Review of the pyrolysis platform for coproducing bio‐oil and biochar

Abstract

Pyrolysis is a relatively simple, inexpensive, and robust thermochemical technology for transforming biomass into bio-oil, biochar, and syngas. The robust nature of the pyrolysis technology, which allows considerable fl exibility in both the type and quality of the biomass feedstock, combined with a distributed network of small pyrolysis plants, would be compatible with existing agriculture and forestry infrastructure. Bio-oil can be used as a fuel in existing industrial boilers. Biochar can be used with existing infrastructure as a replacement for pulverized coal; however, use of biochar as a soil amendment results in signifi cant environmental and agronomic benefi ts. Soil application of biochar is a means of sequestering large amounts of C and may have other greenhouse gas benefi ts. Preliminary reports of the impact of soil biochar applications on crop yields indicate that biochar quality is very important. Biochar is an effective adsorbent for both nutrients and organic contaminants, hence the presence of biochar in soils has been shown to improve water quality in column leaching and fi eld lysimeters studies and it is anticipated to do the same for agricultural watersheds.The pyrolysis platform for producing bio-oil and biochar from biomass appears to be a practical, effective, and environmentally sustainable means of producing large quantities of renewable bioenergy while simultaneously reducing emissions of greenhouse gases. At the present time, the pyrolysis platform is economically marginal because markets for bio-oil and biochar are highly competitive. However, if the USA adopts a program for controlling greenhouse gases, the pyrolysis platform would be highly competitive. Published in

Effects of amendment of different biochars on soil carbon mineralisation and sequestration

“…Most of the C (>99%) from the biochar addition remained in the soil for a long time, indicating that biochar has high C-sequestration potential. The low degradability of C from biochar has been reported in the literature (Kuzyakov et al 2009;Major et al 2010) and is strongly promoted for C-sequestration aims (Lehmann 2007;Laird et al 2009). The small rate constant values for the slow turnover pool (in the order of 10 À6 day -1 ) indicate that the increased C resulting from biochar application will stay in the soil for long time.…”

Midwest vision for sustainable fuel production

“…Systematic comparisons of production potential and nutrient, water, and energy use efficiency for low-input polycultures, mixed grass-legume systems and managed switchgrass systems are essential for optimizing biomass production. Recycling nutrients harvested with biomass to adjacent crop lands through soil biochar applications [36] may enhance nutrient use efficiency at a landscape scale. Soil biochar applications may further enhance system sustainability by improving soil quality [34], reducing nutrient leaching [35,39], sequestering C [70], and increasing yields especially on marginal and degraded soils [71].…”

A CFD study of biomass pyrolysis in a downer reactor equipped with a novel gas–solid separator-II thermochemical performance and products

“…This is a robust thermo-chemical process that takes place in a controlled environment (reactor) to convert low density organic materials into vapour, liquid and solid (bio-char) at a high temperature within the range of 400 °C to 550 °C and in the absence of oxygen [1][2][3]. The vapour is quickly condensed in a quenching system to produce a liquid (bio-oil) and a permanent noncondensable gas (NCG) phase, mainly consisting of CO, CO 2 and small fractions of H 2 and CH 4 [4].…”

“…The process is usually classified as fast pyrolysis If the heating rate is rapid (1000 °C/s -10,000 °C/s) [5] and the gas residence time is less than 2 s [2,6]. Fast pyrolysis of biomass has the advantage of maximising the yield of bio-oil, typically produces 50 to 70% bio-oil, 0 to 30% bio-char, and 15 to 20% NCG [1].…”