MIT researchers discuss a limited availability of options on Carbon-Emissions, especially in the field of global manufacturing sector, due to streamlined processes already applied in the production of different materials:
A new report by researchers at MIT and elsewhere finds that the global manufacturing sector has made great strides in energy efficiency: The manufacturing of materials such as steel, cement, paper and aluminum has become increasingly streamlined, requiring far less energy than when these processes were first invented. However, despite more energy-efficient manufacturing, the researchers found that such processes may be approaching their thermodynamic limits: There are increasingly limited options available to make them significantly more efficient. The result, the team observed, is that energy efficiency for many important processes in manufacturing is approaching a plateau. The researchers looked at how materials manufacturing might meet the energy-reduction targets implied by the Intergovernmental Panel on Climate Change, which has suggested a 50 percent reduction in carbon-dioxide emissions by 2050 as a means of avoiding further climate change. Meanwhile, economists have estimated that global demand for materials will simultaneously double. To reduce energy use by 50 percent while doubling the output of materials, the team — led by graduate student Sahil Sahni and Tim Gutowski, a professor of mechanical engineering at MIT — studied whether manufacturing processes could improve in efficiency by 75 percent. The researchers identified the five most energy-using materials produced, and outlined scenarios in which further energy may be saved in manufacturing. But even in the most aggressive scenario, the team found it was only able to reduce energy use by about 50 percent — far short of its 75 percent goal.
On the other hand, the discussion is open in agriculture for carbon emissions affected by cropping sequence and nitrogen fertilization:
The USDA-Agricultural Research Service’s Northern Plains Agricultural Research Laboratory (NPARL) final BrownBagger presentation for 2013 is set for this Friday, April 5, from noon to 1 pm. It features NPARL Soil Scientist Upendra Sainju, who will discuss “Life-cycle assessment of dryland greenhouse gas emissions affected by cropping sequence and nitrogen fertilization.” In particular, Dr. Sainju will look at dryland malt barley production, including the various management options used for measuring greenhouse gas emissions, soil C sequestration, and dryland malt barley yield and quality and the best options he found to reduce net greenhouse gas emissions while still maintaining grain yield and quality. Traditional dryland farming practices for malt barley include conventional tillage, alternate-year fallow, and high nitrogen fertilization rates, all of which can generate substantial amounts of greenhouse gases (carbon dioxide, nitrous oxide, and methane), according to Sainju. Furthermore, additional carbon dioxide is also generated from fuel used by farm machines for tillage, fertilization, herbicide and pesticide applications and harvest, as well as from machines used by industry for nitrogen fertilizer production and application. On the plus side, atmospheric carbon dioxide can be stored as soil organic matter through plant fixation and returning the residue back to the soil, he noted. To harness that ability, Dr. Sainju’s research looked at the effects of traditional and improved management techniques, including no-tillage and crop rotation with or without nitrogen fertilization in greenhouse gas emissions under dryland malt barley production from 2008 to 2011 in eastern Montana. He calculated net greenhouse gas emissions from various management techniques by taking into account all greenhouse gas sources (carbon dioxide, nitrous oxide, methane, farm operations, and nitrogen fertilization) and sinks (crop residue returned to the soil and carbon sequestration) which remove greenhouse gases from the atmosphere.
More importantly, in the production of materials there is another serious dimension of lean manufacturing:
In his presentation, “Lean Manufacturing’s Unexpected Windfall: a Lower Carbon Footprint,” at ABB Automation and Power World in Orlando, Florida, Charles Cohon, CEO, Prime Devices Corp., said he usually talks about how lean manufacturing makes companies more profitable and gives them a competitive advantage. “This time, let’s talk about carbon footprint – the amount of electricity you use, the fossil fuel you burn, raw material utilization, water usage, sewer emissions – things like that.” Imagine your job is to lower carbon footprint. If you have many employees each driving to the plant, you might institute a carpooling program. A very successful carpooling program might reduce vehicles in half – a 50% reduction in commuting emissions. You might look at the building envelope and HVAC system, and make improvements that reduce natural gas consumption 20%. You could look at your lighting, ovens and fork lifts, and buy more efficient equipment, make operational improvements, or switch fuels to reduce their associated carbon footprints.Now consider the effect of lean manufacturing. Striving to eliminate waste by reducing work-in-process (WIP) and streamlining production can improve sustainability and provide an unexpected windfall in the form of a lower carbon footprint. This is not a new concept: “Consider the waste of overproduction, for example,” Cohon quoted Taiichi Ohno, father of the Toyota Production System. “It is not an exaggeration to say that in a low-growth period such waste is a crime against society more than a business loss.”
Finally, it is becoming clear that innovative applications can give the necessary “manufacturing space” for achieving carbon-emission targets.