PETROCHEMICAL SUPPLY CHAIN’S SHARE IN EMISSION OF GREEN HOUSE GASES, CASE STUDY: SHAZAND PETROCHEMICAL COMPLEX

In this study petrochemical supply chain shares in global warming is studied by monitoring carbon foot print during manufacturing and distribution phase. For id entification and measurement of carbon emissions in petrochemical supply chain, at first step necessary d ta are collected. Then carbon footprint is calcu l ted in manufacturing process. So GHG is measured during fo ssil fuel use for chemical productions and electric ity production in exclusive power plant in production p hase. Also carbon emissions are calculated during chemical process (non-energy use of fossil fuels). The other activity that has an impact on GHG emissi ons is transportation. In this study Intergovernmental Pan el for Climate Change (IPCC) methodology was employ ed. For conducting this research Shazand petrochemical complex in Iran is selected as a case study. The calculations and monitoring GHG will help to greeni ng the petrochemical supply chain.The result shows GHG emissions in Shazad petrochemical complex supply ch ain is 6108960.35 tons per year. 6100434.9 tones CO2equ per year emit from manufacturing phase and 8525 .4 tones CO2equ per year emit from distribution phase. Based on a comparison with statistics from U nited Nation Statistics division reports contributi on of manufacturing phase of Shazand Petrochemical supply chain in global warming is about 0.020% and Based on a comparison with statistics from Iranian fuel Cons ervation Company and energy balance reports the contribution of distribution phase of Shazand Petro chemical supply chain in global warming is about 0. 004%.


