Reducing carbon vs debate
Instead of debating whether global warming is a fact or a myth (Letters, Sept. 29, Oct. 3, Oct. 5 and Oct. 8), it would be more useful to discuss how to reduce carbon dioxide emissions in fuel combustion. An appealing incentive to reduce carbon emissions is that it will also save fossil fuels whose reserves are limited.
Energy, the environment and the economy (the three E’s) are equally important apexes of a triangle that will collapse if one apex is missing. For example, energy taxes or cap and trade will adversely impact the economy and employment, and is not recommended. Public consciousness is more effective than government taxing.
One pound (0.454kg) of fuel carbon produces 3.67 pounds of carbon dioxide emissions. Calculations show that the combustion of bituminous coal, iso-octane (a model compound for gasoline) and methane (the major component of natural gas) emits carbon dioxide at 210, 160 and 130 pounds per million British thermal units (BTU) of their heating values, respectively. One BTU is the amount of heat required to raise one pound of water by 1°F.
The heating value is converted only partly into useful heat because hot flue gas or exhaust gas is vented together with thermal energy into the atmosphere and some heat is also lost through combustion chamber walls. If the thermal efficiency is 30 percent, the carbon emissions of the coal, iso-octane and methane will be 700, 530 and 430 pounds per million BTUs of useful heat.
If the thermal efficiency is improved to 60 percent, the corresponding carbon emissions will be reduced to 350, 270 and 220 pounds per million BTUs.
The thermal efficiency can be improved by cutting down the excess air (without causing incomplete combustion), using oxygen-enriched air (for example, from membrane air separation) for combustion, recuperating heat from combustion products for preheating air, water (for a boiler) or fuel with heat exchangers, and/or partially condensing water vapors in combustion products to recover heat of vaporization with condensers. The improvements can be estimated from technical calculations for different applications.
A demonstration project is going on in West Virginia to study the feasibility of recovering carbon dioxide from coal flue gas and injecting it underground for disposal — instead of venting it into the air.
CHARLES HONG
Columbus, Ohio
Recently, China launched another diplomatic offensive against Taiwan, improperly linking its “one China principle” with UN General Assembly Resolution 2758 to constrain Taiwan’s diplomatic space. After Taiwan’s presidential election on Jan. 13, China persuaded Nauru to sever diplomatic ties with Taiwan. Nauru cited Resolution 2758 in its declaration of the diplomatic break. Subsequently, during the WHO Executive Board meeting that month, Beijing rallied countries including Venezuela, Zimbabwe, Belarus, Egypt, Nicaragua, Sri Lanka, Laos, Russia, Syria and Pakistan to reiterate the “one China principle” in their statements, and assert that “Resolution 2758 has settled the status of Taiwan” to hinder Taiwan’s
Singaporean Prime Minister Lee Hsien Loong’s (李顯龍) decision to step down after 19 years and hand power to his deputy, Lawrence Wong (黃循財), on May 15 was expected — though, perhaps, not so soon. Most political analysts had been eyeing an end-of-year handover, to ensure more time for Wong to study and shadow the role, ahead of general elections that must be called by November next year. Wong — who is currently both deputy prime minister and minister of finance — would need a combination of fresh ideas, wisdom and experience as he writes the nation’s next chapter. The world that
The past few months have seen tremendous strides in India’s journey to develop a vibrant semiconductor and electronics ecosystem. The nation’s established prowess in information technology (IT) has earned it much-needed revenue and prestige across the globe. Now, through the convergence of engineering talent, supportive government policies, an expanding market and technologically adaptive entrepreneurship, India is striving to become part of global electronics and semiconductor supply chains. Indian Prime Minister Narendra Modi’s Vision of “Make in India” and “Design in India” has been the guiding force behind the government’s incentive schemes that span skilling, design, fabrication, assembly, testing and packaging, and
Can US dialogue and cooperation with the communist dictatorship in Beijing help avert a Taiwan Strait crisis? Or is US President Joe Biden playing into Chinese President Xi Jinping’s (習近平) hands? With America preoccupied with the wars in Europe and the Middle East, Biden is seeking better relations with Xi’s regime. The goal is to responsibly manage US-China competition and prevent unintended conflict, thereby hoping to create greater space for the two countries to work together in areas where their interests align. The existing wars have already stretched US military resources thin, and the last thing Biden wants is yet another war.