Process simplification

As tlie separation is often an expensive part of a process, simplifications may be valuable. For example, in a process for hydrofoniiylation of propene. 

Montedison and Mitsui Petrochemical iatroduced MgCl2-supported high yield catalysts ia 1975 (7). These third-generation catalyst systems reduced the level of corrosive catalyst residues to the extent that neutralization or removal from the polymer was not required. Stereospecificity, however, was iasufficient to eliminate the requirement for removal of the atactic polymer fraction. These catalysts are used ia the Montedison high yield slurry process (Fig. 9), which demonstrates the process simplification achieved when the sections for polymer de-ashing and separation and purification of the hydrocarbon diluent and alcohol are eliminated (121). These catalysts have also been used ia retrofitted RexaH (El Paso) Hquid monomer processes, eliminating the de-ashing sections of the plant (Fig. 10) (129). 

There are, however, numerous appHcations forthcoming ia medium- to small-scale processiag. Especially attractive on this scale is the pharmaceutical fine chemical or high value added chemical synthesis (see Fine chemicals). In these processes multistep reactions are common, and an electroorganic reaction step can aid ia process simplification. Off the shelf lab electrochemical cells, which have scaled-up versions, are also available. The materials of constmction for these cells are compatible with most organic chemicals. 

The cost price of a bulk chemical is determined primarily by the cost of raw materials, which could represent > 80% of the total costs. Process development/improvement in bulk chemicals is, hence, focused on decreasing these variable costs, e.g. for a product with a volume of 100,000 tpa and a raw materials quote of 2/kg, 1% increase in yield corresponds to savings of 2 million per annum. In fine chemicals, in contrast, emphasis is placed on the reduction of fixed costs, which are relatively high, by process simplification. For example, for a product with a volume of 100 tpa and fixed costs of 40/kg, if the volume yield (amount produced per unit reactor volume) is doubled, this corresponds to savings of 2 million per annum. 

As mentioned earlier, a major cause of high costs in fine chemicals manufacturing is the complexity of the processes. Hence, the key to more economical processes is reduction of the number of unit operations by judicious process integration. This pertains to the successful integration of, for example, chemical and biocatalytic steps, or of reaction steps with (catalyst) separations. A recurring problem in the batch-wise production of fine chemicals is the (perceived) necessity for solvent switches from one reaction step to another or from the reaction to the product separation. Process simplification, e.g. by integration of reaction and separation steps into a single unit operation, will provide obvious economic and environmental benefits. Examples include catalytic distillation, and the use of (catalytic) membranes to facilitate separation of products from catalysts. 

Whereas this important quotient is calculated solely from the product spectrum, process simplifications are a consequence of combining the rhodium catalyst with the special two-phase process. Compared with the conventional oxo process and with other variants (which, for example, include disadvantegeously thermal separation of the oxo reaction products from the catalyst) the procedure is considerably simplified (as shown in several papers, e.g., [2,12]). 

Direct routes from hazardous elements Routes at increased concentration or even solvent-free Routes at elevated temperature and/or pressure Routes mixing the reactants all at once Routes using unstable intermediates Routes in the explosive or thermal runaway regime Process simplification - e.g., routes omitting the need of catalysts or (complex) separation... 

Process eco-efficiency conversion of biomass derived raw materials with high performance, stability and selectivity, and which preserve the complexity already preformed in biomolecules New catalytic reactor engineering solutions to improve energy and process efficiency Process simplification by effective integration of catalysis and separation in new advanced processes New catalysts able to cope with the natural variability in the quality of raw materials. 

Customizatioi -Design to Capa) -Process Simplif -Constructability -Energy Optimiz iti -Waste Minimiza i< -Predictive MainI -Process Reliabi i... 

Process Simplification VIP The process simplification VIP uses the value methodology and is a formal, rigorous process to search for opportunities to eliminate or combine process and utility system steps or equipment, ultimately resulting in the reduction of investment and operating costs. The focus is the reduction of installed costs and critical path schedule while balancing these value improvements with ejq)ected facility operability, flexibility, and over-alllife cycle costs. 

