Insight into the Sustainable Integration of Bio- and Petroleum Refineries for the Production of Fuels and Chemicals.

A petroleum refinery heavily depends on crude oil as its main feedstock to produce liquid fuels and chemicals. In the long term, this unyielding dependency is threatened by the depletion of the crude oil reserve. However, in the short term, its price highly fluctuates due to various factors, such as regional and global security instability causing additional complexity on refinery production planning. The petroleum refining industries are also drawing criticism and pressure due to their direct and indirect impacts on the environment. The exhaust gas emission of automobiles apart from the industrial and power plant emission has been viewed as the cause of global warming. In this sense, there is a need for a feasible, sustainable, and environmentally friendly generation process of fuels and chemicals. The attention turns to the utilization of biomass as a potential feedstock to produce substitutes for petroleum-derived fuels and building blocks for biochemicals. Biomass is abundant and currently is still low in utilization. The biorefinery, a facility to convert biomass into biofuels and biochemicals, is still lacking in competitiveness to a petroleum refinery. An attractive solution that addresses both is by the integration of bio- and petroleum refineries. In this context, the right decision making in the process selection and technologies can lower the investment and operational costs and assure optimum yield. Process optimization based on mathematical programming has been extensively used to conduct techno-economic and sustainability analysis for bio-, petroleum, and the integration of both refineries. This paper provides insights into the context of crude oil and biomass as potential refinery feedstocks. The current optimization status of either bio- or petroleum refineries and their integration is reviewed with the focus on the methods to solve the multi-objective optimization problems. Internal and external uncertain parameters are important aspects in process optimization. The nature of these uncertain parameters and their representation methods in process optimization are also discussed

Biofuels from algae: technology options, energy balance and GHG emissions: Insights from a literature review

During the last decade(s), algal biomass received increasing interest as a potential source of advanced biofuels production resulting in a considerable attention from research, industry and policy makers. In fact, algae are expected to offer several advantages compared to land-based biomass crops, including: better photosynthetic efficiency; higher oil yield; growth on non-fertile land; tolerance to a variety of water sources (i.e. fresh, brackish, saline) and CO2 re-using potential. The algal growth can be also integrated in wastewater (WW) treatment systems to combine the nutrient streams removal with biofuels production. In addition, a wide range of marketable co-products can be extracted from algae (e.g. chemicals, pharmaceuticals, nutritionals) along with the production of biofuels, under a biorefinery system. Considering the potential benefits, several European-funded pilot projects, under science-business partnerships, have been dedicated to the development of algae technologies in the biofuels and bioenergy sectors. Despite the extensive research and investments in the last decade(s), no large-scale, commercial algae-to-biofuels facilities were implemented yet. In fact, in the current algae cultivation sites, the produced biomass is currently exploited for production of food and feed, combined with the extraction of high added-value products, such as proteins, nutritional supplements and chemicals. We report on the current-status of technology options for the potential exploitation of algae (of both macro- and microalgae species) in the biofuels and bioenergy sectors. We presents a comprehensive review of recent advances on promising algal biofuel production pathways, in terms of technological development, opportunities and limitations to their overall effectiveness. Furthermore, we analyse the main features, assumptions, modelling approaches and results of the algal biofuel pathways considered in the LCA literature. We highlight and interpret the energy and greenhouse gas (GHG) emissions balances resulting from examined LCA studies, in view of the key parameters mainly affecting the results. A comparison of the performance associated to the proposed algal biofuels pathways with that found for conventional fossil derived fuels is also reported.JRC.F.8-Sustainable Transpor

Microalgae Biorefinery Routes and Unit Operation Pre-Project Design, Selection and Sizing

