Advanced Technologies for Biomass

The use of biomass and organic waste material as a primary resource for the production of fuels, chemicals, and electric power is of growing significance in light of the environmental issues associated with the use of fossil fuels. For this reason, it is vital that new and more efficient technologies for the conversion of biomass are investigated and developed. Today, various advanced methods can be used for the conversion of biomass. These methods are broadly classified into thermochemical conversion, biochemical conversion, and electrochemical conversion. This book collects papers that consider various aspects of sustainability in the conversion of biomass into valuable products, covering all the technical stages from biomass production to residue management. In particular, it focuses on experimental and simulation studies aiming to investigate new processes and technologies on the industrial, pilot, and bench scales

Soft-Sensor for Class Prediction of the Percentage of Pentanes in Butane at a Debutanizer Column

Refineries are complex industrial systems that transform crude oil into more valuable subproducts. Due to the advances in sensors, easily measurable variables are continuously monitored and several data-driven soft-sensors are proposed to control the distillation process and the quality of the resultant subproducts. However, data preprocessing and soft-sensor modelling are still complex and time-consuming tasks that are expected to be automatised in the context of Industry 4.0. Although recently several automated learning (autoML) approaches have been proposed, these rely on model configuration and hyper-parameters optimisation. This paper advances the state-ofthe- art by proposing an autoML approach that selects, among different normalisation and feature weighting preprocessing techniques and various well-known Machine Learning (ML) algorithms, the best configuration to create a reliable soft-sensor for the problem at hand. As proven in this research, each normalisation method transforms a given dataset differently, which ultimately affects the ML algorithm performance. The presented autoML approach considers the features preprocessing importance, including it, and the algorithm selection and configuration, as a fundamental stage of the methodology. The proposed autoML approach is applied to real data from a refinery in the Basque Country to create a soft-sensor in order to complement the operators’ decision-making that, based on the operational variables of a distillation process, detects 400 min in advance with 98.925% precision if the resultant product does not reach the quality standards.This research received no external funding

Polymer Membranes for the Separation of Complex Natural Hydrocarbon Feeds

Polymer Membranes for the Separation of Complex Natural Hydrocarbon Feeds Ronita Mathias 231 Pages Directed by Dr. Ryan P. Lively The separation of complex liquid mixtures, which are mixtures without a clear singular solvent, is an emerging area of membrane science. Crude oil is one such complex industrial mixture that is comprised of several tens of thousands of hydrocarbon molecules but is typically fractionated via energy-intensive thermal processes. In this work, specific light fractions of crude oil were separated via novel spirocyclic polymer membranes, with the potential for bypassing significant energy expenditure associated with distillation. Polymeric materials are of interest for membrane fabrication as they are easily processable, inexpensive, and can be easily functionalized for stability. However, for membrane-based fractionation of crude oil to compete with current distillation processes on an industrial scale, multi-stage cascades containing several high-throughput membranes must be optimized. The capability to predict multi-molecule transport in target materials can accelerate the screening and design of materials for cascades that would otherwise require lengthy R&D timelines. Thus, advanced models were also utilized in this work to predict complex mixture permeation in polymeric membranes based only on pure molecule sorption and diffusion inputs. These simplifying hypotheses could enable an extension of predictive capabilities to N-component mixtures of hydrocarbons, of which there are many industrially relevant streams, not limited to crude oil. One of the limitations to the industrial implementation of this type of membrane-based process is whether the polymer membranes can be fabricated in a scalable manner. Therefore, a roll-to-roll dip-coating process was used to demonstrate the continuous fabrication of thin film composite hollow fiber membranes. In this precursive work, a more established spirocyclic polymer, PIM-1, was coated on a commercial polymer support to investigate the feasibility of this process for the novel spirocyclic polymers identified for crude oil separations. Upon successful demonstration, the learnings could be used to develop large-scale polymeric membranes capable of excellent separation performance in complex mixtures coupled with fast transport rates.Ph.D

Unraveling the fingerprints of NOx using stable isotopes: Implications for NOx source partitioning and oxidation chemistry