The process simplification VIP does far more than just evaluate and simplify processing steps. This very productive VIP ensures that low- or zero-value functions or equipment included in the project scope are challenged by experienced world-class experts and eliminated, if possible. This VIP tries to systematically differentiate wants from needs and remove the wants. It can be especially effective for providing a neutral professional environment for identifying and challenging sacred cows and then removing them. Removal of these low- or zero-value functions yields significant profitability improvements to the overall project. Process simplification results in... 

Process simplification is executed in a formal workshop with a trained experienced facilitator. This VIP should always include key participants from each of the project owner s organizations, the engineering contractor organization, key third-party technology licensors, and equipment or systems vendors, where possible. One or more cold eyes reviewers or sul ect matter experts, who have extensive experience, should be included to provide an objective and unbiased perspective. 

This VIP also provides a means for integrating overall plantwide systems. The process simplification VIP is typically performed during the feasibility phase (FEL-2) after the preliminary PFDs and heat and material biances become available. However, for very large and complex projects, considerable value has been gained Iw also performing this VIP at the midpoint or later in the conceptual phase (FEL-1). 

VIPs That Apply the Value Methodology Nearly all VIPs are conducted only once in a project at a sweet spot where maximum benefit is found. For example, the process simplification VIP is anchored at the first appearance of the preliminary PFDs, while the value engineering VIP and the design to capacity VIP are anchored at the first issue of the P IDs. Both oF these apply the value methodology [Society of American Value Engineers International (SAVE)] that has produced excellent results in industry for more than 55 years. The typical approach and steps for these three unique VIPs are presented below. 

The Formal Workshop The formal workshop is always structured to make maximum use of the multi-disciplinary team s time and effort. Such workshops typically require no less than 2 days and as many as 5 days depending on the size and complexity of the project. The required workshop length should be determined by the VIP facilitator. A typical process simplification VIP, value engineering VIP, and design to capacity VIP workshop includes the following phases of a typical job plan that are supported by the Society of American Value Engineers International. 

Compared with the common high-temperature conversion of natural gas and further carbon oxide conversion on a catalyst [131], the current process promotes process simplification the reaction is implemented at relatively low temperature (860-900 °C instead of 1400-1600 °C for existing non-catalytic processes of methane conversion) and an additional unit for catalytic conversion of carbon oxide is excluded (in NH3 production). 

Process development and process simplification are best understood with flowsheets (ref. 3, p. 59 ref. 38-40). A typical flowsheet involving... 

At this point not only were further process simplifications possible but also, and above all, radically new, simplified and more economic processes could be realized I73> 174) in liquid propylene or in the gas phase, completely eliminating the use of solvents (Fig. 58). Furthermore, the particular properties of the support make it possible to prepare the catalyst and, thanks to the replication property, also the polymer in... 

An example of this configuration is filtration of the methane fermentation broth from a sewage sludge liquor [Kayawake et al., 1991]. The liquor is u eated anaerobically in a fermentor. The broth is pumped to a ceramic membrane module which is contained in the fermentor. The retentate is returned to the fermentor while the permeate is discharged to the environment This is schematically shown in Figure 8.2. Although the membrane module is enclosed in the bioreactor for compactness and process simplification, the membrane step in essence follows the fermentation step. 

The revolutionary discoveries by Ziegler and Natta, relating to the low pressure polymerization, respectively, of ethylene and of propylene and other a-olefins onto the previously unknown crystalline polymers, opened a new era in science and technology. Since then, remarkable progress has been made in the fields of coordination catalysis, macromolecular science and stereochemistry. With the discovery and development of the new generation catalytic systems for polyethylene in the late 1960 s, and more recently for polypropylene, enormous progress was made in terms of polymerization process as to economics and product quality Further process simplification and, above all, ever more accurate product quality control by taylor made catalytic systems is the aim of the 1980 s. 

Many companies, both within the chemical industry and in other sectors, have recognized benefits from involving their suppliers and customers in various aspects of their business. The area of supply chain management (SCM) has become a critical element in the overall business strategy of improved productivity, reduced costs, and better control of the quality and potential risks associated with raw materials and intermediates. Proactive management of supplier environmental performance, as practiced by Hewlett Packard, can lead to product and process simplification, improved resource efficiency, product quality enhancement, reduced liability, and customer perception of the company as an industry leader. 

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