GHG Management in Manufacturing Industries | Term Paper | Geography

Read this term paper to learn about:- 1. Introduction to GHG Management 2. Need to Conserve Non-Renewable Resources to Reduce Emission 3. Emission Management by Industries 4. Sectorial Approach to GHG Management.

Term Paper # 1. Introduction to GHG Management:

The list of energy intensive, large primary manufacturing industries include chemical, iron and steel, aluminum, cement, paper and pulp, petrochemicals and other minerals and metals. The less energy intensive sectors or light industries include the rest, such as, manufacturing of food, beverages, tobacco; textiles; wood and wood products; printing and publishing; production of fine chemicals; and the metal processing industry (including automobiles, appliances, and electronics). The emission management in five large energy intensive industries (chemical, iron & steel, aluminum, cement, and paper & pulp).

Non-carbon dioxide GHGs emitted from the manufacturing sector includes nitrous oxide (N₂O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF₆). The use of substitutes for ozone depleting gases has been found to be an effective step to reduce fluorocarcarbon and sulphur hexafluoride. GHG management in manufacturing industries is thus mainly restricted to minimize carbon dioxide emission and in some industries nitrous oxide.

Emissions of carbon dioxide are still the most dominant contribution of manufacturing industry to total greenhouse gas emission. In emission data in manufacturing industries include all direct emissions plus indirect equivalent emissions due to electricity consumption. Nearly a third of the world’s energy consumption and 36% of carbon dioxide (CO₂) emissions are attributable to manufacturing industries. The carbon dioxide emission (36%) figure in manufacturing industries follows the energy consumption pattern (33.3%).

The large primary materials industries, i.e., chemical, petrochemicals, iron and steel, cement, paper and pulp, and other minerals and metals, account for more than two-thirds of these figures, i.e. around a quarter (24%) of total global energy consumption and a quarter of total global carbon dioxide emission. Of metals, iron and steel and aluminum production are very high energy consuming processes and also big emitters.

Overall, industrial energy use has been growing strongly in recent decades. The rate of growth varies significantly between sub-sectors. For example, chemicals and petrochemicals, which are the heaviest industrial energy users, doubled their energy and feedstock demand between 1971 and 2004, whereas energy consumption for iron and steel has been relatively stable. Aluminium industry has been able to reduce emissions considerably due mainly to their R&D efforts.

In recent times, major part of the industrial growth has been in emerging economies. Today, China is the world’s largest producer of iron and steel, ammonia and cement and the worst emitters, but not a signatory to Kyoto Protocol.

Term Paper # 2. Need to Conserve Non-Renewable Resources to Reduce Emission:

To cater for the needs of ever growing population, economic growth at a reasonable rate is essential. Economic growth is expressed in terms of percentage increase in annual GDP (gross domestic products).To produce the increased quantities of the products it is necessary to consume more natural resources, as materials and energy inputs.

Steady growth is, by its nature, an exponential function. A quantity that grows according to an exponential function exhibits a doubling in size at a regular time interval (called the doubling time). With a steady growth rate of 5% per year, the consumption of a non-renewable resource (like coal, petrol, minerals, metals) would be double in approximately 14 years. After another 14 years the rate will have quadrupled.

After a century of 5% annual growth, the resource will be consumed at a rate 130 times the original rate. The rapid depletion of non-renewable resources would make the economic growth unsustainable. The manufacturing industries need to reduce consumption of non-renewable resources for both material and energy needs to make the industrial growth at a sustainable rate. An effective step in this direction would cause substantial reduction in emissions.

Term Paper # 3. Emission Management by Industries:

In order to limit emissions, industries have adopted appropriate measures to suit their specific requirements.

Some of these measures include followings:

i. Developing energy efficient processing systems. The innovative changes in the processing system can lead to higher productivity per unit of power consumption. NEDO (Japan) has published a comprehensive report on global warming counter measures through Japanese technologies for energy savings/GHG emission reductions.

The report covers technologies developed by NEDO for almost all the industries for saving basically energy. Report also contains the reduction in GHG emissions as achieved by industries. Emission efficiency is indicated by the volume of product shipped per unit of equivalent carbon emission.

In Japan, electronic industries use JEITA (Japan Electronic and Information Technology Industries) common index, which is the value of CO₂ emission against net production (monetary value), adjusted using the corporate goods price index announced by the Bank of Japan. A fall in this figure indicates that a given product quantity (monetary value) is produced using less energy. Industries have, in general, improved energy and emission control efficiencies by producing more with less energy consumption.

ii. Reduction in direct emission by increasing the proportion of green inputs, carbon capturing and altering the processing techniques.

iii. Improving life cycles of processing equipments shall lead to increase productivity, less downtime, lower carbon footprints of the equipments, savings in materials and energy due to less requirement of new components etc.

