Claims:1. A novel compound of Formula 1,

Formula 1
wherein, R1 and R2 are selected from hydrogen, C1-C3 alkyl, and C1-C3 haloalkyl.

2. The novel compound as claimed in claim 1, wherein, the said novel compound acts as a promoter for absorption of an H2S gas impurity.

3. A novel formulation for removing at least one acid gas impurity from industrial gases, wherein, the said novel formulation comprises 26-34 weight % of an alkanolamine and 1-9 weight % of the novel compound of Formula 1.

4. The novel formulation as claimed in claim 3, wherein, the said novel formulation comprises 30 weight % of the alkanolamine and 5 weight % of the novel compound of Formula 1.

5. The novel formulation as claimed in claim 3, wherein, the at least one acid gas impurity is an H2S gas impurity.

6. The novel formulation as claimed in claim 3-4, wherein, the alkanolamine is methyldiethanolamine (MDEA).

7. A process for preparing a compound of Formula 1, wherein, the process comprises:
preparing a reaction solution by adding an alkanolamine to a solution of acetyl acetone, stirring the prepared reaction solution for 5-7 hours maintaining the reaction temperature at 60oC;
mixing the above reaction solution in methanol to obtain a reaction mixture;
treating the obtained reaction mixture with sodium borohydride at 0oC, then warming to room temperature and stirring at room temperature for 12 hours; and
treating the reaction mixture as obtained with diluted water and subjecting to centrifugation followed by the removal of water to obtain compound of Formula 1.

8. The process as claimed in claim 7, wherein, the alkanolamine is 2.2 equivalent, the acetyl acetone is 1 equivalent, and the sodium borohydride is 2 to 3 equivalents.

9. The process as claimed in claim 7 to 8, wherein, the alkanolamine is selected from the group consisting of ethanolamine, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, diethanolamine, isopropanolamine, diisopropanolamine, N-methylisopropanolamine, N-ethylisopropanolamine, N-propylisopropanolamine.

10. The process as claimed in claim 9, wherein, the alkanolamine is selected from ethanolamine.

11. The process as claimed in claim 7, wherein, the compound of Formula 1 is,

Formula 1
wherein, R1 and R2 are selected from hydrogen, C1-C3 alkyl, C1-C3 haloalkyl and, wherein, the said compound acts as a promoter for absorption of the H2S gas impurity.
, Description:FIELD OF THE INVENTION:
The present invention describes a novel compound which acts as a promoter for removing acid gas impurities from industrial gases. Further, the present invention also describes a process for preparing the said novel compound. Further, the present invention also describes a formulation having the said novel compound and an alkanolamine, wherein, the said formulation is used for removing acid gas impurities from industrial gases.

BACKGROUND OF THE INVENTION:
In petrochemical industry, the acid gas impurities possess a big industrial and environmental problem. Removal of acid gases from industrial gases is an important process in petrochemical refineries. The amine solvent recovery approach is commonly used method for removal of acid gases such as hydrogen sulfide (H2S) and carbon dioxide (CO2) from the refinery flue gases. The aqueous solutions of alkanolamines, such as diethanolamine (DEA), monoethanolamine (MEA), methyldiethanolamine (MDEA) are commonly used in the said amine solvent recovery approach.

Further, the amine solvent recovery approach involves two step process. The first step involves high pressure and low temperature for absorption of acid gases and the second step involves low pressure/high temperature for regeneration of the alkanolamines. In addition to the alkanolamines, various promoters are also used to improve the efficiency of the absorption of acid gases. Further, to reduce the boiler duty in the regeneration of the alkanolamines, several accelerators for regeneration are also reported in the literature.

XiangFeng Tian et al, publication date August 17, 2019, title “absorption and removal efficiency of low-partial-pressure H2S in a tetramethylammonium glycinate activated N-methyldiethanolamine aqueous solution” discloses the absorption performance including absorption capacity and loading values of low-partial-pressure H2S in tetramethylammonium glycinate ([N1111][Gly]) promoted N-methyldiethanolamine (MDEA) aqueous solution was measured. The apparent absorption rate was calculated from the time-dependent absorption capacity. The effects of absorbent composition, temperature, and H2S partial pressure on absorption capacity and apparent absorption rate were demonstrated. The H2S removal efficiency was verified in a tray tower using the [N1111][Gly]–MDEA aqueous solution as an absorbent, and the results show that the removal efficiency can reach 100%, which met the requirement of the first degree of Chinese cleaner production standard (coking industry, HJ/T 126-2003, I, H2S = 0.2 g/m3). Compared with the traditional amine-based absorbents like MDEA–monoethanolamine aqueous solution, the [N1111][Gly]-promoted MDEA aqueous solution has a higher absorption capacity and a higher absorption rate for H2S. Moreover, when the mass fraction of MDEA reaches up to 50%, the removal efficiency in the tray tower can still reach 100%. The decrease of the water content in the absorbent can greatly reduce the energy cost of the regeneration of rich solution and the cooling of poor solution. Therefore, the new absorbent proposed in this work has good commercial application potential in the field of desulfurization of the coke oven gas.

