KPR SOLVENT CONCENTRATING SYSTEMS

Size: px

Start display at page:

Download "KPR SOLVENT CONCENTRATING SYSTEMS"

Samson Curtis
6 years ago
Views:

1 1 MET!2pRo Systems Division 2. ~72.81 pjp BULLETIN 113i)O KPR SOLVENT CONCENTRATING SYSTEMS FOR CONTROL OF LOW CONCENTRATION VOLATILE ORGANICS \

2 , '. ADVANTAGES OF THE KPR SYSTEM INCLUDE: Low operating costs. High emission capture efficiency. Minimal solid/liquid waste disposal. High system flexibility over a variety of painting conditions. Low maintenance requirements; few moving parts. Long carbon and catalyst life. Constant utility demand with no high low periods. Continuous, non-cyclic operation, unattended. Light weight and small system size for roof mounting or fitting into tight spaces. No carbon bedfire problems. DETAILS OF THE KPR SYSTEM DESIGN Figure 4 shows how a KPR Apparatus can be coupled to a catalytic incinerator. The dilute exhaust stream (A) is introduced into the KPR by the main blower (1) and the stream is prefiltered (2) to remove particulates or high boiling point (>400 deg. F) organic compounds. The dilute stream is passed through the adsorption sector honeycomb made of activated carbon fiber (3) where adsorption of hydrocarbons occurs. The cleaned exhaust (B) is emitted to atmosphere. The desorption sector is purged by outside air (C) introduced to the system by the desorption blower (4) and heated by a gas-to-gas heat exchanger (11). A bypass (10) is provided io control desorption air temperature. The desorption air (D) is introduced into the desorption sector of the honeycomb and exhausts as a hot air stream containing concentrated hydrocarbons (E). The solvent laden air is introduced into the catalytic incinerator (7) by a second blower (5) and preheated with incinerator exhaust gas by another gas-togas heat exchanger (6). The solvent laden air passes through a preheat burner (8) and passes over the catalyst (9) where combustion of hydrocarbons occurs. After passing through.heat exchangers (6) and (11) to extract from the stream the heat,, generated by hydrocarbon combustion, the cleaned stream exhausts to atmosphere (F). Capture efficiency of the KPR for most solvents is 95-98% and similar combustion efficiency over the catalyst can be obtained, resulting in overall hydrocarbon control of over 90%. Prefiltering units which may be required with a KPR System include bag filters for particulates and granular carbon beds for very high boiling organic compounds. The particulate filters for paint spray booth applications include a square frame filter cube for removal of large (>5 micron) sticky paint particles and high efficiency (>90%) cloth bags for small (<5 micron) paint pigment particles. These filters must be changed at regularly scheduled intervals, depending on particulate loading and size disiribution. Traces of high boiling point (>400 deg. F) organic compounds are removed from paint spray booth emissions by use of a thin granular carbon bed before the KPR Rotor. Once saturated with these high boilers, the granular carbon must be removed, replaced and either disposed of or furnace regenerated. The granular carbon should be changed at 5,000 to hour intervals, depending on the concentration of high boiling point organics in the paint spray booth emissions. KPR-C FLOW DIAGRAM Figure 4

3 *"THE UNIQUE KPR ACTIVATED CARBON FIBER ADSORBENT The KPR Solvent Concentrating System uses a unique activated carbon fiber adsorbent formed into a honeycomb. Adsorption of solvent air emission onto KPR activated carbon fiber occurs more rapidly and completely than with granular activated carbon (GAG). Figure 1 is a simplified model, which illustrates that the micropores used for gas phase adsorption are directly at the surface of the fiber in KPR. However, in the case of GAC, almost all of the micropores are \.?.thin the macropores of the granule, making it an energy and tine intensive adsorption media. KPR ROTOR ADSORBING Figure 2 HOW KPR OPERATES The KPR Apparatus is a patented system designed to concentrate dilute solvent emission sources before final treatment by carbon adsorption/solvent recovery or by catalytic/thermal incineration. The key component of the KPR System is the KPR Rotor, which consists of a honeycomb structure element made of activated carbon fiber paper in a corrugated form. Figures 2 and 3 show a schematic representation of a cylindrical KPR Rotor for large size systems. The KPR Rotor turns continuously at a slow speed and is divided into two sectors; one for adsorption and one for desorption. The process exhaust to be treated and the desorbinc hot air flow in opposite directions along the tubular paths through the honeycomb. The hydrocarbons in the process exhaust are adsorbed onto the activated carbon fiber in the adsorption sector, and the carbon fiber is regenerated by hot air in the desorption sector of the KPR Rotor. The desorbed solven: exhausts with the hot air, but in a volume only 1,5 to 1/15 that of the influent to the KPR. HONEYCOMB KPR ROTOR DESORBING Figure 3 4 SOLVENT LADEN AIR + MICROPORE ADSORPTION BY KPR FIBER Figure 1 SOLVENT LADEN REGENERATING AIR SOLVENT LADEN REGENERATING AIR ADVANTAGES OF THE KPR SYSTEM The KPR System is the most cost-effective control device f x paint spray booths, especially when the KPR Apparatus is coupled to a catalytic incinerator, When coupled with a catalytic incinerator, it is possible in many cases to use the heat from incineration of the solvent to supply all the preheat requirements for desorption air and for the incinerator inlet stream. This low or no fuel requirement can result in lower annual operating and capital costs than treatment of the dilute exhaust stream without preconcentration by KPR.

