Use of char for management of paint processing waste

Kruse, Carl W.; Salmeen, Irving T.; Kalis, Edward M.; Carlson, Stephen L.; Demir, Ilham; Kim, Byung R.; Rostam-Abadi, Massoud

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https://hdl.handle.net/2142/2033 Copy

Description

Title

Use of char for management of paint processing waste

Author(s)

• Kruse, Carl W.
• Salmeen, Irving T.
• Kalis, Edward M.
• Carlson, Stephen L.
• Demir, Ilham
• Kim, Byung R.
• Rostam-Abadi, Massoud

Contributor(s)

• Ford Research Laboratory
• Illinois. Department of Energy and Natural Resources. State Geological Survey. (ENR DENR ILENR SGS ISGS)

Issue Date

1994

Keyword(s)

• Carbonization
• Automobile -- Painting
• Paint industry and trade
• Char

Abstract

Volatile organic compounds (VOCs) and paint sludge are generated by painting perations at automobile assembly plants. This study's goal was to demonstrate that paint sludge can be converted to adsorbents for the capture of VOCs. Combining coal with paint sludge was projected to improve the adsorbent quality and might improve economics show a significant economy of the scale of operation. The Illinois State Geological Survey (ISGS) made a series of activated carbons from 1) dried paints, 2) overspray paint materials captured at an assembly plant, 3) coal and 4) with mixtures of paint products with coal. Adsorption capacities of the ISGS carbons were determined in the Ford Research Laboratory with p-nitrophenol as a model adsorbate. Char making, or carbonization as it is often called, is the very old process of heating an organic substance in the absence of air to drive off the noncarbon components, primarily compounds of oxygen and hydrogen. Carbohydrates (a shortened version of carbon hydrates) derive their name from the early observation that they leave carbon when dehydrated by heating in the absence of air or by chemical agents such as sulfuric acid. Organic substances that do not melt, such as wood or nut hulls, produce a porous charcoal of the type marketed for use in home cooking grills. Removing carbon from a char by gasification enlarges the pore sizes and alters the pore size distribution resulting in activated carbons that have high internal surface areas. These activated carbons or those produced by chemical activation are the materials used in adsorption processes. Initial charring of dry paint demonstrated that the product was not a carbon with appreciable surface area. Additionally the paint material went through a melting stage during charring. ISGS researchers turned then to chemical activation with potassium. hydroxide (KOH) as a means of making an activated product. Properties of the control char derived from Illinois coal approximated those of Calgon Corporation commercial carbons. Carbon black and titanium dioxide (Ti02) are pigments in automotive black and white paints, respectively. White paints generally have much higher ash contents than black paints. The ash content of black paints from the two manufacturers in this study were quite different suggesting some noncarbon black pigment was used. The lower the ash content of the adsorbents made, i.e. the more carbon, the better were the adsorbent properties. There was no evidence that ashforming materials assisted in pore development. The quality of sludge-derived adsorbent was between those of adsorbents derived from black and white paints. Blending coal with white paint improved the adsorption capacity of adsorbent. The results of the tests completed on the adsorbents made in this study warrant further study, both technical and economic. Tests using p-nitrophenol to compare adsorption properties of paint-derived adsorbents with those of commercially available adsorbents are being extended at Ford to include selected paint solvents. Confirmation at this level may justify larger scale production of the adsorbents for testing at a scale that provides information useful for preliminary economic calculations.

Publisher

The Center

Series/Report Name or Number

TR Series (Hazardous Waste Research and Information Center) ; 018

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/2033

Sponsor(s)/Grant Number(s)

HWRIC Project Number 92-099

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