CN101864329B - Wet purification method of sequencing batch biomass gas - Google Patents

Abstract

A batch-type biomass gas wet purification method, which is characterized in that it is carried out alternately by two stages of absorption and regeneration, and is completed in the same tower without additional processing equipment, so it has the advantages of small footprint and low investment .

Description

Batch type biomass gas wet purification method

technical field

The invention relates to a biomass gas purification treatment method, in particular to a wet purification method suitable for small and medium-sized production scale biomass gas treatment fields, in particular to a batch-type biomass gas wet purification method.

Background technique

As we all know, during the utilization of biomass gas, gas purification treatment is required according to the requirements of the occasion, and the components to be removed mainly include hydrogen sulfide and carbon dioxide. The purpose of desulfurization is to prevent corrosion of equipment, while the removal of carbon dioxide is mainly used to increase the calorific value of gas and reduce the content of flame retardant gases in the gas. Wet desulfurization and wet decarbonization have become the main technologies for biomass gas purification, such as wet desulfurization technologies such as DDS, PDS, complex iron method, naphthoquinone method, and wet decarbonization technologies including MDEA, DHA and other processes. These technologies The biggest feature is that the raw material gas can be continuously purified, that is, the raw material gas is absorbed and purified by the absorption liquid in the absorption tower, and the absorption liquid (rich liquid) discharged from the absorption tower is heated or air oxidized (aeration) outside the tower. ) and other ways to regenerate, and the regenerated absorption liquid (poor liquid) re-enters the absorption tower to work. The application of this method in the field of biomass gas purification has some problems that need to be solved or improved, such as the problems of complex system flow, large floor area, and high investment, which limit the application in the field of small and medium-sized biomass gas utilization. application.

Contents of the invention

The purpose of the present invention is to solve the problems in the existing wet biomass gas purification process, such as complex process, large equipment footprint, high investment, and unsuitable for the recovery and utilization of biomass gas in small and medium-sized production scales, and to invent a Small footprint, simple process flow, and a wide range of batch-type biomass gas wet purification methods.

Technical scheme of the present invention is:

A batch type biomass gas wet purification method is characterized in that it comprises the following steps:

First, set a liquid storage tank at the bottom of the absorption tower;

Secondly, the absorption liquid regeneration device is installed in the liquid storage tank;

Third, set a regeneration exhaust gas pipe on the upper part of the absorption tower;

Fourth, open the raw material gas inlet pipe, close the regeneration exhaust gas pipe, use the circulation pump to pump the absorption liquid in the liquid storage tank into the upper part of the absorption tower and spray downwards, so that the upward raw material gas and the falling absorption liquid are in reverse contact, To realize the purification of the raw material gas, the purified raw gas is discharged from the absorption tower from the purified gas pipe, and the absorption liquid falls into the liquid storage tank and is continuously pumped into the spray head on the upper part of the absorption tower by the circulation pump to spray downwards, thus circulating;

Fifth, after repeating the fourth step for about 25-35 minutes, close the raw gas inlet pipe, open the regeneration exhaust pipe, start the absorption liquid regeneration device to work continuously for 15-25 minutes, and repeat the first step after completing the regeneration of the absorption liquid The new raw material gas is purified and regenerated again in four steps, and this cycle realizes the wet purification process of batch-type biomass gas.

The absorption liquid regeneration device can be a heat exchanger-type absorption liquid regeneration device. When regenerating, first pass steam into the heat exchanger to heat and regenerate the absorption liquid for 10-15 minutes. The regeneration gas generated during the regeneration process is discharged from the absorption tower The upper part of the regeneration exhaust pipe is discharged, and after the regeneration is completed, the cooling water is passed into the heat exchanger to circulate for 5-10 minutes to cool the absorption liquid.

The absorption liquid regeneration device can also be an aeration tube type absorption liquid regeneration device. During regeneration, the aeration tube can be used to aerate the absorption liquid in the liquid storage tank for 15-25 minutes, and the regeneration gas generated in the regeneration process is from The regeneration discharge gas pipe at the upper part of the absorption tower is discharged.

Beneficial effects of the present invention:

The present invention not only brings into play the characteristics of high purification efficiency of the wet purification method, but also avoids the problems of complex system flow, large floor area and high investment of the traditional wet purification method. The biggest feature of the present invention is that the In the past, the external steam heating or air blowing oxidation regeneration section was moved into the liquid storage tank at the bottom of the absorption tower, so that the washing and purification of the absorption liquid and the regeneration of the absorption liquid were completed in one tower, so that the control of liquid level, Flow balance, pressure balance and other requirements, thus greatly simplifying the process flow, making the equipment occupy a small area and reduce investment.

Absorption and regeneration in the present invention are carried out alternately in the same tower, and regeneration is carried out after a certain period of time after absorption, and absorption is carried out after completion of regeneration.

Description of drawings

Fig. 1 is a flow chart of the batch-sequential biomass gas wet purification process of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1.

