Sustainability: the capacity of smokeless biomass pyrolysis for energy production, global carbon capture and sequestration

Abstract

Smokeless biomass pyrolysis for biochar and biofuel production is a possible arsenal for global carbon capture and sequestration at gigatons of carbon (GtC) scales. The United States can annually harvest over 1.3 Gt (gigaton) of dry biomass. Use of the smokeless (clean and efficient) biomass-pyrolysis technology would enable the United States to converts its 1.3 Gt of annually harvestable biomass to biochar products equivalent to 325 million tons of stable carbon plus significant amount of biofuels including syngas and bio-oils. Currently, the world could annually harvest more than 6.5 GtC y À1 of biomass. The 6.5 GtC y À1 of biomass could be converted to biochar (3.25 GtC y À1 ) and biofuels (with heating value equivalent to that of 6500 million barrels of crude oil). Because biochar is mostly not digestible to microorganisms, a biochar-based soil amendment could serve as a permanent carbonsequestration agent in soils/subsoil earth layers for thousands of years. By storing 3.25 GtC y À1 of biochar (equivalent to 11.9 Gt of CO 2 per year) into soil and/or underground reservoirs alone, it would offset the world's 8.67 GtC y À1 of fossil fuel CO 2 emissions by about 38%. The worldwide maximum capacity for storing biochar carbon into agricultural soils (1411 million hectares) is estimated to be about 428 GtC. It may be also possible to provide a global carbon ''thermostat'' mechanism by creating biochar carbon energy storage reserves. This biomass-pyrolysis ''carbon-negative'' energy approach merits serious research and development worldwide to help provide clean energy and control global warming for a sustainable future of human civilization on Earth.

Agroforestry and biochar to offset climate change: a review

“…In addition, biochar can effectively absorb ammonia (NH 3 ), reducing its loss through volatilization. However, the biochar itself contains a limited amount of available mineral nutrients in its ash content, and therefore, its application in soil is usually done in conjunction with fertilizer management (Lee et al 2010). Nonetheless, the high capacity to absorb nutrients enables their retention in the rooting zone, increasing fertilizer efficiency while decreasing the leaching of nutrients and reducing contamination of underground water sources (Glaser et al 2002;Laird et al 2010a).…”

“…However, the efficiency for long-term C sequestration by biomass is limited because large portion of the C is unstable, returning to the atmosphere as CO 2 through decomposition and respiration in a short time of months to years. Therefore, in order to considerably increase long-term C sequestration, biomass has to be converted to a relatively non-degradable form, such as biochar (Lehmann 2007a;Lee et al 2010). Biochar is a by-product of the C-negative pyrolysis technology for production of bio-energy from organic materials.…”

“…The biochar production scale varies from small to large and technologies vary from batch retort kiln to continuousprocess kiln (Kelpie 2011). Considering an application rate of between 10 and 100 Mg biochar per hectare (Chan et al 2007) and that biochar's C concentration is between 50% ) and 78% (Gaskin et al 2008), and assuming a total area of 1,411 Mha cropland around the world (Lee et al 2010), then the global capacity for storing biochar-C under this landuse is between 7 and 110 Pg. Lee et al (2010) noted that additional infinite amounts of biochar could be sequestered in abandoned mines, underground reservoirs, and geological formations.…”

Characterization of Biochars Produced from Cornstovers for Soil Amendment

“…This "carbon-negative" biomass-pyrolysis energy-production concept of applying biochar as a soil amendment and carbon sequestration agent was initiated in 2002 by Danny Day of Eprida Power and Life Sciences Inc. and one of us (Lee) with a provisional U.S. patent application followed by a PCT application (3). Certain related studies including biochar-related soil research have also indicated the possibility of using biochar as a soil amendment for carbon sequestration (4)(5)(6)(7). This paper explores the effect of pyrolysis conditions on biochar properties.…”

Characterization of energy carriers obtained from the pyrolysis of white ash, switchgrass and corn stover — Biochar, syngas and bio-oil

“…Increasing anthropogenic CO 2 emission and global warming have challenged the world to find new and better ways to meet the world's increasing needs for energy while reducing greenhouse gases [1]. Biomass was once an important source of energy for humankind and it is starting to play the role again [2] because biomass is a clean, cost-effective, CO 2 neutral and low sulfur content renewable material which can be used for heat and fuel production [3].…”