identified as the flow resistance, increased working pressure, and amount of liquid phase flow in the two-phase flow. In addition, the effect of the condenser height was considered. The extreme situation in which the condenser was filled with liquid refrigerant was analyzed through an experiment. The results indicated that a high refrigerant column height would occupy part of the condenser space and decrease the performance of the TPLT. In practical applications, the relationship between the condenser and refrigerant column height should be considered. These influencing factors of the column height in the downcomer should be considered when deciding the geometric parameters and filling ratio of a TPLT system.

System analysis of the secondary condensation unit in the context of improving energy efficiency of ammonia production

We established the mismatch between real and design coefficients of heat transfer, which is predetermined by the underestimation of condensation thermal resistance. The processes of heat exchange in a condensation column are identified and the equations for determining the coefficients of heat exchange, heat transfer and the concentration of ammonia in the circulation gas at the outlet of the column are derived. By applying the method of mathematical modeling, we defined necessary conditions for temperature distribution to exclude from the circuit of the unit for synthesis a turbo-compressor refrigeration unit with electric drive of capacity up to 4000 kW·h and reduction in the cooling temperature of circulation gas from 0 °C to – 5 °C at maximum thermal load with circulation gas on the complex of secondary condensation. The hardware-technological design is developed for the stage of secondary condensation based only on the absorption and steam-ejector refrigeration systems that utilize the heat of material flows of low (above 100 °C) and super-low (to 90 °C) potentials. We defined efficiency indicators for the reduction of specific energy consumption by electricity and natural gas, which are 60 kW·h/t NH 3 and 1.2 m 3 /t NH 3 .

Experimental research on the thermal stratification criteria and heat transfer model for the multi-holes steam ejection in IRWST of AP1000 plant

In AP1000 plant, the Automatic Depressurization System (ADS) 1–3 stages operate to discharge the high-temperature and high-pressure steam from the Reactor Coolant System (RCS) primary side to the large heat sink tank In-containment Refueling Water Storage Tank (IRWST) in accidental conditions. The key equipment’s specific shape and arrangement lead to the complicate flow and heat transfer characteristics in IRWST. In the present work, an overall scaled IRWST&ADS sparger experiment has been built up. The thermocouples matrix, flowmeters, pressure transmitters, heat flux sensors, Particle Image Velocimetry (PIV) technique, and high speed camera are employed for the measurements of the key thermal and flow parameters. The local steam jets condensation phenomena as well as the overall flow and thermal behavior are investigated. The experimental results indicate that the thermal stratification phenomenon is obvious in IRWST. The criteria of Richardson Number and Stratification Number are utilized to predict and evaluate the thermal stratification extent, respectively. An improved ADS arrangement design is further proposed to reduce the thermal stratification. Moreover, the multi-holes lumped “steam condensation column” is modeled with characteristic parameters, then the steam condensation heat transfer coefficient range in chugging condensation process is estimated. The experimental results provide practical engineering application reference for the effective operation of the passive safety system in AP1000 plant.

Design and Construction of a Desalination Prototype Based on HD (Humidification-Dehumidification) Process

The paper deals with a low-temperature thermally driven desalination unit exploiting the HD (humidification/dehumidification) process. The system is a closed air cycle unit and is based on a single-effect humidification/dehumidification technique: heated seawater is introduced into the humidification section of a closed tunnel to saturate the circulating air; then the water vapor in moist air separates within the condensation column, where freshwater production takes place.A HD desalination prototype has been designed, assembled and fully instrumented in order to monitor all physical quantities and to evaluate the performance under different operating conditions. The prototype has been experimentally investigated on a test facility established at the Bergamo University Labs. The results of the measurement campaign are presented and discussed.A computer code for simulating the desalination process has also been developed and it was validated by the experimental data.The modeling procedure investigates air and water thermodynamic properties across every component and allows to predict the HD desalination unit performance, varying seawater and air flow rates, the heat source temperature level and the heat exchanger surfaces.

Semicontinuous Separation of Bio-Dimethyl Ether from a Vapor–Liquid Mixture

In this work, a semicontinuous system is investigated for the separation of biomass-derived dimethyl ether from a vapor–liquid mixture. This novel semicontinuous system operates in a cyclic campaign and utilizes one partial condenser column coupled with a middle vessel to achieve the separation typically carried out using two continuous distillation columns. The performance of six control configurations based on composition or temperature inferential control were analyzed. Dynamic simulation results demonstrate the effectiveness of the semicontinuous system and its temperature inferential control configuration in achieving the separation objectives, remaining within operational limits and rejecting fresh feed disturbances. Finally, the semicontinuous system is compared to the traditional continuous system from an economic standpoint with the sensitivity of operating cost to middle vessel product target purity highlighted.

