What is the process of FGD?

According to [14], the process of FGD is as shown in Figure 1. It involves identification of goal/objectives, identify questions, identify people, select time, place/environment, conduct research, evaluate findings/data and preparation of report. …

What is FGD project?

Flue-gas desulfurization (FGD) is a set of technologies used to remove sulfur dioxide (SO. 2. ) from exhaust flue gases of fossil-fuel power plants, and from the emissions of other sulfur oxide emitting processes such as waste incineration.

What is FGD material?

The settled material called FGD scrubber material or scrubber sludge is an off-white slurry with a solids content in the range of 5 to 10 percent. Because coal fired power plants typically have both a FGD systems and a fly ash removal system, fly ash is sometimes incorporated into the FGD material.

How does limestone remove sulfur dioxide?

Limestone is a naturally occurring calcium carbonate rock which can react with sulfur dioxide. Limestone can therefore be used for desulfurization of flue gases. The reaction of sulfur di- oxide with dry limestone requires a very high temperature such as that available within the actual boiler furnace.

What are the steps in preparing an FGD guide?

  1. Step 1: Choose your topic of interest.
  2. Step 2: Define your research scope and hypotheses.
  3. Step 3: Determine your focus group questions.
  4. Step 4: Select a moderator or co-moderator.
  5. Step 5: Recruit your participants.
  6. Step 6: Set up your focus group.
  7. Step 7: Host your focus group.

What are the 4 key decisions to be made before conducting a FGD?

There are four key decisions to be made: (1) respondent selection; (2) sample size; (3) data gathering; and (4) data analysis.

What is FGD research?

What is an FGD? A Focus Group Discussion (FGD) is a qualitative research method and data collection technique in which a selected group of people discusses a given topic or issue in-depth, facilitated by a professional, external moderator.

How does an FGD scrubber work?

Wet FGD. The process of wet scrubbing typically utilizes an alkaline-based slurry of lime to scrub gases. A shower of lime slurry is then sprayed into a flue gas scrubber, where the SO2 is absorbed into the spray and becomes a wet calcium sulfite. One by-product of that sulfite is it can be converted to salable gypsum.

Why gypsum is used in FGD?

Gypsum can be used as a nutrient source for crops; as a conditioner to improve soil physical properties, and water infiltration and storage; to remediate sodic (high sodium) soils; and to reduce nutrient and sediment movement to surface waters, among other uses.

What is scrubber in FGD?

There are two different designs used for FGD systems: 1. Dry scrubber: This is used to heat up the incoming flue gas to vaporize the liquid in the lime slurry used to scrub the SO2 from the gas, resulting in a dry waste stream. 2. Wet scrubber: This uses an excess of slurry and produces a wet waste stream.

How do you remove HCl from flue gas?

The conventional process to remove HCl and other acid gases (such as SO2) from flue gas is wet scrubbing [1 – 3], in which the hot flue gases contact water or basic aqueous solution and/or suspension.

What is the pH of limestone slurry?

A pH sensor in a recirculating tank is used to control feed of solid lime or limestone. Neither lime nor limestone dissolves well in water and therefore, both are pumped in slurry form to the scrubber tower. Lime slurry is more alkaline, having a pH of 12.5 while limestone slurry is roughly neutral.

How do you make a FGD question?

6 Steps to Create Effective Focus Group Questions

  1. Be Clear About Project Goals. Talk to the project stakeholders and learn what information is critical to the project’s success.
  2. Know What Information Is Already Available.
  3. Brainstorm Preliminary Questions.
  4. Solicit Feedback.
  5. Refine Your List of Questions.
  6. Run a Test.

How do FGD choose participants?

4.2 Method of selection (sampling) The common (and simplest) method for selecting participants for focus groups is called “purposive” or “convenience” sampling. This means that you select those members of the community who you think will provide you with the best information.

How do you write a FGD report?

You can start with a general overview, but then write down each question you asked and include the focus group members’ responses. In addition, include the moderator’s personal views of how enthusiastic or “meh” group members were about certain topics. Add a section that makes recommendations based on your findings.

How is SO2 removed from flue gas?

For the removal of SO2 from flue gas, a wet process using calcium carbonate as an absorbent is most commonly adopted in commercial plants. The wet process shows a high efficiency but needs a large amount of water. SO2 is fixed in the form of calcium sulfate.

Why is FGD required?

FGD is a system which reduces the SOx in flue gas through chemical treatment and converting the captured SOx into a by-product such as Gypsum or Calcium Sulphate or Sulphuric Acid depending upon the type of mechanism used. Dry scrubbing.

At what percentage gypsum is added to cement?

The cement manufacturing industry is the major consumer of gypsum, which is added to the clinker in a percentage of 3–5 wt% [1], [2], [3].

What is FDG gypsum?

FGD gypsum is a synthetic material of identical chemical structure produced as a byproduct from coal-fired electric utilities. Other sources of gypsum include phosphogypsum, citrogypsum and fluorogypsum, which are byproducts of different chemical manufacturing processes1.

How do you remove SO2 from flue gas?

When was the first FGD system installed?

The first major FGD unit at a utility was installed in 1931 at Battersea Power Station, owned by London Power Company. In 1935, an FGD system similar to that installed at Battersea went into service at Swansea Power Station. The third major FGD system was installed in 1938 at Fulham Power Station.

How many FGD units are in use today?

This standard is currently in use today by companies around the world. As of June 1973, there were 42 FGD units in operation, 36 in Japan and 6 in the United States, ranging in capacity from 5 MW to 250 MW.

What is the purpose of the FGD performance test committee?

This committee first convened in 1979 with the purpose of developing a standardized “procedure for conducting and reporting performance tests of FGD systems and reporting the results in terms of the following categories: (a) emissions reduction, (b) consumable and utilities, (c) waste and by-product characterization and amount.”

How is FGD wastewater treated?

However, technological advancements in ion-exchange membranes and electrodialysis systems has enabled high-efficiency treatment of FGD wastewater to meet recent EPA discharge limits. The treatment approach is similar for other highly scaling industrial wastewaters. A venturi scrubber is a converging/diverging section of duct.