2.1 General design considerations -environmental protection .pdf

General Design Considerations Environmental protection Environmental considerations All individuals and companies have a duty of care to their neighbours and to the environment in general. In addition to this moral duty, most countries have enacted strict laws to protect the environme...

General Design Considerations Environmental protection Environmental considerations All individuals and companies have a duty of care to their neighbours and to the environment in general. In addition to this moral duty, most countries have enacted strict laws to protect the environment and preserve the quality of air, water, and land. Vigilance is required in both the design and operation of process plants to ensure that legal standards are met and that no harm is done to the environment. Consideration must be given to 1. All emissions to land, air, and water; 2. Waste management; 3. Smells; 4. Noise; 5. Visual impact; 6. Any other nuisances; 7. The environmental friendliness of the products. Development of a Pollution Control System Developing a pollution control system involves an engineering evaluation of several factors which encompass a complete system. These include investigation of the pollution source, determining the properties of the pollution emissions, design of the collection and transfer systems, selection of the control device, and dispersion of the exhaust to meet applicable regulations A key responsibility of the design engineer is to investigate the pollutants and the total volume dispersed. It is axiomatic that the size of equipment is directly related to the volume being treated, and thus equipment costs can be reduced by decreasing the exhaust volume. Stages of treatment are related to the quantity of pollutants that must be removed. Any process change that favorably alters the concentrations will result in savings. Additionally, consideration should be given to changing raw materials used and even process operations if a significant reduction in pollution source can be attained. The extent to which source correction is justified depends on the cost of the proposed treatment plant. Air pollution control characteristics Waste Minimization Waste arises mainly as by-products or unused reactants from the process or as off specification product produced through misoperation. There will also be fugitive emissions from leaking seals and flanges, and inadvertent spills and discharges through misoperation. In emergency situations, material may be discharged to the atmosphere through vents normally protected by bursting discs and relief valves. Before considering ‘‘end-of-pipe’’ approaches for treating and managing waste products, the design engineer should always try to minimize production of waste at the source. The hierarchy of waste management approaches is 1. Source reduction: Don’t make the waste in the first place. This is the best practice. 2. Recycle: Find a use for the waste stream. 3. Treatment: Reduce the severity of the environmental impact. 4. Disposal: Meet the requirements of the law. Strategies 1. Purification of feeds Reducing the concentration of impurities in the feed usually leads to reduced side reactions and less waste formation. Feed impurities also often lead to degradation of solvents and catalysts. Select a purification approach that does not itself lead to more waste formation. 2. Protect catalysts and adsorbents Deactivated catalysts and adsorbents are solid wastes from the process. In some cases, relatively small amounts of contaminants can cause a load of catalyst or adsorbent to become useless. The catalyst or adsorbent should be protected by using a guard bed of suitable material to adsorb or filter out contaminants before they can damage the catalyst. 3. Eliminate use of extraneous materials When different solvent or mass separating agents are used, this leads to waste formation when the solvents become degraded. Liquid wastes from spent solvents are very common in fine chemicals and pharmaceuticals manufacture. 4. Increase recovery from separations Higher product recovery leads to less product in the waste streams. Higher purity recycle streams usually lead to less waste formation. These benefits must always be traded off against the extra capital and energy costs involved in driving the separation processes to higher recovery or purity. 5. Improve fuel quality Switching to a cleaner-burning fuel, such as natural gas, reduces the emissions from fired heaters. This must be traded off against the higher cost of natural gas relative to heating oil and coal. A technique that is sometimes used for waste minimization is the five-step review: 1. Identify waste components for regulatory impact. 2. Identify waste streams for size and economic impact. 3. List the root causes of the waste streams. 4. List and analyse modifications to address the root causes. 5. Prioritize and implement the best solutions. The information gathered in the first two steps is often collected in an effluent summary worksheet. An effluent summary lists the regulated pollutants produced by the process and summarizes the quantities produced and where they originate. The effluent summary can be used to focus waste minimization efforts and as a design basis for the design of effluent treatment processes. The information in the effluent summary may also be required for obtaining permits to operate the plant or for preparing more formal environmental impact analyses to convince investors or insurers that environmental impact has been properly addressed Waste management When waste is produced, processes must be incorporated in the design for its treatment and safe disposal. The following techniques can be considered: 1. Dilution and dispersion; 2. Discharge to foul water sewer (with the agreement of the appropriate authority); 3. Physical treatments: scrubbing, settling, absorption, and adsorption; 4. Chemical