The major sources of gas flaring and air contamination in the natural gas processing plants: A case study

Global flaring and venting of natural gas is a significant source of greenhouse gas emissions and airborne pollutants that has proven difficult to mitigate. Devastating impact of such emissions both on the climate and environment makes it inevitable for researchers, environmentalists and policy makers to give remarkable focuses on this issue in recent times. This paper revolves around highlighting potential and critical situations, identifying the proper mitigation and focusing on the sources of flaring and contamination to reduce the generation of wastes from the gas processing plants of a domestic natural gas field in Iran. The flaring management of four domestic gas processing plants with the total capacity of 252 million cubic meter natural gas in a day plays an important role in the environmental pollution reduction. The inventory of emissions lists all the individual sources of air contamination in each gas processing plant and the quantities of the emissions. The major sources of gas flaring are the regeneration gas coming from the mercaptan removal unit in Phase 1, the sweeping gas consumption in the flare network in Phase 2 and 3, and the backup stabilization gas flaring in Phases 4 and 5. The adjustment of fuel gas consumption was conducted after the flare network back pressure has been calculated in Phase 2 and 3 by a Flare Net simulator. In order to address the excessive fuel gas network corrosion in Phases 6, 7 and 8, a modification was performed in this gas processing plant. Chemical de-emulsifier injection allowed for removing the debris build-up on the rebuilder's tubes of the condensate stabilization column in Phases 4 and 5. The recycling regeneration gas of the mercaptan removal unit in Phase 1 reduced 55% of the gas flaring in this gas processing plant.

Research and mathematical modeling of heat exchange in the separator condensation column sintesis ammonia aggregate

The paper contains results of mathematical modeling of the separator of condensation column of a block of ammonia secondary condensation. According to the results of experimental and analytical investigations an equation is given to calculate the temperature of the gas flow, needed to determine the heat-exchange surface of the column.

Isolation, structure determination and antibacterial activities of succinamide conjugate diacid from Acinetobacter sp. BJ-L

Strain BJ-L was isolated from the a water sample taken from Xiao Yue River in Beijing and identified as Acinetobacter sp. BJ-L based on the study of its morphology, physiology, biochemistry and 16S rRNA gene sequence. A new antimicrobial substance was produced after the strain was incubated in potato extract medium at 15°C for 72 h. The antimicrobial substance was sequentially purified by reduced pressure condensation, EtOAc extract, and silica gel column chromatography. The structure of the antimicrobial substance was elucidated as succinamide conjugate diacid (SCD) by spectroscopic data interpretation. Structure analysis indicated that SCD is a novel compound and that it could inhibit the growth of some tested bacterial strains with the MIC of 2mg/ml, such as Staphylococcus aureus, Bacillus subtilis, Enterobacter aerogenes and Escherichia coli. Moreover, no obvious toxicity has been found on cultured HUVEC cells with different concentrations of SCD at 5, 10, 15, and 20mg/ml.

The Jasmine discovery, Central North Sea, UKCS

Abstract The Jasmine Field is located in blocks 30/06 and 30/07a on the J Ridge, the southeastern extension of the Forties–Montrose High, which separates the eastern and western basins of the UK Central North Sea. The field was discovered in 2006 and is close to two ConocoPhillips producing fields, Jade and Judy, which serve as useful local analogues. The main West Limb structure is a turtle-back faulted anticline NW of the Joanne salt pillow. The primary reservoir is Triassic in age and consists of stacked fluvial sandstones of the Joanne Member of the Skagerrak Formation. The HPHT exploration wells 30/06-6 and geological sidetrack 30/06-6Z discovered a rich gas condensate column of 2300 ft, some 1100 ft deeper than the mapped independent structural closure of the prospect, and achieved good flow rates on test. To appraise the discovery and assess the potential for significant additional volumes in an adjacent downfaulted terrace, a programme comprising a main well and two sidetrack wells was initiated in 2007. Appraisal well 30/06-7 discovered a 550 ft hydrocarbon column in the Northern Terrace with a hydrocarbon–water contact shallower than that observed in the West Limb, thereby proving structural compartmentalization between the two fault blocks. Good flow rates were achieved from a drill stem test in mechanical sidetrack well 30/06-7Z. Sidetracks 30/06-7Y and 30/06-7X were drilled to confirm the northwestern extension of the West Limb discovery and to test the northern extent of the Northern Terrace accumulation, respectively. This programme has reduced volumetric uncertainty but the trapping mechanism and the ultimate extent of the Jasmine accumulation remain unknown. Comprehensive data acquisition throughout the exploration and appraisal phases, including drill stem testing, core recovery and seismic data reprocessing, has facilitated a detailed reservoir characterization programme. Jasmine represents a significant new high pressure/high temperature resource in the mature Central North Sea and is currently undergoing development planning.

