Energy usage

Stage Classical resolution route Energy (MJ/kg 1) Enzymatic route (no recycle of 4) Energy (MJ/kg 1) 

185 000 tonnes of solvent, an 92% reduction 4800 tonnes of mandelic acid, a 100% reduction 1890 tonnes of Raney nickel catalyst, an 87% reduction 10000 tonnes of starting material 4, a 39% reduction 

The enzymatic route resulted in an energy usage reduction of 82% versus the classical resolution process. This energy usage was based on two main factors (i) 2) Batch Plus version 2006.5 by Aspen Technology. 

Operation Energy/kg 1 (M)/kg) % of total operations Avg. energy per operation (MJ/kg) 

An alternative way of analyzing the data is to break the process down into unit operations, and Table 8.5 summarizes this approach. The unit operations that were considered for energy usage calculations were heat/cool, heat to reflux and 

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It is possible to dispense with the extraction step if the oxidation section is operated at high propylene concentrations and low steam levels to give a concentrated absorber effluent. In this case, the solvent recovery column operates at total organic reflux to effect a2eotropic dehydration of the concentrated aqueous acryflc acid. This results in a reduction of aqueous waste at the cost of somewhat higher energy usage. 

The process operates at 1200°C and < 400 Pa (3 tort) and has a cycle time of 20—24 hours. The reactor is opened at the flange and the metal removed. Energy usage in the furnace is 7-7.3 kWh/kg magnesium. A similar process is used by Brasmag (Minas Givras, Bra2il) (56). 

Energy usage per kg of product highly dependent on heat of vaporization of solvent and number of effects used (can be very energy intensive). 

Computer Control. The use of computer systems to control the operation of submerged arc furnaces, including calcium carbide, has been successfully demonstrated in the United States (see Expert systems Process control). Operations direcdy under control are mix batching, electrode position and sHp control, carbide gas yield, power control, and cooling water systems. Improvements in energy usage, operating time, and product quaHty are obtained. 

Table 1 is an estimate of energy usage by United States industry for 1988 (1). The chemical industry used 21% of the energy consumed by the U.S. industrial sector, and the other three related process industries, paper (qv), petroleum (qv), and primary metals, combined for an additional 50% of the industrial consumption. 

Table 1. Energy Usage by United States Industry in 1988 ...

Another basic consideration is whether crystallization is best carried out on a batch basis or on a continuous basis. The present tendency in most processing plants is to use continuous equipment whenever possible. Continuous equipment permits adjusting of the operating variables to a relatively fine degree in order to achieve the best results in terms of energy usage and product characteristics. It allows the use of a smaller labor force and results in a continuous util-... 

Identify deteriorating performance in instruments, energy usage, equipment, or catalysts. 

Another variant is the lowest achievable emission rate (LAER) for a specific pollutant required for a new source of that pollutant to be located in a nonattainment area (i.e., one which has not attained the NAAQS for that pollutant), LAER is the lowest emission rate allowed or achieved anywhere without regard to cost or energy usage. LAER is intended to be more stringent than BACT or NSPS and is also determined on a case-bycase basis. 

Implementation of P2 (pollution prevention) measures can yield both economic and environmental benefits. However, a balance on energy usage and environmental impacts may have to be struck. New refineries should be designed to maximize energy conservation and reduce hydrocarbon losses. 

In other words, our primary focus is on waste- and pollution-reduction opportunities if these could reduce energy consumption as well, all the better. If energy usage is a particularly prominent factor, then the team should recommend a separate energy audit. 

Reduction in environmental pollution due to lower energy usage and lower emissions to the surroundings... 

Energy usage per cubic meter or square meter of a building, such as for the heat consumption in buildings... 

Energy usage per produced unit of final product(s), for example, energy use for each produced ton of stainless steel... 

Because of these solutions, important technical data can be transferred from local instrumentation (control system) through data-based controllers to a control station with computers. The operator may use the many variations that the software data system provides. Technical data operation may be digital off/on messages such as the status of operation and the performance of alarms or analog measurements such as temperature, humidity, pressure, velocity, energy usage, etc. 

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