Solvent Degradation By Photocatalytic Oxidation

Photocatalytic solvent oxidation had been demonstrated at the pilot scale in two recent field tests located at McClellan Air Force Base AFB in Sacramento, California and at the Fort Carson U. S. Army Installation in Colorado Springs, Colorado Watt et al., 1999 Magrini et al., 1998 . The objective of the tests was to determine the effectiveness of solar-powered photocatalytic oxidation PCO treatment units for destroying emissions of chlorinated organic compounds trichloroethylene and...

Solvent Recovery From Hazardous Wastes

Anilin Flow Diagram

Cleaning performance of solvents Table 22.2.4. Properties of cycloparaffins as a cleaning solvent Table 22.2.4. Properties of cycloparaffins as a cleaning solvent Table 22.2.5. Cleaning performance of solvents The process was previously used for chlorine compounds represented by perchloroethylene and trichloroethyl-ene and for fluorine compounds used for cleaning of press stamped metal parts. However, these compounds are now prohibited for use and production by environmental...

OFRU Recycling GmbH Co KG Babenhausen Germany

Ofru Recycling Asc 100

The Swiss coating manufacturer Karl Bubenhofer AG was planning to acquire various wash plants for cleaning batch, mixing and multi-trip containers efficiently. The contaminated solvents obtained during the wash process were then to be treated automatically by distillation. The distillation plant had to have a suitable output, operate continuously and be simple to operate. Another requirement was the ability to combine this plant with the wash plants in a new building complex. A distillation...

Tableting process of pharmaceutical products

Pharmaceutical Flow Diagram

In a process which produces tablets, a mixture of solvents, containing MDC and methanol and binders is used. Solvents are emitted from the tableting unit. The following process is used to recover the emitted solvent. Feed gas at 50 C from the tableting process is pre-treated by a filter to remove dusts and by a rotary wet scrubber to absorb mainly methanol. During the scrubbing MDC also dissolves in water, although at low concentration. This water is treated in two steps, by a degassing unit at...

Field Test Results Air stripper application

Solar Irradiance Time

The field test at McClellan AFB took place during a 3-week period in April, 1997. System operating conditions included two flow rates 10 and 20 SCFM and variable light intensity. The photoreactor system, designed to perform optimally at 10 SCFM with natural sunlight, was also operated at 20 SCFM to challenge the system. Because of varying solar illumination levels during the day, the system can operate for longer periods at lower flow rates. Residence times in the reactor at 10 and 20 SCFM were...

Adsorption capacity

Macropore Activated Carbon

The adsorption capacity adsorptive power, loading of an adsorbent resulting from the size and the structure of its inner surface area for a defined component is normally represented as a function of the component concentration c in the carrier gas for the equilibrium conditions at constant temperature. This is known as the adsorption isotherm x f c T. There are variety of approaches proceeding from different model assumptions for the quantitative description of adsorption isotherms Table 22.1.3...

Paint booth application

Parabolic Trough Photoreactor

For the paint solvent application, a slipstream of a paint booth vent located at Fort Carson was analyzed to determine the components present with rapid scan gas chromatograph. On any operational day, several paint types are sprayed. The solvent emissions content thus varies during painting operations. In general, the amounts and types of solvent emissions from the Fort Carson paint booth are listed in Table 22.4.2. Figure 22.4.2. Schematic of the 10 SCFM parabolic trough, solar photoreactor...

Energy Recovery From Waste Solvent

Process Flow Diagram Boiler Reference

Specifications of the VOC Table 22.2.10. Specifications of the waste oxidation unit heat boiler It is not always economically justified to recover solvents if they are at very low concentrations and in mixtures. It may be more economicalto burn the solvent blend in a boiler to save fuel. Tables 22.2.9 and 22.2.10 contain the specifications of industrial combustion units. Figure 22.2.12. Flow diagram of energy recovery process. Figure 22.2.12. Flow diagram of energy recovery...

Halogenated Solvent Recovery Coating process

Process Flow Steam Adsorption

A process to recover ethylene dichloride, EDC, and methylene dichloride, MDC, using activated carbon fibers, ACF, is discussed in this section. The gas at approximately 50 C, containing EDC and MDC is received from a painting process. It is pretreated by a filter to remove dusts and passed through a heat exchanger to cool it down to approximately 30-40 C. The pre-treated gas is fed to adsorption columns filled with ACF where the gas is cleaned sufficiently for it to be safely released to...