treatment: precipitation (for example, of heavy metals), neutralization; 5. Biological treatment: activated sludge and other processes; 6. Incineration on land or at sea; 7. Landfill at controlled sites; 8. Sea dumping (now subject to tight international control). Gaseous Wastes Gaseous effluents that contain toxic or noxious substances need treatment before discharge into the atmosphere.. Gaseous pollutants can be removed by absorption or adsorption. Absorption by scrubbing with water or a suitable solvent or base is probably the most widely used method for high-volume gas streams, while adsorption onto activated carbon or a zeolitic adsorbent is used for smaller gas streams Liquid Wastes The waste liquids from a chemical process, other than aqueous effluent, will usually be flammable and can be disposed of by burning in suitably designed incinerators. Care must be taken to ensure that the temperatures attained in the incinerator are high enough to completely destroy any harmful compounds that may be formed, such as the possible formation of dioxins when burning chlorinated compounds. The gases leaving an incinerator may be scrubbed, and acid gases neutralized. In the past, small quantities of liquid waste, in drums, were disposed of by dumping at sea or in landfill sites. This is not an environmentally acceptable method and is now subject to stringent controls Solid Wastes Solid waste can be burned in suitable incinerators or disposed by burial at licensed landfill sites. As for liquid wastes, the dumping of toxic solid waste at sea is no longer acceptable. Aqueous Wastes Aqueous waste streams include process water, utility waste-water, and site run-off. Water that is used or formed in the process must be sent to effluent treatment. Common process water effluents include: o Water contaminated with ammonia or hydrogen sulfide from gas scrubbers; o Salt waters from deionizers, softeners, neutralization steps, and washing operations; o Water contaminated with hydrocarbons; o Biologically contaminated water (for example, fermentation broths) o Spent acid and caustic streams.  The site utility systems produce large waste-water flows. A purge known as a ‘‘blowdown’’ is taken from both the cooling water and the boiler feed water, to prevent the accumulation of solids in either recirculating system. Cooling water blowdown is often the largest contributor to the site waste-water. The blowdown streams can be high in minerals content and also contain chemicals such as biocides and corrosion inhibitors that have been added to the boiler feed water or cooling water It is also a best practice to collect run-off water from the plant area and treat it in the site waste-water plant before discharging it to the environment. As the water flows over the ground around the plant, it can become contaminated with organic chemicals that have leaked from the plant. Most plants are designed so that all the run-off is collected into local sewers or ditches that are routed to the site waste-water treatment plant.  The principal factors that determine the nature of an aqueous industrial effluent and on which strict controls will be placed by the responsible authority are 1. pH 2. Suspended solids 3. Toxicity 4. Biological oxygen demand. The pH can be adjusted by the addition of acid or alkali. Lime (calcium oxide) is frequently used to neutralize acidic effluents. In the case of sulfuric acid, the use of lime leads to formation of calcium sulfate. Calcium sulfate that is potentially contaminated with trace organic material has low value and can be used as road fill. An alternative approach is to neutralize with more expensive ammonia, forming ammonium sulfate, which can be sold as a fertilizer. Suspended solids can be removed by settling, using clarifiers For some effluents it is possible to reduce the toxicity to acceptable levels by dilution. Other effluents need chemical treatment. Noise Noise can cause a serious nuisance in the neighborhood of a process plant. Care must be taken when selecting and specifying equipment such as compressors, air-cooler fans, induced and forced draft fans for furnaces, and other noisy plants. Excessive noise can also be generated when venting through steam and other relief valves and from flare stacks. Such equipment should be fitted with silencers. Vendors’ specifications should be checked to ensure that equipment complies with statutory noise levels, both for the protection of employees as well as for noise pollution considerations. Noisy equipment should, as far as practicable, be sited well away from the site boundary. Earth banks and screens of trees can be used to reduce the noise level perceived outside the site. Visual Impact The appearance of the plant should be considered at the design stage. There is little that can be done to change the appearance of a modern-style plant, where most of the equipment and piping are outside and in full view, but some steps can be taken to minimize the visual impact. Large equipment, such as storage tanks, can be painted to blend in with, or even contrast with, the surroundings. For example, the Richmond Oil Refinery in the San Francisco Bay Area has its storage tanks painted to blend in with the surrounding hills. Landscaping and screening by belts of trees can also help improve the overall appearance of the site.  