HAZOP Study for Kiln Start-up Process of a Cement Production Plant G. Maragos, C. Kouris, Y. Pilihos, S. Zacharis, C. Malami, P.D. Petrolekas

CONTENTS HAZOP Cement kiln start-up process Why? Study process Results Conclusions and Discussion Date

HAZOP HAZard and OPerability analysis 1. Understand design 2. applies systematically “guide-words + process parameters” to identify all potential deviations from the design intent… requires a multidisciplinary team to brainstorm deviations and discuss hazards 1. Understand design 2. Examine potential deviations 3. Discuss hazards and safeguards Parameter Guideword HAZOP WORKSHEETS Deviation Causes Consequences Safeguards Recommendations High temperature Contaminant Too long …. ….. Temperature Pressure Level Flow Composition Control Containment Duration - etc No More Less As well as Part of Reverse Other than Early/Late … Date

Cement kiln Start-up process Raw meal Pre-heater Solid fuels Scope Rotary Kiln Clinker Cement Mill Cement Liquid Fuel Cooler The start-up is a very important operation which involves various steps, different fuels and variable operating conditions Date

Why HAZOP? Significant aspects related to safety and loss prevention are involved during kiln start-up Some events and deviations during start-up led the management of the company to look for a hazard identification method to assist risk management and decision making for potential improvements HAZOP is a practical and effective methodology for identifying hazards and operability problems, and furthermore, it is applied via a team approach which facilitates discussion and brainstorming. In a complex situation HAZOP method can identify critical items and capture most of deviations Transfer of best practice from petrochemical industry to cement industry Hazop new to the plant and company, not common in the industry Complex design with redundancies No clear “start up” procedure and management decision tree Date

Study Process Multidisciplinary team in a series of sessions held on site Scope Process: kiln start-up from the initial ignition phase up to the phase of sustained combustion with solid fuels. Equipment: Preheating fuel facilities, the solid fuels storage, transfer, feeding and burning systems Typical HAZOP guidewords and other deviations generated by the team relevant to the nature of the process (e.g. time/step related) The guidewords were used to prompt the team to brainstorm all potential meaningful deviations for each section of the process, based on the process flow diagrams Study of the start-up sequence was performed, using time/duration related guidewords and a purpose built operational logic diagram The team involved representatives from production, process, maintenance and safety department +experts+consultant Date

Study Process For each deviation possible causes, potential consequences and the safeguards in place were identified and recommendations were made. All the above was recorded in typical HAZOP worksheets A post-HAZOP meeting was conducted, chaired by the plant manager, and with the participation of all department managers Recommendations were grouped and ranked An action plan was formulated and implemented This was evaluated considering investment cost, operational cost, and manpower Date

Results The HAZOP team recorded a total of 112 items and proposed recommendations related to installations, equipment, process and procedures improvements which were grouped into ten categories on the basis of the overall objective of the proposed action All recommendations were ranked using a simple risk matrix and categorized according to the required resources A decision making tool was used to prioritize the implementation timing of all recommendations and to formulate the action plan The aforementioned recommendations are plotted in figure 3 where the risk level categories are plotted against the value of required resources categories. For example recommendations No 1 and 6 are placed on cell AI which means that they regard a high risk item and are highly feasible to implement. These recommendations were the first ones to implement. Date

Conclusions-Discussion Based on the above a robust action plan was formulated which obtained optimum ‘buy-in’ by the plant responsible parties and the company management (accomplished by >50% in two years) Main immediate benefits Formal report Precise & concrete action / focus on solution Very useful for current and future new projects or modifications in the plant HAZOP study process has proved to be also very effective in terms of safety culture as: it proves the important role of line management in safety and familiarizes managers with risk identification and controls it builds strong cooperative spirit on the basis of safety intra departments it proves that existence and observance of clear rules for all operations is a crucial preventive control for safety Date

Conclusions-Discussion The methodology was applied for the first time in the organization and proved to be effective in capturing high risk items in complex systems. Corporate review of this case study concluded that the methodology is of significant technical value for the cement industry as well as very useful for the enhancement of safety culture. Finally, this project became a pilot for similar studies in other plants of the organization worldwide, both for new as for existing installations. Date