4 ff? 4 v.;.,.. ADVANTAGES OF THE KPR SYSTEM INCLUDE: Low operating costs. * High emission capture efficiency. Minimal solid/liquid waste disposal. High system flexibility over a variety of painting conditions. Low maintenance requirements; few moving parts. Long carbon and catalyst life. Constant utility demand with no high low periods. Continuous, non-cyclic operation, unattended. Light weight and small system size for roof mounting or fitting into tight spaces. No carbon bedfire problems. DETAILS OF THE KPR SYSTEM DESIGN Figure 4 shows how a KPR Apparatus can be coupled to a catalytic incinerator. The dilute exhaust stream (A) is introduced into the KPR by the main blower (1) and the stream is prefiltered (2) to remove particulates or high boiling point (>400 deg. F) organic compounds. The dilute stream is passed through the adsorption sector honeycomb made of activated carbon fiber (3) where adsorption of hydrocarbons occurs. The cleaned exhaust (B) is emitted to atmosphere. The desorption sector is purged by outside air (C) introduced to the system by the desorption blower (4) and heated by a gas-to-gas heat exchanger (11). A bypass (IO) is provided to control desorption air temperature. The desorption air (D) is introduced into the desorption sector of the honeycomb and exhausts as a hot air stream containing concentrated hydrocarbons (E). The solvent laden air is introduced into the catalytic incinerator (7) by a second blower (5) and preheated with incinerator exhaust gas by another gas-togas heat exchanger (6). The solvent laden air passes through KPR-C FLOW DIAGRAM Figure 4 a preheat burner (8) and passes over the catalyst (9) where combustion of hydrocarbons occurs. After passing through heat exchangers (6) and (11) to extract from the stream the heat generated by hydrocarbon combustion, the cleaned stream exhausts to atmosphere (F). Capture efficiency of the KPR for most solvents is and similar combustion efficiency over the catalyst can be obtained, resulting in overall hydrocarbon control of over 90%. Prefiltering units which may be required with a, KPR System include bag filters for particulates and granular carbon beds for very high boiling organic compounds. The particulate filters for. paint spray booth applications include a square frame filter cube for removal of large (>5 micron) sticky paint particles and high efficiency (>go%) cloth bags for small (<5 micron) paint pigment particles. These filters must be changed at regularly scheduled intervals, depending on particulate loading and size distribution. Traces of high boiling point (>400 deg. F) organic compounds are removed from paint spray booth emissions by use of a thin granular carbon bed before the KPR Rotor. Once saturated with these high boilers, the granular carbon must be removed, replaced and either disposed of or furnace regenerated. The granular carbon should be changed at 5,000 to 8,000 hour intervals, depending on the concentration of high boiling point organics in the paint spray booth emissions.

$. * \ * APPLICATIONS OF THE KPR SYSTEM KPR installations for paint spray booth Volatile Organic Compound (VOC) emission control have been in operation for many years.$

5 . * \ * APPLICATIONS OF THE KPR SYSTEM KPR installations for paint spray booth Volatile Organic Compound (VOC) emission control have been in operation for many years. When only one or two solvents are involved, the KPR Apparatus has usually been followed by a carbon adsorptionisolvent recovery system. In cases where a complex mixture of solvents is involved, the KPR Apparatus has usually been followed by a catalytic incinerator. Since most paint formulations are very complex blends of solvents plus pigments, it follows that the most cost-effective KPR Systems lor paint spray booth emissions incorporate catalytic incineration. One large volume VOC air emission source where KPR has been applied is automobile paint spray booth emission control. The high air volumes, low concentration of VOC's in the exhaust and the complexity of the paint solvent mixture make KPR plus catalytic incineration a very cost-effective solution to that particular problem. Excellent VOC removal efficiency has been achieved. A typical KPR System installed on an automobile paint spray booth is shown in Figure 6. Two booth areas, which account for most of the VOC emissions for the entire paint spray booth, are KPR HONEYCOMB IN CASE Figure 5 each vented to a KPR. Preliltration of particulates and granular carbon adsorption of high boilers is accomplished prior to booth exhaust entering the KPR Rotor. The KPR Rotor consists of a number of galvanized cases enclosing sheets of KPR corrugated carbon fiber paper (Figure 5). The VOC's are th'en adsorbed onto the KPR carbon, desorbed at a 10-17/1 concentrating factor, and catalytically incinerated. Using heat exchangers to preheat the desorbing air and the incinerator inlet gases minimizes energy input to the system. Overall VOC removal eiiiciency for the system exceeds 90%. KPR AUTO PAINT BOOTH SYSTEM Figure 6 Manufactured under U.S. Patent Addillonat patents applied for. MAIN BLOWER COIL FILTER C COPYRIGHT 1986 ME- -=3 CORPOFATION SF S-E'.'S DIVISION '?e CORPORATION METlmSystems Division 160 CASSELL ROAD * BOX 144 * HARLEYSVILLE. PA (215) * TELEX

Introduction to Control Technology

Chapter 13 Introduction to Control Technology Introduction to Control Technology Carbon adsorption Incineration Condensation Bioreaction Carbon Adsorption 13-1 Activated Carbon A class of materials Produced