INTRODUCTION
Carbon management is the main issue in greening the supply chain. A green supply chain is a new concept appearing in recent literatures.Green Supply Chain Management (GSCM) has emerged as a key approach for enterpriser seeking to make their businesses environmentally sustainable. The notion of GSCM implies the insertion of environmental criteria within the decision-making context of the traditional supply chain management (Emmett and Vivek, 2010). Companies using environmental supply chain management or GSCM are managing tehir supply chian by supplying materials and information systems requirements, designing new methods for performance evolution, applying enviornmnetal goals and supply chian strategies (Naini et al., 2010).
Carbon management could help to greening the supply chain. Integrating carbon footprint into supply chain management can help companies identify the source of carbon impacts in their supply chain. A number of companies in different industry sectors are beginning Science Publications AJES to recognize the carbon issue as one of the critical factors in supply chain management so started to accounting and monitoring their carbon footprint.
Two main reasons exist for companies to exert effort on carbon emission abatement: The first one is voluntary commitment, as a response to pressure from customer preferences, environmental groups and initiatives such as the carbon disclosure project. The second reason is to respond to emission regulations (Hoen et al., 2012). Having quantified the emissions, the important sources of emissions can be identified and areas of emission reductions and increasing efficiencies can be prioritized. This provides the opportunity for environmental efficiencies and cost reductions.
One of the industrial parts that cause CO 2 emissions is petrochemical industry. In 2008 about 1.2 billion tons of petrochemical products were produced. In Iran petrochemical production capacity is 2.5% of world petroleum production and 27% of Middle East petroleum production IHBS, 2010.
Chemical and petrochemical manufactures are the second largest energy-consuming manufacturing sector in the world and accounts for almost 5% of global GHG emissions. It is include direct (on-site) CO 2 emissions from fossil fuel combustion, indirect emissions from electricity consumed during production and release of non-CO 2 gases from various industrial processes (Baumert et al., 2005).
In the context of greenhouse gas emissions, so far most attention has been paid to CO 2 emissions from the combustion of fossil fuels. But a significant fraction of fossil fuels is used for non energy applications. Nonenergy use is here defined as the consumption of fossil feedstocks for the manufacture of synthetic organic materials and chemical products (Patel et al., 2000;2003).
Most of the basic petrochemical productions depend on crude oil for energy and raw material supply. Basic petrochemical productions include two steps: feedstock production (from primary energy sources to feedstocks) and petrochemical productions. In feedstock production, primary energy sources (i.e., crude oil, natural gas, coal and biomass) are extracted and then converted into feedstocks (e.g., naphtha and methanol). In this step, it is possible for some processes to coproduce electricity and fuels. When applicable, primary energy sources can also be used as fuels here. In petrochemical productions, feedstocks are converted into basic petrochemicals, such as ethylene and aromatics, which are then separated from each other. In this step, it is possible for some processes to coproduce fuels (Ren, 2009). These two steps lead to emission of considerable amounts of GHG gases. Figure 1 shows the two Process Steps in Basic Petrochemicals Routes.
The other source of CO 2 emission in petrochemical supply chain is distribution and transportation of raw material and products.
Literature reviews show many research have been done in the field of green supply chain. Zsidisin and Hendrick (1998) by investigating purchasing managers in Germany, the UK and the USA identified four green supply management factors, namely hazardous materials, Investment Recovery (IR), product design and supply chain relationships and determined the existence of these four factors with an exploratory factor analysis. Handfield et al. (2002) developed a decision model to measure environmental practice of suppliers using a multi attribute utility theory approach. Rao and Holt (2005) studied the relationship between the implementation of green supply chains and the economic performance and competitiveness of a sample of Asian firms. Zhu and Sarkis (2004) and Zhu et al. (2007) evaluated the effectiveness of green supply chain management in Chinese manufacturing enterprises and the automobile industry, respectively. De Brito et al. (2008) conduct a survey of stakeholder to explore how green initiatives impact the fashion retail supply chain organization and its performance. They found that green issues in the fashion industry were particularly sensitive due to intense competition, high resource use and concerns about labor practices. Sheu et al. (2005) developed a linear multi-objective programming model that optimized the operations of both forward and reverse logistics in a given green supply chain. These models and frameworks included and defined a variety of characteristics, attributes and scales for green supply chain management practices implementation. Hugo and Pistikopoulos (2005) addressed the inclusion of Life Cycle Assessment (LCA) criteria as part of the strategic investment decisions. Kainumaa and Tawarab (2006) proposed the multiple attribute utility theory method for assessing a supply chain including reuse and recycling throughout the life cycle of products and services. Foerstl et al. (2010) and Pullman et al. (2009) integrate the supplier perspective to sustainable supply chain management. Gonzalez-Benito and Gonzalez-Benito (2006); Locke and Romis (2007); Collins et al. (2007) and  studied green supply chain management downstream side, their results show that customers increasingly want to understand the conditions under which products have been produced and desire products that have been produced in an environmentally sustainable way. Testa and Iraldo (2010) investigated different factors that could have effect on implementation of green supply chain in 4000 company.  (2011) presents a web service collaborative framework for measuring, monitoring and integrating environmental and carbon footprint data in construction supply chains. Tjian et al. (2010) discusses a new application of graphical technique based on pinch analysis for company-level visualization and analysis of carbon footprint improvement. The technique is based on the decomposition of total carbon footprint into material-and energy-based components, or alternatively, into internal and external components. Larsen et al. (2012) discuss how to reduce energy/climate footprint Supply chain management through the use of Environmentally Extended Input-Output Analysis (EEIOA) and Life Cycle Assessment (LCA). Results show that for most sectors a majority of the energy/environmental loads are located in the upstream supply chain, both nationally and abroad.
Despite these researches of modeling carbon footprint across supply chains, there isn't any attempt on monitoring carbon footprint across petrochemical supply chain. So in this study petrochemical supply chain shares in global warming and its role in greening supply chain is studied by monitoring carbon footprint during manufacturing and distribution phase.

MATERIALS AND METHODS
As mentioned above the aim of this study is calculation of GHG in petrochemical supply chain by monitoring carbon footprint in manufacturing chemical products and distribution of these products. Necessary data gathered by doing interviews, using internal reports, published data source and company records. Although suppliers and consumers can influence the carbon footprint, they are not included in this study due to complications the supply phase and due to limited extent to which final consumers can effect carbon emissions occurring in the supply chain.

Introduction to Shazand Petrochemical Company
Shazand petrochemical company as an affiliation of National Petrochemical Company of Iran-Ministry of Oil was founded in 1987. This company has established as a petrochemical Complex for the production of different Petrochemical products such as polyethylene, polypropylene, butadiene, poly-butadiene, acetic acid, Science Publications AJES vinyl acetate, oxide ethylene and ethylene glycol, 2ethyl hexanol and butanols, ethanol amines from Naphtha feedstock (totally 17 presses unit). Table 1 shows Input and output of different process in Shazand petrochemical complex. This tabel shows the amout af input and producs of each unit.
Shazand petrochemical complex is located in Iran, Markazi province, near to city of Shazand, next to the 7th Refinery. It is constructed on the land with surface area of 523 hectares (Fig. 2).

