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Thermogravimetric Analysis of Solvent Interaction with Model TSRU Tailings ComponentsAnsari, Nesma Nasir Unknown Date
No description available.
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Organosolv pulping:a review and distillation study related to peroxyacid pulpingMuurinen, E. (Esa) 18 May 2000 (has links)
Abstract
More than 900 papers related to organosolv pulping have been
reviewed in this thesis. From the information included in those
papers it can be concluded that organosolv pulping processes are
still in a developing stage and are not yet ready to seriously threat
the position of the kraft process as the main pulp manufacturing
process in the world.
Distillation seems to be the main alternative as the process
for recovering the solvent in organosolv pulping. A good reason
for this is that using simple distillation no potentially harmful
components are introduced to the process.
The effect of feed composition on the operation of a separation
sequence in an organosolv process using aqueous formic and acetic
acids and corresponding peroxyacids was studied. When simple distillation
was used as the separation method the effect was found to be significant.
The no ideal nature of the formic acid-acetic acid-water mixture,
which separation was studied, makes the ternary composition space
to divide into four distillation regions. Which region the feed
is located in, obviously determines the economy of the distillation
sequence.
Shortcut calculation methods cannot be recommended to be
used for designing a distillation sequence for the ternary mixture
studied, but they give useful information for the comparison of
such sequences. They were used to choose a limited number of alternatives
for studies with rigorous calculation methods.
Minimum work of separation can also be used to make a satisfying
estimate for the relative easiness of separation of the formic acid-acetic
acid-water mixture.
Thermal integration using pinch technology was also tested
and found very useful for decreasing the thermal energy consumption
of distillation processes.
Thermodynamic efficiencies for separating the formic acid-acetic
acid-water mixture by simple distillation were estimated. They were
found to be lower than the average value for distillation presented
in literature.
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Developing a Novel Ultrafine Coal Dewatering ProcessHuylo, Michael H. 13 January 2022 (has links)
Dewatering fine coal is needed in many applications but has remained a great challenge. The hydrophobic-hydrophilic separation (HHS) method is a powerful technology to address this problem. However, organic solvents in solvent-coal slurries produced during HHS must be recovered for the method to be economically viable. Here, the experimental studies of recovering solvents from pentane-coal and hexane-coal slurries by combining liquid-solid filtration and in-situ vaporization and removing the solvent by a carrier gas (i.e., drying) are reported. The filtration behaviors are studied under different solid mass loading and filtration pressure. It is shown that using pressure filtration driven by 20 psig nitrogen, over 95% of solvents by mass in the slurries can be recovered, and filtration cakes can be formed in 60 s. The drying behavior was studied using nitrogen and steam at different temperatures and pressures. It is shown that residual solvents in filtration cakes can be reduced below 1400 ppm within 10 s by 15 psig steam superheated to 150C, while other parameter combinations are far less effective in removing solvents. Physical processes involved in drying and the structure of solvent-laden filtration cakes are analyzed in light of these results. / Master of Science / Coal particles below a certain size are discarded to waste tailing ponds as there is no economically viable method for processing them. However, a new process called hydrophobic-hydrophilic separation offers a solution to this problem. A hydrophobic solvent is used to displace water from a coal-water slurry, and it is then easier and cheaper to filter and dry this new coal-solvent slurry. In this work experimental studies of recovering solvents from pentane-coal and hexane-coal slurries by combining filtration and drying are reported. The filtration behaviors are studied under different solid mass loading and filtration pressures. It is shown that using pressure filtration driven by 20 psig nitrogen, over 95% of solvents by mass in the slurry can be recovered, and filtration cakes can be formed in 60 s. The drying behavior was studied using nitrogen and steam at different temperatures and pressures to evaporate any remaining solvents. It is shown that the remaining solvents in filtration cakes can be reduced below 1400 ppm within 10 s by using 15 psig steam superheated to 150C as a drying medium, while other parameter combinations are far less effective in removing solvents. Physical processes involved in drying and the structure of solvent-laden filtration cakes are analyzed in light of these results.
