The Dutch Process

Dutching, or alkalizing, is carried out to modify the color and flavor of cocoa. Depending on the degree of alkalization, the color becomes darker and the flavor milder and much less harsh. This process involves the addition of alkali to the milled chocolate liquor accompanied by efficient mixing and the removal of water by heating. 

Chocolate is a suspension of cocoa particles and sugar held in cocoa butter, the manufacture of which entails four unit operations  

SO that mixing and flavor development are optimized. The mixing operation is carried out at 50 to 60°C and usually takes 20 to 25 min, but in an automatic plant the dwell time may be only about 5 min. The aim of this stage is to reduce the particle size of the sugar and promote the loss of unwanted volatile acids. The product is a soft, plastic, pliable, nonflowing mass. 

Refining is a size reduction process. This is carried out in a mill fitted with multiple, water cooled rollers [3-5], Chocolate is usually refined to a particle size of 50-114 pm of which less than 10% are smaller than 5 pm and not more than 20% are larger than 22 pm. It is the distribution of particle sizes that determines the eating quality of the resulting chocolate [8]. 

Tempering is necessary to induce crystallization of the cocoa butter in a stable form in the fluid chocolate mass. Cocoa butter can crystallize in six forms I (y, melts at 17°C and is very unstable), II (a, melts at 21 to 24°C), m and IV (p, melts at 25 to 29°C), V (p, melts at 34 to 35°C and is the preferred form), and VI (associated with chocolate bloom) [9,10]. 

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Lead II carbonate, white lead, PbCOs has been used as a pigment for over 2000 years. It is usually made by a modification of the Dutch process whereby sheets of lead undergo slow decomposition under the action of acetic vapour, moist air and carbon dioxide. It is very toxic when used in paints and in recent years has largely been replaced as a pigment by titanium dioxide, on account of its greater opacity, covering power, cheapness, stability and of course, safety. 

The limited literature on lead paint production or use in nineteenth-century America was rooted in the occupational health literamre, with a particular focus on lead pigment workers and some concern for house and commercial painters (see, for example, Hamilton, 1911 Knerr, 1992). Of particular concern to industrial hygienists and occupational physicians and labor activists were the significant rates of clinical lead poisonings among workers producing white lead by the Dutch Process (Hamilton, 1911 Knerr, 1992). 

Depending on the alkali used, cocoa powder produced by the Dutch process may contain relatively high concentrations of sodium, which may cause problems in persons who are on a low-sodium diet. 

Programs to develop MCFC technology are also under way in Europe. Ansaldo SpA (Italy) is setting up faciUties to produce 1-m cells in an automated process, and their goal is to test 100-kW stacks in 1994. The 100-kW stack is also to be tested by IBERDROLA in Spain as part of a complete power plant system. Two Dutch companies. Stork and Royal Schelde, have joined with the Dutch government to form Brandstofcel Nederland (BCN), which plans to test a 50-kW MCFC and two 250-kW MCFC stacks in 1994. 

Commercial cocoa powders are produced for various specific uses and many cocoas are alkaH treated, or Dutched, to produce distinctive colors and flavors. The alkaH process can involve the treatment of nibs, chocolate Hquor, or cocoa with a wide variety of alkalizing agents (9). 

A wet-process plant maldug cement from shale and hmestoue has been described by Bergstrom [Roc/c Prod., 64—71 (June 1967)]. There are separate facilities for grinding each type of stone. The ball mill operates in closed circuit with a battery of Dutch State Mines screens. Material passing the screens is 85 percent minus 200 mesh. The entire process is extensively instrumented and controlled by computer. Automatic devices sample crushed rock, slurries, and finished product for chemical analysis by X-rav fluorescence. Mill circuit feed rates and water additions are governed by conventional controllers. 

A LCA on treatment options of MPW was performed by the Dutch Centrum voor Energiebesparing en Schone Technologie (CE, Delft) in 1994. This LCA used the VEBA process as an example for feedstock recycling (a.ll). Another LCA was performed by Heyde and Kremer (a.6). Particularly the CE studies suggested that the VEBA process was a bit less advantageous than the Texaco process, mainly due to the fact that the Texaco process does not need agglomeration of MPW as pre-treatment, whereas the VEBA process apparently does. 

Crops, food, and feed. The first recommended method is based on the Dutch Multiresidue Method 2 for A-methylcarbamates, which was originally developed by de Kok et The method has recently been validated by DuPont Crop Protection and Batelle, Geneva Research Centres, for the analysis of methomyl and oxamyl in dry, high-water, high-fat, and high-acid content crops and in various grape processed products. The limit of detection for each analyte is 0.003-0.005 mg kg . ... 

The first important technical development in the chocolate manufacturing process occurred when water-powered mills superseded the use of manual labor to grind cocoa beans. This led to the establishment of many chocolate factories from 1804 to 1840. Early production consisted entirely of a type of chocolate beverage that was somewhat indigestible since none of the cocoa butter was removed during processing. In 1828, the Dutch firm of Van Houten invented the cocoa press, which facilitated the production of cocoa powder by partial removal of the cocoa butter from beans. 