Woo Yun Lee et al, January 15, 2020, title “simultaneous removal of CO2 and H2S from biogas by blending amine absorbents: a performance comparison study” discloses that greenhouse gas treatment is urgently needed because of the impact of climate change caused by greenhouse gas emissions after global economic growth. In this study, post combustion capture was carried out to screen absorbents for simultaneous absorption and regeneration of CO2 and H2S by-products of biogas using N-methyldiethanolamine (MDEA)-based additives. Twelve different absorbents were selected and compared according to the types of the amine group and the alcohol group. The mixture gas of 35 vol % CH4, 15 vol % CO2, and 50 ppm H2S balanced by N2 was used for absorption and regeneration. Absorption and regeneration were carried out at 35°C and 80°C, respectively. The absorbent concentration was fixed at 4.5 wt. % for MDEA and 0.5 wt. % for additives. In the continuous absorption and regeneration experiments, rich loading, lean loading, cyclic loading, absorption rate, and desorption rate were measured according to the loading values of CO2 and H2S using MDEA/additive mixed absorbent. CO2-rich loading was excellent in MDEA/diethylenetriamine (DETA), and CO2 cyclic capacity was excellent in MDEA/bis(3-aminopropyl) amine (APA). H2S-rich loading was superior in MDEA/APA, and H2S cyclic capacity was superior in MDEA/DETA. The CO2 absorption and regeneration rates were excellent in MDEA/piperazine (PZ), and the H2S absorption and regeneration rates were excellent in MDEA/2-amino-2-methyl-1-propanol. MDEA-based blending absorbent showed better absorption and regeneration performance than MDEA, and MDEA/PZ showed good performance for CO2 but very poor performance for H2S. It was confirmed that MDEA/APA was superior for gas composition in the simultaneous absorption and regeneration of CO2 and H2S.

Gerald Vorberg et al (BASF SE), dated Apr-2011, title “a promoter for selective H2S removal: part II” discloses that the processing of sour crudes with high sulphur charges (high-sulphur operation) needs to be controlled and responded to by an increase in the reboiler steam feed rate. In this context, the H2S amine lean loading is one of the guiding values. Bayernoil and BASF jointly decided to conduct a test run with a new promoter formulation added to the generic MDEA solvent using dosing equipment. The promoter formulation itself was provided as an MDEA-diluted premix. The concentration was adjusted and controlled during the test period. This promoter system is non-volatile and is stable at elevated process temperatures. Thus, promoter losses were only expected by removal through the filter system or losses of the amine itself. Based on pilot tests, a drop in H2S lean loading was expected, particularly during high-sulphur operation, as were energy savings or potential capacity increases. As it turned out, a piping connection upstream of the LPG treater E1411 (on the pressure side of the LPG pump) was found to be the only feasible dosing point. Prior to the test run, two operational optimisation phases were conducted to exclude operational phenomena or other effects that could not be attributed to the test phase. Apart from the performance of the entire amine system, the review and test programme also focused on FCC tail gas absorber E1410 and LPG treater E1411 due to their higher sensitivity to changing levels of sulphur charge.

US4814104A discloses a tertiary alkanolamine absorbent containing an ethyleneamine promoter and its method of use. The document also discloses that absorption of carbon dioxide from gas mixtures with aqueous absorbent solutions of tertiary alkanolamines is improved by incorporating at least one alkyleneamine in the solution. The presence of the alkyleneamine promotes the rate of carbon dioxide absorption and the carbon dioxide capacity of the aqueous tertiary alkanolamine solution. As a result, absorption can be carried out in shorter absorber columns, and process energy requirements can be lowered by reducing the rate at which the absorbent solution is circulated.

