Solid Shear
Pressure extrusion of frozen micro-organisms at around -25 C through a small orifice is a well established technique at a laboratory scale using a Hughes press or an X-press to obtain small samples of enzymes or microbial cell walls. Disruption is due to a combination of liquid shear through a narrow orifice and the presence of ice crystals. Magnusson and Edebo 1976 developed a semi-continuous X-press operating with a sample temperature of - 35 C and an X-press temperature of - 20 C. It was...
Liquid Shear
Liquid shear is the method which has been most widely used in large scale enzyme purification procedures Scawen et al., 1980 . High-pressure homogenizes used in the processing of milk and other products in the food industry have proved to be very effective for microbial cell disruption. One machine, the APV-Man-ton Gaulin-homogenizer The APV Co. Ltd, Crawley, Surrey, U.K. , which is a high-pressure positive displacement pump, incorporates an adjustable valve with a restricted orifice Fig. 10.21...
A4 Test Method For The Verification Of Temperature Sensor Location
A4.1.1 This test method is for determining whether the temperature sensor is in the proper position for optimum performance. A4.2.1 The vapor temperature of a pure compound measured by the sensor and its recording instrument is compared to the accepted boiling point for the compound. The test is conducted both at atmospheric pressure and under vacuum of 0.133 kPa 1 mm Hg . A4.3.1 A poorly positioned sensor can give temperatures that are in error due to inadequate heat supply from the vapors. It...
Neat Operation Versus Using Excess Reactant
The reactive distillation columns considered in previous chapters were all operated in neat mode. The two reactants are fed in exactly the correct amounts to satisfy the stoichiometry of the reaction. The control system must be able to detect any imbalance, which will inevitably result in a gradual buildup of one of the reactants and a loss of conversion and product purities. An alternative to operating neat is to operate the reactive column with an excess of one of the reactants. This...
Iii Meat Ingredients
Because of the warm, humid conditions normally utilized for fermentation of semidry sausages, meat ingredients must be of very high quality. Fermentation encourages microbial growth and accelerates chemical reactions, both of which have potential to affect final product quality and may even result in spoilage. Fresh meat with no microbiological or chemical age is essential for manufacturing fermented sausage. If initial microbiological counts on meat are high, undesirable growth may occur...
Control Of Sidestream Columns
In this chapter we study distillation columns that have more than the normal two product streams. These more complex configurations provide savings in energy costs and capital investment in some systems. Sidestream columns are used in many ternary separations, and the examples in this chapter illustrate this application. However, a sidestream column can also be used in a binary separation if different purity levels are desired. For example, two grades of propylene products are sometimes...
Fortran H Extended
Consider first the case where the conventional distillation column has a partial condenser, and the condenser and reboiler duties Qc and QR are specified. The material and energy balance enclosures are the same as those shown in Figs. 11-4, 11-8, and 11-9. Except for stages 2 and N 1, the phase equilibrium functions are of the general form However, in the particular case of stage 2, the set v2appears in the component-material balances, but not the set 2i . Thus, the new set of variables X2i is...
Valves And Steam Traps
Valves attached to fermenters and ancillary equipment are used for controlling the flow of liquids and gases in a variety of ways. The valves may be 1. Simple ON OFF valves which are either fully open or fully closed. 2. Valves which provide coarse control of flow rates. 3. Valves which may be adjusted very precisely so that flow rates may be accurately controlled. 4. Safety valves which are constructed in such a way that liquids or gases will flow in only one direction. When making the...
Growth
The majority of Bacillus species will grow at mesophilic temperatures on commercially prepared nutrient media, although in some cases it is necessary to modify the pH or salt concentration. Obligate thermophilic species such as B. stearothermophilus that do not grow satisfactorily at 37 C are usually grown at 60 C. Moderately thermophilic species, such as B. coagulans, are grown between 45 C and 50 C. The more fastidious insect pathogens, B. larvae and B. popilliae, require the addition of...
Stage Efficiency
The mathematical models presented earlier for rigorous calculations of multistage, multicomponent distillation-type separations assume that equilibrium with respect to both heat and mass transfer is attained at each stage. Unless temperature changes significantly from stage to stage, the assumption that vapor and liquid phases exiting from a stage are at the same temperature is generally valid. However, in most cases, equilibrium with respect to mass transfer is not a valid assumption. If all...
