How can the quinoline-insoluble substances in coal tar be separated economically

The methods currently in use include the solvent method, flash evaporation method, and high-speed centrifugation method. The solvent method yields the highest yield

It’s of little use for the original poster to talk generally about what methods are economical; you need to specify what purpose coal tar is intended for after quinoline is removed. Different purposes, or different levels of quinoline removal, result in varying costs and levels of process complexity. The requirements for materials used in producing needle coke, carbon microspheres, and carbon fibers also differ significantly, and these differences directly determine the costs and investment required

If only a rough processing of the tar is carried out, it is very simple and effective to use a super centrifuge for dehydration while simultaneously removing most of the quinoline-insoluble substances

Most quinoline-insoluble substances can be removed using a centrifuge

The particle size distribution of quinoline determines that single centrifugation separation cannot meet the requirements for high-value-added products.

Methods for removing QI from coal tar pitch or coal tar include distillation, centrifugation, solvent extraction, and modification methods. For reference ； (1) Distillation method: A U.S. patent technology that uses a vacuum separator to separate residues from coal tar pitch, including the separation of QI. Its technical core is to extract a section of material free from QI through vacuum distillation. The process is relatively simple, but the yield is low. (2) Centrifugation method: A U.S. patent technology that uses mechanical devices such as centrifuges or filters to remove QI. Coal tar pitch is fed into a centrifuge at an appropriate temperature and viscosity to separate the centrifugate free of QI from the residue rich in QI; the centrifugate thus obtained is free of QI. This technology **increases the yield of refined material.** (3) Solvent method: Numerous patents from the United States, Japan, Poland, China, and other countries describe the use of aliphatic hydrocarbons and aromatic hydrocarbons in certain proportions to create a mixed solvent, which is then used to treat coal tar pitch in order to initially remove QI. (4) Modification method: Chinese patent; low yield of refined material.

I agree with what was said on the 2nd floor – it depends on what you intend to use it for, and everyone has explained it in detail; it really comes down to what purpose you have in mind