Some insights on clean production

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Implementing clean production to save humanity’s home — A brief discussion on the measures taken by Hainan Refining & Chemical to adopt clean production. As the wheels of history roll into the 21st century, the pace and scale of human technological advancement are unmatched by any previous era; at the same time, the damage inflicted on the environment by humans is also unprecedented in history. In 2001, at the turn of the century, the World Situation Report stated: “Global environmental trends have reached a dangerous crossroads.” ”The environmental conditions of the Earth are deteriorating. ” Environmental problems refer to the situation in which certain parameters of the ecological environment, which consists of the atmosphere, hydrosphere, lithosphere, and biosphere, have deviated from the optimal values suitable for the survival of humans and organisms. Environmental problems vary in scale, with the most serious being global environmental issues. These issues arise from global factors, their impacts spread across the entire world, and their effects can last for decades or even centuries; addressing them requires joint efforts on a global scale. The eight major environmental problems of the contemporary era identified by international organizations such as the United Nations Environment Programme (UNEP) include: global climate change, stratospheric ozone depletion, a sharp decline in species diversity, land desertification, freshwater scarcity, deforestation and its unsustainable use, degradation of the marine environment and marine resources, and the spread of chemicals and persistent organic pollutants (POPs). These environmental problems often interconnect as well, leading to greater harmful effects. The main cause of global climate change is the emission of greenhouse gases. Among greenhouse gases, CO2 has the largest share and the greatest impact on climate change. The largest source of CO2 is the flue gas emitted when carbon-containing fuels are burned. Pre-industrial levels of CO2 in the atmosphere were 280 ppm, and they have now exceeded 370 ppm. If this trend continues, it is estimated that by 2050 they will reach 560 ppm, which means doubling the pre-industrial level. The increase in greenhouse gases in the atmosphere leads to a series of consequences: rising temperatures due to the disruption of the heat balance between the atmosphere and the Earth, expansion of sea water volume as a result of thermal expansion and contraction, and melting of ice caps at the poles and snow cover on mountains. All these factors contribute to rising sea levels, causing coastal lowlands and some islands to be submerged. Disastrous weather phenomena such as droughts and floods occur more frequently, desertification worsens, species go extinct at an accelerated rate, and certain diseases that have been eradicated reappear. It is estimated that, if left unmanaged, the world will suffer annual economic losses of up to $300 billion over the next 50 years starting this year. In fact, the consequences of climate change are already evident; since the 1960s, the thickness of the ice cover in the Arctic Ocean has decreased by 40%. If this trend continues, the rate of melting of Arctic ice will accelerate, eventually leading to the complete disappearance of the ice cover there. The glaciers in the Himalayas are melting at an accelerated pace, and the water levels in nearly 50 glacial lakes are rising rapidly; these lakes could overflow their banks and cause floods within 5 years. If current trends continue, the glaciers in the Himalayas will disappear by 2035. The snow on Mount Kilimanjaro, Africa’s highest peak, has melted by 80% between 1912 and 2000, and it may disappear completely within the next 20 years. As for sea-level rise, it increased by 10 to 20 centimeters during the 20th century. On November 15, 2001, the Pacific island nation of Tuvalu **officially announced its intention to abandon its homeland; 11,000 of its citizens prepared to migrate to New Zealand the following year, thus becoming the first country in the world to carry out a mass relocation due to rising sea levels caused by global warming**. The massive production and use of chlorofluorocarbon chemicals by humans have led to the destruction of stratospheric ozone. In 1977, an ozone hole appeared over Antarctica. In September 2000, the largest ozone hole in history was observed, covering nearly 30 million square kilometers – equivalent to twice the size of the Antarctic continent. The ozone layer, which formed over 2 billion years, had 60% of it destroyed in 1.5 centuries. Rapid changes in the natural environment caused by human production and living activities have led to a sharp decline in species. It is estimated that the rate of species loss in modern times is 1,000 times faster than the natural rate, and 1 million times faster than the rate of species formation. Increased from 1 per day to 1 per hour. According to the IUCN’s latest assessment report from 2000, the world is entering a period of potential mass extinction of species. Endangered species account for 1/8 of the 9,946 bird species in the world, 1/4 of the 4,763 mammal species, and 1/3 of the 25,000 fish species. Two years ago, the World Wildlife Fund’s report \"Life on Earth 2002\" confirmed that humanity’s current exploitative use of Earth’s resources has already exceeded 20% of the planet’s carrying capacity, and this figure continues to rise. The four major biological systems that support human survival needs and economic development—forests, oceans, arable land and grasslands, and climate—are continuing to suffer severe damage. It is evident that environmental and resource issues have become unavoidable survival challenges for contemporary humanity. To ensure a bright future for mankind, it is necessary to adopt sustainable development strategies, a consensus that has been reached by people around the world and **. Severe environmental degradation is caused by the production and consumption patterns of industrial society, which feature extensive extraction, massive production, high consumption, and large amounts of waste. To reduce environmental pressure and achieve sustainable development, the task before us is to pursue clean production in order to make industrial development more environmentally friendly. So what is clean production? Clean