Identification of Apoptosis
The search for simple techniques that allow for the identification of apoptotic cells has attracted a considerable Figure 1. Schematic diagram showing the morphological features of apoptotic and necrotic cell death. The cell shown at stage 1 of necrosis exhibits clear swelling and dilation of mitochondria and Golgi. At this stage, nuclear morphology remains unchanged. By stage 2 of necrosis, disruption of organelles and plasma membrane is apparent, nuclear morphology is altered, and complete...
Packed Columns For Distillation
In bubble cap and perforated plate columns, a large interfacial area between the rising vapour and the reflux is obtained by causing the vapour to bubble through the liquid. An alternative arrangement, which also provides the necessary large interfacial area for diffusion, is the packed column, in which the cylindrical shell of the column is filled with some form of packing. A common arrangement for distillation is as indicated in Figure 11.58, where the packing may consist of rings, saddles,...
Reactive Distillation Design
Figure 3.2 gives the reactive distillation column and the terminology used. The column is fed with two pure reactant fresh feedstreams F0A and F0B. The column has three zones. There are NS trays and a partial reboiler in the stripping section. Above this section, there is a reactive zone with NRX reactive trays. The third section is the rectifying section with NR trays and a total condenser. Figure 3.2 Reactive distillation column. Figure 3.2 Reactive distillation column. Light reactant A is...
Various Approaches To Scale Up And Scale Down Methods
Bubble columns and air-lift vessels tend to be scaled-up on the basis of geometric similarity and constant gas velocity Scragg, 1991 . Under these conditions the KLa and shear rate in the two scales will be similar. The major difference will be the height of the vessels resulting in increased pressure at the base of the larger vessel. This would result in higher oxygen and carbon dioxide solubility which would give a higher KLa but might result in carbon dioxide inhibition. The other problem in...
Module Performance
In previous sections of this chapter we focus on the performance of various MD configurations in lab-used membrane module. Because of small membrane area, there is almost no change in the fluid field when the fluid flows through the ducts of the module. Such parameters as the fluid temperature, velocity and mass flux through the membrane are maintained constant within the membrane module. Such module can be considered as a lumped system, and algebraic equations, as derived in previous sections,...
Treatment Of Sanitary Sewage
All sanitary sewage in the refinery is collected in a common sewage lift station, from which it is pumped to equalization tank TK-101 see Figure 9-8 . The sewage equalization tank is sized for approximately 6hr retention of normal flows plus capacity to accommodate surges associated with peak flows from the lift station. The equalization tank is aerated to prevent the sanitary wastewater from becoming septic. The sewage is treated in two aeration tanks TK-103, with each unit having the capacity...
The Steam Distillation and Solvent Extraction Process
This process has been in use for so short a time that it is not yet well standardized in details and very little literature on the subject is available. The steam distillation part of the process has, however, been studied experimentally.1 The theory of steam distillation of volatile oils outlined in Chapter IV applies in die removal of crude turpentine turpentine and pine oil from resinous wood by means of steam. There are, however, two additions that must be made to the principles previously...
Liquid Mixture Viscosity
Essentially all correlations for liquid mixture viscosity refer to solutions of liquids below or only slightly above their normal boiling points i.e., they are restricted to reduced temperatures of the pure components below about 0.7. The bulk of the discussion below is limited to that temperature range. At the end of the section, however, we suggest approximate methods to treat high-pressure, high-temperature liquid mixture viscosity. At temperatures below Tr 0.7, liquid viscosities are very...
Emissivity
Lf FLAME LENGTH C FLAME CENTER H STACK HEIGHT Lf FLAME LENGTH C FLAME CENTER H STACK HEIGHT Figure 10-5. Thermal radiation from elevated flares. Figure 10-5. Thermal radiation from elevated flares. and the coordinates of the flame center located at L 3 , with respect to the flare tip, are The distance from any point on the ground level to the center of the flame is These equation allow you to determine the radiation intensity over any location. The worst position for a given gas flow and wind...
Info Udy 1
Figure 9.3 Liquid spread profile in a packed column 20-in-ID column, packed with 6 ft of 2-in Pall rings, water study. Data from P. J. Hoek, Ph.D. thesis, University of Delft, The Netherlands, 1983. Wall ow 66,87,140,141-149 . The tendency of liquid to flow toward the walls of packed columns is a fundamental phenomenon associated with packed-column hydraulics. The development of wall flow is illustrated in Fig. 9.4 using typical measurements by Hoek 140 in a pilot-scale column. The column...
Effectiveness of the Integrated Control Scheme
Dynamic simulations suggest that the three control modes are each stable for a wide range of process disturbances despite the cogent process non-linearity and bidirectionality. Thus, the proposed integrated control scheme allows for the column operation to adequately reflect a changing economic environment that could require the process objectives to be regularly revised. The control objectives were derived from the process objectives in a manner which maximised the process linearity and...
