Shaobo Deng

Physical and Chemical Properties of Bio-Oils From Microwave Pyrolysis of Corn Stover

This study was aimed to understand the physical and chemical properties of pyrolytic bio-oils produced from microwave pyrolysis of corn stover regarding their potential use as gas turbine and home heating fuels. The ash content, solids content, pH, heating value, minerals, elemental ratio, moisture content, and viscosity of the bio-oils were determined. The water content was approx 15.2 wt%, solids content 0.22 wt%, alkali metal content 12 parts per million, dynamic viscosity 185 mPa·s at 40°C, and gross high heating value 17.5 MJ/kg for a typical bio-oil produced. Our aging tests showed that the viscosity and water content increased and phase separation occurred during the storage at different temperatures. Adding methanol and/or ethanol to the bio-oils reduced the viscosity and slowed down the increase in viscosity and water content during the storage. Blending of methanol or ethanol with the bio-oils may be a simple and cost-effective approach to making the pyrolytic bio-oils into a stable gas turbine or home heating fuels.

Liquefaction of corn cobs with supercritical water treatment

Corn cob powder was liquefied in a high-pressure reactor. The composition of the gas and liquid phases produced were analyzed. It was found that the yield of the gas phase and liquid phase increased, while the yield of solid residue decreased with increasing temperature. The gas phase was 33.4% to 49.15% (wt %), the liquid phase was 22.6% to 43% (wt %), and the solid phase was 23.6% to 28.25% (wt %) at 5 to 20 min. Liquid yield increased with the addition of potassium hydroxide. Total liquefaction yield decreased with the increasing of corn cob powder content. The gas phase consisted of hydrogen, carbon dioxide, carbon monoxide, methane, and a small amount of hydrocarbon. The liquid phase consisted of cyclic aromatic hydrocarbon, ketone, aldehyde, carboxylic acid, ester, nitrogenated compound, and related derivatives.

Production and evaluation of biodiesel and bioethanol from high oil corn using three processing routes.

Six Korea high oil (KHO) corn varieties varying in germ and endosperm size and oil content (4-21%, wet basis) were subjected to three sequential combinations of milling (M), germ separation (S), fermentation (F), and in situ transesterification (T) to produce bioethanol and biodiesel. Production parameters including saccharification, bioethanol yield, biodiesel yield and composition, and conversion rate were evaluated. The effects of the contents of germ, endosperm size, oil, and non-oil solid mass on the production parameters strongly depended on the processing routes, namely M-F-T, M-T-F, and S-T|F. The M-F-T route produced the highest bioethanol yield while the S-T|F route produced the highest biodiesel yield. The in situ transesterification reaction, if proceeded before fermentation, reduced the bioethanol yield while fermentation and/or presence of endosperm reduced the biodiesel yield.

Liquefaction of Corn Cobs with Supercritical Water Treatment

Corncob powder was liquefied in a high pressure reactor. The composition of the gas and liquid phases produced were analyzed. It was found that the yield of gas phase and liquid phase increased while the yields of solid residue decreased with increasing temperature. The gas phase was 33.4 -49.15% (wt%), the liquid phase 22.6 - 43% (wt%), and solid phase 23.6 - 28.25% (wt%) at 5 - 20 min. Liquid yield increased with the addition of potassium hydroxide. Total liquefaction yield decreased with the increasing of corncob content. The gas phase consisted of hydrogen, carbon dioxide, carbon monoxide, methane, and small amount of hydrocarbon. The liquid phase consisted of cyclic aromatic hydrocarbon, ketone, aldehyde, carboxylic acid, ester, nitrogenated compound and related derivatives.

Microwave Pyrolysis of Biomass

The present study was to investigate the microwave-assisted pyrolysis of corn stoves under different conditions. The process yielded syngas, bio-oils, and solid charcoals. Under our experimental conditions, a power input level above 300 W was necessary to initiate thermal pyrolysis of corn stover. The degradation of solid corn stover increased with increasing microwave power. A higher power input also favored syngas production. Adding 1% pyrolytic charcoal residue to the corn stover increased the yields, particularly the liquid fraction yield. Addition of NaOH to the corn stover as catalyst increased the syngas yield greatly. The chemical profiles of the syngas and bio-oils were determined using GC and GC-MS. This study demonstrated that microwave pyrolysis can be optimized to produce high value syngas and liquid fuels and activated carbons.