Term Paper # 4. Sectorial Approach to GHG Management:

All major sectors of industries have formed common platform of the companies belonging to the sector in their efforts to control emissions. Quite a few of these platforms are global. Sectorial policy ideas such as this could apply to companies not just in the steel sector but in other industries that produce a lot of carbon dioxide – including electricity generation, cement, chemicals and aluminum.

One idea is that businesses active in such areas could, in a post-2012 governmental regime (post Kyoto), be awarded carbon dioxide “permits” by governments on the basis of how proficient they are at cutting greenhouse emissions per unit of economic output.

a. Electricity Generation:

Power plants account for 40 percent of U.S. greenhouse gas emissions and 25 percent of the world. China, South Africa and India host the world’s five dirtiest utility companies in terms of global warming pollution, while a single Southern Co plant in Juliette, Ga., USA emits more annually than Brazil’s entire power sector.

b. Chemical Industry:

Two major emitters of greenhouse gases in chemical manufacturing industries include ammonia and nitric acid. While ammonia production process leads to generation of carbon dioxide, the production of nitric acid can cause nitrous oxide emission. A number of technologies for nitrous oxide mitigation during nitric acid production are available. China is one of the leading producers of ammonia.

Ammonia (NH3) is a major industrial chemical and the most important nitrogenous material produced. Ammonia gas is used in producing fertilizer; heat treating and paper pulping; manufacturing of nitric acid, nitrates, nitric acid ester, nitro compound, explosives of various types, and as a refrigerant. Amines, amides, and miscellaneous other organic compounds, such as urea, are made from ammonia.

The production of ammonia represents a significant non-energy industrial source of CO₂ emissions. The primary release of CO₂ at plants using the natural gas catalytic steam reforming process occurs during regeneration of the CO₂ scrubbing solution with lesser emissions resulting from condensate stripping.

During the production of nitric acid (HNO₃), nitrous oxide (N₂O) is generated as an unintended by-product of the high temperature catalytic oxidation of ammonia (NH₃) and is a significant source of atmospheric N₂O. If not abated, this would be the major source of N₂O emissions in the chemical industry.

A number of technologies for N₂O mitigation during nitric acid manufacture have been developed in recent years. Examples include, option involving direct catalytic decomposition right after the platinum gauzes, and a full-scale catalyst decomposition option.

Nylon production is also responsible for nitrous oxide emission through its requirement for adipic acid production. However, improvements in the removal of nitrous oxide before emissions to the atmosphere, such as by thermal decomposition, can prevent potential emissions form this source by over 90 percent.

According to ACC (American Chemistry Council (ACC)):

i. EPA’s (US Environmental Protection Agency) own measures; the chemical industry has maintained N₂0 emissions from 18.9 Tg CO₂ equivalents (Tetra gram of CO₂ equivalent) to 19Tg CO₂ equivalent in 2008, even as the chemical production has increased.

ii. Emissions of six criteria air pollutants are down over 43% nationwide even as the economy, GDP and population have expanded.

iii. Industrial discharges to the nation’s waterways are but a small fraction of the remaining problems that are now driven by urban and agricultural runoff.

These advances have been achieved, in part, as a result of the development of new technologies and continued investment in new equipment, processes and procedure CIA (Chemical Industries Association, UK) reports that the chemical sector in UK has exceeded its own 2004 climate change agreement target. The sector has improved its energy efficiency by 19.5 per cent since 1998, equivalent to an annual saving of around 3.5 million tonnes of carbon dioxide emissions.

c. Paper and Pulp Industry:

Paper industry accounts for 70% of industrial (nonutility) carbon dioxide emissions’. The figure roughly amounts to 7 million tons of the 10 million tons of industry-wide carbon dioxide emissions. Carbon dioxide reduction potential from industry sector largely tied to paper industry.

Emissions Characterization:

On the average during 2001-2005 periods:

(i) 31% of paper industry CO₂ emissions correspond to carbon neutral,

(ii) 55% of paper industry CO₂ emissions result from coal combustion, and

(iii) 14% of paper industry CO₂ emissions result from gas, oil combustion.

Thus the highest emission (55%) results from coal combustion, hence greatest potential for reduction is to substitute coal by low emission fuels.

