The adsorption of volatile organic compounds

Abstract

Volatile organic compounds (vocs) discharged into the environment cause negative and health hazards. In the recent years adsorption process has been employed to aid in the remediation process of VOC removal. In this project techniques such as adsorption process were employed in the removal of Volatile organic compounds an indoor pollutant at Global Paints Company Limited using activated coffee husks and wood Volatile organic compounds (VOCs) discharged into the environment cause negative and health hazards. In the recent years adsorption process has been employed to aid in the remediation process of VOC removal. In this project techniques such as adsorption process were employed in the removal of Volatile organic compounds an indoor pollutant at Global Paints Company Limited using activated coffee husks and wood as adsorbents. These VOCs arise from paint production process which includes the grinding of pigment, cleaning of the mixer tanks, blending and packaging of the finished paint product. The adsorbents used in the process were used because of their excellent adsorbability and are locally available in Uganda they are also highly efficient in removal of VOCs with a percentage removal ranging from 80%-100% . The main objective of this study was to determine the effectiveness and efficiency in the use of activated coffee husks and wood adsorbents in the adsorption process of VOCs. The adsorbents were activated by using physical (steam) and chemical activating agents (phosphoric acid) for wood and coffee husks respectively. The VOCs were obtained by taking 40g/m3 from a the vent connected to the batch mixing tank and then treated against two adsorbents of mass 250g/m3 at varying duration at constant temperature and pressure. The experimental data was obtained and breakthrough curves were drawn after the adsorption cycle to show how the outlet concentration varies with time and these provided a basis from which the breakthrough times can be obtained to show the time the adsorbent takes to permeate completely through the column. The curves were drawn in excel and the adsorption capacity for each VOC- activated carbon system was calculated to show the adsorption capacity of each activated carbon. From the experimental data it was noted that the best activated carbon system for the adsorption of the VOCs was coffee husks due to its high surface area to volume ratio and high macropore volume this offered greater adsorption capacity to the VOC compared to when using activated wood as an adsorbent. The breakthrough time represented the time it takes for the VOCs to be completely adsorbed by the adsorbent The break through time when activated coffee husks was used as an adsorbent on both acetone and dichloromethane was 140 minutes and 160 minutes respectively. The break through time when using activated wood as an adsorbent for both acetone and dichloromethane was 150minutes and 120 minutes. After wards recommendations to the company were given in relation to the activated carbon selected so that extensions to the batch mixer should be implemented inorder to capture any VOC produced during the process manufacture steps this xi would both improve the working conditions of the workers and the state of the ecological systemas adsorbents. These vocs arise from paint production process which includes the grinding of pigment, cleaning of the mixer tanks, blending and packaging of the finished paint product. The adsorbents used in the process were used because of their excellent adsorbability and are locally available in Uganda they are also highly efficient in removal of vocs with a percentage removal ranging from 80. The main objective of this study was to determine the effectiveness and efficiency in the use of activated coffee husks and wood adsorbents in the adsorption process of vocs. The adsorbents were activated by using physical (steam) and chemical activating agents (phosphoric acid) for wood and coffee husks respectively. The vocs were obtained by taking 40g/m3 from a the vent connected to the batch mixing tank and then treated against two adsorbents of mass 250g/m3 at varying duration at constant temperature and pressure. The experimental data was obtained and breakthrough curves were drawn after the adsorption cycle to show how the outlet concentration varies with time and these provided a basis from which the breakthrough times can be obtained to show the time the adsorbent takes to permeate completely through the column. The curves were drawn in excel and the adsorption capacity for each VOC- activated carbon system was calculated to show the adsorption capacity of each activated carbon. From the experimental data it was noted that the best activated carbon system for the adsorption of the vocs was coffee husks due to its high surface area to volume ratio and high macropore volume this offered greater adsorption capacity to the VOC compared to when using activated wood as an adsorbent. The breakthrough time represented the time it takes for the vocs to be completely adsorbed by the adsorbent The break through time when activated coffee husks was used as an adsorbent on both acetone and dichloromethane was 140 minutes and 160 minutes respectively. The break through time when using activated wood as an adsorbent for both acetone and dichloromethane was 150minutes and 120 minutes. After wards recommendations to the company were given in relation to the activated carbon selected so that extensions to the batch mixer should be implemented in order to capture any VOC produced during the process manufacture steps this xi would both improve the working conditions of the workers and the state of the ecological system0g/m3 at