Process environmental impact

Scheduling of refinery processes environmental impact. e-constraint method along with a MILP method Scheduling of refinery processes was modeled as a mixed-integer linear programming (MILP) model. Song et al. (2002)... 

Recently, a conceptual design-based simulation methodology has been developed for the comparative economic assessment of membrane reactors with conventional catalytic reactors [388]. A basic assumption to the simulation smdy is that the chosen membranes do possess durability and performance characteristics as desired for industrial-scale processing. For the two illustrative dehydrogenation reaction schemes, the cost contribution of membranes and other auxiliary equipment is estimated not to exceed 20% of the total costs. Besides variable and fixed costs in processes, environmental impacts (energy and material inputs, efficiency and environmental releases) associated with manufacturing. 

Phenol is an important raw material for the synthesis of petrochemicals, agrochemicals, and plastics. Examples of the uses of phenol as an intermediate include the production of bisphenol A, phenolic resins, caprolactam, alkyl phenols, aniline, and other useful chemicals. Today, almost 95% of worldwide phenol production is based on the so-called cumene process which is a three-step process (the conversion of benzene and propylene to cumene using supported phosphoric acid catalysts, the conversion of cumene to cumene hydroperoxide with air, and the decomposition of hydroperoxide to phenol and acetone with sulfuric acid). The great interest in the oxidation reaction of benzene to phenol is Unked to some disadvantages of the cumene process (environmental impact, production of an explosive hydroperoxide. 

Rudloff, M., 2005. Biomass-to-Liquid fuels (BtL) — made by CHOREN. Process, environmental impact and latest developments. In Proceedings of the 10th European Automotive Engineering Congress, May 2005, Belgrade. 

Since process design starts with the reactor, the first decisions are those which lead to the choice of reactor. These decisions are among the most important in the whole design. Good reactor performance is of paramount importance in determining the economic viability of the overall design and fundamentally important to the environmental impact of the process. In addition to the desired products, reactors produce unwanted byproducts. These unwanted byproducts create environmental problems. As we shall discuss later in Chap. 10, the best solution to environmental problems is not elaborate treatment methods but not to produce waste in the first place. 

Batch processes can be synthesized by first synthesizing a continuous process and then converting it to batch operation. The process yield is an important measure of both raw materials efficiency and environmental impact. 

The treatment of these issues will be discussed jointly with the health, safety and environment (HSE) departments within the company and with the process and facilities engineers, and their treatment should be designed in conjunction with an environmental impact assessment. Some of the important basic principles for waste management are to ... 

Microbial processes can also detoxify mercury ions and organic compounds by reducing the mercury to the elemental form, which is volatile (86). This certainly reduces the environmental impact of compounds such as methylmercury, however, such a bioprocess would have to include a mercury capture system before it could be exploited on a large scale with pubHc support. 

Lead Azide. The azides belong to a class of very few useflil explosive compounds that do not contain oxygen. Lead azide is the primary explosive used in military detonators in the United States, and has been intensively studied (see also Lead compounds). However, lead azide is being phased out as an ignition compound in commercial detonators by substances such as diazodinitrophenol (DDNP) or PETN-based mixtures because of health concerns over the lead content in the fumes and the explosion risks and environmental impact of the manufacturing process. 

Neste patented an industrial route to a cellulose carbamate pulp (90) which was stable enough to be shipped into rayon plants for dissolution as if it were xanthate. The carbamate solution could be spun into sulfuric acid or sodium carbonate solutions, to give fibers which when completely regenerated had similar properties to viscose rayon. When incompletely regenerated they were sufficientiy self-bonding for use in papermaking. The process was said to be cheaper than the viscose route and to have a lower environmental impact (91). It has not been commercialized, so no confirmation of its potential is yet available. 

The Courtaulds Tencel Process. The increasing costs of reducing the environmental impact of the viscose process coupled with the increasing likelihood that the newer cellulose solvents would be capable of yielding a commercially viable fiber process led Courtaulds Research to embark on a systematic search for a new fiber process in the late 1970s. 

Rayon is unique among the mass produced man-made fibers because it is the only one to use a natural polymer (cellulose) directly. Polyesters, nylons, polyolefins, and acryflcs all come indirectly from vegetation they come from the polymerization of monomers obtained from reserves of fossil fuels, which in turn were formed by the incomplete biodegradation of vegetation that grew millions of years ago. The extraction of these nonrenewable reserves and the resulting return to the atmosphere of the carbon dioxide from which they were made is one of the most important environmental issues of current times. CeUulosic fibers therefore have much to recommend them provided that the processes used to make them have minimal environmental impact. 

Methods for the large-scale production of hydrogen must be evaluated in the context of environmental impact and cost. Synthesis gas generation is the principal area requiring environmental controls common to all syngas-based processes. The nature of the controls depends on the feedstock and method of processing. 

The cathode material is stainless steel. The lead produced by this method analyzes 99.99 + %. The overall power consumption is less than 1 kWh/kg of lead, so that the electrolytic process for treating spent batteries has much less of an environmental impact than the conventional pyrometaUurgical process. 

Many factors affect the mechanisms and kinetics of sorption and transport processes. For instance, differences in the chemical stmcture and properties, ie, ionizahility, solubiUty in water, vapor pressure, and polarity, between pesticides affect their behavior in the environment through effects on sorption and transport processes. Differences in soil properties, ie, pH and percentage of organic carbon and clay contents, and soil conditions, ie, moisture content and landscape position climatic conditions, ie, temperature, precipitation, and radiation and cultural practices, ie, crop and tillage, can all modify the behavior of the pesticide in soils. Persistence of a pesticide in soil is a consequence of a complex interaction of processes. Because the persistence of a pesticide can govern its availabiUty and efficacy for pest control, as weU as its potential for adverse environmental impacts, knowledge of the basic processes is necessary if the benefits of the pesticide ate to be maximized. 

The process starting from lignin has faced serious problems, such as reduced availabiUty and environmental impact. The availabiUty is reduced because the new process for making paper paste yields less Hquor. As a result, it is likely that the larger companies will not reinvest in new factories to process Hquors to meet demand. The process s environmental impact is also problematic because over 160 t of caustic waste are produced for every ton of vanillin manufactured. 

The ethylene-based, balanced vinyl chloride process, which accounts for nearly all capacity worldwide, has been practiced by a variety of vinyl chloride producers since the mid-1950s. The technology is mature, so that the probabiUty of significant changes is low. New developments in production technology will likely be based on incremental improvements in raw material and energy efficiency, environmental impact, safety, and process reUabiUty. 

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