Adsorption Dryer Research Articles

Utilization of Ginger and Its Waste

Ginger has become the focus of research because of its oleoresin and essential oil content. First, the drying process can maintain the quality of post-harvest products and increase the shelf life of dry products. Applying heat by air, microwave, vacuum, and freeze-drying can remove up to 5% (w.b.) of the moisture content of the material. High temperatures provide a greater driving force and result in the best possible product damage. The involvement of an adsorption dryer can be an opportunity to carry out drying at low temperatures by involving a dehumidified air agent. Apart from drying, the extraction process is an essential component of the ginger isolation technique. In addition to temperature, the physical properties involved in this process are density and pressure (having relatively great difficulty in achieving the desired properties). Significant components with GC-MS and GLC tests gave different peak area results from the drying and extraction processes. However, β-phellandrene and camphene represent the presence of ginger essential oil in both methods. Then, the pulp and skin can also be reprocessed through extraction to produce ginger oil and ginger pulp. The sustainability of ginger residue through pyrolysis can produce ginger charcoal products. Meanwhile, the ginger pulp contains sugar, acid, and micro-fibrillation of cellulose (MFC) through hydrolysis. The results of research related to ginger provide opportunities for SMEs to produce post-harvest products in red ginger powder. The extraction process with polar solvents and the role of appropriate technology have encouraged independent economic activities. In addition, dregs from raw materials and by-products can be exploited for opportunities to reduce the waste generated.

Evaluating the efficiency of a proton exchange membrane green hydrogen generation system using balance of plant modeling

A system model of a proton exchange membrane green hydrogen generation system is developed with the intent of demonstrating the dynamic interactions of the system with varying inputs such as electrolyzer current density and hydrogen pressure. The model includes physics-based modules that are validated with available experimental data for the power electronics, electrolyzer stack, pressure swing adsorption dryer, hydrogen compressor, and cooling circuit components of the system. A single electrolyzer system and multi-electrolyzer system are evaluated with varying operating conditions and multi-stack system operating strategies. Increasing electrolyzer cathode pressure results in an overall increase in specific energy consumption but may allow the use of low-pressure storage without the need for a hydrogen compressor. For a theoretical case study of excess renewable energy generation in Texas, the system achieves an overall efficiency of 46.5 % defined as the efficiency of converting electricity into an equivalent energy content of the produced hydrogen.

Development of a Cost-effective Adsorption Dryer for High-quality Aerosol Sampling

Development of a Cost-effective Adsorption Dryer for High-quality Aerosol Sampling

Adsorption dryer for use in railways

Pneumatic brake, which use compressed air as a working medium, is the main brake of rail vehicles. The equipment used in the braking system requires sufficiently clean, without water vapour medium to work properly. Removing water vapour from the air prevents condensation and ice formation during winter, which guarantees correct brake operation. For this purpose, adsorption dryers are used in the railways to ensure the required pressure dew point value. This article includes an overview of available compressed air drying methods, the results of calculations and bench test of the dryer prototype developed at the Institute. Assumptions and requirements for the device intended for use in railways are based on European standards and UIC cards.

Air Drying in an Industrial Compressor

In many industrial applications where compressed air is used it is necessary to increase the quality of the air by decreasing its humidity. This is done by either a condensation or adsorption dryer in the compressor circuit. In this article, the focus is on an industrial adsorption air dryer. The dryer is briefly described together with its function and a selected range of adsorbents suitable for air drying. The paper further deals with the development of a mathematical model of air humidity adsorption which is based on the Pseudo Gas-side Controlled (PGC) model. This paper contains a detailed description of the model and describes its implementation in MATLAB. Finally, the results of the simulations are discussed.

