Header Pressure and Temperature Control

Most steam systems have nominal HP, MP and LP headers. Typically, HP steam is 40bar, MP steam 10bar and LP steam 3bar. These pressures, chosen at the design stage, are not necessarily the most energy efficient. Rather than run at 'design' pressure, it is generally better to experiment by monitoring fuel consump tion as the HP MP LP pressure set points are slowly changed to find the optimum combination. Turbines use less steam if inlet temperature is increased. This is especially important for...

Centrifugal Pumps

This work horse of the process industries offers one of the largest opportunities for energy saving. The design process is usually conservative when specifying pumps, especially when calculating the required discharge pressure. As a result, the pressure drop across the discharge control valve is commonly higher (sometimes much higher) than needed for process control. Many, if not the majority, of centrifugal pumps in the oil, gas and petrochemical industries are specified to meet the Code API -...

Cradle to Grave Carbon Footprints

Cradle -to-grave carbon footprints include the contributions downstream of the production. The upstream part is handled as described in the previous section. Downstream contributions can be very diverse and typically come from logistics Raw Materials. transportation. other Figure 1.7 Cradle-to-gate footprints (electrolysis example) with different allocation methods. and packaging, additional production or finishing, purchasing (mostly a logistic effort), product application and disposal. Most...

Raw Materials

In Section 4.3.1 the carbon footprint or, the method developed by Bayer Technology Services, the Climate Footprint was presented. As a part of the result of carbon footprint analysis, the CO2 load of a product caused by the raw materials is delivered. Now the consultant together with the customer will assess that value and decide if an investigation for alternative raw materials, or an alternative supplier for the same raw materials is a way to decrease the footprint. The search for alternative...

Boiler Water

Water is the working fluid for steam generation and boilers, which are among the most costly and vital pieces of equipment in an industrial complex. Proper treatment and conditioning of water can increase boiler performance, energy efficiency, maintain production capability and reduce operating costs while extending its operational life. Boiler water treatment avoids scaling and corrosion, insuring safe and reliable operation. Lack of appropriate treatment can cause a series of problems to...

Efficiency Parameters of CCS

The efficiency ofCCS as a measure for lowering CO2 emissions is described using various parameters energy requirements for CO2 capture, transport and storage First of all, in the process itself, the CO2 capture rate is an important characteristic value and design parameter. It describes how much of the CO 2 that would otherwise be emitted into the atmosphere is captured from the process and stored. In the three methods developed for CO2 capture from power plants, the capture rate is typically...

Energy Consumption and CO2 Emissions in General

Energy consumption increases with economic development in most countries. From 1990 to 2006 the total primary energy consumption rose from 370 to 500 Exajoule (EJ, 1EJ 1018J) or 35 14 , as shown in Figure 5. The biggest rates of increase can be observed in Asia and Middle East (plus 110 each), whereas the rates of increase are the lowest in Eurasia (minus 25 ) and Europe (plus 13 ). This reflects the economic development of these regions, but on the other hand, it is also a signal for an...

Gas Turbines

A gas turbine is a set of three pieces of equipment with different functions. First an air compressor, where atmospheric air is pressurized and delivered to the second device, a constant pressure combustion chamber, where fuel is injected and burned. Combustion takes place with high excess air. The heated flue gases are then expanded in the third piece of equipment, a turbine, producing power to drive the compressor and excess power is used for driving an external equipment. Due to the large...

Industrial sector Abatement cost curve in Germany 2020

Overall Efficiency optimization of lighting in buildings Overall Heat recovery in ventilation systems air conditioning in buildings Non-ferrous metals Electrolysis efficiency _ improvements Steel CCS Steel Thin slabbing direct casting Overall Optimization of heating systems in buildings Chemicals Efficiency of catalytic converters Steel Production shift from Paper BF BOF to EAF I 25 Overall Mechanical optimizations of drive systems (in diverse motor system applications) M I I 30 I 35 Chemicals...

Further Reading

1 Asociacion regional de empresas de petroleo y gas natural en latinoamerica y el caribe (Regional association of oil and natural gas companies in latin america and the Caribbean, ARPEL) (2002) Environmental Guideline No. 33-2002 Energy Use Monitoring and Tracking. 2 Billege I. (2009) 700 refineries supply oil products to the world. Nafta, 60 (7-8), 401-403, http hrcak.srce.hr file 65010 (accessed 26 April 2010). 3 Energy Information Administration (2009) Office of Integrated Analysis and...

