Optimizing design and cost of seawater reverse osmosis systems

The influence of design parameters, such as raw water temperature and total dissolved solids content (TDS), design pressure, and recovery, on total unit cost for the production of desalinated water from the Arabian Gulf in Saudi Arabia by means of reverse osmosis is presented for plant capacities ranging from 75,000 m³/d to 700,000 m³/d. It is concluded that total unit water cost is significantly influenced by raw water TDS, design pressure and design recovery. It is recommended to investigate the feasibility of operation at increased pressure. Finally, total water costs for reverse osmosis desalination are presented also as a function of salinity, with TDS levels ranging from 3000 mg/l to 55,000 mg/l.     

Membrane processes for water supply and reuse - a question of energy consumption and cost

This paper is limited primarily to reverse osmosis which is the dominating membrane process in commercial plants. Desalination of brackish water and seawater with reverse osmosis, with special emphasis on costs and energy consumption, is the primary subject discussed in the paper. Some aspects of and development trends in industrial and domestic applications of membrane processes are also taken up, particularly with regard to by-product recovery and water reuse in connection with advanced wastewater treatment.The first RO plant to be brought into operation in Riyadh, Saudi Arabia, is located at Salbukh. The investment and total operation costs for this plant have been calculated in the paper. The water cost is at least twice as high as in a continental U.S. location. The main reason for this is the very high cost of civil and local works in Saudi Arabia. A similar calculation has been made for RO seawater desalination.Increased energy costs during the last decade have directed research and development work for all desalination methods towards reducing energy consumption. It is shown in the paper that energy recovery in connection with RO seawater desalination is particularly feasible. Different methods for energy recovery have been investigated and reported, the preferred methods depending on the size of the RO plant. A large underground RO plant for energy recovery, based on utilization of the static pressure instead of high pressure pumps, has also been studied.Another possible energy-saving, but also water quality improving method has been proposed, viz . a combined MSF-RO dual purpose plant. Excess power for reverse osmosis seems to be more and more available in Saudi Arabia due to the high power/water ratio in MSF dual purpose plants compared to the real demand for power and water.     

Prospects of the exploitation of advanced energy resources in water production in the middle east

The utilization of oil and natural gas in water production and in supplying steam for desalination plants is progressing with a remarkable rate in the Middle East and especially in the oil producing countries. Nevertheless, some of the available economically feasible energy sources are yet to be exploited. Available hot brine and steam fields in the Red Sea Deeps and in other locations in the Middle East are a valuable source of useful energy for desalination. The rapidly growing geothermal technology can be utilized in supplying fresh water to the Red Sea coasts for both of the western cities of Saudi Arabia and the new settlements on the eastern Egyptian coast. An assessment is made of the geothermal fields in the area and their characteristics with special consideration of their utility in water desalination projects. Other energy sources are also considered; such as the future exploitation of heavy water and heavy hydrogen isotopes obtained from the Red Sea in energy sources for desalination. In addition, the potential use of natural depressions in the production of power and water is discussed. A comparison is made between these advanced systems and contemporary alternates in a longterm plan for agricultural and industrial expansion.     

Selection of desalination technology, a decision analysis approach and a case study

The state-of-the-art desalination technologies are screened from the point of view of meeting the Saudi Arabian requirements including water/power demand, forecast and future expansions. Also, compatibility with the Saudi Arabian technology development, environment and manpower availability is considered.

Considering MSF and ED as alternate technologies, multi-objective decision analysis is used to select the most preferred technology for Saudi Arabia. The methodology is based upon assessment of the attributes that affect the selection. Some of those attributes include: reliability, operability, maintainability, manpower requirements and utilization of national resources. Utility values are then computed to reflect the preference of decision makers and the values are then combined to give the overall utility for each choice.

The selection method is described and the formal numerical analysis are presented. The methodology is applicable for various situations and is flexible enough for introducing other sets of attributes.     