production aims at the overall optimization of the ecological-economic system as a whole, by continuously taking strategic, comprehensive, and preventive measures throughout the entire process of material transformation. This approach seeks to improve the efficiency of material and energy use, reduce or even eliminate the generation and emission of waste, lessen the excessive consumption of resources in production activities, as well as the risks posed to humans and the environment, thereby achieving sustainable social development. Clean production encompasses three aspects: clean energy, clean production processes, and clean products (including intangible products such as services). Of course, what has been mentioned above are only the macro concepts and general directions of clean production. Human industrial production covers various fields and industries; due to differences in production methods and the products produced, production processes and techniques vary greatly, and the means to achieve clean production also differ accordingly. Below, I would like to share some of my views on how the oil refining industry can implement clean production. Compared to other industries, humanity’s history of using fossil fuels such as oil is indeed not long; the large-scale extraction and processing of oil resources, as well as the development of large-scale industrial operations, have only existed for a few decades. Yet, in just these few decades, the environmental damage caused by the petrochemical industry has been astonishing, and humanity has paid a heavy environmental price for its development. As mentioned earlier, among the eight major environmental problems identified by UNEP in contemporary times, aside from land desertification and the degradation of forest resources—two issues that do not seem to be closely related to the petrochemical industry—the other six environmental problems are all connected to this industry in some way. Over the past few decades, due to limitations in technological capabilities and a lack of awareness regarding environmental protection, oil processing has remained at a primitive and rudimentary level, from extraction and transportation to refining. The recovery rate from oil fields is low, and leaks during storage and transportation frequently occur, causing severe pollution of soil and marine environments. Oil refining is also constrained by the level of development of catalysts, resulting in low conversion rates, low production of light oils, low recovery rates of gas and liquids, and an overall low efficiency in resource utilization. This not only leads to massive waste of energy but also causes severe environmental pollution and ecological degradation. In recent years, as awareness of environmental degradation has grown and environmental protection consciousness has increased, along with the improvement of relevant laws and regulations, the petroleum chemical industry has seen significant changes in its production processes, product structures, and necessary end-of-pipe treatment methods, moving toward the goal of cleaner production that emphasizes energy savings and emission reduction. Firstly, the planning, surveying, and site selection for petrochemical plants have become more rational. The petrochemical industry is subject to potential hazards such as high temperatures, high pressures, flammability, explosiveness, and toxicity. Therefore, when selecting locations for refineries and chemical plants, it is necessary to take into account factors closely related to production, such as the cost of transporting raw materials, the market share of products, and the availability of water and energy resources. At the same time, factors related to environmental protection and health, such as municipal planning, water sources, wind direction, and living conditions, must also be considered. Since the beginning of the 21st century, Sinopec has successively built Hainan Refining & Chemical and Qingdao Refining & Chemical, each with a capacity of tens of millions of tons, in Yangpu, Hainan, and Qingdao. In particular, since the first anniversary of the commercial operation of Hainan Refining and Chemicals, it has undergone multiple inspections by the group company and the **Environmental Protection Administration**, and all emission indicators have met standards that are better than those specified in **regulations**. Thanks to its convenient marine transportation and product market oriented toward Southeast Asia, the economic benefits are also considerable. At present, Hainan Refining & Chemical is making rapid progress toward becoming a benchmark in China’s petrochemical refining industry. Secondly, advanced process flows provide technical support for implementing clean production. As the demand for oil resources increases, global oil reserves are dwindling, and the properties of crude oil are becoming increasingly poor. Crude oil is becoming heavier, with increasing levels of sulfur and nitrogen, resulting in more demanding processing requirements. The simple distillation process not only results in energy waste but also causes environmental pollution; it can no longer meet the requirements of processing heavy crude oil. This necessitates that oil processing companies adopt newer, more environmentally friendly processes. Hainan Refining & Chemicaling adopts a comprehensive plant process flow that includes atmospheric and vacuum distillation, catalytic feed pretreatment, and heavy oil catalytic cracking/hydrocracking. It has achieved a good level in various indicators such as plant configuration and scale, the quality of gasoline and diesel, the yields of gasoline, diesel, and kerosene, the gasoline to diesel ratio, the overall product yield, and the plant’s energy consumption. In the production process of our factory, the overall guidelines for energy conservation, emission reduction, and clean production are evident everywhere. 1. High-efficiency equipment is used, with a clear and rational layout of the equipment and pipelines, resulting in minimal floor space required. If the HC unit uses a double-pass high-pressure heat exchanger, it increases the heat exchange area between the feedstock and the produced oil, reduces the number of heat exchangers required, and maximizes heat recovery. For another example, the RDS unit uses a hydraulic turbine as an auxiliary power source for the reaction feed pump, recovering the pressure energy of the hot high-pressure oil, thereby saving electrical energy and improving economic efficiency as well as the overall utilization rate of energy. 