Technologies to improve energy efficiency and reduce CO₂ emissions include:

i. Switching over from Coal to Natural Gas:

The CO₂ emission from natural gas is around 56% of coal emissions (adjusted for efficiency). However natural gas is ˜3.7 times more expensive than coal and thus not a cost effective solution to paper industry.

ii. Improvement Potential in Chemical Pulping Black Liquid Gasification:

The paper and pulp industry is to play a leading role in the development of second-generation biofuels, such as, gasifying & refining so-called “black liquor” – the oily liquid residue produced in pulping wood to produce paper – to produce both bio-synthesis gas and liquid fuel.

The average U.S. integrated pulp and paper mill has a thermal demand of approximately 40% fossil fuel and ~60% biomass, which is largely met from combustion of black liquor. With a biorefinery, there is no longer an input for fossil fuel-based energy since the pulp and paper facilities run on recovered heat. The outputs include pulp and paper, plus one or more ‘green’ fuels or chemicals. Power input will be an option determined by its cost versus the value of other output streams.

iii. Development in Mechanical Pulping:

The efforts to develop mechanical pulping as a part of advanced paper making technologies have high potential to reduce CO₂ emissions.

iv. Energy Conversion: Increasing the Use of CHP Systems:

Recent studies have identified combined production of heat and power (CHP) as one of the most important technologies for improving energy efficiency and reducing carbon emissions in the US. CHP is especially attractive in industries with constant steam loads and those that generate byproduct fuels.

Chemicals and pulp/paper industries are the two largest industries dominating the CHP market. Combined CHP capacity in these two industries in 1994 was 24.2 GW — 55% of the total industrial CHP capacity. Currently, CHP capacity in both industries has been realized mostly at the sites with high steam loads. However, significant potential still exists at the remaining sites.

The 55% of CHP generation in these two industries would reduce carbon emissions equivalent to 44% of the present carbon emissions in these industries. Also most of the carbon emission reductions can be achieved at negative costs. A barrier for CHP in India is the relatively low plant load factor of 0.534, indicating fluctuations in heat or electricity demand necessitating special care to be taken in plant design and demand side energy management.

d. Metal Production:

i. Iron & Steel:

The integrated iron and steel plant is one of the world’s highest emitters of greenhouse gases, generating 4 per cent of global carbon dioxide emissions yearly. Iron and steel industries make use of a large quantity of coal, good quantities of gas or oil, and some quantities of limestone – all of them generate carbon dioxide. Also the industry needs captive power plant based on fossil fuels.

The production of steel at an integrated iron and steel plant is accomplished using several interrelated processes.

The major processes are:

(1) Coke production,

(2) Sinter production,

(3) Iron production,

(4) Raw steel production,

(5) Ladle metallurgy,

(6) Continuous casting,

(7) Hot and cold rolling, and

(8) Finished product preparation.

The operations for secondary steelmaking, where, ferrous scrap is recycled by melting and refining in electric arc furnaces (EAFs) include (4) through (8) above.

The GHG emissions are generated as:

(1) Process emissions, in which raw materials and combustion both may contribute to CO₂ emissions;

(2) Emissions from combustion sources alone; and

(3) Indirect emissions from consumption of electricity (primarily in EAFs and in finishing operations such as rolling mills at both integrated and EAF plants).

The major processes for direct GHG sources include the sinter plant; non-recovery coke oven battery combustion stack; coke pushing; basic oxygen furnace (BOF) exhaust; and EAF exhaust. The primary combustion sources of GHGs include by-product recovery coke oven battery combustion stack; blast furnace stove; boiler; process heater; reheat furnace; flame-suppression system; annealing furnace; flare; ladle reheater; and other miscellaneous combustion sources.

The primary sources of GHG emissions are blast furnace stoves (43 percent), miscellaneous combustion sources burning natural gas and process gases (30 percent), other process units (15 percent), and indirect emissions from electricity usage (12 percent). For EAF steelmaking, the primary sources of GHG emissions include indirect emissions from electricity usage (50 percent), combustion of natural gas in miscellaneous combustion units (40 percent) and steel production in the EAF (10 percent).

Some basic facts on emission & its control in iron & steel industry:

The iron and steel industry, accounts for about 19% of energy use and about a quarter of direct CO₂ emissions from the industry sector. The CO₂ relevance is not linear to power consumption but quite high due to a large share of coal for coke production, coke for producing molten iron and the coal for captive power plant.

The iron and steel industry has achieved significant efficiency improvements in the past twenty-five years. Increased recycling and higher efficiency of energy and materials use have played an important role in this positive development. Iron and steel has a complex industrial structure, but only a limited number of processes are applied worldwide. A large share of the differences in energy intensities and CO₂ emissions on a plant and country level can be explained by variations in the quality of the resources, the processes used and the overall efficiency.