Lactose-6-phosphate
Figure 2-12. The phosphotransferase system PTS in Gram positive bacteria. As shown in panel A, the PTS cascade is initiated by the cytoplasmic proteins Enzyme I EI and HPr. Phosphorylated HPr HPr P then transfers the phosphoryl group obtained originally from PEP to the substrate-specific Enzyme II complex. The latter consists of several proteins or domains, shown here as EIIA, EIIB, and EIIC. However, depending on the organism and the substrate, EII complexes may be organized differently, for...
Column Reboilers
There are a number of designs of reboilers. It is beyond the scope of this set of introductory notes to delve into their design principles. However, they can be regarded as heat-exchangers that are required to transfer enough energy to bring the liquid at the bottom of the column to boiling boint. The following are examples of typical reboiler types. Tube bundle photo courtesy of Paul Phillips Tube bundle photo courtesy of Paul Phillips Tubesheet photo courtesy of Paul Phillips Fitting a Shell...
Filtering Centrifuges
The driving force for separation in a filtering centrifuge is centrifugal force, unlike filtration where pressure or vacuum is used. The basic principals of Poiseuilles' cake filtration equation can be applied by substituting P pressure with the stress or pressure induced by the bowl contents, which is a function of centrifugal acceleration. See Eq. 8. A wash can be introduced to fulfill different requirements 1. Remove original slurry liquid mother liquid 4. Displace mother liquor with another...
Product Composition Regions for Azeotropic ThreeComponent Mixtures
Let's examine three-component azeotropic mixtures with one binary azeotrope and with two regions of distillation at infinite reflux RegTO Fig. 3.6a . There is some region triangle to the right of separatrix where two points of the bottom product corresponding to one top product point exist. This fact is explained by the S-shape of c-lines in this region Fig. 3.6b, points xB 2 and xB 3 . The main difference between the azeotropic mixtures and also nonideal zeo-tropic mixtures and the ideal ones...
III HAMANATTO A Introduction
Japanese hamanatto is a fermented, intermediate-moisture soybean that belongs to a group of very similar, fermented soybean products that are sometimes called soy nuggets. It is made by fermenting the cooked soybeans with Aspergillus oryzae followed by soaking in a brine or soy sauce, and then dried. It is consumed directly in Japan. It differs from the ordinary natto with its sticky substance on its surface. In Japan, various similar names are used with this type of products such as daitokuzi...
CFermented Whole Soybeans
Ordinary natto is a typical Japanese fermented whole soybean product. Its sticky muci-lageous substance on the surface of soybeans is its characteristic. It is produced by fermenting cooked soybeans with Bacillus natto for a brief period. It has a short shelf life. Table 44 lists the basic steps in the manufacture of ordinary natto. For detailed information on ordinary natto, please refer to the Chapter 30 in this book and the references in this chapter 34,36,41 . Hama-natto is fermented whole...
Internal Hardware Revamps
WHEN EFFECTIVE A quick browse through Sections 5.2.3 and 6.3.4, which list factors affecting capacity and efficiency, can define the effectiveness of this technique. Changing layout may be used effectively to increase column capacity, but the technique is rather limited in its ability to significantly improve column efficiency. It is thus suitable for capacity revamps only. METHODS The methods commonly used depend on the flooding mechanism which restricts capacity, and can simply be deduced...
A Thermodynamically Based Method To Estimate Growth Stoichiometry
In the previous paragraphs the methods for accurate measurement of a growth stoichiometric coefficient, as, for example, the biomass yield on electron donor FDX and the subsequent calculation of all the nonmeasured stoichio-metric coefficients of the macrochemical equation using the conservation principles have been provided. In past decades, the value of FDX for many different microorganisms, different electron donors, C sources, and electron acceptors has been measured under C- and...
Low pressure
This region extends from approximately 10 3 to 10 bar and includes the domain discussed in Sees. 10-3 and 10-4. The thermal conductivity increases about 1 percent or less per bar 68,174,175,176 . Such increases are often ignored in the literature, and either the 1-bar value or the zero-pressure extrapolated value may be referred to as the low-pressure conductivity. TABLE 10-3 Thermal Conductivities of Some Gases at About 1 Bar1 X A BT CT- DT3 X in W m K and T in keivins TABLE 10-3 Thermal...