Molecular sieve zeolites

Molecular sieve zeolites2'10'11 are hydrated, crystalline aluminosilicates which give off their crystal water without changing their crystal structure so that the original water sites are free for the adsorption of other compounds. Activation of zeolites is a dehydration process accomplished by the application of heat in a high vacuum. Some zeolite crystals show behavior opposite to that of activated carbon in that they selectively adsorb water in the presence of nonpolar solvents. Zeolites can...

Pco Pilot Scale Systems Air stripper application

Photoreactor

Figure 1 shows a schematic of the pilot-scale system used at McClellan AFB. This system, scaled from an optimized laboratory reactor, was fabricated by Industrial Solar Technology Figure 22.4.1. Schematic of the 10 SCFM solar photoreactor system used at McLellan AFB. Figure 22.4.1. Schematic of the 10 SCFM solar photoreactor system used at McLellan AFB. Corporation Golden, CO . The reactor, 1.22 m wide by 2.44 m, consisted of a fberglass-re-inforced plastic I-beam frame. A transparent...

Basic arrangement of adsorptive solvent recovery with steam desorption

Basic Steam System

Adsorptive solvent recovery units have at least two, but usually three or four parallel-connected fix-bed adsorbers which pass successively through the four stages of the operation cycle.1-418-23 Cooling Whilst adsorption takes place in one or more of them, desorption, drying and cooling takes place in the others. The most common adsorbent is activated carbon in the shape of 3 or 4 mm pellets or as granular type with a particle size of 2 to 5 mm 4 x 10 mesh . A schematic flow sheet of a two...

Activated Carbon In Fluidized Bed Adsorption Method

Adsorption Column Flow Diagram

This section discusses a solvent recovery process developed by Kureha Engineering Co. Ltd., Japan.1 In this continuous process, spherical particles of activated carbon AC circulate in the adsorption and desorption columns by fluidization. In the adsorption column, the particles form fluidized beds on multi-trays to adsorb the solvent in counter-current contact with the feed gas. The cleaned gas is released from the top of the adsorption-column to the atmosphere. The carbon absorber with...

Packaging printing industry

Schwefelwasserstoff Absorption

In the packaging printing industry solvents like ethyl acetate, ethanol, ketones, tetrahydrofuran THF , hexane and toluene are used in printing. The solvent laden air generally contains between 2 and 15 g m3 of solvent and, depending on the season, 5-18 g m3 of water. Adsorptive recovery with steam desorption was widely used for many years but its disadvantage is that the solvents are recovered in various mixtures containing large amounts of water. The recovery of solvents is complicated...

Safety requirements

Activated Carbon Adsorption Isotherm

Adsorption systems including all the auxiliary and ancillary equipment needed for their operation are subject to the applicable safety legislation and the safety requirements of the trade associations and have to be operated in accordance with the respective regulations.2'19 Moreover, the manufacturer's instructions have to be observed to minimize safety risks. Activated carbon or its impurities catalyze the decomposition of some organics, such as ketones, aldehydes and esters. These exothermic...

Designing solvent recovery systems

Fixed Bed Adsorbers Operations

Designing an activated carbon system should be based on pilot data for the particular system and information obtained from the activated carbon producer. The basic engineering and the erection of the system should be done by an experienced engineering company. Solvent recovery systems would also necessitate the specification of condenser duties, distillation tower sizes, holding tanks and piping and valves. Designing of a solvent recovery system requires the following information Table 22.1.7 ....

Application Of Molecular Sieves

Concentrator Voc

Molecular sieves is a term synonymous in this context to aluminosilicate hydrate also called zeolite. The zeolite is applied to deodorization, gas separation and some other processes. Since this material is, unlike activated carbon, non-combustible, it has increasingly been applied to concentrate volatile organic compounds, VOC. The concentration process discussed here applies to the VOC concentrator developed by Seibu Giken Co. Ltd. Japan.2 The element referred to here as the VOC concentrator...

Petrochemical industry and tank farms

Adsorption Bed

Vapor recovery units are installed at petrochemical plants, tank farms and distribution terminals of refineries. Tank venting gases are normally small in volume, discharged intermittently at ambient temperature and pressure and loaded with high concentrations of organic vapors.2 Processes used for the cleanup of such waste air streams with organic vapor up to saturation point are often combined processes 2,38,39 absorption and pressure-swing adsorption membrane permeation and pressure-swing...

Refrigerator recycling

Condensation processes are especially suitable for the cleaning of low flow highly concentrated streams of exhaust gas.36 The entire waste gas stream is cooled below the dew point of the vapors contained therein, so that these can condense on the surface of the heat exchanger partial condensation . Theoretically, the achievable recovery rates depend only on the initial concentration, the purification temperature and the vapor pressure of the condensables at that temperature. In practice...