The nitrogen (N) and oxygen (O) stable isotope composition (δ15N & δ18O) of nitrogen oxides (NOx )may be a useful tool for constraining NOx emission sources as well as for understanding the atmospheric oxidation pathways responsible for its removal if various NOx sources and sink processes exhibit characteristic isotopic compositions (“fingerprints”). However, this requires (1) an accurate and complete inventory of δ15N(NOx) values from major emission sources, (2) an assessment of the kinetic and equilibrium isotope effects that can impact δ15N and δ18O values of NOx, (3) and test these assumptions by conducting accurate in situ δ15N and δ18O measurements of atmospheric NOx. To this end, I have characterized the δ15N(NOx) signatures from various fossil-fuel NOx sources, including buses, trucks, lawn equipment, natural gasfired boilers, and airplanes. These δ15N(NOx) source characterization studies along with prior studies indicate that soil emission (nitrification/denitrification), “thermal” NOx producedfromfossil-fuelcombustion, and“source” NOx producedfromcoal-fired power plants have relative distinctive values. In addition, both my experimental and theoretical investigations on the isotope effects associated with NOx oxidation indicate that isotopes effects via equilibrium isotope exchange and kinetic isotope effects occurring during NOx oxidation reactions may influence the δ15N and δ18O values of atmospheric nitrate. Using these calculated isotope effects, I developed a simple model for the production of atmospheric nitrate through its three major pathways thatinclude(1)NO2 +•OH→HNO3, (2)N2O5 +surface→2HNO3, and(3)NO3+ R→•R. This model indicated that these pathways result in distinctive δ18O-δ15N relationships that tend to match reported literature values. Finally, in order to evaluate the influences of NOx emission sources and isotope effects on the isotope composition of NO2, which serves as precursor molecule to atmospheric nitrate, ambient NO2 was collected and analyzed for 15N and 18O . These results suggest that δ18O of NO2 has a distinctive diurnal profile reflecting the photochemical cycling of NOx while δ15N of NO2 tends to track with NOx sources with small but significant isotope effects altering daytime δ15N(NO2) by approximately 2-4%. Overall, this research has refined the “fingerprints” of atmospheric NOx and will be useful for future studies aimed at understanding regional and spatial distributions in NOx emission budgets and tracing NOx oxidation chemistry

Twin screw extrusion pre-treatment of wheat straw for biofuel and lignin biorefinery applications

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Pre-treatment of wheat straw(lignocellulosic) biomass is a crucial step as it has direct impact on the subsequent yield of enzymatic saccharification and alcohol fermentation processes in the production of biofuel. Twin screw extrusion is a highly feasible pretreatment method and has been received great interest in the recent year pre-treatment studies. Twin screw extrusion is a continuous process, where the biomass feedstock can be subjected to a combination of simultaneous physical, thermal and chemical treatments. Steam explosion is a batch process and is the most commonly used method for lignocellulosic pre-treatment. In the initial stage of this study, the yield of glucose obtained from enzymatic saccharification for both methods (extrusion and steam explosion) were compared to identify the most effective pre-treatment approach. Effectiveness of the conventional steam explosion pre-treatment was used as benchmark for the directions of development of effective extrusion fractionation for wheat straw. In subsequent study, the impact of physical operating parameters (moisture, barrel temperature, compaction, screw speed and size reduction before extrusion) over twin screw extrusion with and without NaOH were studied. Low temperature (50°C) and increased moisture extrusion were preferred extrusion conditions. Yield of glucose can be improved by addition of NaOH (0.04g / g straw) and barrel temperature profile optimisation. Post extrusion washing was recommended. Findings from FTIR and TGA help to understand the chemical and structural changes took place in the pre-treatment and can be correlated with the glucose yield at the end of enzymatic hydrolysis. Characterisation analysis was extended to FT-NIR, morphology, crystallinity and specific surface area analysis to analyse the structural changes of lignocellulose biomass in extrusion pre-treatment and correlation with glucose yield. Chemometric analysis was used to statistically process large amounts of spectral data. The PCA scores plots showed good cluster segregation of the samples and were thus able to distinguish the effects of different pre-treatment conditions. The PLS regression models for both FTIR and FT-NIR showed good statistical regression and predictive ability correlated to the glucose yield. For the lignin ultilisation study, crude lignin was recovered from black liquor and fractionated with solvents. Lignin and the fractions were characterised with solvent solubility, SEC, UV, FTIR, 1H and 13C NMR and evaluated for the antioxidant activity with AAI ranged from 0.3 to 2.4. Reason for the low performance was proposed and experiment was extended to the intended application performance screening. Lignin application study was further extended to assess the feasibility of using lignin as an antioxidant in carboxylated acrilonitrile-butadiene rubber, XNBR glove. Evaluation involved physical observation, mechanical properties and thermal analysis – DSC-OIT after incorporation of lignin into XNBR glove. Lignin antioxidant performance was compared with current chemical antioxidant in used in industry. A part from antioxidant behaviour, lignin was also found can enhance the softness of XNBR film after accelerated heat aging.This study is funded by the Ministry of Science, Technology and Innovation, Malaysia

Thermo-Catalytic Reforming of waste biomass for alternative fuels production in a framework of decarbonisation

