Questions and Answers of Sustainable Engineering

Many corporations are working toward developing products for which they can claim a zero-carbon footprint. A large manufacturing site uses 25,000 MWh electricity, which is the largest contributor to
How does a Pareto curve represent a "win-lose" situation?
Typical data about beverage packaging are given in Table 17.7. Table 17.7:Answer the following questions based on these data. 1. Calculate the eco-efficiency of beverage packaging using the data
A car rental company owns 100 Chevrolet Cruzes, 50 Toyota Yarises and 50 Ford Focuses. They plan to buy another 50 cars, and owing to new government regulations need to ensure that the average fuel
Can the use of a heuristic for green engineering lead to an environmentally inferior design?
Why is doing "less bad" not good enough for sustainability?
The definition of eco-efficiency in Section 17.2 refers to the Earth's carrying capacity. Section 17.2:Do current eco-efficiency practices meet this goal of the original definition? Justify your
Figure 5.2 provides perspectives on the relationship between business and the environment. Interpret these figures in terms of Pareto curves. Identify all the Pareto curves (lines) in these figures.
Table 17.8 shows the carbon and nitrogen footprints for transportation fuels. Answer the following questions based on these data.Table 17.8:1. Plot the footprints for fossil and first-generation
For a manufacturing process, the dominant value of net present value (NPV) is given by ƒ1 = 35√x + 22, and the dominant value of the global warming potential (GWP) is ƒ2 = 5x2 + 10x + 100. Here,
Consider the design of a paper coffee cup, keeping in mind that it is made of layers of paper and plastic and that such cups are often not accepted by recycling companies. Which of the 12 Principles
Study the graphs of the atmospheric concentration of various gases shown in Figure 2.18. Figure 2.18:What type of behavior do you see? Does this system exhibit homeostasis or homeorhesis? On the
Fill in the blank. "An ecosystem is the smallest unit that is_____________
Why is a reductionist approach inadequate for understanding ecosystems?
Identify some species in various trophic levels of the following ecosystems: (a) A local garden, (b) Intensive agriculture, (c) A fresh water lake, (d) A forest. You may consider such ecosystems
State two benefits of networking in ecosystems.
Trees in England were cut down in the early years of the Industrial Revolution to produce charcoal for making steel. Even today, centuries after the logging, many of these logged areas lack trees.
Maintaining a lawn requires regular mowing. Which stage of ecological succession does the mowing maintain? Explain with the help of Figures 18.11 and 18.12.Figure 18.11 and 18.12: Carbon flux (g Cm-2
As an ecosystem grows, how does the ratio of growth to maintenance change?
What is the significance of leakage in Holling's adaptive cycle?
To understand the benefits of ecological networking, consider all ecosystem activities to have an energy efficiency of 5 percent. The first activity or node in a certain network converts sunlight,
Consider an ecological network consisting of activities as nodes, with each node having an efficiency of 4 percent. The entire network is run by 1000 W of sunlight, which is converted to useful
Migration is a popular strategy among many species. Monarch butterflies migrate between the Sierra Madre mountains in Mexico and many locations across the USA and Canada. Answer the following
The relationship between deer and wolves is considered to be of a predatory nature. Describe how the interaction between grass, deer, and wolves can result in an autocatalytic or self-sustaining
Explain with examples why the release phase of Holling's adaptive cycle is often referred to as creative destruction. It is often claimed that the development of digital photography resulted in
Some of the most diverse ecosystems are in regions that lack a rich supply of resources. Coral reefs and tropical rain forests are two such examples. Explain how these systems are able to thrive in
Explain the meaning of using nature as a model, mentor, and measure.
Give two examples of materials developed by biomimicry. Why is the approach used for developing them called reductionist biomimicry?
Some results from a study of an EIP in Ulsan, Korea are summarized in Table 19.6. For each flow, determine the time required to recover the investment. What is the total reduction in CO emissions due
A start-up company is based on the development of a material that can be used to make recyclable carbon fiber composites. This allows snowboards and scraps from snowboard production to be recycled to
What is a Type III industrial ecosystem?
Selected material and energy flows from a bituminous coal-burning power plant are shown in Table 19.7. The ash and flue gas desulfurization (FGD) residue can be used to produce cement by replacing
What is the benefit of the materials marketplace for bauxite mining?