US6436174B1 discloses a process for removing acidic gas constituents, of the group consisting of CO2, H2S, COS, CS2 and mercaptans, from gases, in which, in an absorption step, a dirty gas rich in acidic gas constituents is brought into contact with an absorption medium, as a result of which a clean gas low in acidic gas constituents and an absorption medium laden with acidic gas constituents are obtained, the absorption medium used being a mixture comprising a) from 0.1 to 50% by weight of one or more mono-cyclic or bicyclic nitrogen heterocycles which are unsubstituted and/or monosubstituted or poly-substituted on the carbon by OH, C1-C3 alkyl and/or C1-C3 hydroxyalkyl and which have from 5 to 14 ring atoms and 1 or 2 heterocyclically bound nitrogen atoms per ring as component A, b) from 1 to 60% by weight of a monohydric and/or polyhydric alcohol as component B, c) from 0 to 60% by weight of an aliphatic aminoalcohol as component C, d) from 0 to 98.9% by weight of water as component D, e) from 0 to 35% by weight of K2CO3 as component E, and where, the sum of components A, B, C, D and E is 100% by weight.

US20080078292A1 discloses absorbing solution according to the present invention is an absorbing solution that absorbs CO2 or H2S in gas or both of CO2 and H2S. The absorbing solution is formed by adding desirably 1 to 20 weight percent of tertiary monoamine to a secondary-amine composite absorbent such as a mixture of secondary monoamine and secondary diamine. Consequently, it is possible to control degradation in absorbing solution amine due to oxygen or the like in gas. As a result, it is possible to realize a reduction in an absorption loss, prevention of malfunction, and a reduction in cost. This absorbing solution is suitably used in an apparatus for removing CO2 or H2S or both of CO2 and H2S.

It is noted that the promoters play a major role in acid gas absorption and accelerate the absorption of acid gases. The commonly used promoters for forward reaction i.e., absorption are specialty diamine groups like piperazine, and amine coated carbon, or amine coated silica. Further, the common accelerator for backward reaction i.e., regeneration is Phosphoric acid and antisolvent.

However, still there is continuous demand for improving the acid gas absorption efficiency and accordingly there is a continuous demand for new chemical species which acts as promoters in the acid gas absorption process show improved efficiency for acid gas absorption when compared to exciting promoters.

OBJECTIVE OF THE PRESENT INVENTION:
The objective of the present invention is to provide a novel compound which improves the acid gas absorption efficiency and thus used for removing acid gas impurities from industrial gases.

The main objective of the present invention is to provide a novel compound which acts as a promoter and accelerate the absorption of acid gases.
The important objective of the present invention is to provide a novel formulation having the said novel compound and an alkanolamine, wherein, the said novel formulation is used for removing acid gas impurities from industrial gases.

Another objective of the present invention is to provide a process for preparing the said novel compound.

SUMMARY OF THE INVENTION:
The present invention discloses a novel compound of Formula 1 and a process for preparing the said novel compound. Firstly, a reaction solution is prepared by adding 2.2 equivalent weight of ethanolamine into 1 equivalent weight of solution of acetyl acetone, then stirring the prepared reaction solution for 6 hours while maintaining the reaction temperature at 60oC. Mixing the said reaction solution in methanol to obtain a reaction mixture. Then treating the obtained reaction mixture with 2 to 3 equivalent weight of sodium borohydride at 0oC, then warming to room temperature and stirring at room temperature for 12 hours. Finally treating the reaction mixture as obtained with diluted water and subjecting to centrifugation followed by the removal of water to obtain compound of Formula 1.

Further, the present invention also discloses a novel formulation having the said novel compound and an alkanolamine, wherein, the said novel formulation is used for removing acid gas impurities from industrial gases.

DETAILED DESCRIPTION OF THE INVENTION:
For promoting an understanding of the principles of the present disclosure, reference will now be made to the specific embodiments of the present invention further illustrated in the drawings and specific language will be used to describe the same. The foregoing general description and the following detailed description are explanatory of the present disclosure and are not intended to be restrictive thereof. It will nevertheless be understood that no limitation of the scope of the present disclosure is thereby intended, such alterations and further modifications in the illustrated composition, and such further applications of the principles of the present disclosure as illustrated herein being contemplated as would normally occur to one skilled in the art to which the present disclosure relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinarily skilled in the art to which this present disclosure belongs. The methods, and examples provided herein are illustrative only and not intended to be limiting.

The present invention discloses a novel compound of Formula 1, wherein, the compound is used for removing at least one acid gas impurity from industrial gases:

Formula 1
wherein, R1 and R2 are selected from hydrogen, C1-C3 alkyl, C1-C3 haloalkyl.

The novel compound as disclosed in the present invention is useful in removing at least one acid gas impurity such as H2S gas impurity. Specifically, the novel compound as disclosed in the present invention acts as a promoter for absorption of the H2S gas impurity.

