焦油主要组份在循环灰下催化裂解的实验研究

在以循环流化床锅炉循环灰为热载体，部分气化产生的半焦为锅炉燃料，煤气为燃气轮机燃料的煤的部分气化联合循环中，降低焦油产率，提高煤气产率是一个技术关键，以焦油的两种主要组份苯和甲苯为研究对象，利用固定床实验台实验研究了一种混煤形成的循环灰条件下的裂解反应特性，测定了裂解反应动力学参数，探讨了循环灰对焦油裂解的催化机理。实验结果表明，与石英砂条件相比，循环灰极大地促进了焦油的裂解程度，气态裂解产物总量     

玻璃工厂混合煤气发生炉的测试及其提高燃料利用率的探讨

国內许多玻璃工厂均是用发生炉煤气作玻璃熔制的燃料,但对固体燃料在煤气发生炉内气化过程中的利用率还重视得不够。研究固体燃料的气化不仅能提高燃料的利用率,更重要的是为稳定玻璃熔制热工制度创造了条件。因此,如何提高气化效率,提高产气率,提高煤气质量是一件十分有意义的工作。杭州玻璃厂燃煤气六机平板玻璃池窑,其煤气由三台AP—13型煤气发生炉供给。81年12月,我们在熔窑热平衡测试的同时,对这三台煤气发生炉也进行了测定,作了灰平衡、物料平衡,计算了气化效率,并整理     

生物质气化焦油催化裂解特性

以白云石为载体制备的Ni基催化剂对松木粉在700℃下气化产生的焦油进行了催化裂解实验研究，并与重油裂解催化剂进行了对比。结果表明：石油化工重油裂解催化剂对生物质气化焦油具有一定的催化裂解作用；Ni的掺入方式和催化剂的煅烧温度对催化剂的性能具有显著的影响。以100～120目白云石粉为载体，900℃下煅烧的Ni基催化剂在700℃(2下焦油裂解对H2和CH4具有很好的选择性(H2为78．3％，H2 CO为92．3％，CH4为2．3％)；100h老化实验显示H2/CO随催化剂活性降低而逐渐减小。     

用太阳能进行煤炭气化

用太阳能进行煤炭气化美国新墨西哥州怀特沙漠试验地区堪莫尔实验室，利用太阳能对煤炭进行气化的第一次试验获得成功。它用太阳能将煤炭加热到１９２０℃，便能生产出可燃煤气。煤气中含有一氧化碳２６．９％、氢５０．９％、甲烷５．４％、碳氢化合物０．７％、二氧化碳...     

温度和压力对加压喷动流化床煤部分气化的影响

在热输入0.1MW的加压喷动流化床煤部分气化炉上以空气和水蒸气为气化剂,进行徐州烟煤的加压部分气化试验。考察了气化温度、压力等因素对煤气成分、煤气热值、干煤气产气率、碳转化率等指标的影响。气化温度是通过调整空气系数来实现的。试验结果表明:气化温度对煤气化过程影响显著,气化温度升高,煤气热值先增大后减小,产气率增加,碳转化率提高。而增大压力,床内气体速度变慢,延长了气化剂在床内的停留时间,另外压力增加改善了床内的流化质量,从而提高了气化效率,改善了煤气质量。     

Texaco和Shell煤气化工艺用于生产甲醇的经济性比较

新一代煤气流床气化工艺主要以Texaco水煤浆气化工艺和Shell干煤粉气化工艺为代表。Shell煤气化工艺操作温度可达1700℃,对煤种适应性高,碳转化率达99％以上。Texaco煤气化工艺的碳转化率为96％～98％。生产每吨甲醇,Shell气化工艺的煤耗量为1．25～1．28t,Texaco气化工艺为1．31～1．40t;Shell气化工艺的氧耗量比Texaco工艺低15％～25％;Shell工艺的总能耗（包括原料煤在内1为51．981GJ,比Texaco工艺低11．21GJ。然而,Shell煤气化工艺的投资高,以60×10^4t／a甲醇装置为例,Shell工艺的总投资为109242万元,Texaco工艺为85444万元：采用Shell工艺生产的甲醇总成本为1373元／t,比Texaco工艺的1277元／t高出约7．5％。同时,Shell工艺装置工业运行稳定性还需要进一步经工业化验证,而Texaco气化工艺在国内已有十几年的生产使用经验,其操作稳定性很高。通过总体经济性比较,在用于甲醇生产时,Shell煤气化工艺相对于Texaco煤气化工艺是没有优势的。     

