Gaseous Carbon Waste Streams Utilization Status and Research Needs (2019) / Chapter Skim
Currently Skimming:
2 Gaseous Carbon Waste Resources
2 Gaseous Carbon Waste Resources
Pages 27-38
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 27... ...
This chapter will also attempt to distinguish between those sources of methane in waste gas that are more likely to be directly reused as fuel rather than chemically transformed through carbon utilization technologies. CHARACTERIZATION OF CARBON WASTE STREAMS Carbon utilization technologies focus on conversion of two major carbon resources -- carbon dioxide and methane -- into useful products.
|
From page 28... ...
Carbon Dioxide Waste Streams Global emissions of carbon dioxide waste caused by human activities, primarily fossil fuel combustion, have been increasing rapidly. Counter to the global trend, carbon dioxide emissions have been decreasing in the United States, from an estimated peak of 5.38 billion metric tons of carbon dioxide in 2004 (after accounting for uptake by forestry and land use change)
|
From page 29... ...
Power Plants About one-third of U.S. carbon dioxide emissions come from electric power plants that burn fossil fuels and generate waste gases at high rates.
|
From page 30... ...
power plants in 2016.
|
From page 31... ...
While emissions from glass production have stayed relatively constant over the past 15 years, emissions from steel production have decreased due to technological improvements and increased scrap streel utilization. Methane Waste Streams Carbon dioxide is fundamentally a low-value, low-energy waste gas that is often emitted in large flows from individual sources.
|
From page 32... ...
of methane in waste gas in the United States might be available for nonfuel carbon utilization, a sector-by-sector analysis of emissions was performed by the committee. As described below, a large fraction of methane emissions in waste gas will face significant barriers to use as a feedstock for carbon FIGURE 2-5 Methane emissions in the United States in 2016.
|
From page 33... ...
For example, the International Energy Agency, in its special section on natural gas in the 2017 World Energy Outlook (IEA, 2017) , estimated that approximately half of methane emissions associated with natural gas production could be reduced at a cost that could be justified based on the fuel value of the natural gas recovered or saved.
|
From page 34... ...
Other sources of methane emissions in natural gas production may be less preventable but nonetheless have limited potential for carbon utilization processes, largely due to their intermittent nature. For example, emissions from compressor and pipeline blowdowns, as well as venting of wells to remove accumulated liquid, can lead to very large flow rates of methane (reaching approximately 1,000 kilograms per hour; Allen et al., 2015)
|
From page 35... ...
Because this landfill gas consists primarily of methane and carbon dioxide, in roughly equal quantities, it has significant energy content. Energy recovery from landfill gases has been practiced for decades in the United States; however, the economic value of this waste gas utilization has been marginal, with landfill gas energy recovery becoming more or less prevalent as the prices of other fuels, most notably natural gas, vary over time.
|
From page 36... ...
MATCHING CARBON WASTE STREAMS WITH UTILIZATION PROCESSES: RESEARCH NEEDS The carbon sources contained in waste streams are rarely available in pure form, and the composition of waste gas streams varies widely, depending on the source of the waste gas. Which chemical species found in gaseous carbon waste streams pose challenges to carbon utilization processes also depends on the utilization technologies to be used.
|
From page 37... ...
2016b. Options for Reducing Methane Emissions from Pneumatic Devices in the Natural Gas Industry.
|
From page 38... ...
2018. Improving Characterization of Anthropogenic Methane Emissions in the United States.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.