A batch type biomass gas wet purification method, it comprises the following steps:

First of all, a liquid storage tank 2 is set at the bottom of the absorption tower 1. If necessary, an absorption liquid replenishment device 3 should be added to the liquid storage tank to make up for the reduced absorption liquid during the purification process, so that the liquid level of the liquid storage tank is always maintained. at a level;

Secondly, the absorption liquid regeneration device 4 is installed in the liquid storage tank 2;

Third, set a regeneration exhaust gas pipe on the upper part of the absorption tower;

Fourth, open the raw material gas inlet pipe 5, close the regeneration exhaust gas pipe 6, use the circulation pump 7 to pump the absorption liquid in the liquid storage tank 2 into the upper part of the absorption tower 1 and spray downwards, so that the upward raw material gas and the falling absorption The liquid is reversely contacted to realize the purification of the raw material gas. The purified raw gas is discharged from the absorption tower 1 from the purified gas pipe 8, and the absorption liquid falls into the liquid storage tank 2 and is continuously pumped into the upper part of the absorption tower 1 by the circulation pump 7. Spray downwards in the head, and so on;

Fifth, after repeating the fourth step for about 25-35 minutes, close the raw material gas inlet pipe 5, open the regeneration discharge gas pipe 6, start the absorption liquid regeneration device 4 to make it work continuously for 15-25 minutes, and complete the regeneration of the absorption liquid. Then repeat the fourth step to purify and regenerate the new raw material gas again. This cycle realizes the wet purification process of batch-type biomass gas.

During specific implementation, the absorption liquid regeneration device 4 can adopt the existing heat exchanger type absorption liquid regeneration device. During regeneration, first feed steam into the heat exchanger to heat and regenerate the absorption liquid for 10-15 minutes. The regenerated gas is discharged from the regeneration exhaust pipe on the upper part of the absorption tower, and after the regeneration is completed, the cooling water is passed into the heat exchanger to circulate for 5-10 minutes to cool the absorption liquid.

The absorption liquid regeneration device can also adopt the existing aeration tube type absorption liquid regeneration device. When regenerating, use the aeration tube to aerate the absorption liquid in the liquid storage tank for 15-25 minutes. The regeneration gas is discharged from the regeneration exhaust pipe at the upper part of the absorption tower.

It can be seen from the above that the absorption and purification of gas by the absorption liquid and the regeneration of the absorption liquid in the present invention are completed in one tower body, so it has the characteristics of small volume and wide adaptability, and it is suitable for large biomass Gas application field, especially suitable for small and medium-sized production scale biomass gas application field. The invention can be applied to gas purification devices for removing hydrogen sulfide, carbon dioxide and the like in biomass gas.

The operating characteristics of the present invention are: when performing gas absorption, separation and purification, the raw material gas pipe is opened, the regeneration discharge gas pipe is closed, the raw material gas enters from the bottom of the absorption tower, and enters from the bottom up in the absorption section 9 (which can be a packing area, a hollow spraying area, bubbling trays, etc.) are in reverse contact with the absorption liquid, the purified gas is discharged from the purification gas pipe, and the absorption liquid is circulated and absorbed by the circulating pump; when the absorption liquid absorbs the raw material gas to a certain stage, the absorption capacity of the absorption liquid is close to saturation , switch to the regeneration working state, at this time close the raw material gas pipe, open the regeneration discharge gas pipe, open the regeneration device (it can be a heat exchanger or aeration pipe, etc.), and the regeneration gas generated during the regeneration process is discharged from the regeneration gas pipe.

The parts not involved in the present invention are the same as the prior art or can be realized by adopting the prior art.

Claims (1)

1. A batch type biomass gas wet purification method is characterized in that it comprises the following steps: First, set a liquid storage tank at the bottom of the absorption tower; Secondly, the absorption liquid regeneration device is installed in the liquid storage tank; Third, set a regeneration exhaust gas pipe on the upper part of the absorption tower; Fourth, open the raw material gas inlet pipe, close the regeneration exhaust gas pipe, use the circulation pump to pump the absorption liquid in the liquid storage tank into the upper part of the absorption tower and spray downwards, so that the upward raw material gas and the falling absorption liquid are in reverse contact, To realize the purification of the raw material gas, the purified raw gas is discharged from the absorption tower from the purified gas pipe, and the absorption liquid falls into the liquid storage tank and is continuously pumped into the spray head on the upper part of the absorption tower by the circulation pump to spray downwards, thus circulating; Fifth, after repeating the fourth step for about 25-35 minutes, close the raw gas inlet pipe, open the regeneration exhaust pipe, start the absorption liquid regeneration device to work continuously for 15-25 minutes, and repeat the first step after completing the regeneration of the absorption liquid Purify and regenerate the new raw material gas again in four steps, so that the cycle can realize the wet purification process of batch-type biomass gas; The absorption liquid regeneration device is an aeration tube type absorption liquid regeneration device or a heat exchanger type absorption liquid regeneration device, and the aeration tube is used to aerate the absorption liquid in the liquid storage tank when the aeration tube type absorption liquid regeneration device is regenerated It takes 15-25 minutes, and the regeneration gas generated during the regeneration process is discharged from the regeneration exhaust pipe on the upper part of the absorption tower; when the heat exchanger type absorption liquid regeneration device is regenerated, steam is first passed into the heat exchanger to heat and regenerate the absorption liquid After 10-15 minutes, the regeneration gas generated during the regeneration process is discharged from the regeneration exhaust pipe on the upper part of the absorption tower. After the regeneration is completed, the cooling water is passed into the heat exchanger to circulate for 5-10 minutes to cool the absorption liquid.