水煤气沸腾煤气化炉荣获江苏省“佳利奖”金奖

江苏工学院专利事务所代理的“水煤气沸腾煤气化炉”发明专利，荣获江苏省第三届优秀专利实施项目“佳利奖”金奖。“水煤气沸腾煤气化炉”由王同章教授等发明。已在江阴、河北、沈阳、景德镇、云南、苏州、广西等地实施，实施金额达701万元。该炉以水蒸汽为气化剂，使用0～6mm的粉煤，制取中热值煤气，其煤气成份为：H2＞55％，Co＜25％，CH42～5％，CO210～15％，O2＜0．4，N2＜5％；煤的灰熔点≥1200℃；煤气热值9000～12290KJ／Nm3；气化强度1000Kg煤／m‘h。这种煤气不仅是理想的化工原料气，而且是理想的民用煤气，为广大中小城…     

生物质流态化催化气化技术工程化研究

在研究开发的内循环锥形流态化气化炉内。对稻草、麦草等软秸秆物料粉碎后，或者直接使用木屑等细粉状原料，进行了热解气化和催化气化的工程化应用试验研究。研究结果表明：气化反应在600—820℃的一个较宽温度范围内，均能稳定连续运行。麦草原料气化所产生的煤气热值比稻草和稻壳都高，其热值可达7716kJ／m^3。木屑气化所产生煤气热值最高则达9064kJ／m^3，远远高于一般生物质气化煤气。对流化床气化来讲，即使在非催化气化条件下，其气化产生的煤气热值比采用下吸式气化炉产生的煤气热值提高40%左右，并且气化温度较固定床(上吸式、下吸式)气化炉低。同时进行的催化气化试验发现，催化剂CaO能明显提高煤气热值、降低CO组分，Na2CO3催化气化能提高气体H2的含量。在800℃试验时，添加催化剂能明显提高气体的热值。     

生物质水蒸气气化利用过程数学模型的建立

分析了甘蔗渣的水蒸气气化过程,基于气化过程的物料平衡和化学平衡关系,建立了一种生物质气化过程的数学模型。用该模型模拟计算甘蔗渣在水蒸气氛围下气化后的气体成分,计算结果与试验数据基本相符,尤其在温度950℃之后,计算值和测量值更接近。以甘蔗渣和木薯渣为例,研究该气化模型的特性。甘蔗渣和木薯渣水蒸气气化的最佳水蒸气/燃料值(S/B)分别为0.3和0.2。气化气组分和气化效果随温度和S/B变化的结果表明:提高温度有利于气化反应的进行,提高S/B,可以增加气体产率,气体热值有所降低。     

流化床气化炉

流化床气化炉可以充分利用床内气固两相间的高强度的传热和传质,使整个床层内温度分布均匀,混合条件好,有利于气化反应的进行。同时,可以利用流化床低温燃烧,在燃烧和气化过程中加入脱硫剂（石灰石或白云石）,将产生的大部分SO2和H2S脱除。由于流化床气化炉内的反应温度一般控制在850～1000℃,因此,它产生的焦油、烃、酚、苯和萘等大分子有机物基本上都能被裂解为简单的双原子或三原子气体,煤气的主要成本是CO和H2,CH4的含量一般少于2％。     

Pyrolysis analysis of different Cuban natural fibres by TGA and GC/FTIR

In this work, the pyrolysis of different Cuban biomass such as: sugar cane bagasse, coffee, residue of tobacco and sawdust of pine has been studied. The pyrolysis was carried out at different temperatures in a small furnace placed at the injection port of a gas chromatograph coupled to a Fourier transform infrared spectrometer (Py-GC/FTIR). Thermogravimetric analysis (TGA) was also carried out using a thermobalance. For tobacco residue, pyrolysis yield of charcoal and liquid products decreases with pyrolysis temperature (300–600 °C). When the pyrolysis is carried out at 300 °C charcoal yield is similar for tobacco residue, sawdust of pine and husk of coffee (≈40%) while for husk of coffee and sugar cane bagasse the charcoal yield is lower but the yield of the liquid product is higher.     

机械活化预处理对蔗渣酶解产糖影响的研究

采用机械活化方法对蔗渣进行预处理,研究其对蔗渣酶解产糖的影响。用红外光谱、X-射线衍射和扫描电镜测定预处理前后蔗渣结构及表面形态的变化,并分析其作用机理。研究结果表明,机械活化用于蔗渣预处理,可明显提高预处理后蔗渣的酶解产糖率。酶解时间为48 h时,蔗渣酶解产糖率从未处理时的19.86%提高到59.34%。蔗渣酶解产糖率的提高是由于机械活化处理使得蔗渣纤维素分子间部分氢键发生断裂、结晶度下降、表面有序结构被破坏的所致。     

Differences in the chemical structure of the lignins from sugarcane bagasse and straw

