Particulate capital cost

Relatively low capital cost Relatively small space requirements Ability to collect particulates as well as gases Collected substances may be recovered by distillation... 

The electrostatic effect can be incorporated into wet scrubbing by charging the particulates and/or the scrubbing-liquor droplets. Electrostatic scrubbers may be capable of achieving the same efficiency for fine-particulate removal as is achieved by high-energy scrubbers, but at substantially lower power input. The major drawbacks are increased maintenance of electrical equipment and higher capital cost. 

In the past, controlled-air incinerators have been the most popular incinerators for biomedical waste destruction. A controlled-air incinerator is a two-chamber, hearth-burning, pyrolytic unit. The primary chamber receives the waste and bums it with less than stoichiometric air. Volatiles released in the primary chamber are burned in the secondary combustion chamber. These units result in low fly ash generation and low particulate emissions. In addition, they have a low capital cost and may be batch operated. They normally do not require air pollution control equipment unless acid gas emissions are excessive. 

Without heat recovery included in a 18.2-metric-ton/day plant, it appears from the data presented in Table VI that a one-shift/ day operation would be preferable to a two-shift/day operation. Figure 2 shows that for a plant with heat recovery, the decision between choosing a one- or two-shift operation is influenced by the value of the steam produced. If the steam has a value of more than 2/10 joule, the two-shift operation is more attractive. Almost 2570 more steam can be produced from a two-shift operation than from a one-shift operation. The addition of a particulate control system increases the capital cost by approximately 80,000 and increases the operating cost by 7/metric ton. ... 

The 45 and 90 metric ton/day facilities were designed to include two and four individual modules, respectively. The modules were operated three shifts/day, five days a week and included automatic ash removal. Heat recovery was included in all of the cases considered. Table VII details the capital costs for these units, both without a particulate control and with fabric filters for particulate control. Table VIII summarizes the operating costs for the installations. For both sizes of installation, particulate control adds 4/metric ton to the operating cost. Figure 3 illustrates the effect of steam value on the operating costs. 

Fiberglass 21 Particulate Capital reduction Oxygen cost... 

Ability to collect gases as well as particulates (especially sticky ones) Ability to handle high-temperature, high-humidity gas streams Capital cost low (if wastewater treatment system not required)... 

Energy consumption for the process is small and the capital costs are minimized SSD provides easier recovery of solvents and particulates Lack of oxygen significantly reduces fire and explosion hazards... 

With regard to the fermenters, the most common configurations are membrane recycle fermentor (MRF) and hollow fibre fermentor (HFF). In the MRF the membrane module forms a semi-closed loop with a conventional fermentation vessel the MRF gives much better performance than the HFF, where the microbial cells are loaded onto the shell-side and the feed is pumped through the lumen side. Further advantages of this system are a cell/particulate-free product stream and the reduction of capital costs. Furthermore, in these systems cell growth is a caitical point. 

The main disadvantage of XRF is the high initial capital cost of instrumentation. The method is used, however, particularly in the analysis of particulate lead in... 

As we have already emphasised, the sensitivity of PI unit operations to contaminants within process steams - such as particulates causing fouling, blockage or corrosive fluids - so the use of PI for effluent treatment has to take into account the fact that many effluents are, by their nature, foul . Obviously care can be taken in the selection of appropriate components for effluent treatment, and a major opportunity for PI is that it can be used as the basis for compact, reduced capital cost and energy-efficient effluent treatment plant. An early UK case study undertaken in the 1990s illustrates the benefits that could accrue to the use of PI in effluent treatment. 

Gasification is a much faster reaction than both POX and SMR however, the capital costs are greater as there are more pre-treatment processes required for coal than methane and the syngas needs more cleaning to remove particulates (Mueller-Langer et al, 2007 Holladay et al, 2009). In addition, gasification offers much lower efficiencies than SMR, of the order of 50-60% (Smith et al, 2005), and is not suitable for smaller scale apphcations. 

Although the use of a plasma torch increases the global electticity cost, it reduces the electrical power required by the off-gas treatment system (exhaust fans, scrubbers, particulate filters) because the off-gas flow rate is much lower than with a burner. Indeed, there is about an 80% off-gas flow rate reduction when using a plasma torch instead of a burner. Not only does this reduce operating costs of the off-gas treatment system in existing plants, it also reduces the capital cost for future plants because a smaller and less complex off-gas treatment system can be purchased. 

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