A coal-based power plant consumes 500 tons of coal per hour to produce 700 MW of electricity. Sixty percent of the heat content in the coal is lost as heat. The coal contains 20 percent ash. The fuel
Using the last three rows of the data in Table 19.3, compare the impact of the industrial ecosystem with the two reference. Identify trade-offs, if any, between the three cases.Table 19.3:scenarios.
An EIP consists of three processes: leather processing, protein hydrolysates manufacturing, and plastofill production. Leather processing produces 65 x 106 m3/yr of tanned leather, 85,000 ton/yr of
Calculate circularity metrics for the paper flow system depicted in Figure 12.12. Compare this system with the global and European economies. What can you conclude about the relative circularity of
Two common examples of activities needed to develop a performance economy are car sharing and electronics take-back (see Box 19.3). Sketch an approximate life cycle system boundary of these
Define traditional ecological knowledge and provide two examples.
What is self-design? How is it different from imposed design?
Choose an indigenous community in any part of the world and determine two ways in which they use traditional ecological knowledge. Is their approach ecologically friendlier than the modern approach
What is a vertical flow subsurface wetland?
Some communities in East Africa seem to have established a mutualistic relationship with a local bird. The bird, called a honeyguide, helps people find bee hives. People collect the honey, and then
What is the key difference between techno-ecological synergy and byproduct synergy?
The effect of temperature on the ability of wetlands to remove nitrates is captured through the relationship of the time constant with temperature, which is given by k = k20θ (T-20) Here, k20 is the
The results of an emergy analysis of various green infrastructure options for treating storm water in Syracuse, New York are summarized in Table 20.5.Table 20.5: Using these results, discuss the
What are the technological and ecological options to maintain soil fertility?
The treatment of urban waste water results in the production of biosolids. This byproduct may be landfilled, incinerated, composted to use as fertilizer, or applied directly to land. Each alternative
A short-rotation coppice in the UK sequesters biomass at the rate of 1 kg/(m2 yr2). Calculate the mean cooling over a typical 16-hour day in the summer. How much will the temperature of the
From the data in Table 20.4: evaluate the trade-off between GHG emissions and NPV, with and without including the agroecosystem service of carbon sequestration. Discuss the feasibility of producing
You wish to utilize 10,000 acres of land to produce energy with no net emission of greenhouse gases. Using the data in Table 20.4, determine a combination of available land-use options to satisfy
Box 20.5 suggests the possibility of relying on vegetation to mitigate industrial air pollution. Suppose that a manufacturing site wishes to get credit for the air quality regulation ecosystem
Define and provide an example of environmental externalities.
It is estimated that, at the present rate, by 2050 there will be more plastic in the ocean than fish. Addressing the issue of plastic pollution is an urgent need and many approaches are being tried.
State some shortcomings of command and control environmental regulations.
Answer the following questions about payment for ecosystem services. Videos available at www.youtube.com/watch?v=gzNWnREZ2xI and http://wqt.epri.com/overview.html may help. 1. In a typical PES
Why is the increase in price due to an environmental tax less than the tax itself?
The emissions trading of sulfur dioxide has been very effective in reducing the total SO emissions in the USA. However, it has resulted in "hotspots." Explain the reasons for this phenomenon.
How do emissions permits provide a "right to pollute"?
A study of ethanol as a transportation fuel reveals that the competitive equilibrium is expected to be at a price of $4 per gallon and a consumption rate of 100 million gallons/day. For a production
Evaluate the approach of inclusive wealth using the six requirements for sustainability assessment listed in Box 3.3. Box 3.3:Can any of the shortcomings of this approach be overcome with the help
Which are the types of capital included in inclusive wealth?
The demand curve for a lawn fertilizer may be represented by P = -3Q+75, while the marginal cost curve is given by C = 2Q. Here, P and C are the price and marginal cost in dollars, respectively,
In March 1989, the Exxon Valdez spilled 38,000 metric tons of crude oil in Prince William Sound, Alaska. Until the more recent Deepwater Horizon spill, this was the largest oil spill in the USA.
Discuss the pros and cons of metrics for quantifying weak and strong sustainability. Can you suggest ways of modifying the inclusive wealth metric to make it stronger?
