Effect of fractional condensers on characteristics,compounds distribution and phenols selection of bio-oil from pine sawdust fast pyrolysis

Bio-oil is a multicomponent mixture of more than 400 types of organic compounds, with high water content. Fractionation of bio-oil may be a more efficient approach for primary separation of bio-oil. In this work, to better understand the effect of fractional condensers on bio-oil yield, physicochemical characteristics, compounds distribution and phenols selection during biomass fast pyrolysis process, a semi-automatic controlled fluidized bed reactor biomass fast pyrolysis system with four-stage condensers was developed. Average temperatures of Condensers 1, 2, 3, 4 were 32.39 °C, 26.74 °C, 24.06 °C and 23.68 °C, respectively. And the bio-oil yields of Condenser 1, 2, 3, and 4 were 26.82%, 7.31%, 1.48% and 9.69%, respectively. Bio-oil collected from Condenser 4 had the lowest water content (9.68 wt%), the lowest acidity (pH = 3.67), and the highest HHV (29.2 MJ/kg). The highest relative contents of compounds collected from Condenser 1, 2, 3 and 4 were 1-(4-hydroxy-3-methoxyphenyl)-2-Propanone (6.95%), trans-Isoeugenol (6.63%), Creosol (5.28%), and trans-Isoeugenol (6.69%), respectively. Fractional condensers affected the compounds distribution, but it has a stronger effect on relative heavy compounds (molar mass > 250) and a weaker effect on relative light compounds (molar mass < 200). Fractional condensers were more conducive to the selection of phenols with relative yield of more than 30%. Phenols, acids and furfurans tended to distribute at higher temperature, while alcohols, ethers and hydrocarbons tended to distribute at relative lower temperature, but the difference was small. The research has provided a reference for the production of bio-oil.     

Simulating the impact of discrete-return lidar system and survey characteristics over young conifer and broadleaf forests

We present a model-based investigation of the effect of discrete-return lidar system and survey characteristics on the signal recorded over young forest environments. A Monte Carlo ray tracing (MCRT) model of canopy scattering was used to examine the sensitivity of model estimates of lidar-derived canopy height, h_lidar to signal triggering method, canopy structure, footprint size, sampling density and scanning angle, for broadleaf and conifer canopies of varying density. Detailed 3D models of Scots pine (Pinus sylvestris) and Downy birch (Betula pubescens) were used to simulate lidar response, with minimal assumptions about canopy structure. Use of such models allowed the impact of lidar parameters on canopy height retrieval to be tested under a range of conditions typically not possible in practice. Retrieved h_lidar was generally found to be an underestimate of ‘true’ canopy height, h_canopy, but with exceptions. Choice of signal triggering method caused h_lidar to underestimate h_canopy by ∼ 4% for birch and ∼ 7% for pine (up to 66% in extreme cases). Variations in canopy structure resulted on average in underestimation of h_canopy by 13% for birch and between 29 and 48% for pine depending on age, but with over-estimates in some cases of up to 10%. Increasing footprint diameter from 0.1 to 1 m increased retrieved h_lidar from significant underestimates of h_canopy to values indistinguishable from h_canopy. Increased sampling density led to slightly increased values of h_lidar to close to h_canopy, but not significantly. Increasing scan angle increased h_lidar by up to 8% for birch, and 19% for pine at a scan angle of 30°. The impact of scan angle was greater for conifers as a result of large variation in crown height. Results showed that interactions between physically modelled (hypothetical) within canopy returns are similar to findings made in other studies using actual lidar systems, and that these modelled returns can depend strongly on the type of canopy and the lidar acquisition characteristics, as well as interactions between these properties. Physical models of laser pulse/canopy interactions may provide additional information on pulse interactions within the canopy, but require validation and testing before they are applied to actual survey planning and logistics.     

Optimization of pelletisation and combustion in a boiler of 17.5 kWth for vine shoots and industrial cork residue

Wood pellets have become an important renewable energy fuel. Nowadays the main raw materials used for their production are wood wastes from wood industries. However, these wood wastes have other uses in Spain and it is necessary to look for other possible raw materials. In this work, vine shoots and industrial cork residue were studied as raw materials. The results showed that pelletisation of vine shoots presented a high energy demand. This energy requirement was reduced with the addition of industrial cork residue. Moreover, industrial cork residue decreased the ash content of pellets and increased their heating value, although it decreased their physical properties at the same time. Regarding combustion, the addition of industrial cork residue decreased the accumulation of ash in the pellet burner and its sintering tendency. The major conclusion of the work is that the most appropriate blend to improve pelletisation and combustion processes is 30% wt. of vine shoots and 70% wt. of industrial cork residue.     

