The functional groups that can be sulfonated or sulfated by SO3 are mainly divided into 4 categories; benzene ring, alcohol hydroxyl group, double bond, A-carbon of Ester group, the corresponding raw materials are alkylbenzene, fatty alcohol (ether), olefin, fatty acid methyl ester(FAME), typical products are industrial linear alkyl benzene sulfonate (hereinafter referred to as LAS), AS, AES, AOS and MES. The following to introduce the development status of existing sulfonic acid and sulfate surfactants according to categorized by the organic functional groups can be sulfonated by SO3.

2.1 alkylaryl sulfonates
Alkyl aryl sulfonate refers to a class of sulfonate surfactants prepared by sulfonation reaction with sulfur trioxide with aromatic ring as organic functional group. Typical products include LAS and long-chain alkyl benzene sulfonate, Heavy alkylbenzene sulfonate (HABS), petroleum sulfonate and alkyl diphenyl ether disulfonate, etc.

2.1.1 Industrial linear alkyl benzene sulfonate
LAS is obtained by sulfonation, aging, hydrolysis and neutralization of alkylbenzene. LAS is usually stored and sold in the form of alkylbenzene sulfonic acid. In actual use, it is neutralized with an alkali. There are also stored and sold in the form as sodium salts. LAS has good wetting, emulsifying, foaming and detergency, and it has good compatibility with other surfactants (AOS, AES, AEO), and it has a wide range of applications in household washing fields such as washing powder, detergent and washing liquid. The disadvantage of LAS is its poor resistance to hard water. It is usually necessary to add calcium and magnesium ion chelating agents during use. In addition, LAS is highly degreasing and has a certain irritation to the skin.
2.1.2 long-chain alkyl benzene sulfonate
Long-chain alkyl benzene sulfonate usually refers to a class of surfactants with a carbon chain length greater than 13, which has good application performance in tertiary oil recovery, and is often used in combination with heavy alkyl benzene sulfonate. The general process is to use HF as a catalyst to make alkylation action by heavy liquid wax dehydrogenation product, such as long-chain alkanes, olelfin mixture with Benzene or Xylene to prepare Long chain alkyl benzene. Then use SO3 membrane sulfonation to prepare long-chain alkylbenzene sulfonic acid.
2.1.3 Heavy alkyl benzene sulfonate
Heavy alkylbenzene sulfonate is one of the main surfactants used in oilfield flooding. Its raw material heavy alkylbenzene is a by-product of the production process of dodecylbenzene, the yield is lower (<10%), so its source is limited. The components of heavy alkylbenzene are relatively complex, mainly including alkylbenzene, dialkylbenzene,
diphenylene, alkylindane, tetralin and so on.
2.1.4 Petroleum sulfonate
Petroleum sulfonate is a type of surfactant prepared by SO3 sulfonation of petroleum distillate oil. The preparation of petroleum sulfonate usually uses the local petroleum distillate oil of the oil field as a raw material. The process of sulfonation includes: gas SO3 film sulfonation, liquid SO3 kettle sulfonation, and gas SO3 spray sulfonation.
2.1.5 Alkyl Diphenyl Ether Disulfonate(ADPEDS)
Alkyl diphenyl ether disulfonate is a class of functional surfactants with double sulfonic acid groups in the molecule. It has special applications in emulsion polymerization, household and industrial cleaning, textile printing and dyeing. Compared with traditional monosulfonate surfactants (such as LAS), disulfonic acid groups give it some special physical and chemical properties, which are very good solubility and stability in 20% strong acid, strong alkali, inorganic salt and bleaching agent solutions. It consists of monoalkyl diphenyl ether bissulfonate (MADS), monoalkyl diphenyl ether monosulfonate (MAMS), and dialkyl Diphenyl ether bissulfonate (DADS) and bisalkyl diphenyl ether monosulfonate (DAMS) are composed, the main component is MADS, and its content is more than 80%. The sulfonated product of alkyl diphenyl ether, alkyl diphenyl ether disulfonic acid, has a very high viscosity. Generally, dichloroethane is used as a solvent and prepared by a kettle sulfonation process.