Heat Integration and Pinch Analysis 189

6.2 Heat Integration Basics 190 6.2.1 Why Heat-Integrate for Optimum Heat Recovery 190 6.2.2 Inter-Unit Heat Integration 191 6.2.3 Benefits of Heat Integration 192 6.2.4.2 Process Modifications 193 6.2.4.4 Utilities Optimization 193 6.2.4.5 Total Site Optimization 193 6.3 Introduction to Pinch Technology 193 6.3.1 The Concept of Quality of Energy 193 6.3.4 Setting the Energy Targets 198 6.3.5 Setting the Area Targets 199 6.3.6 Capital Energy Trade-off 200 6.4 Minimizing the Cost of Utilities...

Transformation Units

The majority of typical process units perform some kind of chemical reaction. We can include in this class conversion units, like thermal cracking, as a coking or a visbreaking, cracking processes, like fluid catalytic cracking, steam cracking and hydrocracking, catalytic reforming, isomerization, alkylation and polymerization. In this same category, we can include the treatment processes, hydrodesulfuriza-tion and hydrotreating. To break and recombine molecules, high pressure, temperature and...

Building Blocks

Building blocks are chemical molecules with multiple functional groups that through transformation can be a source for a wide variety of useful chemicals and synthesis pathways. In 2004, a study from the Biomass Program of the U. S. Department of Energy (DoE) created the 'Top Value Added Chemicals from Biomass' in which twelve chemical building blocks originating from sugar were identified 23 -see Figure 12.6. This detailed report also gives a comprehensive overview regarding potential...

Bioethanol and Bioethylene

Biomass- based ethanol currently substitutes around 3 of the global gasoline consumption. It has a higher octane rate compared with gasoline (98 vs. 80), but has a lower volumetric energy content (67 of gasoline). Therefore, per kilometer driven, around 20 more ethanol is required - 15 , Favorable political conditions for biofuels have stimulated a significant increased in global production. Currently, the major producers are Brazil (sugarcane) and the USA (corn). In Brazil, the integrated...

Intermediate Reboiler or Condenser

Exergy losses can by reduced by the use of an intermediate reboiler 2 . However, this measure does not lower the total energy requirement of a column. But a certain part of the heat is supplied at a lower temperature in reboiler 2 as illustrated in Figure 7.11, Therefore, the energy cost might be reduced. An intermediate reboiler is advantageous only if several external heat sources, for example, steam pressure levels, are available for the individual reboiler. Analogously to an intermediate...

Melt Crystallization by Cooling

Distillation is energy-intensive for solutions that form isomers and azeotropes. In these cases, crystallization can provide better separation and a more energy efficient process. Melt crystallization is the process of separating the components of a liquid mixture by cooling until a quantity of crystallized solid is deposited from the liquid phase. Therefore, melt crystallization is often considered to be commercially attractive, compared with distillation, for the separation of close-boiling...

Cooling Towers

Process plant cooling towers are available in a range of designs. The most common are cross flow and counter flow with air drawn in by induced draft fans. Figures 8.19 and 8.20 below illustrate the main differences. For some reason, cross flow towers are common in North America and counter flow towers predominate in Europe and Asia. In a cross flow tower, air is drawn through the falling water from the side, over the full height of the packing. In a counter flow tower, air enters underneath the...

B

Figure 6.18 Cross-pinch heat transfer. In principle, the region above the pinch requires only hot utility, and that below the pinch only the cold one. An ideal design would reflect this arrangement. Following the logic of this separate heat balances above and below the pinch, the design rules instruct that no heat should be transferred from a hot stream placed above the pinch point to a cold stream placed below the pinch point. If such heat is transferred from the hot side of the pinch to its...

Ancillary Systems

Auxiliary facilities for power cycles are supporting systems for maintaining their operation. Most important among them are water treatment facilities including external and internal treatment. Considering overall plant water demand, external treatment usually lies in a separate unit while internal treatment is by a set of equipment normally near the boilers. Electrical devices for reception, transmission and distribution of purchased and generated electricity can be included in this list. A...

Centrifugal Fans

In process plants, centrifugal fans are mostly found providing air to boilers and furnace air preheaters. Where inlet air filters are required, these should be elevated to reduce the risk of sucking in airborne dust and generously sized. Since fans operate with relatively low pressure ratio, even apparently modest pressure drop across a filter can result in a large increase in fan power required. Fans have either straight radial vanes, forward curved vanes or backward curved vanes. Straight...

Step 2 Flowsheet Decomposition

The object of this step is to identify all the mass and energy flow-paths in the process by decomposing the process into open- and closed- paths for each compound. The closed-paths (CP) represent process recycles from which specific amounts of materials (chemicals) and energy do not leave the process. In other words, they are the flow paths, which start and end in the same unit of the process. An open-path (OP) represents a path for material and energy with an entry- point to the process and an...

Dividing Wall Column

The dividing wall column is a concept frequently used in direct column coupling. In all processes where multicomponent mixtures have to be separated into pure fractions, dividing wall columns are applicable. They are particularly suited to obtain pure medium boiling fractions. A sequential system with at least two columns as shown in Figure 7.14 is required for the separation of a three-component mixture into its pure fractions in conventional systems. A three-component mixture can be separated...

