113- Design of specialized filtration and separation units for feed gas and output gas in the MDEA desulfurization unit of the coalbed methane-coal mine gas to natural gas conversion project

This post was last edited by luoli519 on 2023-11-17 at 09:47. A few years ago, we supplied specialized filtration and separation systems and equipment for a natural gas production project related to the recovery and utilization of coalbed methane, which was being built in Shanxi by a well-known foreign-owned coalbed methane company. These systems included specialized filtration separators for wet feed gas, vane separators for the gas exiting the MDEA absorption towers, KO separation tanks for the exhaust gas from the MDEA regeneration towers, filters for rich and poor MDEA solutions, activated carbon filters, filters before and after ethylene glycol treatment, as well as specialized filtration separators for the gas to be transported outside the facility. Here, we specifically discuss the design of this filtration separator. Another post will be created to discuss other types of separation technology equipment, allowing everyone to search for related technical posts using keywords.

This post was last edited by luoli519 on 2024-4-3 at 11:14. The specialized filtration and separation units used in the processing and transportation of gas and natural gas are designed with a horizontal twin-tube structure in process packages both domestically and internationally (for example, the SALOF process package). As shown in the figure below:

This post was last edited by luoli519 on 2024-4-3 at 11:14. The diameter of the tube is large, serving as the core separation area； The lower cylinder has a smaller size and serves as the liquid-solid temporary storage area. It has a horizontal layout with a low equipment height, primarily to facilitate easy operation and maintenance by personnel. Here, we will mainly discuss the core separation area. This core separation area contains two levels of work chambers ； The first-stage compartment is the filter element compartment; the filter elements used are of the G51F type, and they are designed to separate and remove particles with a size of 3 microns or larger ； The secondary chamber is a dedicated vane separation chamber, and the vane separation internal component set is of the G50 type; it is used to separate and remove the secondary entrained particles that have been pre-aggregated as fluid passes through the filter media in the primary chamber and that are still suspended in the airflow. Those who are interested may refer to the filter separator with a standard structure designed for a foreign project in the attachment.

This post was last edited by luoli519 on 2024-4-3 at 11:14. Some friends have informed us via email and phone that they would like to see pictures of the G51F type primary filter chamber so as to have a clearer understanding. The image below shows a photo of the primary filter element compartment of the aforementioned dedicated horizontal filtration and separation unit, model G51F:

Many people may have seen filters and their internal filter elements, and think that filters are quite common and simple. However, it should be noted that filter elements are divided into two types: filtering type and coalescing type. The former is used for dry gas treatment, while the latter is used for wet gas treatment. There are significant differences in the material, structure, and cost of these two types of filter elements. I have discussed in detail the differences between these two types of filters in other posts on similar topics; those who are interested can search using the relevant keywords.

This post was last edited by luoli519 on 2023-9-27 at 12:41. If people are quite familiar with the filter element compartment, then they know much less about the G50 type secondary vane separation compartment. Furthermore, the G50 type secondary vane separation chamber is a component that must be included in filters and filter-separators; it is used to separate and remove the liquid droplets and mist suspended in the airflow, which are formed as a result of pre-coagulation when the airflow passes through the internal components of the primary chamber, and cannot be separated on their own through mere gravitational settling. In some design firms, the primary filtration chamber is designed and arranged as a separate unit, while the secondary vane separation chamber is also designed and arranged as another separate unit to be used in series behind the filter; this approach is also feasible. However, the costs such as construction price, land use, and piping will be higher.

This post was last edited by luoli519 on 2024-4-3 at 11:15. Here, I’ve also attached pictures of the G50 type secondary vane separation interior compartment for those who are interested to refer to. It should be noted that specialized gas filtration and separation units must be precisely designed using dedicated computational methods for kinetic separation as well as configuration design system platforms in order to meet the stringent technical requirements of such units ； Otherwise, it is highly likely that a filtration separator designed based on experience through \"rough estimates\" or even hunches will fail to meet the design requirements in actual operation. It is essential to pay sufficient attention!

Next, let’s first take a look at the operating parameters of the inlet filter separator for the wet raw gas in the MDEA absorption unit of this project: 1. Process medium: Wet coalbed methane； 2. Operating temperature: 40℃ ； 3. Operating pressure: 4.05 MPaA ； 4. Gas flow rate: 18405 kg/h; 5. Gas density: 40.88 kg/m^3; 6. Gas viscosity: 0.0115 cp ； 7. Gas composition: (mol%) METHANE, 67.67 ； ETHANE，13.86 ； PROPANE，5.01 ； IBUTANE，0.76 ； NBUTANE，1.45 ； IPENTANE，0.37 ； NPENTANE，0.41 ； HEXAN，0.29 ； HEPTANE，0.07 ； N2，4.18 ； CO2，4.48 ； H2S，1.29 ； H2O，0.18。 8. Types of substances carried by the airflow: dust particles, lubricating oil, liquid hydrocarbons, free water droplets and foam, etc.

Let’s take a look at the operating parameters of the filter-separator for the exported commercial gas in this project: 1. Process medium: Pressurized commercial natural gas； 2. Operating temperature: 50 ℃ ； 3. Operating pressure: 7.0 MPaA ； 4. Gas flow rate: 12762 kg/h; 5. Gas density: 62.22 kg/m^3; 6. Gas viscosity: 0.012 cp ； 7. Gas composition: (mol%) METHANE, 75.65 ； ETHANE，13.09 ； PROPANE，3.24 ； IBUTANE，0.28 ； NBUTANE，0.42 ； IPENTANE，0.05 ； NPENTANE，0.04 ； HEXAN，0.01 ； HEPTANE，0.00 ； N2，4.80 ； CO2，2.42。 8. Types of substances carried by the airflow: dust particles, lubricating oil, liquid hydrocarbon droplets and foam, etc.

Our company has precisely designed the feed gas inlet filtration and separation unit using a proprietary dynamic separation design system platform; the details are as follows: 1. Name of the separator: NOVEL G51F type horizontal feed gas inlet filtration and separation unit； 2. Primary filtration chamber: Model G51F-436RC; 3. Secondary separation chamber: Model G50 ； 4. Equipment dimensions: ID 400mm * SM/SM2 3000mm ； 5. Separation efficiency: carriers with a size of 4N*3 microns and above ； 6. The initial pressure drop shall not exceed 10 kPa, with a maximum allowable pressure difference of 300 kPa ； 7. Operational flexibility: 15%-110%.