Engineering Commons^™

Removal Of Vocs From Air By Absorption And Stripping In Hollow Fiber Devices, Tarun K. Poddar

Dissertations

Large volumes of exhaust air streams contaminated with volatile organic compounds (VOCs) such as toluene, xylene, acetone etc. are discharged into the atmosphere by various industrial facilities. Common technologies for VOC emission abatement e.g., activated carbon adsorption, absorption in a liquid, incineration and catalytic oxidation, have many strengths as well as considerable limitations. In this study, a regenerative absorption-based removal of VOCs from N₂ in an inert, nonvolatile, organic liquid flowing in compact hollow fiber devices has been developed. The process eliminates flooding, loading and entrainment encountered in conventional absorption devices.

Contaminated air/N₂ stream was fed through the …

Computer-Aided Process Design For Waste Minimization, Konstadinos Abeliotis

Dissertations

Problems related to process design with environmental considerations have been studied in this dissertation. A new heuristic design methodology has been formulated with the objective of minimizing the adverse environmental impact of chemical processes.

This hierarchical methodology starts with the definition and analysis of a process flowsheet followed by quantification of the process environmental loads. The quantification of environmental loads is an essential aspect of this methodology, because it serves as the comparative measure for environmental performance.

If the calculated environmental loads do not satisfy the environmental constraints (e.g., regulatory limits), waste minimization is investigated in the following order:

• Pollution …

The Effect Of Chlorine, Sulfur And Phosphorus Compounds On Deactivation Of Palladium Catalysts, Tai-Chiang Yu

Dissertations

The effects of HCl, H₂S, tributyl phosphate (TBP), P₂O₅, and zinc dialkyldithophosphate (ZDP) as catalyst poisons for methane oxidation over palladium catalysts supported on γ-alumina were investigated in this study. The overall reaction rate of methane oxidation over palladium catalysts can be simplified into a pseudo first order reaction under excess oxidation conditions.

The deactivation of the catalyst poisoned by HCl is attributed to the loss of active sites due to volatilization of PdCl₂. H₂ treatment at 200 °C can reactivate the catalyst poisoned by HCl at temperatures of up to …

Removal Of Vocs From Waste Gas Streams By A Hollow Fiber Permeator, Varinder Pal Malik

Theses

Removal of various VOCs from air/nitrogen feed streams using a novel hollow fiber membrane was studied. Hollow Fiber Module (HFM) used had composite silicone membranes wherein an ultrathin (~ 1μm), nonporous silicone rubber membrane layer had been plasma polymerized on a porous (porosity: 0.4) polypropylene substrate. VOCs studied were toluene, methanol, acetone, methylene chloride and hexane. Primary focus was on single VOCs, although separation of VOC mixtures was also briefly studied. HFM was found to be extremely effective in removing various VOCs from feed streams. Removal of 90-99 % of various VOCs was achieved at low feed flow rates and …

Biodegradation Of Mixed Wastes : Basic Kinetics And Reaction Engineering For Cyclic Reactor Operation, Kung-Wei Wang

Dissertations

This study dealt with the determination of the detailed kinetics of the biodegradation of mixed substrates by pure cultures, and with reaction engineering studies of bioreactors employed in treatment of substitutable substrates under cyclic operation.

In the first part of the study the degradation of phenol and 4-chlorophenol (4-CP) by two strains of Pseudomonas species was investigated. Strain P. putida 0 was found to be capable of utilizing both phenol and 4-CP as sole carbon and energy sources. This suggests that this strain follows the ortho-cleavage pathway for the aromatic ring. Strain P. putida N could grow on phenol, and …

Modeling The Fate Of Volatile Organic Compounds In Wastewater Treatment Facilities; Implementation Of Volatilization Models In Envirocad, Vinita Chhahira

Theses

The 1990 Clean Air Act Amendments have identified wastewater treatment facilities as a major source of volatile organic compound (VOC) emissions. VOCs present in wastewater discharges affect the quality of receiving waters, while emissions to the air affect downwind populations. The primary mechanisms involved in VOC removal from a wastewater treatment facility are volatilization and stripping, biodegradation, and sorption to either suspended or biological solids. Although many models have been developed to predict the fate of VOCs in wastewater treatment facilities, no model completely predicts emissions for an entire wastewater treatment facility. The focus of this work is to incorporate …

A Comparison Of Anhydrous Ethanol Production From Ethylene And From Corn Utilizing Life Cycle Analysis Methodology, Gregory Morse

Theses

There is currently much concern with the impact on the environment due to industrial processes. One method to assess this impact is to perform a Life Cycle Analysis (LCA) on the process. Life Cycle Analysis is made up of three stages; Life Cycle Inventory Analysis, Life Cycle Impact Assessment, and Life Cycle Improvement Assessment. In this study, Life Cycle Inventory Analysis methodology was applied to two industrial processes for producing anhydrous ethanol. The first process is the fermentation of corn, and the second is the hydration of ethylene using water and a catalyst. Each process was first modeled using the …

Experimental And Numerical Determination Of Fluid Velocity Profiles And Turbulence Intensity In Mixing Vessels, Chun-Chiao Chou

Dissertations

In this study, both a laser-Doppler velocimeter (LDV) and a computational fluid dynamic (CFD) software package (FL UENI) were used to experimentally determine and numerically predict the velocity distribution of an unbaffled and a baffled mixing vessel. Two types of impellers were employed, namely a flat blade turbine (FBT) and a pitched blade turbine (PBT). These impellers were studied in a single-impeller or multiple-impeller configuration in the unbaffled and baffled vessels. The flow characteristics in the impeller regions were measured by LDV and used as boundary conditions in the numerical computation. Turbulence effects were numerically simulated using either the k-c …

Combustion Of Methyl Chloride, Monomethyl Amine, And Their Mixtures In A Two Stage Turbulent Flow Reactor, Fuhe Mao

Dissertations

The feasibility of converting fuel-bound chlorine and nitrogen into HCl and N₂ with reduced pollutant emissions of CO, NO, and unburned hydrocarbons was investigated in a two-stage turbulent flow reactor. The study consists of four segments: completion and validation of the experimental facility, experimental and modeling studies of methyl chloride (CH₃Cl) combustion, similar studies on monomethyl amine (CH₃NH₂), and finally studies on simultaneous CH₃Cl and CH₃NH₂ combustion.

Validation of the experimental facility was made by combustion of ethylene (C₂H₄) and air under both fuel-lean …

Volatilization Of Volatile Organic Compounds From Complex Wastewaters, Syed Sikandar Qadry

Theses

A variety of volatile organic solvents used in the pharmaceutical and specialty chemical industries end up in wastewater collection and treatment systems. EPA has classified these VOCs into groups depending on their potential to volatilize from the wastewaters. In making this classification, Henry's Law, which is valid at very low concentrations, has been used to describe the vapor-liquid equilibrium. But, in reality the concentrations observed in the wastewaters are often too high for Henry's Law to be valid and it is inappropriate to assume that equilibrium has been achieved for every compound.

This project evaluates the volatilization rates, both experimental …