Case Study Process using Bio-Char: Ray Chrisman, Atodyne and Affiliate Faculty, Forest Resources, UW

Transcription

1 Case Study Process using Bio-Char: Ray Chrisman, Atodyne and Affiliate Faculty, Forest Resources, UW Presented with permission from BEST Energies, INC.

2 What is Agrichar TM biochar? Agrichar TM product is derived from Slow Pyrolysis which involves heating biomass in the absence (or reduced supply) of air Agrichar TM product delivers significant agricultural and environmental benefits whilst sequestering carbon in soil

3 The terra preta example of product performance Photos: Julie Major, Cornell University

4 Terra-Preta: Evidence of longevity years old Amazon - Extreme environment for fast organics turnover 10% Total Carbon, 35% of which is Black Carbon. Char 3.5% of total soil.

5 Increased Productivity 1a: Soil only 3a: Soil + Char 30 cm 70 cm 4a: Soil + NPK Char 105 cm 2a: Soil + NPK 55 cm

6 The Gigaton environmental challenge In 2005, globally averaged concentrations of carbon dioxide in the atmosphere reached their highest levels ever recorded (Science Daily, Nov. 4, 2006). Stabilizing CO 2 at 400 ppm requires approximately 35 GT CO 2 (~10 GT carbon) to be withdrawn from the atmosphere by

7 Annual carbon fluxes

8 Lehmann et al., 2006, Mitigation and Adaptation Strategies for Global Change, in press How Char can help Organics to Land Vs Char

9 Biochar a Gigaton response Annual potential for biochar sequestration 10 5 Gt Carbon High Hypothetical (40% biomass to biochar) Low Gaunt unpublished Source: Lehmann, 2007, Nature

10 There are many variations for pyrolysis for energy & Agrichar TM Fast pyrolysis is the most widely reported variation: It has a residence time of a few seconds and requires a very rapid heating of the particles to achieve high conversion to bio-oils, syngas and solids. Requires careful selection of feedstocks and extensive investment in pretreatment of the feedstocks to achieve proper particle size. Kit/docs/AREED_pics_overview.pdf -

11 Three basic approaches to pyrolysis Gasification (produces little char and will be not be discussed) Fast pyrolysis Slow pyrolysis These are generally based on process parameters such as temperature, residence time and biomass heating rate

12 The pyrolysis processes typically produce three general product types based on physical state A gas that includes syn-gas A complex hydrocarbon liquid and water A solid char The relative yields and composition of these products are a function of process conditions.

13 The process conditions and typical yields Slow pyrolysis generally has a long residence time and lower temperature with char being a principle product. Fast pyrolysis has a much shorter residence time and higher temperatures with bio-oil being the principle product.

14 Bulk composition of a typical biomass material

15 In addition to the bulk materials, biomass has the following components Extractables such as resins, starches, waxes, lipids, hydrocarbons and various phenolics which in total are only about 1-5% on a dry basis. Water Ash which is the metal ions and silica. Ash can vary from 0.5% for most woods to over 20% in some plants with much of it silica in rice hulls.

16 BEST Energies uses Slow Pyrolysis Lower heating rates than fast pyrolysis Produce only syn-gas and Agrichar TM products. Approximately 35% by weight of the dry feed material is converted to Agrichar TM products.

17 BEST s Australian Demo facility Fully continuous with Integrated drying Handles biomass with up to 50% moisture Can process high and low ash biomass Syngas produced runs 300 kwe internal combustion engine Can be scaled to process 48 & 96 dry ton/day

18 Key technical challenges Biomass drying Biomass composition Product properties as a function of processing conditions Product performance in the soil Lifetime in the soil

19 Next steps for Agrichar TM biochar Creating demand for Agrichar TM biochar is crucial to delivering the Gt vision. Demonstration of benefits of biochar is needed at agriculturally and environmentally relevant scales. Supply of biochar is currently a major constraint to this research. Development of optimized Agrichar TM products & pyrolysis applications.

20 BEST supports International research in the use of biochar BEST Energies hosted the first annual International Agrichar conference in Gosford, Australia in 2007 The next conference will be held in Newcastle, Sept 2008 We propose to use the St Andrews award to stimulate research and demonstration of the benefits of biochar We will launch the Agrichar Innovation Competition at the International Biochar Initiative (IBI) conference at Newcastle University using the award to provide Agrichar TM products to research groups