Ozone-Aided Corn Steeping Process

ABSTRACT The present research evaluated the feasibility of using ozone (O3) to replace sulfur dioxide (SO2) in corn steeping. Traditionally, steep water contains 0.1–0.2% sulfur dioxide to promote starch-protein separation and high starch yields, and to control microbial growth. However, residual SO2 in starch products affects product quality and jeopardizes the “organic products” claims. Also, SO2 discharged to the environment pollutes water and air. Ozone is a strong oxidant and disinfectant with a capability to control the growth of putrefactive microorganisms in steeping systems, and to break down the endosperm protein matrix and, hence, improve starch release. This study demonstrates that an ozone-aided steeping (OAS) process had starch yields as high as conventional SO2 steeping. OAS processes can be conducted at a lower temperature (20°C vs. 50°C) and for shorter times (36 hr vs. 48 hr) than the conventional SO2 processes, suggesting significant energy savings and increased productivity. We have fo...

EFFECTS OF DESIGN PARAMETERS OF PLANAR, SILENT DISCHARGE, PLASMA REACTORS ON GASEOUS AMMONIA REDUCTION

Odor control is a challenging issue for both animal producers and researchers due to the complexity of the odor components. Previous studies have demonstrated that non-thermal plasma is capable of decomposing dilute, complex polluting gases, and has the potential for animal house and waste odor reduction. In this study, we developed planar, silent discharge, non-thermal plasma reactors for decomposition of ammonia. Both the ammonia reduction efficiency and energy efficiency of the reactors were evaluated under different reactor configurations and operational conditions. Results showed that planar, silent discharge, reactors could achieve a wide range of ammonia reduction efficiencies depending on the operational conditions.

Non-thermal food pasteurization processes: an introduction.

Abstract: The food industry and consumers have significant interest in nonthermal pasteurization processes because they offer better quality and nutrition retention and are more energy efficient than traditional thermal processes. Non-thermal processes may also create value-added products and open new market opportunities. This chapter will provide an overview of several non-thermal processes with the potential for producing valued-added foods, including pulse electric field (PEF), high hydrostatic pressure (HHP), ionizing irradiation, UV light, non-thermal plasma (NTP), and concentrated high intensity electric field (CHIEF). Their respective mechanisms for inactivating microorganisms, technical characteristics, and current status of the application of these processes will be discussed.

NON-THERMAL PLASMA DISINFECTION OF Escherichia coli ON ALMOND

This study was done to investigate the applicability of non-thermal plasma (NTP) technology for the disinfection of almond. Almonds were spiked by selected microorganisms with dipping in E. coli culture broth followed by drying. The spiked almonds were treated with NTP at various operating conditions for different duration of treatment. The sterilization pattern of the microorganisms was analyzed. NTP was very effective on disinfection of E. coli on almond, showing almost 5-log reduction after 30 s treatment at 30 kV and 2,000 Hz. The NTP disinfection effect against E. coli on almond increased with the voltage and the frequency. The NTP sterilization of E. coli followed the 1st order reaction kinetics, and the sterilization rate constants varied with almond types and grades. The E. coli cells at logarithmic phase were more sensitive to the NTP than those at stationary and declining phases.

Non-thermal food pasteurization processes

Abstract: The food industry and consumers have significant interest in nonthermal pasteurization processes because they offer better quality and nutrition retention and are more energy efficient than traditional thermal processes. Non-thermal processes may also create value-added products and open new market opportunities. This chapter will provide an overview of several non-thermal processes with the potential for producing valued-added foods, including pulse electric field (PEF), high hydrostatic pressure (HHP), ionizing irradiation, UV light, non-thermal plasma (NTP), and concentrated high intensity electric field (CHIEF). Their respective mechanisms for inactivating microorganisms, technical characteristics, and current status of the application of these processes will be discussed.