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Multi-objective Optimization of Butanol Production During ABE FermentationSharif Rohani, Aida 05 December 2013 (has links)
Liquid biofuels produced from biomass have the potential to partly replace gasoline. One of the most promising biofuels is butanol which is produced in acetone-butanol-ethanol (ABE) fermentation. The ABE fermentation is characterized by its low butanol concentration in the final fermentation broth. In this research, the simulation of three in situ recovery methods, namely, vacuum fermentation, gas stripping and pervaporation, were performed in order to increase the efficiency of the continuous ABE fermentation by decreasing the effect of butanol toxicity. The non-integrated and integrated butanol production systems were simulated and optimized based on a number of objectives such as maximizing the butanol productivity, butanol concentration, and butanol yield. In the optimization of complex industrial processes, where objectives are often conflicting, there exist numerous potentially-optimal solutions which are best obtained using multi-objective optimization (MOO). In this investigation, MOO was used to generate a set of alternative solutions, known as the Pareto domain. The Pareto domain allows to view very clearly the trade-offs existing between the various objective functions. In general, an increase in the butanol productivity resulted in a decrease of butanol yield and sugar conversion. To find the best solution within the Pareto domain, a ranking algorithm (Net Flow Method) was used to rank the solutions based on a set of relative weights and three preference thresholds. Comparing the best optimal solutions in each case study, it was clearly shown that integrating a recovery method with the ABE fermentation significantly increases the overall butanol concentration, butanol productivity, and sugar conversion, whereas butanol yield being microorganism-dependent, remains relatively constant.
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Multi-objective Optimization of Butanol Production During ABE FermentationSharif Rohani, Aida January 2013 (has links)
Liquid biofuels produced from biomass have the potential to partly replace gasoline. One of the most promising biofuels is butanol which is produced in acetone-butanol-ethanol (ABE) fermentation. The ABE fermentation is characterized by its low butanol concentration in the final fermentation broth. In this research, the simulation of three in situ recovery methods, namely, vacuum fermentation, gas stripping and pervaporation, were performed in order to increase the efficiency of the continuous ABE fermentation by decreasing the effect of butanol toxicity. The non-integrated and integrated butanol production systems were simulated and optimized based on a number of objectives such as maximizing the butanol productivity, butanol concentration, and butanol yield. In the optimization of complex industrial processes, where objectives are often conflicting, there exist numerous potentially-optimal solutions which are best obtained using multi-objective optimization (MOO). In this investigation, MOO was used to generate a set of alternative solutions, known as the Pareto domain. The Pareto domain allows to view very clearly the trade-offs existing between the various objective functions. In general, an increase in the butanol productivity resulted in a decrease of butanol yield and sugar conversion. To find the best solution within the Pareto domain, a ranking algorithm (Net Flow Method) was used to rank the solutions based on a set of relative weights and three preference thresholds. Comparing the best optimal solutions in each case study, it was clearly shown that integrating a recovery method with the ABE fermentation significantly increases the overall butanol concentration, butanol productivity, and sugar conversion, whereas butanol yield being microorganism-dependent, remains relatively constant.
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Evaluation of Solvent Resistant Nano-Filtration (SRNF) Membranes for Small-Molecule Purification and Recovery of Polar Aprotic Solvents for Re-UseAnim-Mensah, Alexander R. January 2007 (has links)
No description available.
