(62d) Direct Inter-Processes Integration for Energy Efficiency Optimization and GHG Emissions Reduction in Oil Refining

Industrial communities are invited to conserve energy resources not only to give a chance to pre-developing countries and future generations to grow and prosper but also to preserve the environment. Energy efficiency optimization is a quick answer to energy-based GHG emissions reduction. It enables us get two targets with one arrow. From GHG emissions outlook, energy efficiency optimization applications in industry can help us get out tens of thousands of cars abstractly from our roads and practically from our air every year.

Since the emanation of the pinch technology and its evolution to pinch analysis technique and the adaptation of MINLP techniques for process synthesis of mega complexes, the direct inter-processes integration has been considered impractical. For inter-processes “energy” integration many arguments against the direct inter-processes integration are certainly valid.

Plants are normally have different start up and shut down times; the processes can work at partial loads; the processes can have seasonal changes in its operating conditions; utility systems, heaters, coolers and HEN capital will not be reduced and may be even increased due to differences in processes/plants schedule and operation philosophy; the disturbance in one process plant can propagate to another one if they are mass and/or energy integrated; the distance-time/velocity lags in process will affect the controllability of integrated processes; the geographical distances among processes will cost us energy in pumping or compression and capital in piping; plants’ safety might be impacted due to the travel of a fluid from one “hazardous” area classification to another; the fear of leakage and so on. Therefore, direct inter-processes integration while is beneficial to energy conservation and the GHG emissions reduction as will be demonstrated in the paper, is still to date almost ignored in the industrial community. Due to those concerns most of the current methods for inter-process integration are indirect and conducted using buffer systems. Buffer systems are either steam system, boiler feed water, hot water system, hot oil system or sometimes combinations of them. The industrial community does agree that, direct integration approach in inter-process integration (between several plants) is efficient and can render more saving in energy consumption and energy-based greenhouse gas emissions beyond the maximum possible using intra-integration only. In this paper, we demonstrated that huge potential for energy consumption and GHG emissions reduction in oil refining can be attained through smart integration among processes. The paper has two folds of results. First, while we agree with the validity of some of the arguments against the direct inter-processes/plants integration we believe and will demonstrate that we still have room for improvement in energy efficiency enhancement and energy-based GHG emissions reduction. We will identify at the targeting phase best possible scenarios for inter-processes integration and the most cost effective solution(s) now and in the future via “Plants’ Smart Matching”, without the discouraging solutions which require many inter-connections among plants as sometime reported in literature. Second, the intuition that mandates sophisticated inter-plants integration to achieve good benefits, the more you integrate among the processes (new mega sites consists of integrated refining, chemical, petrochemical and plastics plants), the better you save in energy consumption is not always true. The paper presents those two results and demonstrates the benefit that could be obtained from the direct inter-processes integration through two industrial case studies.