H.I. Abualhamayel

A method of obtaining fresh water from the humid atmosphere

Abstract This paper proposes to use a suitable liquid desiccant to extract fresh water from the humid atmosphere. The night-time moisture absorption and the day-time moisture desorption take place in the same unit. It consists of a flat, blackened, tilted surface and is covered with a single glazing. During the night, the strong absorbent flows down as a thin film over the glass cover in contact with the humid ambient air. Due to absorption of moisture from the ambient air at night, the absorbent becomes diluted. In order to recover the fresh water from the weak absorbent, it flows down as a thin film over the absorber during the day and is heated by solar energy. The water that evaporates from the absorbent rises to the glass cover by convection where it is condensed on the underside of the glass cover. The absorbent leaving the unit becomes strong and ready for moisture absorption at night. The performance of the unit was computed analytically for typical summer climatic data for the month of August in Dhahran, Saudi Arabia, by solving the energy balance equations. It is shown that for the given operating conditions it is possible to obtain about 1.92 kg of water per m2 of the unit. The influence of absorbent concentration and its flow rate on the performance of the system are briefly discussed in the paper.

Water recovery from the atmosphere

Water precisely fresh water is essential for live. The artificial fresh water production by desalting processes implies the utilization of energy. The ambient atmosphere contains a large quantity of water in the form of vapor and this endless source of water can be recovered for general use. In this paper, a method is proposed to use liquid desiccant to extract atmospheric moisture. The proposed system uses a single flat, tilted surface exposed to atmosphere as an absorber. In this paper, an analytical procedure for calculating the mass of water absorbed by the desiccant from the ambient atmospheric air in the absorber as a function of meteorological quantities and the desiccant initial conditions has been presented.

Hydrogen highway: An overview

This article presents the status of the technology to conceptualize hydrogen as a fuel and fuel cell car and hydrogen fueling station i.e. hydrogen infrastructure. Hydrogen is the lightest and most abundant element in the universe and it is an energy carrier. It can be produced from several sources using various methods and delivered to the fueling station or even it can be produced at the fueling station. Electrolysis of water or reforming of hydrocarbons such as natural gas can produce hydrogen in a big plant or even at the fueling station. But when it is produced using renewable energy such as wind, solar, geothermal, or hydroelectric, it has zero emissions in well to wheel. Hydrogen powdered vehicles either burns hydrogen in an internal combustion engine, or reacts with oxygen in a fuel cell. Developing a chain of hydrogen-equipped fueling stations and other infrastructure along the city road or highway, which will allow hydrogen powered cars to travel, is basically the concept of hydrogen highway. More substantial delivery infrastructure for hydrogen will require the use of high-pressure compressors for gaseous hydrogen and liquefaction system for cryogenic hydrogen. Hydrogen can be transport by road via cylinders, tube trailers, cryogenic tankers, and in pipelines or can be produced onsite. Each of these delivery and production modes requires a significantly different fueling station design. While hydrogen dispensers are basically the same regardless of the delivery or production mode, but the compressed and liquid hydrogen fueled vehicles are completely different. These combinations of hydrogen delivery or production at the station, compressed or liquid hydrogen dispensing, and various components and integration alternatives make up the array of hydrogen fueling station design and visualize total hydrogen infrastructure. Today, all the major automobile manufacturers have one or more prototype hydrogen fuel cell cars in their lineup. Again the advent of onsite hydrogen production system and/or home hydrogen fueling stations can help with the present infrastructure shortcoming. Companies such as Honda, ITM Power and Hydrogenics have at least prototype home hydrogen production and pumps, that may be available soon.

A simple analysis of solar desalination of seawater

Abstract A tilted solar still has been studied in application to desalinate the seawater. It essentially consists of a flat, blackened, tilted surface with a transparent glazing as a covering. The seawater trickles down as a thin film over the absorber and is heated by solar energy. The water vapor that evaporates from the liquid film is condensed on the under side of the glass cover and the fresh water flows along the glass surface by gravity into troughs. A simple expression is derived in this paper by using approximations to estimate the mass of fresh water evaporated from the seawater as a function of climatic conditions and initial condition of the seawater through a simplified vapor pressure correlation.

Application of Desiccant Technology for Concentrating Liquid Foods - Experimental Investigation

A single tube, stainless steel, liquid desiccant falling film evaporator was built and tested with the calcium chloride solution as the liquid desiccant to concentrate liquid foods. Experiments were conducted in the above setup with sugar solutions as the liquid food. To minimize water vapor mass transfer resistance, non-condensibles were removed from the system by a vacuum pump. No steam was used to drive this evaporator.The liquid food was heated to about 48ºC when the ambient temperature was 40ºC. The single tube double falling film evaporator was tested to determine the effect of desiccant concentration, temperature, and flow rate on the evaporation rate. The effect of liquid food concentration, temperature, and flow rate on evaporation rate was also studied. An uncertainty and error analysis for the experimental data was performed. It was demonstrated that liquid desiccants could provide enough energy, through heat of absorption, to evaporate a liquid food in a falling film evaporator with vapor transfer lines.