This report reviews recent developments in ethylbenzene (EB) manufacturing technologies and studies in detail the suggested process; Production of Ethylbenzene via Side Alkylation of Toluene by Methanol. The desired amount of ethylbenzene as the product is 303 tonne/day, which finally reduced to 30.21 tonne/day .For this production rate, a 322 tonne/day feed rate containing toluene and methanol was calculated to reach to 99.2% of purity. Chapters 1 through 3 provide an introduction to ethylbenzene and different feasible process for producing of this chemical. A detailed consideration of the process of producing ethylbenzene by toluene and methanol is presented in chapter 4. The use of computer software in process design as well as simulation and calculation parts are described in chapter 5 followed by a discussion on human health, environmental and safety aspects of the main products in chapter 6. The various costs involved in industrial processes, cost estimation, cost accounting and other subjects dealing with economics are covered both qualitatively and quantitatively in chapter 7 and finally, a discussion and conclusion on report writing in chapter 9.