Proposal title: Biogas robust processing with combined catalytic reformer and trap Acronym: BioRobur Initiative: Fuel Cells and Hydrogen Joint Undertaking (FCH-JU) Funding scheme: Collaborative project Call identifier: SP1-JTI-FCH.2 Topic: SP1-JTI-FCH.2012.2.3: Biogas reforming Start date of project: 1 May 2013 Duration: 36 months Deliverable: D7.3 Final safety analyses of the BioRobur fuel processor accomplished Organisation name of lead contractor for this deliverable: HySyTech S.r.l. Author: G.Piras (HST); L. Marchisio (HST) 1
1 Index 1 INDEX... 2 INTRODUCTION... 3 1. THE HAZOP ANALYSIS... 3 1.1 Severity and Likelihood definition... 3 2 LIST NODES... 5 3 HAZOP WORKSHEET... 6 4 SAFETY INTEGRITY LEVELS (SIL) ANALYSIS... 10 4.1 The Risk Graph Method... 10 4.2 SIL Worksheet... 12 5 CONCLUSIONS... 15 ANNEX 1 - BIOROBUR PLANT PROCESS AND INSTRUMENTATION DIAGRAM... 16 ANNEX 2 - BIOROBUR PLANT MASS & ENERGY BALANCE... 17 2
Introduction This document summarizes the results of the task 7.3 Final safety analysis of the BioRobur fuel processor accomplished. The purpose of the report is to provide a reliability, availability and safety analysis of the system. 1. The HAZOP analysis The HAZOP procedure is widely recognized and accepted in the process industries, and is well documented and detailed in many publications. A HAZOP is a systematic analysis that takes into account each element of the process to identify ways in which any deviations from the normal process conditions and its consequences could take place and, on the basis of the latter, to recommend any corrective actions which are considered necessary. The P&ID of the Plant is divided into subsections or nodes. Each subsection contains one or more process equipment where the possible deviations are examined. Basically, the deviations are analyzed by means of a system of Guide Words and Standard Deviations. The possible consequences are assigned a magnitude ("Severity") and probability ("Likelihood"). The combination of the possible levels of magnitude and probability produces the risk matrix. If necessary, the level of risk is reduced through certain corrective actions. In order to realize the HAZOP analysis is used the software PHA-Pro. This software helps with the implementation of risk policies and programs based on company or industry standards and guidelines including: Process Safety Management (PSM) programs under OSHA 1910.119; Seveso II Directive; Control of Major Accident Hazards (COMAH); IEC 61511 (the specific derivation of IEC 61508 for the process industry) and ANSI/ISA S84.00.01. 1.1 Severity and Likelihood definition The magnitude (or severity) of an event is defined in table 1. Low High Severity 1 The highest between No health impacts and Minimal economic impact (1% CAPEX) 2 The highest between Minor health impacts and short maintenance time (48 hours - 3% CAPEX) 3 The highest between Severe Injury (permanent invalidity like eye s lost or similar) and long maintenance time (15 days - 10% CAPEX) 4 The highest between Death of almost one person and economic impact over 25% CAPEX Table 1: Definition of severity 3
The probability that an event will happen is defined with the likelihood. In table 2 four different categories of the probability are reported. Low High Likelihood 1 Not expected to occur during facility life (0/15 years) 2 Could occur once during facility life (1/15 years) 3 Could occur several times during facility life (2-14/15 years) 4 Could occur on an annual basis (or more often) Table 2: Definition of likelihood The combination of severity and likelihood produces is illustrated as a risk matrix, which is shown in figure 1. Figure 1: the risk matrix The residual risks are divided into four categories: From 1 to 4 the acceptable risks and no risk control measures are needed; The value 6 indicates the acceptable risks with a control; The value 8 indicates the not desirable risks; in this case the risk control measures have to be introduced within a specified time period; From 9 to 16 the unacceptable risks are identified and the risk control measures have to be introduced. The level of risk can be reduced through corrective actions. 4
