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Air Products Proposed Acetylene Production Facility Major Hazard Installation Regulations Risk Assessment Report v2.0
Ref: 0220780
June 2014
www.erm.com
MHI 0012
ENVIRONMENTAL RESOURCES MANAGEMENT AIR PRODUCTS ACETYLENE PLANT MHI
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EXECUTIVE SUMMARY
Air Products Limited identified the proposed Acetylene Production facility
they wish to erect at Daleside, south of Johannesburg in the Gauteng Province
(hereafter referred to as the facility or the site) as having the potential to
affect the health and safety of employees as well as members of the public in
the event of a major incident. Hence there is a need to manage the risks and
ensure compliance with the Major Hazard Installation Regulations which
were promulgated under the Occupational Health and Safety Act No. 85 of
1993 in 1998 and revised in 2001 (1) . The current Major Hazard Installations
Regulations are attached in Annex B.
The proposed Acetylene Gas production facility will be situated in the
Midvaal Local Municipality, which falls within the jurisdiction of the
Sedibeng District Municipality in Gauteng. The proposed development site is
located on Stand 88 and 89 of Valley Settlements Agricultural Holdings at
Daleside. The site is approximately 7 km to the north of Meyerton and
situated between the M61 (Springbok Road) and the R 59. The site can be
accessed via Tilliet Road, just off the M61 (refer to Figure 1.1). The total area of
the site is 4 ha.
The site is largely undeveloped and is currently zoned for industrial purposes
and is bound by Tilliet Road to the east, a manufacturing facility to the north,
vacant and undeveloped land to the west and another manufacturing facility
to the south.
In this Acetylene manufacturing plant, acetylene is produced by reaction of
calcium carbide with water. The acetylene gas is the cleaned, compressed and
filled into cylinders. These cylinders are filled with acetone and packing rings
and the acetylene is dissolved in this liquid.
The Air Products Acetylene Production facility will be developed in a phased
approach, with 2 defined phases:
Phase 1:
The first phase of the project will encompass 1 acetylene generator vessel,
6 compressors and 2 filling halls with a total projected production capacity
of 14 400 m3/day
Phase 2:
The second phase of the project will involve the duplication of the Phase 1
section of the project and will thus involve the addition of 1 acetylene
generator vessel 6 compressors and 2 filling halls which will raise the total
projected production capacity of the site to 28 800 m3/day.
(1) Regulation R.692 Occupational Health and Safety Act (85/1993): Major Hazard Installation Regulations.
ENVIRONMENTAL RESOURCES MANAGEMENT AIR PRODUCTS ACETYLENE PLANT MHI
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Major transport routes in close proximity to the site:
The R59 Sybrand Van Niekerk Freeway is located approximately 700
m to the west of the site
There are no other registered Major Hazard Installations in the area of the
proposed Air Products site.
The aim of the project was to undertake a Quantified Major Hazard
Installation (MHI) Risk Assessment of the proposed Air Products site, with the
objective to assess the risk to people off site via the Fatality approach.
FATALITY - LOCATION SPECIFIC INDIVIDUAL RISK
Figure 1 represents the location specific individual risks (LSIR) for
hypothetical persons located indoors. It can be seen that none of the risk
contours extend beyond the proposed Air Products Acetylene Plant site
boundaries.
Figure 2 represents the location specific individual risks (LSIR) for persons
located outdoors. Once again it can be seen that none of the risk contours
extend beyond the proposed Air Products Acetylene Plant site boundaries.
The main reason for the differences in risk levels for those indoors as opposed
to those outdoors is primarily due to the fact that the worst case scenarios of
explosions involving loss of containment of acetylene gas cause high fatalities
to individuals located indoors as opposed to those outdoors due to building
collapses.
Figure 1 Location Specific Individual Risks of Fatality Contours for Persons Located Indoors
Figure 2 Location Specific Individual Risks of Fatality Contours for Persons Located Outdoors
ENVIRONMENTAL RESOURCES MANAGEMENT AIR PRODUCTS ACETYLENE PLANT MHI REPORT V2.0
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Societal Risk
Societal Risk for the proposed Air Products Acetylene plant was calculated but the risk levels were so low that they did not appear on the FN Curve graph.
CONSEQUENCES
From a consequence perspective there are potential off-site effects from either
Acetone pool fires or Acetylene explosions, both resulting from a loss of
containment.
The following plot, Figure 3 shows the extent of an Acetone pool fire and it can
be seen that the 6.3 kW/m2 radiation level does not extend beyond the site
boundaries
Figure 4 shows that the worst case consequences, which are those posed by
loss of containment of Acetylene Gas, do however result in overpressure
generated by explosions extending some 82 metres beyond the proposed Air
Products Acetylene Plant site boundaries to the West, 70 metres beyond the
site boundaries to the North, 28 metres beyond the site boundaries to the East
and only a few metres beyond the site boundaries to the South for the final
double installation.
