Gasification of Bio-oils to Syngas in Fluidized Bed Reactors

Bio-fuels are renewable and clean which can be used as alternatives to fossil fuels or can be used in combination with them. Biomass is a main source of bio-fuels production: it is a renewable resource and its conversion to energy releases no net CO2 to the environment. Bio-oil, the valuable liquid product obtained from biomass through pyrolysis, may be either combusted to generate carbon-neutral electricity or converted to a synthesis gas from which chemicals or clean fuels can be produced. Producing bio-oil from biomass and then converting the bio-oil to syngas has several advantages: The bio-oil may be generated in distributed or mobile plants and then shipped to a central facility for conversion to syngas, thus avoiding the expensive transportation of bulky and perishable biomass. The syngas produced from bio-oil is cleaner than syngas produced directly through biomass gasification. Finally, valuable green chemicals may be extracted from the bio-oil before it is converted to syngas. This thesis focuses on investigation of syngas production from bio-oil through thermal and catalytic reactions. Low bio-oil conversion and syngas yield were achieved from thermal cracking experiments in a pilot plant bubbling fluidized bed. A novel induction heated batch-wise micro reactor was designed and developed to test catalysts for bio-oil gasification. Catalytic gasification of bio-oils in this micro reactor revealed that a syngas with desired yield can be produced from bio-oil with maximum conversion provided there is a suitable catalyst and sufficient operating conditions such as temperature, residence time and steam in the reactor

Inversion and Symmetries of the Star Transform

The star transform is a generalized Radon transform mapping a function of two variables to its integrals along "star-shaped" trajectories, which consist of a finite number of rays emanating from a common vertex. Such operators appear in mathematical models of various imaging modalities based on scattering of elementary particles. The paper presents a comprehensive study of the inversion of the star transform. We describe the necessary and sufficient conditions for invertibility of the star transform, introduce a new inversion formula and discuss its stability properties. As an unexpected bonus of our approach, we prove a conjecture from algebraic geometry about the zero sets of elementary symmetric polynomials

Lattice models and super telescoping formula

In this paper, we introduce the super telescoping formula, a natural generalization of well-known telescoping formula. We explore various aspects of the formula including its origin and the telescoping cancellations emerging from symmetric patterns. We also show that the super telescoping formula leads to the construction of exactly solvable lattice models with interesting partition functions.Comment: 14 page

Business Model Innovation and Firm Performance: The Role of Mediation and Moderation Factors

Business model (BM) innovation is vital for today’s businesses. However, BM innovations can be irreversible, and therefore, in comparison to product, service or process innovation, entail bigger risk and ambiguity. Understanding the way in which BM innovation exerts influences over firm’s performance would help business-owners to be more effective. Based on a systematic literature review, a model to examine how BMI impacts firm performance through mediating and moderating factors was developed. Based on in-depth analysis of 37 articles, we identified twenty moderating factors classified in four groups, i.e., Firm- Characteristics, Industry-Characteristics, BM Implementation, and BM Practices, and ten mediating factors, categorized in three sub-groups, i.e., Revenue Growth, Efficiency Growth, and Enhancing the Organizational Capabilities. This paper offers the grounding for empirical research as well contribute to the development of tools to assess the effectiveness of the BMI

Catalytic property of olivine for bio-oil gasification

Introduction Biomass is an attractive renewable source of fuel and energy. Thermochemical processes can convert biomass to a liquid bio-oil or to a syngas. The advantage of using bio-oil as an intermediate is that, in contrast with both raw biomass and gas, it can easily be produced in small distributed units, stored and transported. Not only can platform chemicals and clean fuels be produced from syngas, but hydrogen is itself an alternative fuel. A high hydrogen production is usually desired: for example, methanol production requires a syngas with a molar H2/CO ratio of 2. Therefore, maximum hydrogen production has been a major objective in steam reforming/gasification of bio-oil. An appropriate catalyst is one of the most important operating factors in syngas production. Olivine (with general formula of (Mg,Fe)2SiO4) is a mineral material that has been investigated in biomass gasification to crack tars in the product gases; it is attrition resistant in fluidized bed reactors and has catalytic activities in gasification processes because of its iron content. However, pre-treatment of olivine, particularly, calcination temperature is crucial to make it catalytically active. It has been claimed that iron content of olivine must be in the form of iron oxide when it is introduced in the gasification reactor; gases such as hydrogen and carbon monoxide, which are produced in gasification reactors, reduce the iron oxide to metal iron (Fe0) that is an active catalyst of gasification reactions. Please click Additional Files below to see the full abstract