1- Start of work: In 1993, after Farabi Petrochemical Co. announced the need for p-toluenesulfonic acid (PTSA) as a catalyst, in the process of phthalic anhydride esterification, the plan to acquire the know-how of PTSA production via two professors of Faculty of Chemistry of Isfahan University of Technology (researchers) and in the laboratories of that faculty were started with the agreement and financial support of the university. After about 9 months and conducting initial laboratory tests, these two succeeded in building a semi-industrial unit (pilot) for the continuous production of crude PTSA, with a capacity of about 10 kg/h. After the negotiations and agreement with university authorities, the researchers started to establish a Research & Manufacturing Co. It should be noted that according to the contract with the university, this company must pay one percent of the PTSA sales to the university annually for ten years. 2- After registering the company and finding some investors, in 1997 the company was established in its current location (Montazerie Industrial Town, in the Najafabad area of Isfahan) after providing the basic utilities of water, electricity, gas, storage tanks for raw materials (toluene and sulfuric acid) and the residence of the workers (due to the need to produce in three continuous shifts around the clock), first a reactor made of glass tubes (available in Iran) with the capacity of producing 1000 kg of crude PTSA per day started working. It should be mentioned, since according to the relevant chemical equation, the initial product was always accompanied by a sufficient amount of sulfuric acid, first, a method for mass and efficient production should be found as the marketing of the product is proceed. This operation continued until 2000. 3- In 2000, after the construction of a suitable building, with at least 12 parallel reactors, PTSA production increased to 8 tons per day. 4- In the same year, we managed to convince some Iranian detergent-powder manufacturing companies to use a PTSA process product, called STS, to improve the quality of their manufactured products and also to increase the quality of the products that can be supplied to their customers, and then take action. Let's find the method of preparation and industrial implementation for the mass production of this new product. At this stage, the company's production capacity reached 10 tons per day of STS. 5- In 2001, following the request of detergent powder manufacturing companies, the research and development unit of the company succeeded in finding a method to produce colored granules based on suitable bentonite soil, with the quality required by the relevant industries, in tons per day capacity. 6- In 2005, based on the experiences gained for the production of PTSA and access to metal reactors, coated with ceramics or glass layers in Iran, designed, build, and install a new, durable advanced, and flexible quality for sulfonation of all kinds of aromatic compounds, with a capacity of seven tons per day. 7- In 2005, based on the needs expressed by cattle farms, the research and development unit of the company succeeded in producing auxiliary materials based on the conversion of bentonite to solve the acidosis problem of cattle farms and produce this product with the required capacity of ten tons per day 8- In 2006, at the same time as the government decided to use naphtha cut for car engine fuel, and as a result, the production and supply of toluene and other aromatic compounds, the main feedstock of PTSA and STS products, was stopped, it was not possible to continue production in the company. In the following years, after the re-supply of toluene and the price of these products of Isfahan Petrochemical Co. increased several times, the production and sales of these products in Sepahan Farzin Chemical Company were no longer affordable. 9- Sepahan Farzin Chemicals Co. currently produces ten different products based on bentonite processes and processed bentonites, and its research and development units are trying to produce several new products.The results of more than 20 years of work and efforts of Sepahan Farzin Chemicals Co. have been to create a system that can successfully implement its designs on laboratory, semi-industrial, and industrial scales with exemplary agility.