How are some utilities relying on social pressure to encourage individuals to reduce their home energy use?
Does taking a course on sustainable engineering affect individual behavior toward greater sustainability? Why or why not?
How is deep ecology different from shallow ecology?
Does Pope Francis' encyclical in Box 22.1 Align with shallow ecology or deep ecology? Justify your answer in detail.Box 22.1: BOX 22.1 Excerpts from Pope Francis' Encyclical, "Laudato Si: On Care for
Describe recent efforts in at least two religions toward sustainable development. Explain the motivation behind these efforts and the barriers to their success.
What is Pope Francis' position on carbon trading?
What is the Mad Max scenario for the future?
Despite the insight provided by Ostrom's design principles for the sustainable management of common resources, tragedies of the commons continue to occur. One prominent example is the increasing
Compare the fishing practices of the Cree with the scientific approach of maximizing yield. How do both strategies address the multiscale and complex nature of managing fish as a common resource?
Why is technological skepticism the recommended worldview?
Unsustainable use of groundwater is causing the depletion of many aquifers across the world. Groundwater is a common pool resource that cannot be seen and is often developed by precipitation over
Explain the possible outcomes if we adopt a technologically optimistic world view. Which outcomes are sustainable?
Which Sustainable Development Goals connect most closely with sustainable engineering? Provide a detailed justification and discuss the methods that can be used. Take a look at the UN SDG websites
Consider an emerging technology that has the potential to greatly benefit people but is also likely to cause ecological degradation. Discuss how society may respond to the adoption of such a
Give examples of practices that were once widely accepted but are now unthinkable. Select one such practice and learn about its history. What role did individual action play in enabling the change?
What is a performance economy?
Generating a joule of electricity requires 1.2 joules of biomass and 0.3 joules of additional energy. Determine the energy return on investment and energy efficiency.
For the US Sankey diagram shown in Figure 12.7.Figure 12.7:Calculate the energy efficiency of power generation and the four sectors. Obtain the Sankey diagrams for the USA from the cited source for
Why has the EROI of crude oil decreased over time?
From the US Sankey diagram, identify the least efficient and most efficient economic activities.
Sankey diagrams for various countries are available at http://flowcharts.llnl.gov. Obtain the flowcharts for China, Germany, Saudi Arabia, and USA for 2011. Compare the overall efficiency of each
Compare the material efficiency of the economies of the world and the European Union.
An input-output model is given as This system uses 300 J of energy for $50 of throughput in sector 1, and 100 J of energy for $100 of throughput from sector 2. All of this energy is used for
A home heating system maintains the indoor temperature at 20 C. The outside temperature is 0 C. A furnace burns natural gas to heat a 1:4 mixture of outside and inside air. The resulting air is at a
Professors David Pimentel and Bruce Dale debated the use of net energy analysis for determining "The Cost of Biofuels. Answer the following questions based on this article. Table 12.4 contains data
Consider the electricity generation system in the USA as shown in the Sankey diagram of Figure 12.7. Assuming that 70 percent of the total feedstock entering this system is converted into
For the rice preparation problem in Example 12.5, if three cups of water are used to wash the rice before cooking, draw the Sankey diagram and determine the material efficiency. Example 12.5 Cooking
For nickel flows in China, how has the material efficiency changed between 2000 and 2005? Perform this calculation with and without accounting for imports and exports.
Liquid iron at 1000 οC cools to 750 οC. Determine the lost work and generated entropy. Where does this entropy go? The specific heat of liquid iron is 0.197 cal/g οC.
What is the relationship between exergy and entropy?
Consider a water heater meant to increase the temperature from 25 οC to 100 οC. A manufacturer advertises the heater as 80 percent efficient. This is the first law efficiency, which means that 20
Explain why the exergetic efficiency of a process is less than 100 percent even when its energy efficiency is 100 percent.
A domestic boiler heating system is heating the outside air at 5 οC up to 20 οC with 80 percent first law efficiency. Determine the second law efficiency of this system. Draw the corresponding
What is the lost work in a perfectly reversible process?
A compressed air system stores the energy generated by solar panels on the company buildings' rooftops during the weekend for use during the week. The generated electricity over the weekend is used

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