Environmental Protection Because of the greater concern for the continued degradation of the environment, the regulatory agencies has systematically been rewriting and tightening many policies and regulations. The Environmental Protection Agency (EPA) is a regulatory agency based in the United States that focuses on environmental protection and regulation. EPA was designed to protect the environment focused on the removal of pollutants from gas, liquid, and solid waste streams. India has its own environmental regulatory framework, and the Indian government has established the Ministry of Environment, Forest and Climate Change (MoEFCC) to oversee environmental matters in the country. In India, environmental regulations and standards are set and enforced by the Central Pollution Control Board (CPCB) at the national level and State Pollution Control Boards (SPCBs) at the state level. These regulatory bodies are responsible for implementing and enforcing environmental laws, issuing permits, and monitoring compliance with environmental standards. https://moef.gov.in Environmental Auditing An environmental audit is a systematic examination of how a business operation affects the environment. It will include all emissions to air, land, and water; and cover the legal constraints, the effect on community, the landscape, and the ecology. Products will be considered, as well as processes. When applied at the design stage of a new development, it is more correctly called an environmental impact assessment. The aim of the audit or assessment is to 1. Identify environmental problems associated with the manufacturing process and the use of the products before they become liabilities 2. Develop standards for good working practices 3. Provide a basis for company policy 4. Ensure compliance with environmental legislation 5. Satisfy requirements of insurers 6. Minimize the production of waste, an economic factor  Life-Cycle Assessment Life-cycle assessment is a more exhaustive procedure than environmental auditing and is used to compare the long-term sustainability of alternative designs. A life-cycle assessment considers all the environmental costs and impacts of the process, its feedstocks, and the physical plant itself, from initial construction to final decommissioning and site remediation. The methods for carrying out a life-cycle assessment are given in ISO standards 14040, 14041, 14042, 14043, and 14044. https://www.iso.org/obp/ui/en/#iso:std:iso: 14040:ed-2:v1:en  Environmental Impact Assessment (EIA) The EIA process is a regulatory requirement that aims to assess the potential environmental impacts of proposed industrial or developmental projects before they are granted environmental clearance. The preparation of an EIA requires determining what environmental standards require compliance by the project, obtaining baseline data, examining existing data to determine environmental safety of the project, preparing an effluent and emission summary with possible alternatives to meet acceptable standards, and finally preparing the environmental statement or report. Since it may require a full year to obtain baseline data such as air quality, water quality, ambient noise levels, ecological studies and social surveys, emissions, and effluents, studies should take place concurrently to avoid delay in preparing the EIA. The EIA process in India is primarily governed by the Environmental Impact Assessment Notification of 1994, issued under the Environment (Protection) Act, 1986. Subsequent amendments and notifications have further refined and expanded the scope of the EIA process. The EIA process in India is governed by the EIA Notification issued by the MoEFCC, and project-specific guidelines are followed.  Issued by MoEFCC , the EIA Notification provides guidelines and procedures for assessing the potential environmental impacts of various developmental projects. The EIA Notification specifies the categories of projects that are subject to mandatory environmental clearance and outlines the process that project proponents must follow to obtain such clearance. Key components typically covered in the EIA Notification include: 1. Categorization of Projects: ü The notification categorizes projects into various categories (e.g., Category A and Category B) based on their potential environmental impact. ü Category A projects require a more detailed scrutiny process. 2. Applicability of EIA: ü The notification specifies the types and sizes of projects that fall under the purview of the EIA process, ensuring that projects with significant environmental implications undergo a thorough assessment. 3. Procedure for Environmental Clearance: ü It outlines the step-by-step process that project proponents must follow to obtain environmental clearance. ü This includes activities such as screening, scoping, public consultation, preparation of the Environmental Impact Assessment (EIA) report, and appraisal by regulatory authorities. 4. Public Participation: üThe EIA Notification emphasizes the importance of public participation in the decision-making process. üIt mandates public consultation during the EIA process to gather feedback and concerns from local communities and stakeholders. 5. Timeframes: üThe notification includes timelines for different stages of the EIA process, providing a framework for efficient decision-making. 6. Monitoring and Compliance: üIt outlines mechanisms for monitoring and ensuring compliance with environmental clearance conditions post-project implementation. 7. Amendments and Updates: üThe EIA Notification is subject to periodic amendments and updates to address emerging environmental issues, incorporate new technologies, and improve the effectiveness of the EIA process.  https://moef.gov.in/moef/division/environm Stages of EIA ent-divisions/environmental-impact- assessment-eia/introduction/index.html These stages help identify, predict, and mitigate adverse effects on the environment. The EIA process is widely recognized and followed globally, and it plays a crucial role in sustainable development. The key stages of the EIA process are: 1. Screening Identify the project's scope, size, and nature. Refer to predefined criteria to categorize projects as per their potential environmental impacts. Projects falling under certain thresholds may be exempt, while others may proceed to the next stages. 2. Scoping: Engage stakeholders, including regulatory bodies, local communities, and experts. Identify key environmental issues, concerns, and potential impacts. Determine the scope and depth of the EIA study based on identified issues. Develop a scoping document outlining the study's objectives, methodology, and boundaries. 