Further, the present invention discloses a process for preparing the said novel compound of Formula 1. Firstly, a reaction solution is prepared by adding an alkanolamine to a solution of acetyl acetone, then stirring the prepared reaction solution for 5-7 hours while maintaining the reaction temperature at 60oC. Mixing the said reaction solution in an aliphatic alcohol to obtain a reaction mixture. Then treating the obtained reaction mixture with sodium borohydride at 0oC, then warming to room temperature and stirring at room temperature for 12 hours. Finally treating the reaction mixture as obtained with diluted water and subjecting to centrifugation followed by the removal of water to obtain compound of Formula 1.

The alkanolamine as used in the preparation of the said novel compound is selected from the group consisting of ethanolamine, N-methylethanolamine, N-ethylethanolamine, N-propylethanolamine, N-butylethanolamine, diethanolamine, isopropanolamine, diisopropanolamine, N-methylisopropanolamine, N-ethylisopropanolamine, N-propylisopropanolamine.

Specifically, the alkanolamine is selected from ethanolamine.

The aliphatic alcohol as used in the preparation of the said novel compound is selected from the group consisting of methanol, ethanol, isopropanol, propyl alcohol, tert-butyl alcohol, or combinations thereof. Specifically, the aliphatic alcohol is selected from methanol.

Preparation Example -1:
In an exemplary embodiment, the present invention discloses a novel compound of Formula 1 and a process for preparing the said novel compound. Firstly, a reaction solution is prepared by adding 2.2 equivalent of ethanolamine to 1 equivalent of a solution of acetyl acetone, then stirring the prepared reaction solution for 6 hours while maintaining the reaction temperature at 60oC. Mixing the said reaction solution in methanol to obtain a reaction mixture. Then treating the obtained reaction mixture with sodium borohydride (2-3 equivalent) at 0oC, then warming to room temperature and stirring at room temperature for 12 hours. Finally treating the reaction mixture as obtained with diluted water and subjecting to centrifugation followed by the removal of water to obtain compound of Formula 1.
1H-NMR Study:
1H-NMR (500 MHz, CDCl3): d 4.91 (2H, s), 4.07–4.06 (1H, brm), 3.67 (4H, m), 3.61–3.55 (1H, m), 3.33 (4H, m), 2.20 (1H, brs), 1.92–1.90 (3H, m), 1.15–0.99 (6H, m).
Chemical Reaction:

The present invention also discloses a novel formulation of an alkanolamine and compound of Formula 1. The said novel formulation is used for removing acid gas impurities from industrial gases.
In an embodiment, the said novel formulation incudes 26-34 weight % of an alkanolamine and 1-9 weight % of the novel compound of Formula 1.
In a preferred embodiment, the said novel formulation comprises 30 weight % of the alkanolamine and 5 weight % of the novel compound of Formula 1. Wherein, the alkanolamine is methyldiethanolamine (MDEA).
Specifically, the said novel formulation is used for removing H2S gas impurity which is present in industrial gases.
The following table 1 illustrates the H2S loading of the novel formulation as claimed in the present invention, specifically the novel formulation as presented in table 1 includes methyldiethanolamine (MDEA) and compound of Formula 1.
Experimental Protocol for H2S Absorption Study:
Aqueous solution of the amine absorbent is loaded into the vapour liquid equilibrium (VLE) cell using the piston pump. The temperature in the climatic chamber is set at the desired value. The desired gas concentration is prepared in the mixed gas tank. The gas is then routed to the VLE cell until a predetermined pressure (3-10 bar) is achieved. Further, the gas flow will be stopped. As the gas starts absorbing in the solvent, the pressure of the VLE cell starts decreasing and finally at the equilibrium the pressure becomes constant. Subsequently, the gas is again dosed into the VLE cell till the predetermined pressure (3-10 bar) is attained. The gas flow is again stopped to attain new equilibrium state and the gas and liquid concentrations are evaluated. The loading values are calculated based on CHNS values.
Table 1: H2S absorption studies
MDEA (weight %) Compound 1 (weight %) Water (weight %) H2S loading (mmol/mmol of amine)
35 0 65 0.32 (at High pressure)
30 5 65 0.41 (at High pressure)
35 0 65 0.085 (at low pressure)
30 5 65 0.11 (at low pressure)

The H2S absorption study data reveals that H2S absorption as achieved at high pressure is 0.41 mmol for 5 weight % of compound 1 and 30 weight % of methyldiethanolamine (MDEA). The H2S absorption as achieved at low pressure is 0.11 mmol for 5 weight % of compound 1 and 30 weight % of MDEA.