Design and performance analysis of compressed air adsorption dryer with heatless regeneration mode

Design and performance analysis of compressed air adsorption dryer with heatless regeneration mode

Electrothermal Desiccant Regeneration Technique for Air Dehumidification

Adsorption dehumidification and drying equipment is essential general equipment for domestic and industrial use. The most commonly used type in industry is the compressed air adsorption dryer. The analysis results show that the heat loss of the traditional heat air regeneration system of the compressor dryer is 39.4%, and the exhaust waste heat is 32.4%. The actual use of heat energy for desiccant regeneration is only 28.2%. Therefore, this study uses an innovative electrothermal adsorbent unit (ETAU) to regenerate the desiccant. By directly heating the adsorbent, heat loss can be effectively improved. On the other hand, the composite arrangement of zeolite and activated alumina is used. The inlet compressed air is firstly treated by the activated alumina, which has a high adsorption capacity in the high relative humidity condition, then a zeolite is used as a second part to make the dew point reach –40 °C. In the regeneration step, the airflow direction is reversed, whereby the zeolite is regenerated by the ETAU, and the waste heat of the exhaust air is used to regenerate the activated alumina, which reduces the temperature of the exhaust air. Compared with the traditional heat air compressed air system, the two technologies can save about 27% energy in total.

Preparation and Characterization of a New Composite Adsorption Materials Composed of Two Activated Alumina and Microporous Molecular Sieve and Its Adsorption Property to Water

In order to improve the comprehensive performance of solid adsorption desiccant for compressed air adsorption dryer and reduce the loss rate of adsorption dryer, a new type of binary composite solid adsorption material suitable for compressed air drying is put forward. This material is composed of activated alumina (matrix) and 4A molecular sieve and 13X molecular sieve respectively in the proportions of 95%/5%, 90%/10% and 85%/15%. Static characteristic analysis is first made on three macro characteristic parameters, including the compressive strength, specific surface area and static water adsorption (60%RH). Thereafter, microscopic surface morphology analysis on composite material samples are employed. Comparative analysis result shows that, for compressed air drying, the activated alumina/13x molecular sieve with the proportion of 85%/15% is better than the 90%/10% activated alumina/4A molecular sieve composite solid adsorption material.

Investigation of the processes of adsorbent regeneration by compression heat in an adsorption dryer of compressed air

The results of numerical modeling of the processes of drying and regeneration of the adsorbent by heat of compression are presented on the example of the scheme of adsorption drying with the separation of the air flow on the stage of the cooling of the adsorbent. The dynamics of temperature and humidity parameters within the technological columns at all three stages of the adsorption and regeneration cycle was evaluated. It is shown that the considered scheme of adsorption drying allows to provide rather stable average dew point of the dried compressed air without losses on the adsorbent purging.

Diagnostics of Uneven Heating of the Adsorbent by Microwave Radiation and Measures to Increase the Uniformity of Its Heating

In Europe, 3 % of the electricity consumed by industry is spent on the production of compressed air. At the same time, the payment for electricity consumed by the compressor is the largest share in the structure of the factorys costs. In modern production, compressed air requires drying to meet the requirements of the equipment and for various technological processes. In this case, a large amount of compressed air is lost thus, improving the design of air dryers is an important step for improving energy efficiency. In this paper is developing a method for reducing the energy costs of the heated desiccant dryers is developed by mean of regenerating adsorbents using microwave energy.In the process of developing heaters using microwave energy, the main problem is the achievement of a uniform heating of the material. The same problem also arises when using microwave energy to regenerate the adsorbent in the adsorption dryer. Due of above-mentioned, the problem by dynamically changing the configuration of the heater chamber and waveguide systems is solved by using of increasing the uniformity of heating and two opposite waveguides in the heater design with a variable phase of one of them. A specific condition for conducting experiments is obtained. Particularly the adsorption dryer chamber is a cylindrical vessel that is filled with an adsorbent and has predetermined proportions. A significant change of these proportions adversely affect at the adsorption process during the operation of the desiccant.

Safety Analysis and Fault Automatic Recognition Technology of Regenerative Adsorption Dryer

In oil and gas processing station, the regenerative adsorption dryer absorbs the compressed air moisture to ensure the dew point of the gas. Once the dryer fails, it will cause the water dew point to rise, which will affect the operation parameters of the device in winter when the automatic control valves freeze. Control valves freezing can lead to serious consequences such as release, gas-Migration, and unqualified product quality and so on, which are difficult to deal with. The pressure of dryer and regenerative pressure are characterized by a certain periodic change when dryer is working. This paper introduces the automatic identification technology of the dryer fault. Logic analysis through DCS system can identify faults by analyzing the time curve of regenerative pressure, catching abnormal changes of the curve during the failure of dryer. The automatic identification technology of the dryer fault will be achieved in a short time and send out alarm signal to ensure the safe operation of the oil and gas treatment station. It is highly valuable for wide extension and application.

