Evaluation And Industrial Application Of Cracking Feedstock In Tianjin Ethylene Plant

Ethylene is the basic raw material for the production of three major kinds of synthetic materials and organic chemicals. However, shortage of domestic ethylene resources has become the most critical factor which constrains the development of ethylene industry in China. The choice and optimization of cracking feedstock are significant for reducing production cost of ethylene and improving the competition of domestic petrochemical products,which also is an imminent issue to be solved for Chinese ethylene industry.Considering the status quo of Tianjin Ethylene Plant about ten year operation, such as shortage of resources, low self-fed rate of feedstock, less room of choice, small margin of optimization and less operation benefit, this thesis has made thorough analysis on the issue of how to exert the integrated advantage of existing Tianjin refinery and chemical plant and achieve 100% self-fed rate of cracking feedstock. Through simulating the operation conditions of SRT-IV furnace and CBL-IV furnace, the properties of the raw materials and cracking yields were evaluated for hydro-cracking residue, diesel and LPG, naphtha from coke gasoline and diesel hydrogenation unit as well as raffinate, LPG, extraction and pentane oil from reforming unit. The boiling range of different feedstock, sulfur and hydrogen content, PONA, BMCI and K value were measured. The yields of ethylene and propylene were abtained at different cracking temperature, W/O ratio and outlet pressure. Proper process parameters and processing scheme have been worked out for each kind of feedstock, which provided positive reference for industrial production.Industrial application test was conducted for the first time by using the prepared feedstock. The results showed that the yields of both ethylene and diolefin were improved, ethylene production capacity was increased and 100% self-fed rate of feedstock was achieved in Tianjin Ethylene Plant through optimization of both process and machinery. The trials and practical application have accumulated us great experience for the upcoming Tianjin 1 Million MT/Y Ethylene Project.