Figure 3 Area Enveloped by the Largest Acetone Pool Fire (D5)
37.5 kW/m2
12.5 kW/m2
6.3 kW/m2
Figure 4 Areas Enveloped by the Largest Explosion Scenario Phase 2 Double Generator Rupture
0.05 Bar
0.2 Bar
0.35 Bar
ENVIRONMENTAL RESOURCES MANAGEMENT AIR PRODUCTS ACETYLENE PLANT MHI REPORT V2.0
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CONCLUSIONS
Due to potential incidents resulting in consequences extending beyond the proposed Air Products Acetylene Plant site boundaries from potential Acetlyene explosions, the site should be considered as a Major Hazard Installation in line with the current legislation. Environmental Resources Management Southern Africa (Pty) Ltd would declare the Air Products proposed Acetylene Plant located at Tilliet Road, Daleside near Meyerton in the Gauteng Province as a Major Hazard Installation (MHI) as outlined in the current legislation. As a result of being declared a MHI, the Requirements of the MHI Regulations must be followed completely to ensure the proposed Air Products Acetylene Plant is legally compliant. Copies of this risk assessment must be submitted to the Local Provincial Director of the Department of Labour, the Chief Inspector of the Department of Labour Head Office in Pretoria and the Local Authorities.
CONTENTS
1 INTRODUCTION 1
1.1 GENERAL INTRODUCTION 1
1.2 REQUIREMENTS OF THE MHI REGULATIONS 6
2 RISK ASSESSMENT & MANAGEMENT METHODOLOGY 7
2.1 DEFINITIONS 7
2.2 PROCESS OF RISK MANAGEMENT 7
2.3 HAZARD IDENTIFICATION 9
2.4 CONSEQUENCE ANALYSIS 9
2.4.1 Harm Criteria for Consequence Analysis 9
2.4.2 Consequence Modelling 9
2.5 FREQUENCY OF MAJOR ACCIDENT HAZARDS 11
2.6 RISK CALCULATION 12
2.7 RISK ASSESSMENT 13
3 POTENTIAL MAJOR HAZARDS 14
3.1 INTRODUCTION 14
3.2 HYDROCARBON POOL FIRES 14
3.3 FLASH FIRES 15
3.4 VAPOUR CLOUD EXPLOSIONS 15
3.5 ASPHYXIANT 16
4 ENVIRONMENTAL SITE SETTINGS 17
4.1 SITE LOCATION 17
4.2 METEOROLOGY 19
4.3 REQUIREMENTS OF OTHER ENVIRONMENTAL LEGISLATION 20
5 DESCRIPTION OF FACILITIES 21
5.1 DESCRIPTION OF SITE OPERATIONS 21
5.1.1 Bulk Storage Facilities 29
5.2 DESCRIPTION OF PRODUCTS STORED ON SITE 29
5.3 POPULATION DATA 30
6 APPROACH TO THE ASSESSMENT 31
6.1 TERMINOLOGY 31
6.2 HARM CRITERIA 31
6.2.1 Thermal Radiation 31
6.2.2 Explosion Overpressure 32
6.2.3 Flash Fire Flammability Limit 33
6.2.4 Fatality Probabilities 33
6.3 ASSESSMENT CRITERIA 37
6.3.1 Risk Tolerability Criteria for fatality approach 38
6.3.2 Individual Risk of Fatality Criteria 39
6.3.3 Societal Risk Criteria 40
6.4 METHODOLOGY 41
7 RISK ASSESSMENT 43
7.1 HAZARD IDENTIFICATION 43
7.1.1 Failure Scenarios 43
7.2 ESTIMATION OF CONSEQUENCES 47
7.2.1 Pool Fires 47
7.2.2 Asphyxiant Nitrogen Dispersion 50
7.2.3 Acetylene Explosion Modelling 50
7.3 ESTIMATION OF INCIDENTS 55
7.3.1 Frequency of Storage Vessels, Pipework and Cylinder Failures and also Off
Loading Road Tankers 55
7.4 RISK CALCULATION 58
7.4.1 Location Specific Individual Risk for the site Fatality Assessment 58
7.4.2 Societal Risk 61
7.5 ESCALATION EFFECTS 62
8 NEIGHBOURING MAJOR HAZARDOUS INSTALLATIONS 63
9 EMERGENCY PLANNING 64
9.1 MAJOR HAZARD INSTALLATION REGULATIONS, SECTION 6 - ON SITE EMERGENCY
PLAN 64
10 CONCLUSIONS 66
10.1 CONCLUSIONS 66
ANNEX A ERM CERTIFICATES OF ACCREDITATION
ANNEX B MHI REGULATIONS
ANNEX C MATERIAL SAFETY SHEETS
ANNEX D CONSEQUENCE AND FREQUENCY ANALYSIS
ANNEX E EMERGENCY RESPONSE PLAN STILL TO BE COMPILED BY AIR PRODUCTS
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