Plant Efficiency in Iron and Steel Industry:

The efficiency is closely linked to several elements including technology, plant size and quality of raw materials. This partly explains why the average efficiency of the iron and steel industries in China, India, Ukraine and the Russian Federation are lower than those in OECD countries.

These four countries account for nearly half of global iron production and more than half of global CO₂ emissions from iron and steel production. Outdated technologies, e.g., open hearth furnaces are still in use in Ukraine & Russia. In India, new, but energy inefficient, technologies such as coal-based direct reduced iron production play an important role.

These technologies can take advantage of the local low-quality resources and can be developed on a small scale, but they carry a heavy environmental burden. Raw material constraints, such as poor quality of coking coal also lead to energy inefficiency. The slow updating of technology is another constraint. In China, low energy efficiency is mainly due to a high share of small-scale blast furnaces, limited or inefficient use of residual gases and low quality ore.

Waste Energy Recovery in the Iron and Steel Industry:

This tends to be more prevalent in countries with high energy prices, where the waste heat is used for power generation. This includes technology options such as coke dry quenching (CDQ) and top-pressure turbines. CDQ also improves the coke quality, compared to conventional wet quenching technology.

Primary Energy Savings Potential:

The identified primary energy savings potential is about 2.3 to 2.9 EJ per year through energy efficiency improvements, e.g., in blast furnace systems and use of best available technology. Other options, for which only qualitative data are available, and the complete recovery of used steel can raise the potential to about 5 EJ per year. The full range of CO₂ emissions reductions is estimated to be 220 to 360 Mt CO₂ per year.

Global Sectorial Approach in Steel Industry:

The steel industry has endorsed a global approach as the best way for steel to help address climate change. The International Iron and Steel Institute (IISI) approved the next stage in the establishment of a Global Sectorial Approach for steel. The organization will collect and report the carbon dioxide emissions data of steel plants in all the major steel producing countries. Establishment of the data on a common and consistent basis is the starting point for the setting of commitments post-2012 on a national or regional basis.

The steel industry in North America, Western Europe and Japan has reduced energy consumption per unit of production by 49 percent in the last 25 years, according to an IISI statement. The steel industry now accounts for three percent to four percent of global man-made greenhouse gas emissions.

Over 90 percent of steel industry emissions come from iron production in nine countries or regions: Brazil, China, EU-27, India, Japan, Korea, Russia, Ukraine and the USA. In a study of global sectoral approaches, CCAP investigated a transnational approach in which all countries face similar benchmarks, a sectoral Clean Development Mechanism (CDM) approach emphasizing carbon credits, and a bottom-up approach envisaging 8 of 69 financial and technology assistance from advanced economies to support ambitious no-lose crediting baselines in developing countries.

This study was supported by the Competitiveness and Innovation Framework Programme of the European Commission, and the study’s objective was to help move beyond voluntary actions and facilitate participation by developing countries in international climate change actions.

Cap and trade regional policies such as those currently used in the EU are not effective in reducing carbon dioxide emissions, said Philippe Varin, IISI Executive Committee Member and CEO, Corus. “Constraining production from the best emission performing plants is not the solution for a globally competitive industry such as steel. An effective approach for the steel industry requires the participation of all major steel producing countries and a focus on improving emissions per unit of production.”

Energy Efficiency Improvements:

The iron and steel industry is energy intensive; consequently, many of the options available to reduce GHG emissions involve improved energy efficiency. Current energy consumption is approximately 19 million British thermal units per ton of steel (MMBtu/ton) (22.1 GJ/tonne) for integrated mills and 5.0 MMBtu/ton (5.8 GJ/tonne) for EAFs. DOE estimates that a reduction of 5.1 MMBtu/ton (5.9 GJ/tonne) (27 percent) is possible for integrated mills (half from existing technologies and half from research and development [R&D]). A reduction of 2.7 MMBtu/ton (3.1 GJ/tonne) (53 percent) is possible for EAFs (two- thirds from existing technologies).

ii. Nonferrous- Aluminum:

Amongst the common non-ferrous metals, aluminum production by electrothermal reduction using carbon electrode, is a very high energy consuming process(175 GJ/ton compared to 20.5 GJ/ton for iron & steel) accompanied by large quantities of carbon di­oxide emission (12.7 tonnes/tonne of A1, 5 times that of steel, 14 times that of cement).