EFFECT OF THE APPLICATION OF MICROWAVE ENERGY ON THE REGENERATION OF THE ADSORBENT

Today, energy conservation is a priority. This is due to the shortage of energy resources, the growth of their cost and global environmental problems. The production of compressed air is a wery costly and power-consuming process. One of the areas of energy saving is to improve the quality of the air preparation equipment, in particular, to increase the energy efficiency of this type of devices such as adsorption dryers for compressed air. Reduction of unnecessary energy losses in this sphere is possible due to the use of innovative technologies. The functioning of the adsorption dryer is associated with the consumption of compressed air, which is consumed during the periodic regeneration of the adsorbent. The practical value of the research includes an explanation of the regularity of the influence of the temperature drop, at which the adsorbent regeneration process takes place, on the reduction of the airflow loss during the proceedings of the dryer.

Parametric analysis of thermal-pulse regeneration of activated alumina in temperature swing adsorption process used for gas dehydration

In many industrial applications of temperature swing adsorption (TSA) dryers, the heat for adsorbent generation is provided by heat sources with unstable temperatures (such as waste heat and exhaust steam); thus, the adjustments of purge gas flow rates are frequently needed to compensate the varying heating temperatures. In this study, we investigated the TSA operation method for the efficient utilization of the thermal energy with varying grades. A comprehensive mathematical model to accurately simulate the TSA drying process was presented and validated using the experimental data. A parametric study was conducted on an industrial-scale TSA compressed air dryer. The effects on the purge gas requirements of heating temperatures and purge gas flow rates were analyzed under different conditions of the feed water concentration. It was found that the purge gas requirements for cooling do not substantially vary with the heating temperatures as well as the purge gas flow rates, and even among the different feed water concentrations there is a small changing attitude of the purge gas requirements for cooling. A relationship equation between the heating temperature and the purge gas flow rate is obtained, which allows one to operate the TSA dryer to adapt to the varying conditions of the cooling water temperature and heat source temperature.

Evaluation of paddy quality dried with zeolite under medium temperature

Drying becomes important role to obtain good quality product in post-harvest treatment for paddy. Adsorption drying process taken place on medium operation temperature can be an option to enhance paddy quality. The aim of this study was to evaluate the quality of paddy dried with zeolite as adsorbent. In case, paddy from local farmer in Semarang was dried from initial moisture content 23% (wet basis) under different temperature 40 and 60°C, both with and without zeolite. Moisture content was observed by gravimetry every 15 minutes during 60 minutes drying time. Furthermore, the quality of paddy represented by percentage of head rice and proximate was analyzed after drying process completed. Results showed that compared to conventional drying without zeolite, the adsorption dryer was more superior in term of drying time as well as product quality improvement and there are no much differences in proximate analyzed result.

Actively cooled plasma-facing components and coolant removal system in KSTAR

This paper deals with the first commissioning of active cooling system and coolant removal system for plasma-facing components (PFCs). During 2015 KSTAR campaign, we have achieved a 55s long pulse H-mode plasma operation. However, some plasma shots were terminated, not because of instabilities or limitation of heating power, but because of safety limit applied to the PFCs temperature: upper boundary to lock the system is 400°C to protect the machine, and unlocked at 200°C. In order to overcome this limitation and to achieve longer pulse, an active cooling system is installed. With the active cooling, the temperature of lower divertor is about 302°C lower than that of upper divertor and returned quickly to initial temperature resulting in reduction of shot interval: Inertial cooling takes much longer time to unlock the safety inter-lock. One technical issue of this active cooling of PFCs is to remove coolant from the “cooling line”. The cooling line, pipe system inside the PFCs are also used to bake the PFCs. Therefore, a coolant removal system is assembled. The system is consists of adsorption dryer (external heater non purge air dryer), gas cooler, pipes and valve components. The coolant removal system was operated for 8days during PFC baking operation period. The dew point of requirement value (<−40°C) was decreased to −80°C, and then PFC baking operation was well done. And we could be achieved a 70s long pulse H-mode plasma at 2016 campaign.

