DEVELOPMENT OF METHODOLOGY FOR ENVIRONMENTAL AUDIT OF INDUSTRIES IN INDIAN CONTEXT

Abstract

Tho present rononrch is nddronnod to tho development of n broad baaed framework and methodology ror Environmental Audit in current Indian context, and validation of the developed methodology through a case study in Fertiliser Industry. Accordingly, Environmental Audit in this research has taken cognizance of the following : Environmental Audit undertaken in developed countries comprises two components, viz. assessment and verification of environmental systems Endeavour on environmental protection thus far in India has relied on strict regulatory measures with little regard to economic productivity Preventive and reactive approaches do not complement each other in the current practices of environmental management in India as reflected in legislative, administrative and policy formulations. Thus the Environmental Audit in the context of free market economy in Iidia may be defined as a pragmatic management tool comprising systematic, documented, periodic and objective evaluation of production and environment management systems to ensure resource conserving modes of manufacturing, and costeffective environmental protection as a consequence of improved material, water and energy effectivity for enhanced economic productivity and acceptable environmental quality and health of employees and genert.l public. The aoove definition recognises the potential for resource conservation in manufacturing processes with concomitant reduction in the cost of production and pollution control, and comprises comparative analysis of the process technology in use vis-a-vis the state-of-the-art technology available in that sector with concomitant implications on raw materials and energy use effectivity, Mi also tho quantum and characteristics of residues. The definition interalia considers shifts towards cleaner production technologies through comparative analysis of various competing alternatives in industrial sectors based on technological, economic, societal and environmental considerations as a part of Environmental Audit. (i) The components considered while formulating a broad based framework and methodology for Environmental Audit are : Production technology/ Process of manufacturing Material Usage - Energy Usage Water Usage Air, Wastewater and Noise Emissions Solid and Hazardous Waste Emissions Health and Safety Legal and Social Obligations The prime purpose of Process Audit is to check whether an industry has adopted a strategy of pollution prevention based on cleaner technologies of production that conserve resources, and recycle raw materials, energy and water; reuse wastes as secondary raw materials; and recover byproducts for the conservation of resources. Process audit provides the manufacturing plants with a measured analysis of their raw material consumption, and measures for improvements in resource conservation. Elements of Process Audit are : Waste minimisation at source (process changes, fuel substitution, raw material changes) End-of-the-pipe (EOP) treatment methods designed to recover raw materials, energy, water and by-products Utilisation of wastes as secondary raw materials Elements of Material Audit are Raw material consumption vis-a-vis stoichiometric requirements Substance flow measurements Performance evaluation of process equipments Material balance analysis (ii) Elements of Energy Audit are : Energy Generation/ procurement and Distribution Energy consumption vis-a-vis stoichiometric requirements Energy flow measurements Performance evaluation of energy consuming equipments Energy balance analysis Elements of Water Audit are : Raw water source Performance evaluation of raw water treatment units Water consumption vis-a-vis stoichiometric requirements Water balance analysis Elements of Air, wastewater and Noise Emissions Audit are : Emission Inventory (continuous and periodic) Work-zone air quality (fugitive emissions) - Noise measurements Calibration checks for pollution control equipments Performance evaluation of air, water and noise pollution control equipments Reuse, Recycling and by-product recovery analyses Elements of Compliance Audit are Air emissions Wastewater emissions Noise emissions Solid waste emissions Hazardous waste emissions Klomontn of Iloalth and CJnfoty Audit are : Safety in transportation and storage of chemicals - Process safety Chemical hazards and their control Fire prevention and protection Safety management Occupational Health/Industrial hygiene systems Emergency response systems (iii) The application of the methodology for Environmental Audit developed in this research has been validated through a case study of Fertiliser Industry. ^ The selected Fertiliser Industry is a single streamline plant and comprises 900 MTPD ammonia plant, 1500 MTPD urea plant, and other allied offsite facilities