Additionally, the use of fluoride (cryolite) in the process generates PFC, such as CF₄ and C₂F₆, with CO₂ equivalent as 6500 and 9200 respectively. For a global production of 30 million tons of primary aluminium, about 390 million tons of CO₂ result in totaling 0.9% of total anthropogenic GHG emissions. Aluminum industry has been able to reduce emissions considerably due mainly to R&D efforts.

A1COA (Aluminum Company of America) reached the goal of reducing GHGs emissions by 25% (from 1990 levels) in 2003, with increased aluminum production figures. The company believes that the aluminum industry can be “greenhouse gas neutral” by 2020. Alcoa has used hydroelectric power as a major energy source, for its operation around the world and evaluating the feasibility of building the world’s first geothermal powered aluminum production plant.

The electrochemical reduction process in a cryolite (fluoride) bath using graphite electrode, generates large volume of carbon dioxide gas and PFCs. The PFCs, such as CF₄ and C₂F₆, have very high global warming potential. Aluminum industry is working on ‘inert anode’ to replace graphite anode, which would stop producing carbon dioxide and PFCs. Worldwide use of ‘inert electrode’ to produce aluminum shall reduce GHG emission by nearly 40 million metric tons.

In 2007, Alcoa launched “carbon capture” technology in their plant in Western Australia, In this process, carbon dioxide is mixed with bauxite residues (byproduct in the production process), thus locking up carbon dioxide. The resulting product is alkaline in nature, which can be used for road foundation, building materials, or an additive to improve soil.

e. Cement:

Cement is considered as one of the most widely used material. Its production plant is one of the worst emitter of GHGs. The cement is made by heating limestone and clay until they fuse into a material called clinker, which is then ground and mixed with various additives to form cement. The heating by coal and the decomposition of limestone lead to generation of large quantities of carbon dioxide.

Three main areas in which reduction in emission are planned, includes:

i. To make kiln more fuel efficient in order to reduce energy required per ton of clinker production. This is a key area of improvement.

ii. Replace fossil fuel, like coal by farm wastes or used tyres. Environmentalists have started crying foul, since burning of waste release noxious chemicals.

iii. Mix more additives into cement & thereby reducing proportion of emission intensive clinker. Building codes limit the extent the cement can be diluted.

iv. Waste heat recovery & use for power generation/ co-generation.

v. Overall energy efficiency improvement.

The largest opportunities for improving energy efficiency and reducing CO₂ emissions related to energy inputs in the cement/concrete industry are mostly related to cement manufacturing. The calcining of limestone (CaCO₃ = CaO + CO₂) produces 0.785 tonnes of CO₂ per tonne of CaO. There is no technological or physical way to reduce calcination reaction emissions. Cement contains about 61% CaO.

Hence, the calcining reaction produces roughly 0.48 tonnes of CO₂ for each tonne of cement manufactured. Pyroprocessing accounts for 74% of the cement/concrete industries energy consumption (93% of cement’s manufacturing energy requirement) and operates at roughly 34% thermal efficiency.

This low thermal efficiency provides many opportunities to improve performance. The improvement in energy efficiency has been achieved by switching over to ‘dry’ process from earlier ‘wet’ process, use of non-fossil fuels, cogeneration and other innovative practices. Realistic and cost-effective energy savings are smaller, but achievable.

It is reckoned by cement industries that about 5% of world’s emissions of carbon dioxide are due to cement, which is double the emission figure of aviation industry. EU has imposed restriction on emissions from cement kilns. Also the major cement producers have an outfit called the Cement Sustainability Initiative, which imposed voluntary cut on emissions. Lafarge and Holcim pledges to cut emissions/ton of cement by a fifth by 2010 and Comex by a quarter by 2015. So far they are in track in their commitments.

Despite the above marginal measures for emission reduction per ton of cement, the increasing demand would result in higher total emissions. Cement industries have developed stronger and more flexible cements and concretes, the use of which by construction industries can lead to requirements of lesser quantities and thus lowering total emission figure. China is the largest producer of cement followed by India and thus the big emitters in this sector. Both the countries are on the right track to reduce emissions with the available technologies. The United States ranks third in the world in overall cement output.

EU Legislations on Industrial Emissions:

Carbon dioxide (CO₂) emissions from petrochemicals, ammonia and aluminium manufacturing industries will be included in the EU emissions trading scheme (EU ETS) post-2013, according to the draft climate change bill published by the European Commission (EC) on January, 2008. The bill must be approved by both the Council of the EU (national ministers) and the European parliament before it becomes law. The EC hopes that a final decision adopting modifications to the directive will be taken by 2009.