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Modelling and optimisation of oxidative desulphurization process for model sulphur compounds and heavy gas oil : determination of rate of reaction and partition coefficient via pilot plant experiment : modelling of oxidation and solvent extraction processes : heat integration of oxidation process : economic evaluation of the total processKhalfalla, Hamza Abdulmagid January 2009 (has links)
Heightened concerns for cleaner air and increasingly more stringent regulations on sulphur content in transportation fuels will make desulphurization more and more important. The sulphur problem is becoming more serious in general, particularly for diesel fuels as the regulated sulphur content is getting an order of magnitude lower, while the sulphur contents of crude oils are becoming higher. This thesis aimed to develop a desulphurisation process (based on oxidation followed by extraction) with high efficiency, selectivity and minimum energy consumption leading to minimum environmental impact via laboratory batch experiments, mathematical modelling and optimisation. Deep desulphurization of model sulphur compounds (di-n-butyl sulphide, dimethyl sulfoxide and dibenzothiophene) and heavy gas oils (HGO) derived from Libyan crude oil were conducted. A series of batch experiments were carried out using a small reactor operating at various temperatures (40-100 °C) with hydrogen peroxide (H2O2) as oxidant and formic acid (HCOOH) as catalyst. Kinetic models for the oxidation process are then developed based on 'total sulphur approach'. Extraction of unoxidised and oxidised gas oils was also investigated using methanol, dimethylformamide (DMF) and N-methyl pyrolidone (NMP) as solvents. For each solvent, the 'measures' such as: the partition coefficient (KP), effectiveness factor (Kf) and extractor factor (Ef) are used to select the best/effective solvent and to find the effective heavy gas oil/solvent ratios. A CSTR model is then developed for the process for evaluating viability of the large scale operation. It is noted that while the energy consumption and recovery issues could be ignored for batch experiments these could not be ignored for large scale operation. Large amount of heating is necessary even to carry out the reaction at 30-40 °C, the recovery of which is very important for maximising the profitability of operation and also to minimise environmental impact by reducing net CO2 release. Here the heat integration of the oxidation process is considered to recover most of the external energy input. However, this leads to putting a number of heat exchangers in the oxidation process requiring capital investment. Optimisation problem is formulated using gPROMS modelling tool to optimise some of the design and operating parameters (such as reaction temperature, residence time and splitter ratio) of integrated process while minimising an objective function which is a coupled function of capital and operating costs involving design and operating parameters. Two cases are studied: where (i) HGO and catalyst are fed as one feed stream and (ii) HGO and catalyst are treated as two feed streams. A liquid-liquid extraction model is then developed for the extraction of sulphur compounds from the oxidised heavy gas oil. With the experimentally determined KP multi stage liquid-liquid extraction process is modelled using gPROMS software and the process is simulated for three different solvents at different oil/solvent ratios to select the best solvent, and to obtain the best heavy gas oil to solvent ratio and number of extraction stages to reduce the sulphur content to less than 10 ppm. Finally, an integrated oxidation and extraction steps of ODS process is developed based on the batch experiments and modelling. The recovery of oxidant, catalyst and solvent are considered and preliminary economic analysis for the integrated ODS process is presented.
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Modelling and optimisation of oxidative desulphurization process for model sulphur compounds and heavy gas oil. Determination of Rate of Reaction and Partition Coefficient via Pilot Plant Experiment; Modelling of Oxidation and Solvent Extraction Processes; Heat Integration of Oxidation Process; Economic Evaluation of the Total Process.Khalfalla, Hamza Abdulmagid January 2009 (has links)
Heightened concerns for cleaner air and increasingly more stringent regulations on
sulphur content in transportation fuels will make desulphurization more and more
important. The sulphur problem is becoming more serious in general, particularly for
diesel fuels as the regulated sulphur content is getting an order of magnitude lower,
while the sulphur contents of crude oils are becoming higher. This thesis aimed to
develop a desulphurisation process (based on oxidation followed by extraction) with
high efficiency, selectivity and minimum energy consumption leading to minimum
environmental impact via laboratory batch experiments, mathematical modelling and
optimisation.
