paper<\/a> by MIT Energy Initiative (MITEI) Director William H. Green, graduate student Sayandeep Biswas, MITEI Director of Research Randall Field, and two others.<\/p>\n\u201cAmmonia has the most carbon dioxide emissions of any kind of chemical,\u201d says Green, who is the Hoyt C. Hottel Professor in Chemical Engineering. \u201cIt\u2019s a very important chemical,\u201d he says, because its use as a fertilizer is crucial to being able to feed the world\u2019s population.<\/p>\n
Until late in the 19th century, the most widely used source of nitrogen fertilizer was mined deposits of bat or bird guano, mostly from Chile, but that source was beginning to run out, and there were predictions that the world would soon be running short of food to sustain the population. But then a new chemical process, called the Haber-Bosch process after its inventors, made it possible to make ammonia out of nitrogen from the air and hydrogen, which was mostly derived from methane. But both the burning of fossil fuels to provide the needed heat and the use of methane to make the hydrogen led to massive climate-warming emissions from the process.<\/p>\n
To address this, two newer variations of ammonia production have been developed: so-called \u201cblue ammonia,\u201d where the greenhouse gases are captured right at the factory and then sequestered deep underground, and \u201cgreen ammonia,\u201d produced by a different chemical pathway, using electricity instead of fossil fuels to hydrolyze water to make hydrogen.<\/p>\n
Blue ammonia is already beginning to be used, with a few plants operating now in Louisiana, Green says, and the ammonia mostly being shipped to Japan, \u201cso that\u2019s already kind of commercial.\u201d Other parts of the world are starting to use green ammonia, especially in places that have lots of hydropower, solar, or wind to provide inexpensive electricity, including a giant plant now under construction in Saudi Arabia.<\/p>\n
But in most places, both blue and green ammonia are still more expensive than the traditional fossil-fuel-based version, so many teams around the world have been working on ways to cut these costs as much as possible so that the difference is small enough to be made up through tax subsidies or other incentives.<\/p>\n
The problem is growing, because as the population grows, and as wealth increases, there will be ever-increasing demands for nitrogen fertilizer. At the same time, ammonia is a promising substitute fuel to power hard-to-decarbonize transportation such as cargo ships and heavy trucks, which could lead to even greater needs for the chemical.<\/p>\n
\u201cIt definitely works\u201d as a transportation fuel, by powering fuel cells that have been demonstrated for use by everything from drones to barges and tugboats and trucks, Green says. \u201cPeople think that the most likely market of that type would be for shipping,\u201d he says, \u201cbecause the downside of ammonia is it\u2019s toxic and it\u2019s smelly, and that makes it slightly dangerous to handle and to ship around.\u201d So its best uses may be where it\u2019s used in high volume and in relatively remote locations, like the high seas. In fact, the International Maritime Organization will soon be voting on new rules that might give a strong boost to the ammonia alternative for shipping.<\/p>\n
The key to the new proposed system is to combine the two existing approaches in one facility, with a blue ammonia factory next to a green ammonia factory. The process of generating hydrogen for the green ammonia plant leaves a lot of leftover oxygen that just gets vented to the air. Blue ammonia, on the other hand, uses a process called autothermal reforming that requires a source of pure oxygen, so if there\u2019s a green ammonia plant next door, it can use that excess oxygen.<\/p>\n
\u201cPutting them next to each other turns out to have significant economic value,\u201d Green says. This synergy could help hybrid \u201cblue-green ammonia\u201d facilities serve as an important bridge toward a future where eventually green ammonia, the cleanest version, could finally dominate. But that future is likely decades away, Green says, so having the combined plants could be an important step along the way.<\/p>\n
\u201cIt might be a really long time before [green ammonia] is actually attractive\u201d economically, he says. \u201cRight now, it\u2019s nowhere close, except in very special situations.\u201d But the combined plants \u201ccould be a really appealing concept, and maybe a good way to start the industry,\u201d because so far only small, standalone demonstration plants of the green process are being built.<\/p>\n
\u201cIf green or blue ammonia is going to become the new way of making ammonia, you need to find ways to make it relatively affordable in a lot of countries, with whatever resources they\u2019ve got,\u201d he says. This new proposed combination, he says, \u201clooks like a really good idea that can help push things along. Ultimately, there\u2019s got to be a lot of green ammonia plants in a lot of places,\u201d and starting out with the combined plants, which could be more affordable now, could help to make that happen. The team has filed for a patent on the process.<\/p>\n
Although the team did a detailed study of both the technology and the economics that show the system has great promise, Green points out that \u201cno one has ever built one. We did the analysis, it looks good, but surely when people build the first one, they\u2019ll find funny little things that need some attention,\u201d such as details of how to start up or shut down the process. \u201cI would say there\u2019s plenty of additional work to do to make it a real industry.\u201d But the results of this study, which shows the costs to be much more affordable than existing blue or green plants in isolation, \u201cdefinitely encourages the possibility of people making the big investments that would be needed to really make this industry feasible.\u201d<\/p>\n
This proposed integration of the two methods \u201cimproves efficiency, reduces greenhouse gas emissions, and lowers overall cost,\u201d says Kevin van Geem, a professor in the Center for Sustainable Chemistry at Ghent University, who was not associated with this research. \u201cThe analysis is rigorous, with validated process models, transparent assumptions, and comparisons to literature benchmarks. By combining techno-economic analysis with emissions accounting, the work provides a credible and balanced view of the trade-offs.\u201d<\/p>\n
He adds that, \u201cgiven the scale of global ammonia production, such a reduction could have a highly impactful effect on decarbonizing one of the most emissions-intensive chemical industries.\u201d<\/p>\n
The research team also included MIT postdoc Angiras Menon and MITEI research lead Guiyan Zang. The work was supported by IHI Japan through the MIT Energy Initiative and the Martin Family Society of Fellows for Sustainability.\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"Ammonia is one of the most widely produced chemicals in the world, used mostly as fertilizer, but also…\n","protected":false},"author":2,"featured_media":61849,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[45603,45609,45601,45602,114,45607,4405,45606,45604,45605,45600,85,46,45599,45610,45611,45612,45608],"class_list":["post-61848","post","type-post","status-publish","format-standard","has-post-thumbnail","category-business","tag-ammonia-production","tag-bill-green","tag-blue-ammonia","tag-blue-green-ammonia","tag-business","tag-climate-crisis","tag-decarbonization","tag-emissions-reduction","tag-fertilizer-production","tag-fuel-cells","tag-green-ammonia","tag-il","tag-israel","tag-mitei","tag-randall-field","tag-randy-field","tag-sayandeep-biswas","tag-william-green"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/61848","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/comments?post=61848"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/posts\/61848\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media\/61849"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/media?parent=61848"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/categories?post=61848"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/il\/wp-json\/wp\/v2\/tags?post=61848"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}