A Study on Operating Method to Save Energy from the Adsorption Dryer in the Process of Purifying Compressed Air

A Study on Operating Method to Save Energy from the Adsorption Dryer in the Process of Purifying Compressed Air

Wireless H2S Sensor Uses Nanotechnology To Improve Safety In Oil and Gas Facilities

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 166544, ’An Innovative Wireless H2S Sensor Based on Nanotechnology To Improve Safety In Oil and Gas Facilities,’ by Marco Piantanida, SPE, Maurizio Veneziani, and Roberto Fresca Fantoni, Eni, and William Mickelson, Oren Milgrome, Allen Sussman, Qin Zhou, Ian Ackerman, and Alex Zettl, University of California at Berkeley, prepared for the 2013 SPE Offshore Europe Oil and Gas Conference and Exhibition, Aberdeen, 3-6 September. The paper has not been peer reviewed. Real-time monitoring of pollutant, toxic, and flammable gases is important for health and safety during petroleum-extraction and -distribution operations. Currently, many methods exist for detecting such gases, but most sensors suffer from slow response times, high power consumption, high costs, or an inability to operate in harsh conditions. This paper demonstrates a small, low-cost, low-power, highly sensitive nanomaterial-based gas sensor specifically targeted for the detection of hydrogen sulfide (H2S). Introduction Current personal monitors for H2S are typically electrochemical-based sensors because of their low power consumption, relatively small size, and satisfactory selectivity. However, electrochemical cells typically have fairly slow response times and are prone to degradation or errors at extreme temperatures and humidity. Semiconducting-metal-oxide (SMO) sensors have fast response times and simple interface electronics and can operate in harsh conditions, making them a mainstay of industrial monitoring. However, the power required to operate a conventional SMO sensor is typically hundreds of milliwatts. Therefore, operation of a handheld monitor using conventional SMO sensors is not feasible for long-term monitoring. To overcome this problem, the authors have fabricated very-low-power microheaters and functionalized them with tungsten oxide (WO3) nanoparticles to create an H2S sensor suitable for long-term battery-powered operation. Description and Application of Equipment and Processes Microheaters. Two types of microheaters are used in this research. The first is a commercially available microheater. This microheater uses a serpentine platinum heater sandwiched between a thin silicon nitride membrane on the bottom and a silicon oxide membrane on the top. Two gold electrodes provide electrical contact to the sensing layer. The second type of microheater was designed and fabricated at the University of California at Berkeley in the Center of Integrated Nanomechanical Systems. This microheater uses a suspended polysilicon bridge as the heater. The heater is isolated from the sensing layer with a thin silicon layer above and below the heater. Two platinum electrodes on top of the heater bridge provide electrical contact with the sensing layer. Nanoparticle Functionalization. The WO3 nanoparticles used in this study were suspended in isopropanol by means of ultrasonication and deposited on the microheaters by spincasting or dropcasting. Sensor Measurement. The WO3- nanoparticle-based microheater sensors are measured by use of a source-measure unit (SMU). One channel of the SMU is used to apply a voltage to the microheater and measure the current. The other channel is used to apply a voltage to the nanoparticle sensing layer and measure the current through the sensing layer. Data are collected with open-source instrument control software. Gas Delivery. The sensors are exposed to a gas stream of varying analyte concentration by means of a custom-made gas-delivery system. Using mass flow controllers, the gas concentrations are diluted from a target-gas cylinder balanced in nitrogen with air, which was cleaned and dried in-line through activated-carbon filtration and pressureswing adsorption dryers before dilution with the target gas. The humidity of the gas stream is controlled by a controlled evaporator mixer. The concentration of H2S was monitored by use of a reference sensor. Presentation of Data and Results Nanomaterials, especially metal-oxide nanomaterials, have been inventively researched for sensing applications because of their large surface-area/volume ratios, which enhance the effect surface reactions and adsorption have on their electrical properties. Nanostructured materials also have the beneficial capability of being heated to high temperatures using very little power. Previous research has shown that WO3 nanomaterials perform well as a sensor for H2S. However, as with most metal-oxide sensors, the sensors must be heated to obtain sufficient sensitivity and response times. Therefore, the authors constructed WO3-nanoparticle-based microheater sensors for detection of H2S.