2. Change from intermittent to continuous operation to reduce the number of shutdowns and startups, maintain continuity and stability in the production process, thereby improving the yield of finished products and reducing waste emissions. For example, RFCC and CCR units employ catalyst on-line regeneration technology, while RDS units use a single-series sulfidation scheme to achieve separate start-up and shutdown of the two series. 3. Optimize the layout of the equipment, improve coordination between upstream and downstream components, reduce intermediate steps, make maximum use of thermal energy, and minimize emissions from these intermediate stages. For example, the 3.1 million tons per year RDS unit and the 1.2 million tons per year HC unit at Hainan Refining & Chemical share one set of high-pressure water injection facilities, one set of desulfurization lean ammonia liquid systems, as well as one ammonia-rich liquid flash tank, which reduces equipment investment costs ； Under stable operating conditions, each device should aim for direct feeding, thereby reducing heat losses from intermediate storage. 4. Centralization and scaling of end-of-pipe treatment. Diesel hydrogenation, catalytic feedstock pretreatment, and hydrocracking light gas are combined and fed into the light gas desulfurization tower located in the RDS unit; the acidic water from the RDS and HC units is sent to the acidic water stripping unit. These measures minimize energy losses and wastewater and exhaust gas emissions that may occur at intermediate stages. 5. Improve the level of resource recycling by achieving internal circulation within the facility, within the plant, and along the industrial chain, thereby eliminating emissions at the source. For example, sulfur is extracted from acidic water, and the purified water is recycled in the RDS and HC high-pressure water injection systems; after low-temperature desulfurization, it is used as feed gas for hydrogen production units. After the RDS is replaced, the catalysts are sent to steel mills to recover the metals contained within them. Again. Refining units need to be equipped with advanced automatic control systems to achieve optimized process control. Efficient automation devices not only reduce production costs but also essentially eliminate potential safety hazards during device operation. Without an efficient and reliable instrument interlock system, in oil refining plants that operate under high temperature, high pressure, and in the presence of hydrogen, human effort is practically insignificant in the event of an emergency. Without safe and reliable emergency shutdown devices, accidents will develop in an uncontrollable direction, and catastrophic incidents are inevitable. Such disasters can result in equipment damage and economic losses in mild cases, while in severe cases they can lead to casualties and serious environmental pollution. Hainan Refining & Chemical has multiple emergency shut-off valves installed in the RDS and HC high-pressure hydrogen-handling units, which play a significant role in preventing pressure surges, reactor over-temperature, and dry burning of the heating furnace tubes. In short, safe production, energy conservation and emission reduction, and clean production form an organic whole that restricts and influences one another. Their goal is to establish a win-win development model that promotes economic prosperity while being environmentally friendly, thereby achieving sustainable development. Clean production is also a relative concept; so-called clean processes, clean products, and clean energy are defined in comparison to existing processes, products, and energy sources. Therefore, implementing clean production is itself a continuous process of improvement; as society and the economy develop and science and technology advance, it is necessary to set updated goals from time to time in order to achieve higher standards. For the petrochemical industry, achieving clean production and energy conservation requires not only the advancement of catalytic technologies but also careful attention, close observation, and critical thinking on the part of every engineering and technical professional. Based on the actual production conditions and operational experience, it is necessary to continuously come up with optimization and improvement measures. Clean production is a technology that includes source reduction techniques, recycling techniques, and harmless treatment techniques, among others ； Clean production is also a strategy that includes setting strategic goals, strategic planning, strategic steps, etc ； Clean production is also a philosophy that reflects harmonious coexistence between society and nature, coordinated development of the economy and the environment, and a balance between spiritual and material needs. This is in high degree of consistency and essential unity with our party’s goal of building a harmonious society. Achieving energy conservation and emission reduction, implementing clean production, and realizing sustainable development is a challenging and lengthy process that concerns not only a country’s economy and people’s livelihoods but also the survival of humanity and that of our common home – this blue planet. As a rapidly rising major power in the East, we have an undeniable responsibility in this regard. Looking to the future, there is still a long way to go before our country can fully embrace clean production. (In the context of the nationwide push for clean production across various industries, Sinopec Group urges its subsidiaries, branch companies, and oil refining enterprises to effectively implement clean production measures, organizes all employees to study the theoretical knowledge related to clean production, and identifies environmental pollution issues such as leaks and spills that occur during production. To this end, from 7 p.m. to 9 p.m. on March 8, 2009, Unit 3 of Hainan Refining and Chemicals’ Operations Department held a meeting on the first floor of the office, where comrades such as safety engineers gave lectures on the basic concepts of clean production as well as our company’s plans for implementing clean production; the insights gained from this meeting were then written down as mentioned above