Local Heat Transfer Coefficient of Steam Condensation with High Fractional Noncondensable Gas in the Dewvaporation Desalination Process

A tubular condenser column was designed and constructed to evaluate the performances of the condensation process with a high fractional noncondensable gas in the dewvaporation desalination process. An experimental investigation has been conducted to determine the local condensation heat transfer coefficient, which is related to steam−air mixed gas condensation in an annulus around a vertical copper tube. The results show that the local heat transfer coefficient decreases with increase of the distance from the mixed gas inlet, and varies from 200 to 1900 W/m2·°C, which is high enough for steam condensation in the presence of a high fractional noncondensable gas. The correlation of steam condensing local heat transfer coefficient in the presence of a high fractional noncondensable gas was developed in terms of the local mixture Reynolds number, Jakob number, and ratio of noncondensable gas mass fraction. It is found that the correlation has a good agreement with the experimental data.

Effects of high fractional noncondensable gas on condensation in the dewvaporation desalination process

A shell and tube condenser column was designed and constructed to evaluate the performances of the steam condensation process with high fractional noncondesable gas. The process is related to steam–air mixed gas condensation in an annulus around a vertical copper tube with 10 mm outside diameter. In order to investigate the effect of condensing column length on overall heat transfer coefficient, the columns with various length of 2.5 m, 2.0 m, 1.6 m, 1.3 m and 1.0 m were tested with steam-air mixed gas, respectively. The test variables were as follows: mixed gas inlet temperatures range from 92 to 68°C; inlet air mass fraction from 34 to 81%; inlet mixed gas velocity from 1.08 to 10.80 m/s and mixture inlet Reynolds number from 500 to 5000. The results show that the overall heat transfer coefficient decreases as the condensing column length increases under the same mixed gas inlet Reynolds number. The overall heat transfer coefficient varied from 350 to 3000 W/m 2°C, which is high enough for steam condensation in the presence of a high fractional noncondensable gas. It has promising application in dewvaporation desalination process at pilot scale. The correlation of steam condensing heat transfer coefficient in the presence of a high fractional noncondensable gas was developed along condensing column height.

Modeling, simulation and optimization: Mono pressure nitric acid process

Abstract The present work focuses on a strategy for optimizing mono pressure weak nitric acid plants. The optimization strategy addresses important processes which include oxidation of ammonia to nitric oxide, heat recovery from product stream of ammonia oxidation reactor and absorption accompanied by complex chemical reactions of multi-component nitrogen oxide gases into water. In design and optimization of nitric acid process, it is essential to understand the rate controlling step for ammonia oxidation process, strategy to be adopted for heat exchanger network design, rates of mass transfer and chemical reaction for nitrogen oxide absorption and the combined effects of several equilibria. The work addresses these issues taking through the complexities in the above mentioned processes. The parametric sensitivity of few parameters such as ammonia to air ratio, excess oxygen/air, selectivity, power recovery based on the performance efficiency of compressor and expander, inlet and outlet nitrogen oxide composition in condenser and absorption column have been a part of our investigation either explicitly or implicitly. Further, for the absorption column, the effects of geometrical parameters, excess air, extent of absorption, product acid concentration, temperature and pressure have been analyzed for the purpose of optimization of nitric acid plant. All parameters having major influence on annualized cost of product acid have been analyzed and presented.

Measurement of Coulomb interactions in an electron beam monochromator

Electron energy loss spectroscopy in the TEM with sub-0.1-eV energy resolution requires the incorporation of an electron beam monochromator in the condenser column. At high beam currents, the statistical Coulomb interactions in the monochromator broaden the energy distribution (Boersch effect) and blur the apparent source, thus limiting the energy resolution and spatial resolution of the microscope. We have built a monochromator (Wien filter type) with a length of 50 mm and measured the blurring of the energy dispersed beam for various beam currents. At low beam currents, the observed blur agrees reasonably well with the theoretical size of the blur. We calculate the theoretical magnitude of the Boersch effect in the filter, and we conclude that the combined action of the Boersch effect and the blur does not impede an energy resolution better than 0.1 eV as long as the total beam current is below ≈30 nA.

A Theoretical Model of Film Condensation in a Bundle of Horizontal Low Finned Tubes

The previous theoretical model of film condensation on a single horizontal low finned tube is extended to include the effect of condensate inundation. Based on the flow characteristics of condensate on a vertical column of horizontal low finned tubes, two major flow modes, the column mode and the sheet mode, are considered. In the column mode, the surface of the lower tubes is divided into the portion under the condensate column where the condensate flow is affected by the impinging condensate from the upper tubes, and the portion between the condensate columns where the condensate flow is not affected by the impinging condensate. In the sheet mode, the whole tube surface is assumed to be affected by the impinging condensate. Sample calculations for practical conditions show that the effects of the fin spacing and the number of vertical tube rows on the heat transfer performance is significant for R-12, while the effects are small for steam. The predicted value of the heat transfer coefficient for each tube row compares well with available experimental data, including four fluids and five tube bundles.