Deep desulphurization of model sulphur compounds (di-n-butyl sulphide, dimethyl
sulfoxide and dibenzothiophene) and heavy gas oils (HGO) derived from Libyan crude
oil were conducted. A series of batch experiments were carried out using a small reactor
operating at various temperatures (40 ¿ 100 0C) with hydrogen peroxide (H2O2) as
oxidant and formic acid (HCOOH) as catalyst. Kinetic models for the oxidation process
are then developed based on `total sulphur approach¿. Extraction of unoxidised and
oxidised gas oils was also investigated using methanol, dimethylformamide (DMF) and
N-methyl pyrolidone (NMP) as solvents. For each solvent, the `measures¿ such as: the
partition coefficient (KP), effectiveness factor (Kf) and extractor factor (Ef) are used to
select the best/effective solvent and to find the effective heavy gas oil/solvent ratios.
A CSTR model is then developed for the process for evaluating viability of the large
scale operation. It is noted that while the energy consumption and recovery issues could
be ignored for batch experiments these could not be ignored for large scale operation.
Large amount of heating is necessary even to carry out the reaction at 30-40 0C, the
recovery of which is very important for maximising the profitability of operation and
also to minimise environmental impact by reducing net CO2 release. Here the heat
integration of the oxidation process is considered to recover most of the external energy
input. However, this leads to putting a number of heat exchangers in the oxidation
process requiring capital investment. Optimisation problem is formulated using
gPROMS modelling tool to optimise some of the design and operating parameters (such
as reaction temperature, residence time and splitter ratio) of integrated process while
minimising an objective function which is a coupled function of capital and operating
costs involving design and operating parameters. Two cases are studied: where (i) HGO
and catalyst are fed as one feed stream and (ii) HGO and catalyst are treated as two feed
streams.
A liquid-liquid extraction model is then developed for the extraction of sulphur
compounds from the oxidised heavy gas oil. With the experimentally determined KP
multi stage liquid-liquid extraction process is modelled using gPROMS software and the
process is simulated for three different solvents at different oil/solvent ratios to select the best solvent, and to obtain the best heavy gas oil to solvent ratio and number of
extraction stages to reduce the sulphur content to less than 10 ppm.
Finally, an integrated oxidation and extraction steps of ODS process is developed based
on the batch experiments and modelling. The recovery of oxidant, catalyst and solvent
are considered and preliminary economic analysis for the integrated ODS process is
presented.
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Avaliação do impacto ambiental em processos de reaproveitamento de resíduos pelo setor de tratamento de resíduos e solventes do IQUSP e proposta de minimização de riscos em disciplinas de química orgânica experimental / Environmental impact assessment on waste recycling processes for treatment sector residues and solvents from the Chemistry Institute of the University of São Paulo and proposed risk minimization in experimental organic chemistry coursesMartins, Claudia Regina 28 September 2015 (has links)
Preocupados com aspectos ambientais relacionados com a recuperação de solventes e, também, com os riscos envolvidos em experimentos trivialmente executados em disciplinas de Química Orgânica Experimental, utilizamos critérios numéricos para avaliá-los e determinar a viabilidade de se adotarem práticas alternativas, em ambas as frentes. Neste contexto, comparamos, do ponto de vista ambiental, a viabilidade de recuperação de alguns solventes, por destilação, no Setor de Tratamento de Resíduos e Solventes (STRES), com a incineração completa dos mesmos materiais, em incinerador industrial. Para isto, procedemos à separação, por destilação, dos componentes de algumas misturas de solventes. Após determinação das composições dos destilados, por cromatografia em fase gasosa, inserimos os dados obtidos no software ECOSOLVENT para comparamos os impactos ambientais (considerando o EI99 como indicador da Avaliação do Ciclo de Vida) destas destilações com os das incinerações das misturas brutas. Para a maior parte dos casos, foi constatado um menor impacto ambiental para os processos de destilação, justificando-se a continuidade dos trabalhos do STRES. Quanto aos experimentos de Química Orgânica Experimental, combinamos a pontuação de riscos sugerida pela National Fire Protection Association-USA, com o critério de Economia Atômica, tanto para os processos tradicionais como para as modificações sugeridas. Estas últimas levaram, numericamente, a riscos menores, sem alteração das Economias Atômicas. / Concerned with environmental issues related to the recovery of solvents and also to the risks involved in trivial Experimental Organic Chemistry practices, we used numerical criteria to evaluate the feasibility of adopting alternative practices on both fronts. In this context, we compared, from the environmental point of view, the recovery feasibility of some solvents, by distillation, at the Setor de Tratamento de Resíduos e Solventes (STRES), with their complete incineration in an industrial incinerator. Therefore, we proceed to the separation, by distillation, of the components of some mixtures of solvents. After determining the composition of the distillates, by gas chromatography, we input the obtained data into the ECOSOLVENT software in order to compare the environmental impacts (considering the EI99 indicator for the Life Cycle Assessment calculations), arising from these distillations, with those from direct incineration of the crude mixtures of solvents. For most cases, distillation impacts were found to be smaller than those for incineration, thus justifiyng the existence of STRES. As for the Experimental Organic Chemistry practices, we cobined the American National Fire Protection Association`s risks score with the Atom Economy concept for the current, and for some suggested modified procedures. These latter ones led to numerical smaller risks without changing the Atomic Economies.