Enhancing The Food Product Drying with Air Dehumidified by Zeolite

The demand of powdered food products such as soups, sauces, dried yeasts and herbal medicine is increasing for consumer convenience. Mostly, these products have been produced with drying process either, direct sunlight, conventional, or modern dryer. The direct sunlight dryer depends on the daily weather both in the product quality and process continuity. Meanwhile, conventional dryer results high energy consumption as well as low product quality due to the introduction of hot air. In addition, modern dryer process can improve the product quality, but the energy efficiency was fair. This study discusses the design and application of adsorption dryer with zeolite for food product. As samples, the carrageenan isolated from seawed and roselle extract were dried. Here, the air as drying medium was dehumidified by zeolite to enhance the driving force at lower temperature. The study was conducted in various air velocity, temperature and relative humidity. Results showed that the air temperature had the most superior effect both on product quality and drying rate. The higher temperature, the higher drying rate but the lower product quality. Air dehumidification had a positive effect on product quality and drying for low operational temperature. For all cases, it was recommended that the drying around70°C or below was favorable for reasonable quality and drying rate.

Enhancement of Energy Efficiency and Food Product Quality Using Adsorption Dryer with Zeolite

Drying is a basic operation in wood, food, pharmaceutical and chemical industry. Currently, several drying methods are often not efficient in terms of energy consumption (energy efficiency of 20-60%) and have an impact on product quality degradation due to the introduction of operational temperature upper 80oC. This work discusses the development of adsorption drying with zeolite to improve the energy efficiency as well as product quality. In this process, air as drying medium is dehumidified by zeolite. As a result humidity of air can be reduced up to 0.1 ppm. So, for heat sensitive products, the drying process can be performed in low or medium temperature with high driving force. The study has been conducted in three steps: designing the dryer, performing laboratory scale equipment (tray, spray, and fluidised bed dryers with zeolite), and evaluating the dryer performance based on energy efficiency and product quality. Results showed that the energy efficiency of drying process is 15-20% higher than that of conventional dryer. In additon, the dryer can speed up drying time as well as retaining product quality.

A Mixed Integer Formulation for Energy-efficient Multistage Adsorption Dryer Design

This work presents a mixed integer nonlinear programming (MINLP) formulation for the design of energy-efficient multistage adsorption dryers within constraints on product temperature and moisture content. Apart from optimizing temperatures and flows, the aim is to select the most efficient adsorbent per stage and product to air flow configuration. Superstructure models consisting of commonly used adsorbents such as zeolite, alumina, and silica-gel are developed and optimized for a two-stage, low-temperature, adsorption drying system. Results show that the optimal configuration is a hybrid system with zeolite as the first-stage adsorbent and silica-gel as the second-stage adsorbent in counter-current flow between drying air and product. A specific energy consumption of 2,275 kJ/kg is achieved, which reduces to 1,730 kJ/kg with heat recovery by a heat exchanger. Compared to a conventional two-stage dryer at the same drying temperature, this represents a 59% reduction in energy consumption. The optimal system ensures the exhaust air temperature of the first-stage regenerator is high enough to regenerate the second-stage adsorbent so no utility energy is spent in the second stage. A higher second-stage adsorbent wheel speed favors energy performance as it becomes optimized for energy recovery while the first is optimized for dehumidification. Although this work considers three candidate adsorbents in a two-stage system, the same reasoning can be applied to systems with more stages and adsorbents. The developed superstructure optimization methodology can, by extension, be applied to optimize multistage hybrid drying systems in general for any objective.