Catalytic oxidation of volatile organic compounds (VOCs) – A review

Abatement of various types of VOCs by adsorption/catalytic oxidation: A review

Non-thermal plasmas for non-catalytic and catalytic VOC abatement.

A review on photocatalysis for air treatment: from catalyst development to reactor design

Environmental remediation relies mainly on using various technologies (eg, adsorption, absorption, chemical reactions, photocatalysis, and filtration) for the removal of contaminants from different environmental media (eg, soil, water, and air) The enhanced properties and effectiveness of nanotechnology-based materials makes them particularly suitable for such processes given that they have a high surface area-to-volume ratio, which often results in higher reactivity This review provides an overview of three main categories of nanomaterials (inorganic, carbon-based, and polymeric-based materials) used for environmental remediation The use of these nanomaterials for the remediation of different environmental contaminants—such as heavy metals, dyes, chlorinated organic compounds, organophosphorus compounds, volatile organic compounds, and halogenated herbicides—is reviewed Various recent examples are extensively highlighted focusing on the materials and their applications

https://www.mdpi.com/1420-3049/23/7/1760/pdf/1

Nanotechnology for Environmental Remediation: Materials and Applications.

Volatile Organic Compounds (VOCs) are among the most common air pollutants emitted from chemical, petrochemical, and allied industries. VOCs are one of the main sources of photochemical reaction in the atmosphere leading to various environmental hazards; on the other hand, these VOCs have good commercial value. Growing environmental awareness has put up stringent regulations to control the VOCs emissions. In such circumstances, it becomes mandatory for each VOCs emitting industry or facility to opt for proper VOCs control measures. There are many techniques available to control VOCs emission (destruction based and recovery based) with many advantages and limitations. Therefore, deciding on a particular technique becomes a difficult task. This article illustrates various available options for VOCs control. It further details the merits, demerits and applicability of each option. The authors hope that this article will help in critically analysing the requirements and accordingly decide on the appropriate strategy to control VOCs.

Removal of Volatile Organic Compounds from polluted air

Realization of the adverse effects of volatile organic compounds (VOCs) in the environment and the consequent enforcement of stringent regulations, accelerated the research and developmental activities across the world for achieving economic solutions. As a result, several advanced concepts of adsorption, a commercialized separation technology, have emerged. The availability of so many options means the industrialists, consultants and researchers experience problems in selecting the appropriate one. The present paper, through analysis of the type and concentration of VOCs, VOCs vs adsorbent suitability, the extent of separation required, and different adsorption techniques based on traditional and new advanced concepts, is an attempt to establish a qualitative guideline for the selection of the appropriate technique for recovery of VOCs.

Selection of appropriate adsorption technique for recovery of VOCs: an analysis

Adsorption of ethyl acetate, a toxic volatile organic compound, on activated carbon is studied. Adsorption isotherms at temperatures of 30, 45, and 55 °C are obtained. Langmuir isotherm parameters, saturation capacity, and heat of adsorption are found from the experimental data. The overall mass-transfer coefficient of ethyl acetate is evaluated using the uptake curve method. A mathematical model, with consideration of nonisothermal and nonadiabatic processes without axial dispersion of mass and energy and on the basis of the linear driving force approximation, well-predicted the experimental breakthrough data. Results show that the isotherms are of Brunauer type I and well-fitted with the Langmuir isotherm model. The saturation capacity of ethyl acetate on activated carbon is 0.73−0.487 kg/kg in the temperature range of 303−328 K. The heat of adsorption both by van't Hoff and by Clausius−Clapeyron equations are on the order of 105 J/kg. The overall mass-transfer coefficient is on the order of 10-4 s-1.

Studies on Adsorption of Ethyl Acetate Vapor on Activated Carbon

Adsorption behavior of ethyl acetate is studied on a 5A molecular sieve at four temperatures. The Langmuir, Freundlich, and Langmuir−Freundlich isotherm model parameters and overall effective mass transfer coefficient using the uptake curve method are evaluated. The results of the 5A molecular sieve are compared with those of the 13X molecular sieve and activated carbon reported in the literature. Results show that the isotherms are of Brunauer type I and are well-fitted by the Langmuir isotherm for all the adsorbents. 13X shows adsorption capacity between activated carbon and 5A, where 5A shows the minimum. Enthalpy of adsorption and overall effective mass transfer coefficient are of the order of 105 J·kg-1 and 10-4 s-1, respectively.

Aloke K. Ghoshal

Papers

Removal of Volatile Organic Compounds from polluted air

Selection of appropriate adsorption technique for recovery of VOCs: an analysis

Studies on Adsorption of Ethyl Acetate Vapor on Activated Carbon

Comparison of Adsorption of Ethyl Acetate on Activated Carbon and Molecular Sieves 5A and 13X