like 2 x 100 MTPH High pressure steam boilers, 2 x 7.5 MW gas turbines, raw water pretreatment and demineralisation plants, cooling towers, inert gas generator, storage tanks, urea silo, bagging plant and emission control plant. The industry is a Gas-based Fertiliser Complex with Natural Gas requirement of about 1.3 million SM3/day supplied by the Gas Authority of India Ltd. (GAIL) through a 90 km long pipeline from the Krishna-Godavari basin. The raw water requirement of 14.55 MLD is drawn from the Samalkot Summer Reservoir which is 13 km away from the plant. The plant generates about 3000 M3/ day of liquid effluent, which is treated at the effluent treatment plant and then pumped for irrigation to the greenbelt. The ammonia plant, based on Haldor Topsoe's Steam ^ reformation technology, with a design energy consumption of 7.8 MM K Cal/MT ammonia, has a conventional front-end with desulphurisation, primary reforming, secondary reforming, high and low temperature shift conversion, and carbon-dioxide removal by Giammarco-Vetrocoke technology. The urea plant is based on Snamprogetti's total recycle stripping process using ammonia as the self stripping agent. The salient features of the Ammonia and Urea plant in the selected Fertiliser Industry are : > Ammonia plant is the first of its kind to use 25/35 Cr-Ni-Nb alloy for tho primary reformer tubes at the grass root level, which is capable of operating at lower steam : carbon ratio (2.5-3.0) without carbon formation in tubes and results in lower skin temperature and higher overall furnace efficiency Low heat Giammarco-Vetrocoke (GV) process is adopted for carbon-di-oxide removal (iv) The case study has been conducted in three phases Phase I : Pre-audit activities Phase II : On-site activities Phase III : Post-audit activities The pre-audit activities commenced with the development of an audit plan, which included delineation of scope, priority areas for examination, and explanation of the procedure. Questionnaires and protocols were developed for collection of background information. The on-site audit activities commenced with a meeting with the concerned personnel of the Industry. Material and energy measurements were taken during this phase. Identification of sampling locations for Water Audit, Wastewater and Air Emissions Audit, and Compliance Audit was an important step in this phase followed by the sampling and analysis excercises. The post-audit activities included technology assessment; development of material, energy and water balance diagrams; and exploration of conservation potential in the industry. Technology assessment for fertiliser industry was undertaken as a part of the process audit. A combination of Delphi and Analytical Hierarchy Process (AHP) was adopted for ranking of alternative technologies. The parameters selected for ranking of technology options for ammonia and urea production are raw material, energy, water-use and stack emissions per tonne of production alongwith total cost of production. The assessment reveals that the most appropriate technologies for ammonia and urea production are M.W. Kollogg's Technology, and Snamprogetti's ammonia stripping process, respectively. (v) The conclusions drawn from the present research are summarised below : Developed methodology considers shifts towards cleaner production technologies through comparative analysis of various competing alternatives in industrial sectors based on technological, economic, societal, and environmental considerations and helps in creating centralised database on availability of and accessibility to cleaner technologies of industrial production Developed methodology helps to adopt a strategy of pollution prevention in industries based on cleaner technologies of production that conserve resources, and recycle raw materials, energy and water; reuse wastes as secondary raw materials,- and recover byproducts for the conservation of resources. Clean technology may be selected on the basis of ranking of available alternate technologies for an industry. Ranking of technology should be done on a rational basis. In the present research, a combination of Delphi-AHP method has been proposed for the same Developed methodology provides the manufacturing plants with a measured analysis of their raw material consumption, and measures for improvement in resource conservation alongwith the cost-effective environmental protection measures as a consequence of improved material, energy and water effectivity Validation of the developed methodology through a case study in fertiliser industry reveals that the implementation of identified measures results in substantial savings by way of improved production and environmental conditions in the industry The protocols developed in this research could be utilised to conduct Environmental Audit in any industrial sector with appropriate modifications.