Fouling and gasification studies

沉积在热交换器和其他加工设备的表面上在能源和操作效率方面是昂贵的。如果可以确定结垢的根本原因，就可以进行设计或操作更改以减轻问题。在碳氢化合物体系中沉积的机制包括自氧化、聚合、沥青质的不相容、焦化反应、硫化铁的形成等。本研究的目的是确定某些复杂流体（如含硫原油）结垢的潜在机制，并获得结垢速率的定量表达式，以供作业者或设计人员用于控制结垢。研究方法是使用间歇式反应器进行反应和沉淀研究，然后在再循环传热回路中进行污垢测量。过程变量的影响和流体、沉淀物和沉积物的广泛表征有助于确定机制。模型用于表达结果并对速率行为进行预测。工具包括沥青质絮凝滴定、流体和沉积物的溶剂分馏，以及SEM、EDX、TGA和DRIFTS等标准方法。主题包括原油污染；重油系统沥青质沉淀、结焦与结垢的关系重油蒸汽系统中微滴的沉积以及石脑油和汽油中的自氧化污染。新颖之处在于全面的研究方法，所研究的真实流体，以及可用于研究的独特设施，这些设施允许在工业重要条件下获得真实数据。支持未来生物质精炼厂概念的研究也在进行中。与上述类似的方法正被应用于研究生物质热解油在加热过程中的行为。我们之前对煤和生物质的气化研究正在扩展到从生物油/木炭浆中生产合成气。

Deposition onto surfaces of heat exchangers and other processing equipment is costly in terms of energy and operating efficiency. If root causes of fouling can be established, design or operating changes can be made to mitigate the problem. Mechanisms leading to deposition in hydrocarbon systems include autoxidation, polymerization, incompatibility of asphaltenes, coking reactions, iron sulphide formation etc. The objectives of this research are to determine the underlying mechanisms of fouling for certain classes of complex fluids ( eg sour crude oils), and obtain a quantitative expression for the fouling rate which operators or designers can use to control fouling. The research approach is to use batch reactors for reaction and precipitation studies, followed by fouling measurements in re-circulation heat transfer loops. Effects of process variables and extensive characterization of fluids, precipitates and deposits helps to identify mechanisms. Models are used to express results and make predictions of rate behaviour. Tools include asphaltene flocculation titrations, solvent fractionation of fluids and deposits, and standard methods such as SEM, EDX, TGA and DRIFTS. Topics include crude oil fouling; relation between asphaltene precipitation, coking and fouling in heavy oil systems; deposition of fine droplets from heavy oil vapour systems; and autoxidation fouling in naphthas and gas oils. Novelty lies in the comprehensive research approach, the real fluids studied, and the unique facilities available for the research which permit realistic data under industrially important conditions. Research is also underway supporting the concept of a future biomass refinery. Similar approaches to those given above are being applied to study biomass pyrolysis oil behaviour during heating. Our previous gasification research with coal and biomass is being extended to produce synthesis gas from bio-oil/wood char slurries.