Separation Units

Nevertheless, the very first process in oil processing historically is still the core process of any refinery, the physical separation. All distillations fall into this class, atmospheric, superatmospheric and vacuum distillation, as also any light ends recovery or specialty separations, like LPG specification or propane-butane separation. In this rank are included any solvent extractions, like crude oil desalting and dewatering. Distillation and Fractioning Units Petroleum is a mixture of...

Manufacturing and Product Allocation

For a cradle-to-gate carbon footprint the final step is usually the production of the respective substance and depending on the chosen boundary limits potentially including filling and packaging. The production is analyzed based on a balance of all material, utilities and energies flowing into and out of the unit. Usually the balance should be done on average numbers for a certain period of time, for example, one year of production. Non-continuous streams like for batch operations or for...

Biocatalysis for the Production of Emollient Esters

The biocatalytic production of chemicals offers intrinsic properties. Commonly mentioned attributes are unusually high selectivity and operation under milder conditions. Recently the sustainability of biocatalytic processes for the production of cosmetic ingredients, in particular emollient esters has been quantified 30 . The frequently used emollient ester, myristyl myristate, was used as a model study. An enzymatic production system using immobilized Lipase B from C. antartica under real...

Implementation of Energy Awareness in Plants

Markus Rowenstrunk and Susanne Mutze-Niewohner Environmental awareness issues and energy conservation have increased throughout many societies in recent years. The World Commission on Environment and Development (Brundtland Report, 1987), the Kyoto Protocol (1998), an international environmental treaty to the United Nations Framework Convention on Climate Change (UNFCCC), numerous other conferences, treaties, organizations, and activists have made tremendous efforts to raise awareness with the...

Energy Awareness and Environmental Sustainability

Individual people and entire organizations are not likely to actively preserve energy or in general act in an environmental friendly way, unless they are aware of the issue and its problems. But what does being aware mean Even though there are many sophisticated definitions of awareness, just in the field of psychology for example, referring to consciousness, the Oxford Dictionary (fourth edition) offers a simple but very useful definition. It states that being aware means having knowledge or...

Flares and Flare Systems

Obviously, any flaring is undesirable and ideally a flare release should only occur during emergency upsets. However, there are often many hundreds of valves connected to the flare system-control valves as well as pressure relief valves-and it can be difficult to keep these leak-free, especially since maintenance access to the flare system is limited. There are two main groups-elevated flares and ground flares. The traditional elevated pipe flare requires a continuous purge as well as...

Power Cycles

In a simple approach, industry energy requirements can be summarized to heat and power, and as mentioned in the beginning of this chapter, they can be supplied by an external third party, a utility provider, that can sell them separately in various and suitable forms. This approach can simplify tremendously energy management of the plant, allowing owners to concentrate on the core business, but it may imply a huge lost opportunity for energy efficiency. Since heat and power are merely diverse...

Heat Integration and Heat Recovery

Heat recovery is described in detail in Chapter 6 of this book. Of course standard methods such as pinch point analysis (see for instance 4 ) are part of an energy study. Input data for a pinch point analysis are the heat streams in a plant and their temperature levels. There are some rules deduced from the pinch point theory. The consultant will evaluate if the actual heat exchanger network in the plant fulfills these rules. Then pinch point analysis or use of a software tool that applies the...

Prearrangements and Preanalyses

Prearrangements that have to be done to develop the design of an awareness program start with the identification and gathering of relevant information on any energy matter in the organization. For example, is detailed information about the level of energy use and cost already available or if not, who can provide it When this information is on hand, it has to be assessed what theoretical potentials of energy saving exist and which measures can be beneficially implemented to reach the overall...

Brayton cycle

Figure 10.4 Temperature vs entropy for Brayton cycle. (On this graph areas represent energy.) Figure 10.4 Temperature vs entropy for Brayton cycle. (On this graph areas represent energy.) and operational costs can be quite expensive. The main pieces of equipment, boilers, steam turbines and eventually huge condensers are very expensive in terms of equipment itself and installation costs. Operational costs range high also, because of manpower and chemicals, since each energy unit produced...

CO2 Saving Limitations of Single Productbased Systems

In Figure 12.7 the cumulative energy demand (CED) of producing existing functional chemical families from the 'traditional petrochemical route' and the 'potential biorefinery route' is presented. CED and CO2eq are interrelated and following the average stoichiometry reveals a conversion factor of 0.071 tonCO 2eq GJ fossil energy. On the right hand side (crop image) regional agricultural intensity and the crops specific chemical composition yield an associated energy cost for the Figure 12.7...