Characteristics of Aerosol Formation and Emissions During Corn Stalk Pyrolysis

Ning Li,Jiale Zhang,Zhihe Li,Yongjun Li

doi:10.3390/en13225924

Abstract

The inevitable emission of aerosols during pyrolysis can negatively affect the downstream process and even pollute the environment. In this work, the characteristics of aerosols were investigated during corn stalk pyrolysis at 400–900 °C. The effects of other operation conditions on the aerosol emissions were also probed with online and offline instruments. Results show the yield of aerosol presents a regular change with temperature in a wide range ratio of 3.4–8.7 wt.%. The aerosol size distribution reveals a unimodal form mainly in the 1.1–2.1 μm accumulation range and the maximum emission achieved is about 35 mg/g for SR and SP at 500 °C. Nevertheless, SL gives about 34 mg/g at 600 °C. High temperature promotes the decomposition of polymers into partciles with small diameter (less than PM1.0). The microtopography of aerosol presents spherical droplets, elongated-like liquid and solid particles that form heterogenous or homogeneous aggregations, that also happen on account of collisions. Aerosols contain mostly organic matter, a small amount of salt and over 50% of volatile organic carbon molecules (VOCs) in the total organic carbon (OC). Proper gas flow, high vapor concentration and longer path way boost the yield of bio-oil and reduce the emission of aerosols. The direct contact is beneficial for adequate extraction, but also causes additional solvent emissions.

Highlights

Biomass-derived fuels are recyclable, abundant, multiduty and CO2 neutral energy sources that amount to approximately 10 times the world’s current energy consumption (1.08 × 1010 tons of oil/year) [1,2] and half of that amount can be sourced from lignocellulosic wastes [3].Faced with such vast resource reserves, simple and inefficient household combustion is the initially dominant mode for cooking and heating [4]
Aerosols are transported into the downstream process steps by non-condensable gas and cause corrosion and deposition on the surface of equipment that accelerates the damage to facilities and reduces the quality of the bio-oil and synthesis products [11] which increases the demand for removal equipment [12]
The characteristics of aerosols formed from different tissues during corn stalk pyrolysis were investigated at 400–900 °C in a fixed bed reactor

Summary

Introduction

Biomass-derived fuels are recyclable, abundant, multiduty and CO2 neutral energy sources that amount to approximately 10 times the world’s current energy consumption (1.08 × 1010 tons of oil/year) [1,2] and half of that amount can be sourced from lignocellulosic wastes [3]. Faced with such vast resource reserves, simple and inefficient household combustion is the initially dominant mode for cooking and heating [4]. If not properly handled, the emitted aerosols are considered

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Conclusion