3. Baseline Data Collection: Gather data on the existing environment, including air and water quality, biodiversity, soil composition, cultural and socio-economic aspects, etc. Establish a reference point for assessing changes caused by the project. Utilize scientific methods and data collection techniques to ensure accuracy. 4. Impact Prediction and Assessment: Predict the potential impacts of the project on the environment based on the collected baseline data. Consider both direct and indirect effects, short-term and long-term impacts. Assess impacts on ecosystems, human health, and socio-economic conditions. Evaluate cumulative impacts, taking into account other existing and planned projects. 5. Formulation of Mitigation Measures: Propose measures to prevent, minimize, or compensate for identified adverse impacts. Consider technological, engineering, or procedural solutions. Focus on enhancing positive effects and reducing negative consequences. Develop a comprehensive plan for implementing mitigation measures during project execution. 6. EIA Report Preparation: Assemble all information into a detailed and comprehensive EIA report. Include project description, baseline data, impact assessment, mitigation measures, and relevant supporting documentation. Ensure clarity, transparency, and scientific rigor in the report. 7. Review by Regulatory Authorities: Submit the EIA report to regulatory authorities for review. Regulatory bodies, such as the Expert Appraisal Committee (EAC), assess the report's completeness, accuracy, and adherence to environmental norms. Public comments received during public consultations are considered during the review. 8. Public Consultation Conduct public hearings to provide affected communities and stakeholders with information about the project and its potential impacts. Solicit public feedback, opinions, and concerns. Consider public input in decision-making. 9. Decision-making Regulatory authorities make a decision based on the EIA report, public consultations, and regulatory reviews. Decide to grant environmental clearance, deny clearance, or request modifications to the project. Include specific conditions that the project must adhere to during implementation 10. Post-Clearance Monitoring and Auditing Implement post-clearance monitoring and auditing programs. Regularly monitor the project's adherence to the conditions specified in the environmental clearance. Submit periodic reports to regulatory authorities to demonstrate compliance and address any deviations. Environmental Regulations When planning and designing a plant in India, several key environmental regulations need to be considered: 1. Environment (Protection) Act, 1986 Encompassing a broad range of environmental concerns, this act grants regulatory powers to the central government. Industries are required to obtain environmental clearances for certain activities through the Environmental Impact Assessment (EIA) process. 2. Water (Prevention and Control of Pollution) Act, 1974 Regulates water pollution by establishing standards for the discharge of pollutants into water bodies. Industries need to comply with effluent standards and obtain necessary permits for water use. Environmental Regulations 3. Air (Prevention and Control of Pollution) Act, 1981 Governs air quality standards and emissions from industries. Industries must adhere to emission standards and obtain necessary permits to control air pollution. 4. Hazardous and Other Wastes (Management and Transboundary Movement) Rules, 2016 Provides guidelines for the management of hazardous wastes. Industries generating hazardous waste must follow specific procedures for collection, treatment, and disposal.  Environmental Regulations 5. Biomedical Waste Management Rules, 2016 Regulates the management of biomedical waste generated by healthcare facilities. Industries involved in healthcare or generating biomedical waste must comply with rules for segregation, treatment, and disposal. 6. E-Waste (Management and Handling) Rules, 2016 Focuses on the proper management and disposal of electronic waste. Industries involved in the manufacturing or handling of electronic products must adhere to guidelines for the environmentally sound management of e-waste. Environmental Regulations 7. Forest (Conservation) Act, 1980 Regulates the diversion of forest land for non-forest purposes. Industries planning projects that require forest land need to obtain prior approval for such diversions. 8. Environmental Impact Assessment (EIA) Notification, 1994 and its Amendments Mandates the assessment of potential environmental impacts for certain projects. Industries falling under the specified categories are required to undergo the EIA process for obtaining environmental clearances. Environmental Regulations 9. Public Liability Insurance Act, 1991 Requires industries handling hazardous substances to take out insurance coverage for potential liability arising from accidents. 10. National Green Tribunal (NGT) Act, 2010 Establishes the National Green Tribunal, a judicial body to hear cases related to environmental issues. Industries may face legal actions if found violating environmental norms. The NGT has jurisdiction over civil cases involving a substantial question related to the environment. It has the power to hear matters pertaining to the violation of environmental laws, and it covers a wide range of issues, including air and water pollution, forest conservation, biodiversity, and more. 11. Coastal Regulation Zone (CRZ) Notification, 2019 Regulates activities in coastal areas to protect the coastal environment. CRZ notifications provide guidelines and restrictions for various developmental activities such as construction, tourism, and industrial projects within each identified coastal zone.