Polyvinyl chloride pipe degradation studies in natural environments

PVC pipes are generally stabilized with lead, tin, or calcium-zinc based additives. The performance of PVC products in outdoor applications is highly dependent on the types of stabilizers used and environmental factors such as UV radiation, temperature, humidity, rain, dust, etc. This study involves two-year exposure of a lead-stabilized and titanium dioxide-pigmented PVC pipe at Dhahran (Saudi Arabia) and Miami, Florida. The white pigmented PVC pipes are mostly used outdoor for low pressure potable water services, irrigation in greenhouses, and electrical conduits in Saudi Arabia. The PVC pipe formulation stabilized with Pb-stabilizer provides good light stability and is also widely used for potable water pipes. The pipes are exposed not only to the natural environment during outdoor usage but also to high UV doses, and to high temperatures during transportation, installation, and long-term storage. Changes in the exposed pipe were monitored using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetery (DSC), and mechanical properties testing. The data show that the PVC pipe lost 50 percent of its elongation at break within 12 to 16 months at Dhahran and more than 24 months in Florida during outdoor exposure. The growth of carbonyl groups and the lowering of the glass transition temperature (T_g) was also observed during this exposure period. The extents of degradation of the PVC pipe exposed at the Dhahran and Florida sites were compared.     

Reliability analysis of reverse osmosis plant

The increasing complexity of desalting plants demands consideration of operational and maintenance factors in the design phase. Applications of the fault tree techniques to RO sea water desalination systems are illustrated; critical failure problem areas are identified and methods of improving the performance of the RO desalination plants are recommended. Failure data has been extracted from operation and maintenance reports of the operating RO desalination plants in Jeddah, Saudi Arabia. An assessment is also made of the impact of failures and outages on the availability of the plant.     

Obesity and eating habits among college students in Saudi Arabia: a cross sectional study

Background  

During the last few decades, the Kingdom of Saudi Arabia (KSA) experienced rapid socio-cultural changes caused by the accelerating economy in the Arabian Gulf region. That was associated with major changes in the food choices and eating habits which, progressively, became more and more "Westernized". Such "a nutritional transition" has been claimed for the rising rates of overweight and obesity which were recently observed among Saudi population. Therefore, the objectives of the current work were to 1) determine the prevalence of overweight and obesity in a sample of male college students in KSA and 2) determine the relationship between the students' body weight status and composition and their eating habits.     

Engineering management of nuclear desalination plants—a case study,Saudi Arabia

Engineering management and manpower aspects of potential nuclear desalination projects in non-nuclear countries are considered here with emphasis on safety and quality assurance. Detailed investigation is made of manpower and staffing requirements of dual-purpose nuclear power and desalination plants. Organization and management of typical overall nuclear programs and individual plants are studied to provide specific recommendations of procedures compatible with countries having little or modest industrial activity. Saudi Arabia was selected as a specific case for this study; however, the results apply generally to countries at the same industrial development level. The case of Saudi Arabia is of interest due to the peculiarities of a shortage in human capital and a lack of industries necessary to support desalination and nuclear energy activities.     

Performance study of water desalination methods in Saudi Arabia

Saudi Arabia is an arid desert country without rivers or sweet water lakes, however, it does have vast amount of groundwater and seawater. In order to make these waters suitable for human consumption and industrial use, most of their salts must be removed by some means. The desalination methods most frequently used in the Kingdom are: Multistage flash (MSF) evaporation, reverse osmosis (RO), and electrodialysis (ED).During the last decade, we have witnessed a spectacular growth of desalination plants. This growth is expected to continue in the next decade. The present production capacity of all desalting plants in Saudi Arabia is estimated to be 750,000 m³/day; this figure will be most likely tripled in the next five years.This paper is a report on a performance study of the most significant desalination plants in the Kingdom. The plants, which include MSF and seawater and brackish water RO plants, were selected either because of their size or their importance to the desalination technology. The plants are briefly described and their performances are discussed.     