浅谈新型环保绿色给水管材——PEX管

根据生产厂家资料及在福州“武夷绿洲一期”工程中的应用情况,介绍PEX管的优良性能、应用领域、主要材料、以及设计和施工过程中应注意的问题。     

新型起泡剂250A对安徽某铜矿石的浮选效果

250A是中国矿业大学新研制的一种新型、价廉、易降解、低污染的选铜起泡剂,为了检验其高效性,以安徽铜陵某低品位原生铜矿石为试样进行了选铜试验。在磨矿细度为-0.074 mm占75%的情况下,以条件试验确定的药剂用量为粗选用量,参照现场工艺流程进行了2种起泡剂的浮选效果对比试验。结果表明：250A总用量为241 g/t的情况下,铜精矿铜品位和铜回收率分别为21.56%和87.32%;松醇油总用量为360 g/t的情况下,铜精矿铜品位和铜回收率分别为21.67%和87.19%。两相比较可知,250A比松醇油更高效,有助于选铜企业降本增效。     

Effect of different levels of pine honey addition on physicochemical,microbiological and sensory properties of set‐type yoghurt

In this study, the effects of different levels of pine honey addition (3%, 5% and 7% w/v) to the yoghurt milk on starter bacteria, physicochemical and sensory characteristics of set‐type yoghurts during the storage were investigated. Antioxidant activity and total phenolic content of yoghurts with added honey increased compared to control yoghurt. There was a significant increase in water‐holding capacity (WHC), viscosity, total solids, redness (a*) and yellowness (b*) values of the yoghurt samples with the addition of honey at higher concentrations, whereas water activity (aw), pH and luminosity (L*) values decreased. Viscosity and WHC of the yoghurts increased during the storage.     

松木家具设计新探

本文就目前松木家具设计存在的问题进行研究,认为影响松木家具技术特征和艺术特征的关键在于造型,而影响造型设计的主要因素在于材料本身,提出了通过改变松木外观属性来进行松木家具设计创新的新方法。     

松针中组织自由水氚的测量

本文用生物样品与有机溶剂共沸蒸馏分离法对秦山核电厂附近秦山上松针中组织自由水氚进行测量。选择甲苯为共沸蒸馏溶剂。松针与甲苯共沸蒸馏,组织自由水回收率达90%。结果表明,松针中组织自由水氚浓度为1.8 Bq/L,与同期大气中氚化水蒸气(HTO)的浓度在同一水平。     

Pheromone receptor cell specificity in interpopulational hybrids ofIps pini (Coleoptera: Scolytidae)

Electrophysiological studies of pheromone receptor cells keyed to ispdienol were performed in laboratory-raised hybrids of the eastern and western populations of the pine engraver,Ips pini. As previously shown in the parental beetles, the receptor cells keyed to ipsdienol could be classified as two distinct types: one keyed to (+)- and one to (–)-ipsdienol. None of the 20 ipsdienol cells recorded from F₁ hybrids were of an intermediate type. Recordings of the summated receptor responses (EAGs) showed no significant difference between parental beetles and hybrids. Similar results were obtained in reciprocal crosses, eastern females with western males and the reverse. Thus, there was no indication that sex-linked alleles determined the specificity of the ipsdienol receptor cell. The ratio between (+) and (–) cells was 146 in the hybrids compared to 112 in the western and 912 in the eastern populations.     

微波辅助提取松针中莽草酸的工艺研究

研究了微波辅助提取松针中莽草酸的提取工艺,考察了微波温度、料液比、微波功率、乙醇浓度和微波时间等因素对莽草酸提取率的影响,通过正交试验优化了提取工艺。结果表明,松针中莽草酸提取的最佳工艺条件为:微波温度35℃,料液比1∶20(g/mL),微波功率550W,乙醇浓度35%,微波时间90s,在此条件下,莽草酸的提取率可达11.312mg/g。