In Europe, the production of alternative biofuels represents a very relevant economic and innovative target, as several European directives and regulations are enacted to secure support for the sustainable development throughout the transport sector. To satisfy the continuity of biofuels production avoiding the risks of technological failures or feedstocks shortage, the use of wastes and second-generation biomass represents a promising solution in terms of availability, economic convenience and environmental impact on overall emissions. In fact, they can be produced worldwide without competing with other industrial uses (e.g. food industry, livestock bedding, horticulture etc.) or having possible negative impacts on environment and biodiversity. The real diversifier for the competitiveness as well as the feasibility of biofuels production is the technology. Among several thermochemical conversion systems, the patented Thermo-Catalytic Reforming (TCR©) represents a flexible and reliable technology, capable to convert a wide range of advanced feedstocks in value-added products and fuels (i.e. char, oil and syngas). In this research, waste carbon fibres (CF) and solid grade laminate (SGL) have been investigated in a 2 kg/h lab-scale TCR reactor at the University of Birmingham. They are widely used in the industrial sectors and in many applications such as construction material, furniture, electronics as well as in vehicles, aerospace industry, sporting goods and medical field, thus contributing to high volumes of waste at end of life. Globally, about 130 million of tons of kraft paper is annually produced and partly destined to SGL production and the global demand of carbon fibres in 2022 is equal to 127,000 tons. To evaluate the suitability of TCR technology for SGL and CF, the characterisation of both feedstocks was accomplished, and it was concluded SGL and CF can be processed via TCR. The main energy carriers (char, oil and syngas) were generated under pyrolysis temperatures of 500°C for SGL and 600°C for CF and reforming temperature of 650°C for SGL and 680°C for CF, respectively. The different temperatures were set according to the preliminary investigation carried out on TGA for both feedstocks. The SGL oil showed good properties and its HHV reached a value of 32.72 MJ/kg. However, a successive upgrading was required to meet specifications for its use as drop in fuels. On the contrary, the CF oil production was negligible, even if its calorific value was 30 MJ/kg. The syngas produced from the treatment of SGL and CF was rich in hydrogen (about 20-40 vol%). Lastly, char revealed a calorific value of 25.94 MJ/kg and 20 MJ/kg for SGL and CF, respectively, thus exhibiting potential as a fuel as well as a catalyst in the gasification process. Overall, TCR of SGL and CF represents a novelty and it can be a promising route for the valorisation of this type of wastes. Finally, a techno-economic analysis for a commercial TCR3000 plant suggests that the technology is affordable and suitable to be commercialised

Short-Term Fluctuations of Carbon Isotope Levels in Atmospheric Carbon Dioxide

Natural 14C fluctuations are known to have occurred over periods of 50 to thousands of years during the last 10 millennia. As the fluctuations represent deviations from the basic assumptions of the radiocarbon dating method, major research programmes have concentrated on the establishment of the main trends of secular 14C variations. Recent work has questioned the assumed constancy of natural C levels over shorter time periods of 10 years and has thus implied the reduced effectiveness of present calibration curves to the age-correction of shortlived dating samples. In this research, annual atmospheric 14C concentrations in the northern hemisphere have been studied through analyses of 19th Century single tree rings. Natural C fluctuations of 2% over the 11-year sunspot cycle appear to have occurred in correlation with solar activity. Consequently, an additional error of at least +/-80 years is inevitable in the radiocarbon age determination of dating samples of lifetime 1 year. In addition, the selection of dating samples which incorporate the products of 10-11 years' growth (or a multiple of this) is urged by the apparent relationship between annual C levels and the 11-year sunspot cycle. It is suggested that the origin of this relationship lies in changes in 14C production and in internal atmospheric mixing through the modulation of incident radiation by variations in solar activity. Annual atmospheric C concentrations in the southern hemisphere during this century have also been studied through analyses of tree rings, wines, seeds and wool. No correlation between southern hemisphere 14C activity and the 11-year sunspot cycle has been observed. It is believed that the greater surface area of the southern oceans may be responsible for observed 14C differences between hemispheres through enhanced uptake and exchange of atmospheric CO2. Variations of the stable carbon isotope composition of atmospheric CO2 during the 20th Century have been detected by mass-spectrometric measurements of the 13C/12C ratios of single tree rings. A decrease of 0.2% has been observed in the atmospheric 13C/12C ratio as a result of the input of isotopically lighter CO2 from fossil fuel combustion. The temporal trend of the 13C/12C variations suggests that industrial CO2 has been removed from the atmosphere at an increased rate during the past few decades. Generally, the study implies non-uniform CO2 transfer rates across the atmosphere/biosphere/ocean interface during this century

Soybean

Soybean is an agricultural crop of tremendous economic importance. Soybean and food items derived from it form dietary components of numerous people, especially those living in the Orient. The health benefits of soybean have attracted the attention of nutritionists as well as common people

Physico-chemical speciation and ocean fluxes of Polycyclic Aromatic Hydrocarbons

Thesis (Ph. D.)--Joint Program in Oceanography, Massachusetts Institute of Technology/Woods Hole Oceanographic Institution, 1997.Includes bibliographical references.by Örjan Gustafsson.Ph.D