Background and Challenges
Hydrogen produced from water splitting and clean energy sources is predicted by many to be a clean fuel that will serve as a substitute for conventional fuels because its oxidation does not emit greenhouse gases. Numerous thermochemical water splitting cycles have been proposed for clean hydrogen production. The copper-chlorine (Cu-Cl) cycle has a relatively low temperature requirement compared with other cycles and therefore is viewed as a promising method.
1. GENERAL THEORY OF FLUID FLOW
Fluid flow is a transport process of unbalanced forces or stresses governed by the three primary conservation laws of momentum, energy, and mass. Conservation laws form a fundamental basis of the solution for all engineering flow problems, with the following relation applicable to the analysis of the system or control volume, where X represents the conserved quantity:
Plate Number and Resolution: Indicators of Qualitative Reliability
Introduction
Analytical quality control is the set of processes and procedures designed to produce and ensure a reliable measurement from an analytical system. The purposes of analytical quality control (as opposed to process quality control) are to demonstrate the successful performance of the analytical system (in the short term, a process known either as validation or bench-marking), and to gather the data that will allow prediction of the need for non-routine maintenance (in the long term). The goals of such a quality program is to ensure the reliability of the analyzer’s results, to maximize the analyzer’s “Up time,” and to minimize the costs associated with analyzer maintenance. The regular and frequent analysis of a quality reference material, together with trend analysis performed on the results, can be used to predict the need for preventive maintenance, non-routine maintenance, and to demonstrate which components of the analytical system need to be serviced.
The process gas chromatograph (or GC) delivers both qualitative and quantitative results, so both qualitative (retention time) and quantitative (response) axes must be tested regularly. A systematic primary study, performed during instrument commissioning, demonstrates the short-term precision of the process analyzer and will provide results to which future analytical quality control measurements can be compared.
The method for extracting bitumen from oil sands currently used in commercial mining operations is a flotation process in which oil sands are combined with hot water and the slurry is aerated. This method generally is referred to as the Clark hot water process. Clark’s method promotes the attachment of bitumen to air bubbles, creating a lower-density froth that floats and can be recovered through gravity settling.
Mined and crushed ore typically is conditioned for extraction in one of two ways: steam tumblers or a hydrotransport (H-T) pipeline. In both cases, ore and hot water are combined (additional steam is added to the tumblers) and the slurry is agitated to ablate the ore and free the bitumen for extraction.
Introduction
There has been increasing emphasis on the production of liquid fuels from renewable sources. Biodiesel has been proposed as one of those fuels because its production can be carbon-neutral and its use can help achieve energy independence.
Most of the biodiesel produced in the United States is made from soybean oil. In this process, soybean oil (which is composed mostly of the triolein triglyceride) is mixed with an alcohol (typically methanol) and a catalyst (typically sodium hydroxide or potassium hydroxide). With this feedstock, the reaction that produces methyl oleate (biodiesel) and glycerol by-product is: Read More »
Visit almost any modern compounding facility today, and you will find a twin-screw extruder pumping out plastic pellets. The most productive of these high-speed, energy-input (HSEI) extruders can produce over 50,000 kilograms of finished plastic compounds per hour. Thanks to their inherent process design flexibility, HSEI twin-screw extruders can perform a wide variety of compounding work, including straight mixing, polymerization, devolatilization, and reactive extrusion. Read More »
Chemical engineers know better than anyone the difficulties in turning a promising lab curiosity into an actual product. Consider, for example, aluminum-water reactions as a means for generating hydrogen gas. For decades, researchers have been trying to tap the commercial potential of these reactions, which have the potential to produce hydrogen without the high costs and energy inefficiency of steam reforming and electrolysis techniques and systems. Over the years, there have been scores of patents and technical papers documenting efforts to harness the hydrogen-generating power of aluminum-water reactions. Read More »
Renewed World Energies applies time-tested engineering strategies to the design of its cutting-edge algae bioreactor.
Among the general public, interest in alternative fuels tends to rise and fall with each tick in the price of traditional gasoline. However, the growing importance of energy security and environmental protection means that alternative fuels are here to stay. The real question nowadays is which types of alternative fuels will have the greatest staying power. Read More »
