STUDYING ABSORPTION CONDITION METHYLDIETHANOLAMINE TO PROCESS PURIFICATION NATURAL GAS

Шариков Ю.В.¹, Самойлов Р.В.²

¹Профессор, доктор технических наук; ²Студент, Национальный минерально-сырьевой университет «горный» (горный университет)

ИССЛЕДОВАНИЕ АБСОРБЦИОННЫХ СВОЙСТВ МЕТИЛДИЭТАНОЛАМИНА В ПРОЦЕССАХ ОЧИСТКИ ПРИРОДНОГО ГАЗА

Аннотация

В статье проводятся исследования свойств метилдиэтаноламина и рассматриваются реакции взаимодействия сорбента с сероводородом, сернистыми примесями и диоксида углерода в технологии очистки природного газа. Проведено  сравнение  с другими сорбентами и выявлены преимущества использования данного сорбента.

Ключевые слова: исследование свойств, очистка, сорбент, сравнение, преимущества.

Sharikov I.V.¹, Samoylov R.V.²

¹Professor, Dr. of Science (Chem. Engng.); ²Student. National mineral resources university  (mining university)

STUDYING ABSORPTION CONDITION METHYLDIETHANOLAMINE TO PROCESS PURIFICATION NATURAL GAS

Abstract

The article contains investigation results  of properties a metildietanolamin  and using it in purification technology of natural gas by interaction of a sorbent with hydrogen, sulphurous impurity and carbon dioxide. The parallel of comparing with other sorbents is drawn and advantages of use this sorbent are revealed.

Keywords: investigation of properties, purification, sorbent, comparing, advantages.

Introduction

Extracted natural gas usually contains a large amount of impurities to be removed before transportation for reducing corrosive activity. The amount and composition of such impurities depend on the field and purification methods are determined largely by the composition and quantity. For example, for gas produced in Astrakhan field is characterized by a large number of the content of hydrogen sulfide and carbon dioxide. [1]

 

Production field	H2S, %	CO2, %
Astrakhan	13.96	25.37
KGPU	4	2.5
Orenburg Gas-Condensate Field	1,7	0,60
Pokrovskoe	0,2	0,10
Gazlinskoe	0,07	0,16

Description of the properties of sorbents and their comparative characteristics.  

Physics-chemical properties of MDEA and MEA

Advantages of MDEA:

• Low corrosiveness of the solution
• Degree of saturation of more than MEA , this means that the amount of the circulating solution and the energy consumption for its circulation and less regeneration
• The use of MDEA saves energy ( heating steam ) is also due to the lower heat of desorption MDEA compared to the IEA , the regeneration of the absorbent
• Reduce foaming
• On the inner surfaces of equipment no deposits arising due to degradation of the previously applied absorbents based MEA increases the heat exchange efficiency, which also reduces energy consumption
• The application of the absorbent solution based on the MEA observed loss due to entrainment vapor in the desorption step, where the temperature reaches a flow of 115 °C - 130 °C. In the application of MDEA having a boiling point (247 °C) is significantly higher than that of MEA (170 °C) during regeneration entrainment amine solution at the operating temperatures of the absorbers, is greatly reduced, to a value close to zero. [2]

Methods of studying the process of sorption purification and determination of optimal treatment regimes based on two methods.

The experimental method is much more expensive and labor resources for practicing modes.Modeling method using specialized software package HYSYS.This approach allows for the analysis of the thermodynamic properties and phase equilibrium, as well as the existing models of bank machines to build the technological scheme of purification, the resulting scheme to conduct a study to determine the optimum operating conditions purification scheme with different composition of the source of natural gas. Using this approach, we have created an input stream of gas, based on the composition of natural gas Astrakhan field and taking into account performance. Further technological scheme has been developed, a software package HYSYS, the purification process using MDEA as absorbent. For the calculation of the thermodynamic properties and equilibrium states was used amine method and Peng -Robinson.With the resulting circuit (Figure 1) studied the effect of pressure, flow absorbent and effectiveness of plates on the degree of purification of natural gas and bring it to the desired composition of the impurity.

Fig. 1 - Scheme of treatment of natural gas

Fig. 2 - The dependence of the pressure difference from the concentration in the absorber of the product obtained at the outlet of the absorber

Using the diagram (Fig.1) produced digital calculations, in which the method of selection chosen concentration of MDEA for gas treatment. At a concentration of MDEA - 17% of the obtained results (Fig.4.5). Under the same conditions, and use as a sorbent DEA output results obtained (Fig. 3).

Fig. 3 - Concentration at the inlet of the absorber

Fig. 4 - The concentration of the product

Fig. 5 - The concentration of  purification products sorbent DEA

Established scheme model may be used also in operator advisor mode when running on natural gas purification plants, for adjusting the technological mode when changing the composition of the inlet gas and productivity of the plant.Conclusion: In the course of the study were presented advantages of quality and economy of use MDEA product as it is stronger and more effective sorbent that allows to achieve higher purity. Comparisons of graphs which show comparative diagrams for refining natural gas by different sorbents.

References

1. Мановян А.К. Технология первичной переработки нефти и природного газа. 2-е Издание 2001г. - 567 с.
2. Анализ применения новых сорбентов в процессах абсорбционной очистки технических и природных газов от сероводорода и углекислого газа. [Электронный ресурс] URL: http://www.nifhi.ac.ru/~kinetics/Mdea/Seminarhtml