Separation of n-paraffins by selective adsorption

A study has been undertaken of the vapor-phase adsorptive separation of n-alkanes from Kuwait kerosene (Kuwait National Petroleum Company, heavy kerosene) using zeolite molecular sieves. Due to the shortage of information on the adsorption of multicomponent systems in the open literature, the present investigation was initiated to study the effect of feed flowrate, temperature, and zeolite particle size on the height of mass transfer zone (MTZ) and the dynamic capacity of the adsorbent for multicomponent n-alkanes adsorption on a fixed-bed of zeolite type-5A. The optimum operating conditions for separation of the n-alkanes has been identified so that the effluent would also be of marketable quality. The effect of multicycle adsorption-desorption stages on the dynamic behaviour of zeolite using steam as a desorbing agent has been studied and compared with n-pentane and n-hexane as desorbing agents. The separation process comprised one cycle of adsorption using a fixed-bed of zeolite type-5A. The bed was fed with vaporized kerosene until saturation had been achieved whereby the n-alkanes were adsorbed and the denormalized material eluted. The process of adsorption-desorption was carried out isobarically at one atmosphere. A mathematical model has been developed to predict the breakthrough time using the method of characteristics. The results were in a reasonable agreement with the experimental values. This model has also been utilized to develop the equilibrium isotherm. Optimum operating conditions were achieved at a feed flowrate of 33.33 x 10-9 m3/s, a temperature of 643 K, and a particle size of (1.0 - 2.0) x 10-3 m. This yielded an HMTZ value and a dynamic capacity of 0.206 m and 9.6S3 x 10-2 kg n-alkanes/kg of zeolite respectively. These data will serve as a basis for design of a commercial plant. The purity of liquid-paraffin product desorbed using steam was 83.24 wt%. The dynamic capacity was noticed to decrease sharply with the cycle number, without intermediate reactivation of zeolite, while it was kept unchanged by intermediate reactivation. Normal hexane was found to be the best desorbing agent, the efficiency of which was mounted to 88.2%

Terrorist Threats to the Environment in Iraq and Beyond

The environmental consequences of political conflict are a growing problem throughout the world. Not only nations, but a variety of terrorist and insurgent groups have shown a disturbing tendency to make use of intentional environmental destruction in the pursuit of their political agendas. Currently, scenarios of environmental terrorism in Iraq are particularly dire, due to the changing political situation in that country, the vulnerability of its petroleum infrastructure, and the precedent set by the catastrophe in Kuwait during the 1991 Gulf War. The international community should remain aware of the real threat of sudden, intentional environmental destruction, and should take preventative steps, while preparing for the possibility of a major event. Steps can be taken to provide for security and emergency response, while the promotion of social justice and educational initiatives can help to decrease the likelihood of such an event. Further research should be conducted to identify the most effective strategies for reducing the threat of environmental terrorism in specific regions. (c) 2010 by the Massachusetts Institute of Technology.

REVIEW AND DEVELOPMENT OF ENVIRONMENTAL IMPACT STATEMENTS IN KUWAIT: A STEP TOWARDS MITIGATION OF ENVIRONMENTAL CRISIS ASSOCIATED WITH MAJOR PROJECTS

Major development projects, within the third review of the Kuwait Master Plan (KMP3), are proposed for the period (2005–2030). These projects include, among other things, the construction of new towns, industrial areas, power plants, highways, hospitals, waterfront projects and sanitary projects. All of these projects are well known to have adverse environmental impacts unless necessary precautions are taken in their planning stages. As per Article 8 of Law 21 of 1995 and its amendments, the proponents of such projects are requested to submit a comprehensive Environmental Impact Statement (EIS) document for review before an environmental permit is given by the Environment Public Authority (EPA) in Kuwait. There is at present inadequate information available to help the proponents in this task, and the aim of this paper, is to provide a set of preliminary guidelines for the review and development of EIS documents for various types of major development projects. Although the examples focus on Kuwait, the principles discussed are generally applicable. The future challenges to enhance the review and development process are also discussed.Environmental Impact Assessment (EIA), Environmental Impact Statement (EIS), EIS review, development projects, Kuwait master plan