Traditional processing

Palm fruits potentially have oil-rich flesh (mesocarp) or kernel (endo-carp), or in some species both. These oil sources have been used by local populations probably for thousands of years, and various traditional methods for recovering the oil have been developed. 

The way in which these steps are carried out varies to some extent according to the morphology of the fruit being treated, and also from village to village. 

Steps 1 and 2 often involve allowing the fruit to ferment in a heap for several days. This usually permits easy detachment of individual fruit and may soften the flesh sufficiently to move on to step 3 or 4. Often, however, the fruit flesh is further softened by boiling. The fruit may then be pounded in a mortar, or may be emptied into a large oil-tight container such as a clay-lined pit or an old canoe. A liquid phase is then separated by treading or squeezing the pulp. The liquid phase is skimmed, may be filtered through a coarse mesh and boiled to remove the water. 

Typically such a process recovers no more than 40-50% of the available oil. The recovery of kernel oil requires the following steps  

Stage 1 depends very much on the fruit type, and, for example in the coconut, may require a cutting implement to remove the fibrous coating, followed by a hammering action to break the shell. 

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Solvent Extraction Technology. The use of solvent extraction technology to replace traditional processes has been the subject of considerable research and development effort since the 1970s (12,14—21). This newer technique was being used commercially as of 1995 in at least three of the principal refineries. 

Direct Saponification. Direct saponification of fats and oils is the traditional process utilized for the manufacturing of soap. Commercially this is done through either a kettle boiling batch process or a continuous process. 

Soybeans. Vktuady ad soybeans processed in the United States are solvent-extracted with hexane to recover the od. This traditional process is outlined in Figure 4. Beans arriving at the plant are cleaned and dried, if necessary, before storage. When the beans move from storage to processing, they are cleaned further and may be dried and adowed to equdibrate at 10—11% moisture to facditate loosening of the seed coat or hud. They are then cracked. 

Consequently the total process time is reduced from at least five weeks to 16 d representing a reduction of 19 d or 54%. The resulting advantages ate enormous compared to the traditional process. 

Traditional Processes. The two primary stripping vapors are steam and air. Steam is used when the concentration of bromine in brine is greater than 1000 ppm. The advantage is that bromine can be condensed direcdy from the steam. Air is used when seawater is the source of bromine because very large volumes of stripping gas are needed and steam would be too expensive. When air is used the bromine needs to be trapped in an alkaline or reducing solution to concentrate it. 

The process illustrated in Exhibit 3-4 is fairly typical of a traditional process that was designed without Quality Management processes and techniques built in. 

Traditional process flow diagrams are clear, quickly prepared and easily reviewed for conformity with ISO 9000 requirements. However, it is not easy to identify some types of process breakdowns, such as gaps in coverage, processes that follow the organizational hierarchy and inappropriate allocation of tasks within the organization. 

Since traditional process flow diagrams can be developed from the process maps, it is probably slightly better to use the mapping approach. If traditional flow diagrams are required they can be generated later to help identify redundancies, bottlenecks, etc. 

The metals are obtained from the metallic phase of the sulphide matte or the anode slime from electrolytic refining of nickel. In the traditional process for the platinum metals, their separation was facilitated by their solubility in aqua regia and convertibility into PdCl - or PtCl - salts. Nowadays, substantial amounts are obtained using solvent extraction. 

CuCl, especially in a single crystal form, is extensively used as an optical material for its special optical properties. Orel et al. [2] first proposed a new method to obtain CuCl particles by the reduction of Cu with ascorbic acid. Several dispersants were used in the reduction and monodispersed CuCl particles can be obtained by selecting the proper dispersant and reduction conditions. In this work, the above method was used to modify the traditional process of CuCl preparation, namely, by reducing the Cu " with sodium sulfite to obtain the highly active CuCl catalyst to be used in the direct process of methylchlorosilane synthesis. 

Similarly, a catalytic route to indigo was developed by Mitsui Toatsu Chemicals (Inoue et al, 1994) to replace the traditional process, which dates back to the nineteenth century (see earlier), and has a low atom efficiency/high E factor (Fig. 2.15). Indole is prepared by vapour-phase reaction of ethylene glycol with aniline in the presence of a supported silver catalyst. The indole is selectively oxidised to indigo with an alkyl hydroperoxide in the presence of a homogeneous molybdenum catalyst. 

In 2001 a 220,000 tonnes per annum plant for the production of ethyl acetate using a silica-supported HPA was successfully commissioned on the BP Chemicals site in Hull, UK. A schematic of the Avada plant is shown in Figure 2 (7). The Avada process is superior to other traditional processes in terms of... 

As already mentioned, sulphuric acid is by far the most common carbonising agent. In traditional processes, it is applied at 4-5% concentration with a dwell time of 3-5 minutes. So-called rapid processes apply 7-8% sulphuric acid with very short dwell times, typically 5 seconds. When used alone, there is a danger that localised droplets of highly concentrated sulphuric acid can be formed, with consequent damage to the wool. The critical conditions for this to occur are met when the acid concentration reaches 40-45% [286-288]. 

Process Control. The traditional process control will be expanded toward new applications such as nonlinear process control of biosystems. However, in the commodity chemicals industry there will be increased need for synthesizing plantwide control systems, as well as integrating dynamics, discrete events, and safety functions, which will be achieved through new mathematical and computer science developments in hybrid systems. 

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