Two major residues are produced by the sugarcane industry, the fibrous fraction following juice extraction (bagasse), and the harvest residue (straw). The structures of the lignins from these residues were studied by pyrolysis coupled to gas chromatography-mass spectrometry (Py-GC/MS), nuclear magnetic resonance (NMR), and derivatization followed by reductive cleavage (DFRC). Whereas the lignin from bagasse has a syringyl-rich p-hydroxyphenyl:guaiacyl:syringyl (H:G:S) molar composition of 2:38:60, the lignin from straw is guaiacyl-rich (H:G:S of 4:68:28). The compositional differences were also reflected in the relative abundances of the different interunit linkages. Bagasse lignin was primarily β–O–4′ alkyl-aryl ether substructures (representing 83% of NMR-measurable linkages), followed by minor amounts of β–5′ (phenylcoumarans, 6%) and other condensed substructures. The lignin from straw has lower levels of β-ethers (75%) but higher relative levels of phenylcoumarans (β–5′, 15%) and dibenzodioxocins (5–5/4–O–β, 3%), consistent with a lignin enriched in G-units. Both lignins are extensively acylated at the γ-hydroxyl of the lignin side-chain (42% and 36% acylation in bagasse and straw), predominantly with p-coumarates (preferentially on S-units) but also with acetates (preferentially on G-units) to a minor extent. Tetrahydrofuran structures diagnostically arising from β–β-coupling (dehydrodimerization) of sinapyl p-coumarate or its cross-coupling with sinapyl alcohol were found in both lignins, indicating that sinapyl p-coumarate acts as a monomer participating in lignification. The flavone tricin was also found in the lignins from sugarcane, as also occurs in other grasses.     

Oxidative catalytic steam gasification of sugarcane bagasse for hydrogen rich syngas production

Reactive Flash Volatilization (RFV) is an emerging thermochemical method to produce tar free hydrogen rich syngas from waste biomass at relatively lower temperature (<900 °C) in a single stage catalytic reactor within a millisecond residence time. Here, we show catalytic RFV of bagasse using Ru, Rh, Pd, or Re promoted Ni/Al₂O₃ catalysts under steam rich and oxygen deficient environment. The optimum reaction conditions were found to be 800 °C, steam to carbon ratio = 1.7 and carbon to oxygen ratio = 0.6. Rh–Ni/Al₂O₃ performed the best, resulting in highest hydrogen concentration in the synthesis gas at 54.8%, with a corresponding yield of 106.4 g-H₂/kg bagasse. A carbon conversion efficiency of 99.96% was achieved using Rh–Ni, followed by Ru–Ni, Pd–Ni, Re–Ni and mono metallic Ni catalyst in that order. Alkali and Alkaline Earth Metal species present in the bagasse ash and char, that deposited on the catalyst, was found to enhance its activity and stability. The hydrogen yield from bagasse was higher than previously reported woody biomass and comparable to the microalgae.     

Improving bioethanol production from sugarcane: evaluation of distillation, thermal integration and cogeneration systems

Demand for bioethanol has grown considerably over the last years. Even though Brazil has been producing ethanol from sugarcane on a large scale for decades, this industry is characterized by low energy efficiency, using a large fraction of the bagasse produced as fuel in the cogeneration system to supply the process energy requirements. The possibility of selling surplus electricity to the grid or using surplus bagasse as raw material of other processes has motivated investments on more efficient cogeneration systems and process thermal integration. In this work simulations of an autonomous distillery were carried out, along with utilities demand optimization using Pinch Analysis concepts. Different cogeneration systems were analyzed: a traditional Rankine Cycle, with steam of high temperature and pressure (80 bar, 510 °C) and back pressure and condensing steam turbines configuration, and a BIGCC (Biomass Integrated Gasification Combined Cycle), comprised by a gas turbine set operating with biomass gas produced in a gasifier that uses sugarcane bagasse as raw material. Thermoeconomic analyses determining exergy-based costs of electricity and ethanol for both cases were carried out. The main objective is to show the impact that these process improvements can produce in industrial systems, compared to the current situation.     

Effect of temperature on the gasification of olive bagasse particles

A semi-batch fluidized-bed gasifier was used to investigate the experimental gasification process of olive bagasse particles, an olive oil industry residue. The effect of bed temperature was studied, in the range of 750 to 900 °C. The oxidant agent was air, fed at constant flowrate, and sand particles were used as bed material. The bagasse particles used had diameters within 1.25–2 mm and the biomass was characterized in terms of its higher heating value and ultimate analysis. During each run, several gaseous samples were collected to be further analysed by gas chromatography allowing the quantification of CO, CO₂, H₂, CH₄, O₂ and N₂. The reaction mechanism of the gasification process is determinant on the composition of the producer gas. Experimental results showed that higher bed temperatures favoured gas production as well as other gasification performance parameters. Best results were obtained for a bed temperature of 850 °C.     