Bunker and McWilliams found that two beverages prepared from instant cocoa (with Dutch process cocoa) contained 10 to 17 mg caffeine per cup.37 Table 7 lists the theobromine and caffeine concentration of hot cocoa and chocolate milk prepared from instant mixes. Zoumas et al. analyzed five commercial hot cocoa mixes and reported an average of 65 mg per serving of theobromine and 4 mg per serving of caffeine.28 Similar results were reported by Blauch and Tarka.36... 

But "imports and exports" were merely business then. When Germany began to replace her imports of petroleum, we acclaimed again the miracle of industrial substitutes. The world naphtha supply would last only twenty to thirty years. Germany could not get enough naphtha from the United States, Russia, Venezuela, Persia, the Dutch Indies, and Rumania. With Farben s new hydrogenation process, Germany could make all the naphtha she wanted. 

Dutch An obsolete process for making basic lead carbonate pigment (white lead) by exposing metallic lead to vinegar and carbon dioxide. Reportedly first described by Theophrastos around 300 BC. Also known as the Stack process because the metal ingots were arranged in vertical stacks. See also Thompson-Stewart. 

NSM A Dutch process for making ammonium nitrate, offered by Uhde. Not to be confused with another NSM (New Smoking Material), a tobacco substitute developed by ICI in the 1970s but later abandoned. 

Stamicarbon [Staatsmijnen carbon] Stamicarbon bv is the licensing subsidiary of the Dutch chemical company DSM. It offers a number of processes, including HPO and HSO. Historically, the process for which the company was best known was a coal carbonization process today, a urea-manufacturing process is probably its most important one. 

To verify the developed concepts underlying the structured 7-stage protocol in a reactive way, they were applied to an analysis of recent accidents in the Dutch chemical process industry. Despite the limitations in the information available from the accident database, it could be deduced that all accidents were preceded by precursors, and even that similar precursors had led to similar accidents, implying that companies had failed to learn from these re-occurring deviations which were in fact pre-warning signs of impeding accidents. 

In Chapter 5 the conceptual approach from the previous Chapter will be tested and evaluated and finally applied to a single case study in the Dutch chemical process industry. This exercise is performed to test the conceptual approach in practice. The findings of the case study will be evaluated and will lead to refinements in the conceptual approach. Finally a structured protocol will be derived and applied to the same case study to ascertain if the structured protocol is effective and suitable for practical use and leads to answering the research questions posed in Chapter 1. 

In Chapter 7 the derived structured protocol will be applied to multiple case studies in the Dutch chemical process industry. Three case studies will be conducted to derive the answers on the posed research questions and to confirm or reject the results from the case histories in the previous Chapter. The case studies will be carefully selected so that the outcomes of the analysis are predictable for all three cases. This replication strengthens the generalization and overall validation of all case studies and the research in general. 

In addition to these selection criteria, the limitations of the author s contacts and the willingness of companies to participate, narrowed the search for a suitable case down to a small Dutch company (< 30 people). This company produces in batches, falls under the Dutch Seveso-II directive (BRZO, 1999) and authorized access to the relevant data. The selected company had experienced some serious accidents recently, in spite of using many technical safety systems. Thus the management was aware of the necessity to enhance both safety and the reliability of the operational process. 

In this Chapter further evidence is provided that precursors exist long before they escalate into an accident. It will be demonstrated that the existence of precursor information could have been used to foresee and even prevent recent accidents with hazardous substances. Moreover, a set of precursors retrieved from 17 recent accidents in the Dutch chemical process industry is used to validate the 7-stage protocol developed in the previous Chapter. In spite of the limited accident information it is shown that if a proper control action had been initiated, all of these 17 accidents could have been prevented. 

Are accidents always unforeseeable , Proceedings of the annual Loss Prevention Symposium AIChE, New Orleans, pp. 483-492. The remainder of this Chapter is based on a paper by Sonnemans P.J.M., Korvers P.M.W., Brombacher A.C., Beek van P.C., Reinders J.E.A., 2003. Accidents, often the result of an uncontrolled business process — a study in the (Dutch) chemical industry, Quality Reliability Engineering International 19(3), pp. 183-196. 

The results from the study into identical accidents show that precursors often do exist prior to accidents. The existence of precursors prior to accidents creates the opportunity to derive indicators for accidents. To actually obtain a better understanding of how and why accidents can occur in spite of the presence of precursors prior to accidents, in the next Section 17 recent accidents from the Dutch chemical process industry will be analysed using the 7-stage protocol. 

That precursors are frequently observed in accident trajectories was stated in the previous Section. In this Section 17 recent accidents in the Dutch chemical process industry are taken and their accompanying precursors and ineffective control processes in the companies identified. This study is executed from hindsight using limited accident information which is the reason for adapting the analysis protocol so that the results of most stages can still be retrieved. 

The next Chapter will apply the 7-stage protocol pro-actively in three different case studies in the Dutch chemical process industry, identifying why hazardous situations still exist in the companies in spite of the enormous number of safety measures present. 

The protocol developed in Chapter 5, which was applied on accidents as shown in Chapter 6, is applied on three cases in the Dutch chemical process industry. First, the cases are selected according the criteria stated in Chapter 5. Secondly, the developed protocol of analysis is applied on these selected cases, to identify why and how it is still possible that accidents may occur despite precursors and several existing safety barriers. Thirdly, the results from the analysis are further elaborated on, indicating the problems in current safety management systems, allowing accidents to occur. 

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