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Avaliação do impacto ambiental em processos de reaproveitamento de resíduos pelo setor de tratamento de resíduos e solventes do IQUSP e proposta de minimização de riscos em disciplinas de química orgânica experimental / Environmental impact assessment on waste recycling processes for treatment sector residues and solvents from the Chemistry Institute of the University of São Paulo and proposed risk minimization in experimental organic chemistry coursesClaudia Regina Martins 28 September 2015 (has links)
Preocupados com aspectos ambientais relacionados com a recuperação de solventes e, também, com os riscos envolvidos em experimentos trivialmente executados em disciplinas de Química Orgânica Experimental, utilizamos critérios numéricos para avaliá-los e determinar a viabilidade de se adotarem práticas alternativas, em ambas as frentes. Neste contexto, comparamos, do ponto de vista ambiental, a viabilidade de recuperação de alguns solventes, por destilação, no Setor de Tratamento de Resíduos e Solventes (STRES), com a incineração completa dos mesmos materiais, em incinerador industrial. Para isto, procedemos à separação, por destilação, dos componentes de algumas misturas de solventes. Após determinação das composições dos destilados, por cromatografia em fase gasosa, inserimos os dados obtidos no software ECOSOLVENT para comparamos os impactos ambientais (considerando o EI99 como indicador da Avaliação do Ciclo de Vida) destas destilações com os das incinerações das misturas brutas. Para a maior parte dos casos, foi constatado um menor impacto ambiental para os processos de destilação, justificando-se a continuidade dos trabalhos do STRES. Quanto aos experimentos de Química Orgânica Experimental, combinamos a pontuação de riscos sugerida pela National Fire Protection Association-USA, com o critério de Economia Atômica, tanto para os processos tradicionais como para as modificações sugeridas. Estas últimas levaram, numericamente, a riscos menores, sem alteração das Economias Atômicas. / Concerned with environmental issues related to the recovery of solvents and also to the risks involved in trivial Experimental Organic Chemistry practices, we used numerical criteria to evaluate the feasibility of adopting alternative practices on both fronts. In this context, we compared, from the environmental point of view, the recovery feasibility of some solvents, by distillation, at the Setor de Tratamento de Resíduos e Solventes (STRES), with their complete incineration in an industrial incinerator. Therefore, we proceed to the separation, by distillation, of the components of some mixtures of solvents. After determining the composition of the distillates, by gas chromatography, we input the obtained data into the ECOSOLVENT software in order to compare the environmental impacts (considering the EI99 indicator for the Life Cycle Assessment calculations), arising from these distillations, with those from direct incineration of the crude mixtures of solvents. For most cases, distillation impacts were found to be smaller than those for incineration, thus justifiyng the existence of STRES. As for the Experimental Organic Chemistry practices, we cobined the American National Fire Protection Association`s risks score with the Atom Economy concept for the current, and for some suggested modified procedures. These latter ones led to numerical smaller risks without changing the Atomic Economies.
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