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Previous issue date: 2013-09-09 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Natural gas, although basically composed by light hydrocarbons, also presents
contaminant gases in its composition, such as CO2 (carbon dioxide) and H2S (hydrogen
sulfide). The H2S, which commonly occurs in oil and gas exploration and production
activities, causes damages in oil and natural gas pipelines. Consequently, the removal of
hydrogen sulfide gas will result in an important reduction in operating costs. Also, it is
essential to consider the better quality of the oil to be processed in the refinery, thus resulting
in benefits in economic, environmental and social areas. All this facts demonstrate the need
for the development and improvement in hydrogen sulfide scavengers. Currently, the oil
industry uses several processes for hydrogen sulfide removal from natural gas. However,
these processes produce amine derivatives which can cause damage in distillation towers, can
cause clogging of pipelines by formation of insoluble precipitates, and also produce residues
with great environmental impact. Therefore, it is of great importance the obtaining of a stable
system, in inorganic or organic reaction media, able to remove hydrogen sulfide without
formation of by-products that can affect the quality and cost of natural gas processing,
transport, and distribution steps. Seeking the study, evaluation and modeling of mass transfer
and kinetics of hydrogen removal, in this study it was used an absorption column packed with
Raschig rings, where the natural gas, with H2S as contaminant, passed through an aqueous
solution of inorganic compounds as stagnant liquid, being this contaminant gas absorbed by
the liquid phase. This absorption column was coupled with a H2S detection system, with
interface with a computer. The data and the model equations were solved by the least squares
method, modified by Levemberg-Marquardt. In this study, in addition to the water, it were
used the following solutions: sodium hydroxide, potassium permanganate, ferric chloride,
copper sulfate, zinc chloride, potassium chromate, and manganese sulfate, all at low
concentrations (?10 ppm). These solutions were used looking for the evaluation of the
interference between absorption physical and chemical parameters, or even to get a better
mass transfer coefficient, as in mixing reactors and absorption columns operating in counterflow.
In this context, the evaluation of H2S removal arises as a valuable procedure for the
treatment of natural gas and destination of process by-products. The study of the obtained
absorption curves makes possible to determine the mass transfer predominant stage in the
involved processes, the mass transfer volumetric coefficients, and the equilibrium
concentrations. It was also performed a kinetic study. The obtained results showed that the
H2S removal kinetics is greater for NaOH. Considering that the study was performed at low
concentrations of chemical reagents, it was possible to check the effect of secondary reactions
in the other chemicals, especially in the case of KMnO4, which shows that your by-product,
MnO2, acts in H2S absorption process. In addition, CuSO4 and FeCl3 also demonstrated to
have good efficiency in H2S removal / O g?s natural, embora seja composto basicamente de hidrocarbonetos leves, apresenta
tamb?m em sua composi??o gases contaminantes como o CO2 (Di?xido de carbono) e o H2S
(Sulfeto de hidrog?nio). O H2S, que comumente ocorre nas atividades de explora??o e produ??o
de ?leo e g?s, danifica as tubula??es de transporte do petr?leo e do pr?prio g?s natural. Por isso, a
elimina??o do sulfeto de hidrog?nio levar? a significativa redu??o dos custos de opera??o e a uma
melhor qualidade do ?leo destinado as refinarias, resultando assim num beneficio econ?mico,
ambiental e social. Tudo isso demonstra a necessidade de desenvolvimento e aprimoramento de
sequestrantes que removam o sulfeto de hidrog?nio da ind?stria de petr?leo. Atualmente existem
v?rios processos para o tratamento do g?s natural, utilizados pela ind?stria petrol?fera para
remo??o do H2S, no entanto, eles produzem derivados de aminas que danificam as torres de
destila??o, formando precipitados insol?veis que provocam entupimento dos dutos e originam
res?duos de grande impacto ambiental. Por isso, a obten??o de um sistema est?vel em meio
reacional inorg?nico ou org?nico capaz de remover o sulfeto de hidrog?nio sem formar
subprodutos que afetem a qualidade e o custo do processamento, transporte e distribui??o do g?s
natural ? de grande import?ncia. Para estudar, avaliar e modelar a transfer?ncia de massa e a
cin?tica da remo??o do sulfeto de hidrog?nio (H2S) montou-se uma coluna de absor??o contendo
an?is de raschig, por onde o g?s natural contaminado com H2S atravessava uma solu??o aquosa
de compostos inorg?nicos estagnada, sendo por esta absorvida. A essa coluna foi acoplado a um
sistema de detec??o de H2S com interface com o computador. Os dados e Equa??es do modelo
foram resolvidos pelo m?todo de m?nimos quadrados modificado de Levemberg-Marquardt.
Neste estudo al?m da ?gua foram utilizadas as solu??es de hidr?xido de s?dio, permanganato de
pot?ssio, sulfato de cobre, cloreto f?rrico, cloreto de zinco, cromato de pot?ssio, sulfato de
mangan?s, a baixas concentra??es, na ordem de 10 ppm, com o objetivo ? avaliar a interfer?ncia
entre par?metros f?sicos e qu?micos da absor??o, ou mesmo buscar um melhor coeficiente de
transfer?ncia de massa como ? o caso dos reatores de mistura e colunas de absor??o operando em
contra corrente. Nesse contexto a avalia??o da remo??o do H2S surge como um procedimento
valioso para o tratamento do g?s natural e destino dos subprodutos do processo. Os estudos das
curvas de absor??o obtidos permitiram determinar a etapa controladora da transfer?ncia de massa
dos processos envolvidos, os coeficientes volum?tricos de transfer?ncia de massa e as
concentra??es de equil?brio, assim como, efetuar um estudo cin?tico. Os resultados mostraram
que a cin?tica de remo??o do H2S ? maior para o NaOH, mas como o estudo foi realizado em
baixas concentra??es de reagente pode-se verificar o efeito das rea??es secund?rias nos outros
reagentes, principalmente no caso do KMnO4, que mostra seu sub produto, MnO2, tamb?m atua
na absor??o do H2S. O CuSO4 e o FeCl3 tamb?m apresentaram boa efici?ncia de remo??o
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/15926 |
| Date | 09 September 2013 |
| Creators | Silva Filho, Luiz Ferreira da |
| Contributors | CPF:59545844434, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4798645D3, N?brega, Geraldine Ang?lica Silva da, CPF:02201080488, http://lattes.cnpq.br/2114102220321647, Lopes, Francisco Wendell Bezerra, CPF:02485210470, http://lattes.cnpq.br/8791819081924591, Dantas, Tereza Neuma de Castro, CPF:07286937391, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783139Z0&dataRevisao=null, Oliveira, Humberto Neves Maia de, CPF:22179763468, http://lattes.cnpq.br/7302633941782540, Dantas Neto, Afonso Avelino, Barros Neto, Eduardo Lins de |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Engenharia Qu?mica, UFRN, BR, Pesquisa e Desenvolvimento de Tecnologias Regionais |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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