Design Procedures
Two general procedures are available for designing fractionators that process petroleum, synthetic crude oils, and complex mixtures. The first, which was originally developed for crude units by Packie Trans. Am. Inst. Chem. Eng. J., 37, 51 1941 , extended to main fractionators by Houghland, Lemieux, and Schreiner Proc. API, sec. III, Refining, 385 1954 , and further elaborated and described in great detail by Watkins op. cit. , utilizes material and energy balances, with empirical correlations...
Steam Stripping
The term steam stripping can be applied to any system where rising steam vapors in a column strip out the volatile components in the liquid. In particular, the term is applied to systems where steam is used to strip out partially miscible organic chemicals, even though the organic chemicals have boiling points above water. For example, toluene, which has a boiling point of 110 C, can be stripped out of water with steam. The low solubility of toluene in water changes the activity coefficient,...
Salting
Salt is an essential ingredient that provides flavor, enhances syneresis, and contributes to the preservation of most cheeses. Even the simple step of salting, however, represents an important variable during cheese manufacture. Salt can be applied directly i.e., in dry form to the milled curds, as in the case of Cheddar, or salt can be rubbed onto the surface of hooped cheese, as in the case of some blue cheese varieties e.g., Gorgonzola and Roquefort . Alternatively, some cheeses, such as...
Formation of flavour compounds
A multitude of compounds contribute to beer flavour. Many of these are derived directly from the raw materials used to produce the wort. In this respect the blend of malt and hops are influential. However, fermentation has the most significant impact on flavour development. Both ethanol and carbon dioxide contribute to beer flavour, imparting 'warming' and 'mouth tingle' characters, respectively. The essential character of any beer is determined by the plethora of other yeast metabolites, that...
Process Studied
The reaction of methanol with unsaturated C5 isoamylenes 2-methyl-1-butene and 2-methyl-2-butene produces TAME. The liquid-phase reversible reactions are 2M1B MeOH TAME 2M2B MeOH , TAME This system is fundamentally a ternary system with inerts. The methanol fresh feedstream is essentially pure. The hydrocarbon feed comes from an upstream catalytic cracking unit. It is a mixed C5 stream that contains not only the two reactants 2M1B and 2M2B but also other C5s such as isopentane, n-pentane,...
Boilers 1
It's easy to worry too much about building or acquiring a boiler. There is an incredible variety of materials, designs and heating methods to choose from, but in the end, all we really want to do is gently boil some liquid and contain its vapors. Amateur distillers frequently use boilers in the range of 4 to 50 liters 1 to 12 US gallons . You should choose your size by carefully considering how much you intend to ferment, and how often you plan to run your still. It is easy and common to build...
Chapter 4 Fortified Wines
Food, Fermentation and Micro-organisms Charles W. Bamforth Copyright 2005 by Blackwell Publishing Ltd Fortified wines are those in which fermented, partially fermented or unfermented grape must is enriched with wine-derived spirit. According to the European Union EU regulations, such liquor wines are those with an acquired alcohol content of 15-22 by volume and a total alcohol content of at least 17.5 by volume. The chief fortified wines are sherry originating in Spain, notably Jerez de la...
Energy Considerations For Evaporation System Design 1
The single largest variable cost factor in making a separation by evaporation is the cost of energy. If crude oil is the ultimate source of energy, the cost of over 126.67 per m3 20 per barrel is equivalent to more than 3.33 for 1 million kJ. Water has a latent heat of 480 kJ kg at 760 mm of mercury, absolute, so the energy required to evaporate 1 kg of water exceeds 0.16 cents. Therefore, the efficient utilization of energy is the most important consideration in evaluating which type of...
Table 423 MTBE Operating Conditions
REACTOR TEMPERATURE F 175 SPACE VELOCITY, LHSV hr1 4.9 CATALYTIC COLUMN COLUMN TOP TEMPERATURE F 145 COLUMN TOP PRESSURE psig 100 REFLUX DRUM PRESSURE psig 97 COLUMN BOTTOM TEMPERATURE F 276 COLUMN BOTTOM PRESSURE psig 114 NUMBER OF PLATES 40 C4 FEED WASH COLUMN COLUMN TOP PRESSURE psig 169 COLUMN TEMPERATURE F 104 NUMBER OF PLATES 20 RAFFINATE WASH COLUMN COLUMN TOP TEMPERATURE F 104 COLUMN TOP PRESSURE psig 202 COLUMN BOTTOM TEMPERATURE F 104 COLUMN BOTTOM PRESSURE psig 216 COLUMN TOP...
t4iMrb
Solution of Example 1-6 With the aid of the above equations, the number of plates required to effect the specified separation may be determined. To plot the operating line Eq. 1-37 for the rectifying section, the y intercept DXD Vr is computed in the following manner. Since Vr Lr D, and Lt Lr, it follows that PXD Xd _ 0.96 Q3 Vr Lr D 1 3.2 Since y2 XD for a total condenser , the point y2, X D lies on the 45 diagonal. The y intercept and the point y2, X D locate the operating line for the...