Pretreatment of bagasse and coconut fibres for enhanced anaerobic degradation by rumen microorganisms

The effect of chemical pretreatment and particle size on anaerobic digestion of bagasse and coconut fibres by rumen micro organisms was studied. Both chemical pretreatment and pa rticle size affected total fibre degradation and productions of methane and volatile fatty acids from these waste materials significantly (P < 0.05) compared to the untreated materials. Pretreatment of bagasse with sodium hydroxide, hydrochloric acid and ammonium hydroxide followed by incubations for 168 h increased fibre degradation by 11, 31 and 14 %, respectively. Pretreatment of coconut fibres increased their extent of degradation by 55, 74 and 46 %, respectively. Methane yield from bagasse was increased by 44, 32, and 22 %, and that from coconut fibres was increased by 73, 76 and 46 %, respectively. With the same pretreatment, amounts of volatile fatty acids produced from bagasse and coconut fibres increased by 42, 37 and 11 %, and 40, 28, and 11 %, respectively.By reducing particle sizes of bagasse and coconut fibres from 5 mm to less than 0.85 mm, the extent of total fibre degradation was increased by over 40%. The yields of methan produced from these fibres increased by an average of 30 %, and those of volatile fatty acids increased by about the same order of magnitude. The suitability of using pretreated lignocellulosic waste biomas s as a substrate for methane production in a Rumen Derived Anaerobic Digestion-process is discussed.     

Co-combustion characteristics study of bagasse,coal and their blends by thermogravimetric analysis

Co-combustion technology was used to investigate the combustion of bagasse and bagasse blending with coal at different ratios (20%, 50%, and 70% bagasse in weight) using thermogravimetric analysis (TGA). The results show that three stages were observed during bagasse combustion and the main combustion process occurred at the second stage. Compared with combustion of coal, the co-combustion of bagasse blending with coal has lower first peak temperature (T_p1), slightly lower average reaction rate (R_v), and higher reaction rate at the first peak (R_p1). The best blend ratio of bagasse/coal is 20%/80%, and the inhibitory effect is found during the co-combustion.     

Carbonisation of bagasse in a fixed bed reactor: influence of process variables on char yield and characteristics

Carbonisation experiments on samples of sugar cane bagasse were conducted in a static fixed bed reactor to determine the effect of process variables such as temperature, heating rate, inert sweep gas flow rate and particle size on the yield and composition of solid product char. Experiments were performed to the final temperatures of 250–700°C with heating rates from 5 to 30°C/min with nitrogen sweep gas flow rate of 350 cc/min. Additional tests were aimed at studying the effect of different flow rates of nitrogen sweep gas from 0 to 700 cc/min during carbonization and different particle size fractions of bagasse. The results showed that as the carbonisation temperature was increased, the yield of char decreased. The reduction in yield was rapid up to a final temperature of 500°C and was slower thereafter. The yield of char was relatively insensitive to the changes in heating rate and particle size. Increasing the sweep gas flow rate to 350 cc/min reduced the yield of char. It appears the presence of inert sweep gas reduced secondary reactions which promoted char formation. The proximate analysis of the char suggests that fixed carbon and ash content increased with temperature. The char obtained at temperatures higher than 500°C have high carbon content and is suitable as renewable fuel and for other applications. The carbonization of bagasse has the potential to produce environmental friendly fuels and can assist in reducing deforestation for the production of charcoal.     

Assessment of sugarcane bagasse gasification in supercritical water for hydrogen production

Sugarcane bagasse is one of the major resources of agricultural biomass waste in the world. In this work, supercritical water gasification characteristics of sugarcane bagasse were investigated. The effect of temperature (600–750 °C), concentration (3–12 wt%), residence time (5–20 min) and catalysts (Raney-Ni, K₂CO₃ and Na₂CO₃) on bagasse gasification were studied. A kinetic study on the non-catalytic and Na₂CO₃ catalytic bagasse gasification was conducted to describe the kinetic information of the bagasse gasification reaction. The results showed that a higher reaction temperature, a lower bagasse concentration and a longer residence time could favor the gasification of bagasse, leading to a higher hydrogen yield. Bagasse was nearly completely gasified at 750 °C without using any catalyst and the carbon gasification efficiency could reach up to 96.28%. The addition of employed catalysts remarkably promoted the bagasse gasification reactivity. The maximum hydrogen yield (35.3 mol/kg) was achieved at 650 °C with the Na₂CO₃ loading of 20 wt%. The experimental data fitted well with a homogeneous model based on a Pseudo-first-order reaction hypothesis. The kinetic study showed that Na₂CO₃ catalyst could lower the activation energy E_a of bagasse gasification from 117.88 kJ/mol to 78.25 kJ/mol.