Manufacturing Phase
In a manufacturing phase in petrochemical supply chain green house gases emit from fossil fuel consumption during chemical production and electricity production. Also GHG emit from Non-energy use of fossil fuels. Calculation based methods typically entail the collection of (a) activity data, in the form of the quantity of fuel consumed for combustion purposes and(b) emission factor data, in the form of information on the characteristics of the fuel combusted and the efficiency of the oxidation process (IPCC, 2006).
In order to calculate GHG emissions due to fossil fuels combustion in 17 processes the following equations is applied base on GHG protocol methodology: Where: E = Mass emissions of CO 2 (short tons or metric tons) A f,v = Volume of fuel consumed (m 3 ) F ox = Oxidation factor to account for fraction of carbon in fuel that remains as soot or ash F c,v = Carbon content of fuel on a volume basis (metric tons C/m 3 )  In Shazand petrochemical complex GHG emissions also release during production processes in where hydrocarbon feedstock are used as input. The general methodology employed to estimate this part of emissions associated with each industrial process involves the product of activity level data, e.g., amount of material produced or consumed and an associated emission factor per unit of consumption/production according to the following method (IPCC, 2006):

AJES
Where: TOTAL ij = Process emission (tonnes) of gas i fromIndustrial sector j A j = Amount of activity or production of processMaterial in industrial sector j (tonnes/yr) EF ij = Emission factor associated with gas i per unit of Activity in industrial sector j (tonne/tonne)

Distribution Phase
In a supply chain distribution phase consist of distribution of row material and distribution of product to customers. In Shazand petrochemical complex main row material is naphtha and naphtha is transferred by pipeline. At the downstream side product transferred to the domestic and international markets. Due to the dispersion and diversity of the roots of domestic market transport data collection in this p was not possible.
To deliver products to international markets, at fist products transfer to ports at the north and south of Iran (depending to the destination).
For exporting products annually 2600 truck travel to Bandarabas port, 4097 truck travel to Bandare-emam Khomeini port and 7079 truck travel to northern ports. Total loading weight is 145000000 kg.
IPCC methodology is employed to calculate transport emissions: Emissions = Σα Fuela * EFa Emission = Emissions of GHG (kg) Fuela = Fuel sold (TJ) EFa = Emission factor (kg/TJ). a = Type of fuel (e.g., petrol, diesel, natural gas, LPG) Table 2 shows the result of calculation of GHG emissions in 17 process units and power plant due to fossil fuels consumption. As can be seen total GHG emission in Shazanad petrochemical complex in this part of manufacturing phase of supply chain is 625702.9 tons per year.

RESULTS
According the result of Table 3 5474732.05 tons per year GHG emitted during non-energy use of fossil fuels. Totally 6100434.95 tones of GHG per year emitted during production phase in Shazand petrochemical supply chain. Table 4 show the result of GHG emission in distribution phase of supply chain. Total GHG emissions in this phase 8525.4 tone co 2 equ per year.
As can be seen in Table 5 total GHG emissions in Shazad petrochemical complex supply chain is 6108960.35 tones CO 2 equ per year. 6100434.95 tones CO 2 equ per year emit from manufacturing phase and 8524.4 tones CO 2 equ per year emit from distribution phase.

DISCUSSION
The main aim of is this study has been to show the share of petrochemical industry in global warming. To find out the Shazand petrochemical complex share in global warming, results of calculation compared to intenational statistics. Table 6 shows the contribution of manufacturing phase of Shazand Petrochemical supply chain in global warming Based on a comparison with statistics from United Nation Statistics division reports and Table 7 shows the contribution of distribution phase of Shazand Petrochemical supply chain in global warming Based on a comparison with statistics from Iranian fuel conservation company and energy balance reports. This study is early attempt to monitor carbon emissions across chemical process and discusses carbon footprint in petrochemical industry. This study is provide some evidence on how to measure supply chain (manufacturing and distribution phase) carbon footprint. This study can be extended by measuring carbon footprint in entire supply chain of petrochemical company.

CONCLUSION
Results show total GHG emissions in Shazad petrochemical complex supply chain is 6108960.35 tones CO 2 equ per year.Based on a comparison with statistics share of manufacturing phase of Shazand Petrochemical supply chain in global warming is about 0.020% and contribution of distribution phase of Shazand Petrochemical supply chain in global warming is about 0.004%.
This study is early attempt to monitor carbon emissions across petrochemical process and discusses carbon footprint in petrochemical industry. This study is provide some evidence on how to measure supply chain (manufacturing and distribution phase) carbon footprint. This study can be extended by measuring carbon footprint in entire supply chain of petrochemical company.