Viii Future Trends
The market for probiotic drinks is booming, and clinical work with probiotics continues to provide support for their benefits. Yakult, from Japan, is the world's largest probiotic dairy beverage, followed by Actimel from Danone 81 . The dividing line between yogurt and cultured milks is becoming thinner. Probiotic strains may become the sole fermenting agents in yogurt and fermented milk 82,83 . Biogaia and Farm Produce Marketing Ltd. have signed an agreement to market and sell drinkable yogurt...
B Molds Used for Dairy Products
The use of molds such as Penicillium roqueforti and Penicillium camemberti has a long history in the production of cheese, and their use as starter cultures goes back to the beginning of the 19th century. P. roqueforti is used as a secondary starter culture in the production of blue-veined cheeses, but it may also occur spontaneously in a number of other foods, and for some types of cheeses it is regarded as a contaminant. The fact that P. roqueforti is able to grow at high NaCl and low O2...
Heat Transfer In Evaporators
Whenever a temperature gradient exists within a system, or when two systems at different temperatures are brought into contact, energy is transferred. The process by which the energy transport takes place is known as heat transfer. Because the heating surface of an evaporator represents the largest portion of the evaporator cost, heat transfer is the most important single factor in the design of an evaporation system. An index for comparing different types of evaporators is the ratio of heat...
Bioreactor Operation Modes
The three popular modes of operation of mechanically agitated reactors for cell cultivation are batch, fed-batch and continuous operations. The mechanically agitated reactors are equipped with capabilities for on-line and off-line sensing of a variety of culture characteristics, such as pH, temperature, concentrations of dissolved gases such as CO2 and O2 , biomass concentration, cell morphology, concentrations of various components of the nutrient medium, total protein content of cells,...
Centrifugation
Micro-organisms and other similar sized particles can be removed from a broth by using a centrifuge when filtration is not a satisfactory separation method. Although a centrifuge may be expensive when compared with a filter it may be essential when 1. Filtration is slow and difficult. 2. The cells or other suspended matter must be obtained free of filter aids. 3. Continuous separation to a high standard of hygiene is required. Non-continuous centrifuges are of extremely limited capacity and...
Continuous fermentation
The use of very large combined fermentation and conditioning vessels in a uni-tank process is in essence a strategy which seeks to increase productivity by a combination of shortening process times and reducing capital costs. Thus, the uni-tank process is more rapid than the traditional separate fermentation and conditioning tank approach and with very large vessels there is an opportunity to minimise the ratio of surface area to volume. An alternative approach is continuous fermentation in...
Twelve
Tray design encompasses the determination of the column diameter and the tray spacing as well as a number of mechanical considerations. The scope of the material in this chapter is limited primarily to the fundamentals involved in the design of single-pass sieve trays. The fundamentals involved in the design of valve trays are essentially the same as those involved in sieve trays. No attempt is made to treat bubble-cap trays, since valve and sieve trays have been used extensively in new...
The Challenges Faced at Large Scale in SLF and SSF
The major challenge in the scale-up of aerobic submerged liquid fermentation processes is the transfer of O2 into the liquid at a sufficient rate to obtain high cell densities. Scale-up strategies that address this transfer, which is characterized by the parameter kLa, have long been available in the area of SLF Kossen and Oosterhuis 1985 . Although heat transfer calculations must be done, in order to provide sufficient cooling capacity, heat removal is typically not an overly challenging task....
Refinery Fuel Oil System
The purpose of refinery fuel oil system is to ensure a constant, regular supply of oil to burners of steam boilers and to process furnaces. The system includes facilities for storage, pumping, heating, and distribution of oil at suitable pressure and viscosities so that the atomization and burning of oil is possible. A typical refinery home fuel system is shown in Figure 10-9. The aim of the fuel oil system design is that operational changes to one furnace will not cause fluctuation of supply...
Plate Columns
Distillation may be carried out in plate columns in which each plate constitutes a single stage, or in packed columns where mass transfer is between a vapour and liquid in continuous countercurrent flow. Plate columns are now considered, and packed columns are discussed in Section 11.11. The number of theoretical stages required to effect a required separation, and the corresponding rates for the liquid and vapour phases, may be determined by the procedures described previously. in order to...