2 List Nodes The plant is divided into seven nodes. Each of this is characterized by design conditions, list of equipment into the node, session of analysis and date of the review. The Nodes are reported in table 3. Node Type Design Conditions/Parameters Drawings / References Equipment ID Comment Session Revision # Revision Date 1. Air feeding Centrifugal Compressor Heat Exchanger Line Flow: 72 kg/h; Temp: 20 C; Pressure: 1 barg. 2. Biogas feeding Control Valve Centrifugal Flow: 43,3 kg/h; Temp: 19 C; Pressure: 5 barg. Compressor Heat Exchanger Instrumentation & Control 3. Water feeding Centrifugal Pump Flow: 34.4 kg/h; Temp: 10 C; Heat Exchanger Pressure: 9 barg. Relief Valve Instrumentation & Control 4. Ejector Ejector Pin: 10 bara; Pout: 1,55 bara Heat Exchanger Annex 2_M&EB K-200 E-200 T-200 Annex 1_BRB.01.13.P&ID0308.REV12 Annex 2_M&EB Annex 1_BRB.01.13.P&ID0308.REV12 Annex 2_M&EB P-100; E-100; Annex 1_BRB.01.13.P&ID0308.REV12 E-101; E-102; H-100. Annex 2_M&EB J-700; H-700; Annex 1_BRB.01.13.P&ID0308.REV12 E-700. P&ID only for construction P&ID only for construction P&ID only for construction P&ID only for construction 2. 15/04/2014 02 25/01/2016 2. 15/04/2014 02 25/01/2016 2. 15/04/2014 02 25/01/2016 2. 15/04/2014 02 25/01/2016 5. ATReactor Reactor Flow: 149,8 kg/h; Temp: 730 C; Relief Valve Pressure: 1,5 barg. 6. Soot-Trap Reactor Flow: 149,8 kg/h; Temp: 730 C; Relief Valve Pressure: 0,5 barg. Annex 2_M&EB R-700; P&ID only for construction Annex 1_BRB.01.13.P&ID0308.REV12 Annex 2_M&EB S-700 P&ID only for construction Annex 1_BRB.01.13.P&ID0308.REV12 2. 15/04/2014 02 25/01/2016 2. 15/04/2014 02 25/01/2016 7. Flare Flare System HF 2. 15/04/2014 02 25/01/2016 Table 3: List of Nodes 5
3 HAZOP Worksheet For each node the possible deviations, their causes and consequences are identified. The risk ranking (RR) of an event is estimated by definition of likelihood (L) and severity (S). If necessary, a safeguard and possible recommendations are introduced and the risk ranking is recalculated after the risk reduction. The results of HAZOP analysis are reported into table 3 6
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Table 4: HAZOP analysis. 9
4 Safety Integrity Levels (SIL) analysis Safety Integrity Levels (SIL) is a measurement of performances required for a safety instrumented function (SIF). In the functional safety standards, based on the IEC 61508 standard, four SIL are defined. SIL 4 is the most dependable and SIL 1 the seal, meanwhile a indicates has no special safety requirements. A typical SIL study consists of the following steps: 1. Identify the SIF using previous HAZOP studies; 2. Assign target SIL to the SIF using the Risk Matrix 4.1 The Risk Graph Method The Risk Graph method is based on the principle that the risk is proportional to the consequences and the frequencies associated with a dangerous event. In this study, only consequences (C) regarding people and operators is considered. The frequency results from the composition of the 3 following parameters: The frequency (F) at which people and operators are present in the place of possible danger and the potential exposure time to the event. The possibility (P) that the present people avoid the event consequences. The possibility (W) that the event occurs in the absence of the safety function in question (while still considering the possible presence of other safety functions). Figure 2 shows the SIL determination with the Risk Graph Method: Figure 2: The Risk Matrix 10
Figure 3 summarizes the parameters which interfere with assigning the SIL in the risk graph method. Figure 3: Parameter definition - Risk Graph Method 11
4.2 SIL Worksheet 12
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Table 5: SIL analysis. 14
5 Conclusions The HAZOP SIL analysis shows the reliability and safety of the control system. All the recommendations are identified before the risks reduction has been implemented. The Plant presents only the low risks or the residual risks that will be managed by using appropriate procedures. The manage recommendations are summarized in the table 6. Table 6: Manage recommendations. The SIL analysis confirms that no special safety requirements are needed. In any case the partners decided to reuse the Safety PLC Unit present into the Delta-V system to manage the interlocks and the control loops related to the Emergency Shut Down (ESD) as described in the Deliverable 5.3. 15
Annex 1 - Biorobur Plant Process and Instrumentation Diagram 16
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D7.3 Safety analyses Annex 2 - Biorobur Plant Mass & Energy Balance 18 27/01/2016
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