Presently, dried distiller's grains with solubles (DDGS) are mainly used as the livestock feed. However, the high fiber content in DDGS limits its use as the diet for animals. Therefore, with increasing production of DDGS in recent years, it is desirable to find some new uses of DDGS for fuels and/or for high value chemicals. In this paper, experiments on pyrolysis of DDGS by spouted-entrained bed and by fixed bed are carried out, and the pyrolytic liquids are analyzed by GC/MS. It was found that the composition of the liquid by pyrolysis of DDGS in 490–570 °C by spouted-entrained bed is rather complex, and varies with pyrolytic temperature. However, the pyrolysis of DDGS material is not quite suitable to the process by spouted-entrained bed, due to a severe clogging problem inside the reactor. By fixed bed, the composition of the oil phase of the liquid obtained in 490–610 °C is much simpler, mainly phenol derivatives, fatty acids and their esters. When pyrolyzed at 570 °C with catalyst of CaO, aliphatic and aromatic hydrocarbons are generated more, while fatty acids and their esters are much reduced.Highlights► Compositions of the liquid products from pyrolysis of DDGS were analyzed by GC/MS. ► Components in pyrolytic liquid by spouted-entrained bed are rather complex. ► Oil phase by fixed-bed is simpler as phenols, fatty acids and their esters. ► Spouted-entrained bed is not proper for frequently clogging problem. ► Aliphatic and aromatic hydrocarbons are more generated under catalysis of CaO.

Experiments on pyrolysis of Chinese Fugu coal were carried out with a downer reactor, and the effects of temperature and coal feeding rate on product distribution were investigated. It was found that the gas yield increases with increasing temperature, and the yield of tar increases with increasing coal feeding rate. When temperature is 650 °C with coal feeding rate of 12 kg/h, the yield of tar reaches the highest value of 10.29 wt % (dry coal basis). Compared to cocurrent downer reactor, the countercurrent downer reactor favors higher yields of C2 + C3 and tar.

Bio-oil can be an important fuel resource for automobiles in the future, while its complex composition restricts the direct application of the bio-oil extremely. So it is necessary to separate the complex mixture to relatively simplified fractions for goal directed specific treatments to reach the fuel quality for automobiles, and meanwhile different functional chemical materials and fine chemicals can be obtained. So it is significant to investigate the bio-oil component separating methods. Herein the method of column chromatography by the packing material of silica gel with two series of eluants of cyclohexane-benzene-methanol and cyclohexane-dichloromethane-methanol were investigated for component fractionation of the raw wood tar (oil fraction of the liquid product by slow pyrolysis of wood). The analytical results show that the components in cyclohexane are rich in alkoxyl-monophenols; the components of alkyl-monophenols and five ring oxygen-containing compounds are abundant in benzene and in dichloromethane similarly; in the methanol fraction, the components are diverse and diphenols are relatively in higher content, comparatively small polar molecules and five ring oxygen-containing compounds are more abundant in the methanol fraction after being eluted by dichloromethane, and the content of 1-(4-hydroxy-3-methoxyphenyl) -2-propanone is higher after being eluted by benzene.

Coal bio-oil slurries (CBS) with different coal concentrations are prepared by mixing Yangquan anthracite and biomass fast pyrolysis oil. The rheological properties of CBS are examined. The result shows that the solid concentration of CBS can reach 42% without any additives. The rheological behavior of the prepared CBS can be described by the Bingham plastic fluid model. Its apparent viscosity decreases with increasing shear rates, and the yield stress increases with increasing solid concentrations. The CBS keeps its static stability for 3−4 days with no formation of soft sediment. The steam gasification experiment of CBS is carried out on a lab-scale apparatus with a fixed bed reactor. The effects of reaction temperature and steam to carbon ratio (S/C) on the gas yield and component distribution are investigated. The result shows that the yield of H2 and CO increases with temperature and that the ratio of H2/CO decreases with temperature and increases with S/C. The higher heating value of the gas product is about 12 MJ/Nm3.

The catalytic gasification of char from co-pyrolysis of coal and wheat straw was studied. Alkali metal salts, especially potassium salts, are considered as effective catalysts for carbon gasification by steam and CO2, while too expensive for industry application. The herbaceous type of biomass, which has a high content of potassium, may be used as an inexpensive source of catalyst by co-processing with coal. The reactivity of chars from co-pyrolysis of coal and straw was experimentally examined. The chars were prepared in a spout-entrained reactor with different ratios of coal to straw. The gasification characteristics of chars were measured by thermogravimetric analysis (TGA). The co-pyrolysis chars revealed higher gasification reactivity than that of char from coal, especially at high level of carbon conversion. The influence of the alkali in the char and the pyrolysis temperature on the reactivity of co-pyrolysis char was investigated. The experimental results show that the co-pyrolysis char prepared at 750 °C have the highest alkali concentration and reactivity.

A better understanding of the influence of particle size on pyrolysis and char reactivity is of crucial importance in optimizing the integrated process combining coal topping (coal fast pyrolysis) with char gasification. Different size fractions of two types of coal and demineralized coal were pyrolyzed in a spouted bed. The resulting chars were characterized by X-ray diffraction, and char reactivity was determined in a thermogravimetric analyzer (TGA). Within the range of particle sizes investigated, an increase in particle size results in an increase of char yield, which may be caused by the secondary reactions of volatile matters inside the coal particles. No significant difference in crystallinity was observed for the chars from different size fractions of the parent coals, while more crystallinity was observed for the chars from demineralized coals, which suggests that minerals in the coal play a role in the reduction of char crystallinity during pyrolysis. Char reactivity for raw coals decreased with the increasing of the particle size. For the demineralized coal samples, the change in char reactivity with the increasing of the particle size was reduced. Both the secondary reactions of volatiles and mineral distribution are believed to cause the influence of coal particle size on char reactivity.