{"id":64357,"date":"2019-06-27T06:41:21","date_gmt":"2019-06-27T04:41:21","guid":{"rendered":"https:\/\/rss.nova-institut.net\/public.php?url=http%3A%2F%2Fwww.biofuelsdigest.com%2Fbdigest%2F2019%2F06%2F20%2Fiowa-state-university-researchers-find-biochar-ideal-for-slow-release-fertilizer%2F"},"modified":"2019-06-24T19:17:18","modified_gmt":"2019-06-24T17:17:18","slug":"iowa-state-researchers-studying-slow-release-fertilizer-to-feed-crops-improve-water-quality","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/iowa-state-researchers-studying-slow-release-fertilizer-to-feed-crops-improve-water-quality\/","title":{"rendered":"Iowa State researchers studying slow-release fertilizer to feed crops, improve water quality"},"content":{"rendered":"

Researchers looking to add value to biochar<\/a> \u2013 a solid, porous co-product of heating corn stalks and other sources of biomass to produce liquid bio-oil in a process called pyrolysis<\/a> \u2013 were studying its physical and chemical properties.<\/strong><\/p>\n

\"Robert
Robert C. Brown and Santanu Bakshi, left to right, are part of a team looking for ways to make biochar — a black powder that’s a co-product of bio-oil production — more useful and valuable. Photosby Christopher Gannon.<\/figcaption><\/figure>\n

\u201cWe\u2019ve calculated biochar\u2019s incredible ability to store carbon in a small package,\u201d said Robert C. Brown, director of Iowa State\u2019s Bioeconomy Institute<\/a>. \u201cOne day it might be valued at $200 per ton for its ability to remove carbon from the atmosphere, but currently it\u2019s only worth about $40 per ton \u2013 the energy value of burning it as a coal substitute.\u201d<\/p>\n

So, what could add value to this black powder, making pyrolysis a more economically attractive biofuel technology?<\/p>\n

Maybe biochar could be mixed with biomass to improve the quality of biogas from anaerobic digestion? Or maybe it could help control livestock odors? Or, maybe it could be mixed with composted manure and the fibrous leftovers of anaerobic digestion to produce a fertilizer?<\/p>\n

A research team led by Brown \u2013 who\u2019s also an Anson Marston Distinguished Professor in Engineering<\/a> and the Gary and Donna Hoover Chair in Mechanical Engineering<\/a> \u2013 won a two-year, $1,469,448 grant to find valuable applications for biochar<\/a>. The grant is from the Biomass Research and Development Initiative, a joint program of the U.S. Departments of Agriculture and Energy.<\/p>\n

Biochar as a sponge<\/h3>\n

The grant put Santanu Bakshi, an assistant scientist at the Bioeconomy Institute, to work on yet another biochar project. He\u2019s worked with the material for most of the decade, starting as a doctoral student at the University of Florida looking into how biochar could be used to reduce copper toxicity in the soils supporting citrus groves. In another project, Bakshi showed the effectiveness of biochar in removing arsenic from drinking water.<\/p>\n

That led to biochar projects, including arsenic sticking \u2013 adsorbing \u2013 to the surface of biochar and another that involved capturing phosphorous from wastewater.<\/p>\n

As often happens during research, all those projects built on each other to produce a new discovery. Bakshi discovered that biochar produced from biomass pretreated with iron sulfate, an inexpensive byproduct of steel making, can adsorb to its surface up to 12 times the phosphate as biochar from untreated biomass.<\/p>\n

The iron sulfate pretreatment developed at Iowa State was designed to increase the yield of sugar from pyrolysis of woody and grassy biomass. Like starch from corn, this sugar can be fermented to produce biofuels.<\/p>\n

But the pretreatment also boosted biochar performance in another important way.<\/p>\n

Biochar\u2019s surface mostly holds negative charges. And so does phosphate \u2013 an anion that has more negatively charged electrons than positively charged protons. The two should repel each other. But, when biomass is treated with iron sulfate before pyrolysis, the surface of biochar is modified so it can readily adsorb anions to its surface.<\/p>\n

In lab tests, Bakshi has measured 48,000 milligrams of phosphate adsorbed per kilogram of pretreated biochar, compared to 4,000 milligrams adsorbed per kilogram of untreated biochar.<\/p>\n

And so, biochar could be mixed with manure to adsorb phosphate \u2013 a major plant nutrient \u2013 and then applied to soil as a solid fertilizer.<\/p>\n

\u201cWith this technology, we\u2019re trying to improve the recycling of phosphates to the soil,\u201d Bakshi said.<\/p>\n

Stable and slow<\/h3>\n

The application of nutrients via biochar \u2013 unlike some fertilizers used today \u2013 is stable in the soil and won\u2019t wash away in the rain or leach into groundwater. That could improve the quality of water running off farm fields, decreasing the nutrients that feed algal blooms that take up oxygen in water, helping to create the Gulf of Mexico\u2019s \u201cdead zone.\u201d<\/a><\/p>\n

Bakshi also found biochar doesn\u2019t release adsorbed phosphate quickly. He\u2019s calculated that it releases nearly 18 milligrams of phosphorous per kilogram of soil after three hours of continuous leaching with water \u2013 just about equal to the 22 milligrams of phosphorous per kilogram of soil that\u2019s recommended for growing crops.<\/p>\n

By oxidizing the iron in the pretreatment process, Bakshi said even more phosphate can be adsorbed and released, nearly 23 milligrams per kilogram of soil after three hours of leaching with water.<\/p>\n

\u201cPhosphate adsorbed on biochar can provide the phosphorous needed by crops,\u201d Bakshi said. \u201cBut being less soluble in water than conventional fertilizer means the phosphorous will remain in the fields during rainstorms rather than being washed away.\u201d<\/p>\n

Because they\u2019re also negatively charged anions, Bakshi said the process should also work with nitrates, another major plant nutrient associated with water-quality problems. He\u2019s planning lab tests to determine if that\u2019s the case.<\/p>\n

There will also be greenhouse tests with potted crop plants and eventually field tests.<\/p>\n

\u201cThis might change how farmers apply fertilizer treatments,\u201d Brown said.<\/p>\n

And that idea wasn\u2019t even in the researchers\u2019 successful grant proposal.<\/p>\n

\u201cThis is so typical of research,\u201d Brown said. \u201cYou come up with something you didn\u2019t even expect \u2013 and here we have a form of charcoal that could be used as slow-release fertilizer.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Researchers looking to add value to biochar \u2013 a solid, porous co-product of heating corn stalks and other sources of biomass to produce liquid bio-oil in a process called pyrolysis \u2013 were studying its physical and chemical properties. \u201cWe\u2019ve calculated biochar\u2019s incredible ability to store carbon in a small package,\u201d said Robert C. Brown, director […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","nova_meta_subtitle":"","footnotes":""},"categories":[5572],"tags":[12738,5842,5817],"supplier":[1185],"class_list":["post-64357","post","type-post","status-publish","format-standard","hentry","category-bio-based","tag-biochar","tag-biomass","tag-research","supplier-iowa-state-university"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/64357","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=64357"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/64357\/revisions"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=64357"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=64357"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=64357"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=64357"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}