Seawater desalination by reverse osmosis : Plant design,performance data,operation and maintenance (Tanajib,Arabian Gulf Coast)

A systematic interpretation of critical combinations of feed water, pretreatment and membranes and adequate conclusions can avoid setbacks of reverse osmosis processes. Reputed systems manufacturers will find the right approach if their tasks will be changed from a limited responsibility — for design, construction, installation and commissioning only — to an overall responsibility which includes operation and maintenance.In 1982/83 Preussag received from Aramco in Saudi Arabia the order for the first temporary reverse osmosis seawater desalination plant at Tanajib, Arabian Gulf Coast, with a total net capacity of 600,000 gpd. The orders were placed on a turnkey basis including operation and maintenance.The highlights of the RO seawater desalination plant are: shallow beach wells, ultrafiltration, vacuum deaeration, high-pressure multi-stage centrifugal pumps with energy recovery turbine, single stage reverse osmosis and free programmable logic and process controller.During the first more than one and a half years of operation, product quantity and quality has always met the requirements of Aramco's specification. The excellent experiences until today with the first temporary Tanajib reverse osmosis seawater desalination plant permit the conclusion that RO technology can avoid major setbacks and may face the competition with the distillation processes with confidence.     

浙江省海水淡化工程"十一五"水利规划

在对沿海和海岛地区实地调查、收集大量资料的基础上,分析研究了海水淡化技术的应用现状、适用性、吨水投资、制水成本以及对水源和运行管理等要求,对浙江省海水淡化工程进行了规划。规划近期规模为2．69万m^3／d,远期新增2．85万m^3／d,总建设规模5、54万m^3／d,规划工程近期建设投资21770万元,远期23100万元;规划确定的滩涂水资源水处理工程规模,近期为7000m^3／d,工程投资5600万元;远期为81000m^3／d,工程投资56700万元。文章还提出了开源节流、节能的建议措施。     

中东国家化妆品和盥洗用品市场

叙述了中东地区各国化妆品和盥洗用品市场的现状。随着海湾地区和沙特阿拉伯国家人们可任意支配收入的增加和旅游业的发展,带动了这一地区化妆品市场的增长。曾经一度使用的天然油皂也逐渐被外国品牌的液体皂和浴用凝胶所代替。驱动这一地区化妆品和香水增长的主要国家是富油区的沙特阿拉伯和阿拉伯联合酋长国的一些海湾国家——科威特、巴林和卡塔尔,这些国家的经济增长主要是由石油支配。此外,商场和美容保健中心的繁荣也反映出海湾国家化妆品和香水的消费在世界上也处于领先地位。     

Comparative cost analysis of nuclear versus oil-fired dual-purpose desalination plants

Prospects for the application of nuclear energy to sea water desalination for the Kingdom of Saudi Arabia have been evaluated here based only on economic considerations. Updated capital costs of power plants and current prices of oil and nuclear fuel are used. Information on the Kingdom's water demand and current status of water desalination is provided. A comparison is also made of costs of water production from power-cum-desalination nuclear plants versus oil-fired plants. Only dual-purpose nuclear plants are considered because of their overall economic advantages over single purpose (water only) plants. The scope of available data and information can not be provided in such detail as to allow for system planning or for a site-specific feasibility study. However, the results provide guidelines for more in-depth analysis. The results show that, compared to oil-fired plants, there is a net saving of costs in using nuclear plants for desalination. If interest on capital is disregarded in calculation of total capital costs and also in calculation of annual capital charges, the economic advantages of nuclear power plants improved significantly over the oil-fired power plants.     

Operational data analysis of MSF desalination plants. A case study of Jeddah I

Monthly operation and maintenance reports of the oldest large MSF plant in Saudi Arabia, Jeddah I, are analyzed to extract information or generic operation and design problems and to seek means for the mitigation of such problems. The accumulated records are quantified to provide estimates of equipment failure rates. Three systems are found to be the major contributors to plant outage namely, make-up water, brine recycle and sea water intake systems. Root causes of the plant unscheduled shutdowns or reductions in water production are assessed to examine generic reasons for deviations of MSF systems from standard expected performance.     

Weather-Induced Degradation of Plastic Pipes

A number of plastic materials, such as unplasticized poly(viny1 chloride) (uPVC), acrylonitrile-butadiene-styrene (ABS), high-density polyethylene (HDPE), poly-(vinylidene fluoride) (PVDF), and chlorinated poly(viny1 chloride) (cPVC), are available for numerous applications. uPVC and HDPE pipes are used in pressurized piping systems in Saudi Arabia for industrial, agricultural, domestic, and general-purpose applications. Some studies have been carried out to investigate the causes of failure in plastic pipes, which is very high in the area. In this chapter an overview of the failure of plastic pipes is presented, with emphasis given to failure of pipes due to severe weather conditions in Saudi Arabia.     

Crop response to sulfur-coated urea (SCU) and other N-carriers in sandy soils of Saudi Arabia

Nitrogen losses due to leaching, volatilization and denitrification result in low fertilizer efficiency. Slow-release N fertilizers are proposed to minimize these losses, and sulfur-coated urea (SCU) has been examined. A greenhouse study was conducted using two coarse textured: loamy sand and sandy loam soils from Al-Kharj, Saudi Arabia to compare sulfur-coated urea (SCU) with urea, ammonium nitrate (AN) and ammonium sulfate (AS) and to determine the effectiveness of single appliction of SCU over split application of soluble N sources. Tomato (Lycopersicon esculentum L.) and sorghum (Sorghum bicolor L.) were grown as indicator crops. Dry matter yields showed a significant increase with SCU fertilizers over other sources applied single or split, particularly in loamy sand soil. SCU-22 resulted in a consistent increase of dry matter yield and N-uptake compared to SCU-30 and SCU-40. The potential benefit of using SCU in coarse textured soils appers to be promising for increasing N fertilizer efficiency. Producing these slow release N fertilizers seems feasible if a coating step is added to the manufacturing process of urea produced from some fertilizer plants in Saudi Arabia.Contribution from the Regional Agriculture and Water Research Center (RAWRC), Ministry of Agriculture and Water, Riyadh, Saudi Arabia. Presented in Div. S-8, Am. Soc. Agron. Meeting, Atlanta, GA, November 1981.     

Reactor Developments in Hydrotreating and Conversion of Residues

Many industrialized western countries depend on imported foreign crude. In 1977, for example, the United States imported 46% of its oil and petroleum products, chiefly from Saudi Arabia, Iran, and other OPEC nations. By September 1, 1983, the United States imported only 28% of its oil. The chief suppliers were Mexico, with 826,000 barrels per day, Canada, with 479,000, and Venezuela, with 419,000. Saudi Arabia is now seventh on the list of suppliers for the United States. This shift is responsible for the trend toward a heavier crude supply mix on the international market. Transportation fuels and petrochemical feedstocks are in increasing demand; hence many refiners would like to get out of the fuel oil business, More “bottom-of-the-barrel” conversion capability will be required in many refineries to efficiently process these heavier feedstocks and maximize production of light products.     

Reactor Developments in Hydrotreating and Conversion of Residues

Many industrialized western countries depend on imported foreign crude. In 1977, for example, the United States imported 46% of its oil and petroleum products, chiefly from Saudi Arabia, Iran, and other OPEC nations. By September 1, 1983, the United States imported only 28% of its oil. The chief suppliers were Mexico, with 826,000 barrels per day, Canada, with 479,000, and Venezuela, with 419,000. Saudi Arabia is now seventh on the list of suppliers for the United States. This shift is responsible for the trend toward a heavier crude supply mix on the international market. Transportation fuels and petrochemical feedstocks are in increasing demand; hence many refiners would like to get out of the fuel oil business, More “bottom-of-the-barrel” conversion capability will be required in many refineries to efficiently process these heavier feedstocks and maximize production of light products.     

Energy and exergy use in the utility sector of Saudi Arabia

We present an analysis of energy and exergy utilization in the utility sector of Saudi Arabia by considering the sectoral energy and exergy flows for the years 1990-2001. Energy and exergy analyses were conducted for its two subsectors, namely power-only plants and power/distillation plants, and hence the energy and exergy efficiencies were obtained for comparison. The power/distillation plant subsector appeared to be more energy/exergy efficient compared to the conventional power-only plant subsector for the particular reference conditions assumed in the analysis. A comparison of the overall energy and exergy efficiencies of Saudi Arabian utility sector with the Turkish utility sector is also presented for the year 1993. Although the sectoral coverage is different for each country, it is useful to illustrate the situation of how energy and exergy efficiencies vary. The turkish utility sector appeared to be more efficient for that particular year. Power/distillation makes a significant contribution to Saudi Arabia's overall power generation in the utility sector.