Microalgae, or microscopic algae, have been studied as a natural marine resource for a number of economically relevant applications and several options exist for recovering and pro-cessing the biomass to obtain intracellular metabolites. This work presents the laboratory results from two proposed Nannochloropsis sp. microalgae biorefineries for the production of oil, high-value pigments, proteins and carbohydrates. Concerning the microalgal cell disruption processes, an overview of the technologies available was performed and bead milling was found to be potentially suitable for large scale microalgae biorefineries. Since petroleum-derived solvents such as dichloromethane, toluene or hexane are toxic and non-renewable, innovative and sustainable extractions using D-limonene, olive oil and etha-nol were tested to extract valuable lipids and pigments. Different membranes were also tested aiming the solvent recovery of ethanol and D-limonene. Regarding rejections of pigments and fatty acids, high values were achieved using organic solvent resistant membranes, proving to be possible to fractionate valuable biomolecules with a green and clean process. Afterwards, the laboratory results were extrapolated to mass balance calculations to select the biorefinery route by conducting a simplified economic analysis through equipment sizing and the cost estimation of the major equipments. The biorefinery route using olive oil as solvent was found to be the most promising process to study because, combined with the lower estimated CAPEX, the olive oil extract might be a highly profitable product rich in EPA fatty acid, as a product with significant health benefits for the human population

Interdependence of Financing Parameters and Processing Improvements in the Design of Economically Competitive Algal Biofuel Production Pathways

Financing parameters have often been considered exogenous variables in techno-economic analyses of algal biofuels production systems; these parameters reflect investment risk, a function of the processing techniques used and uncertain regulatory support, and are therefore linked to biorefinery design and current policy. Variations in financing parameters, representing regulatory policies (e.g. tax credits, loan guarantees, accelerated depreciation methods) and a range of investment risk are modeled to evaluate the impact of each on the economic competitiveness of novel algal biofuel processing techniques. The benefits from financing improvements are found to increase with the percent of the annual production cost from capital expenses, effectively incentivizing the development of processes which increase the ratio of annual capital to operating expenses. The availability of incentives and feasibility of investment risk reduction therefore impacts the choice of sub-process alternatives in the design of algal biofuel production systems for maximal cost competitiveness with conventional fuels.Master of Scienc

Factors Affecting Microalgae Production for Biofuels and the Potentials of Chemometric Methods in Assessing and Optimizing Productivity

Microalgae are swift replicating photosynthetic microorganisms with several applications for food, chemicals, medicine and fuel. Microalgae have been identified to be suitable for biofuels production, due to their high lipid contents. Microalgae-based biofuels have the potential to meet the increasing energy demands and reduce greenhouse gas (GHG) emissions. However, the present state of technology does not economically support sustainable large-scale production. The biofuel production process comprises the upstream and downstream processing phases, with several uncertainties involved. This review examines the various production and processing stages, and considers the use of chemometric methods in identifying and understanding relationships from measured study parameters via statistical methods, across microalgae production stages. This approach enables collection of relevant information for system performance assessment. The principal benefit of such analysis is the identification of the key contributing factors, useful for decision makers to improve system design, operation and process economics. Chemometrics proffers options for time saving in data analysis, as well as efficient process optimization, which could be relevant for the continuous growth of the microalgae industry

Techno-economic, uncertainty, and optimization analysis of commodity product production from biomass fast pyrolysis and bio-oil upgrading

Advanced biofuel is a promising replacement to fossil fuels for the purpose of protecting the environment and securing national energy supply, but the high cost of producing advanced biofuels makes it not as competitive as petroleum-based fuels. Recent technology developments in biomass fast pyrolysis and bio-oil upgrading introduced several innovative pathways to convert bio-oil into other commodity products, such as bio-asphalt, bio-cement, dextrose and benzene, toluene, xylene (BTX). Before commercializing these products, a comprehensive techno-economic analysis should be employed to examine the economic feasibility of producing them. This thesis compared the economic performance of biofuels, biochemicals, and hydrocarbon chemicals portfolios and optimized the product selection of an integrated bio-refinery. Based on a fast pyrolysis and bio-oil fractionation system, three product portfolios were proposed: biofuels (gasoline and diesel), biochemicals (bio-asphalt, cement and dextrose) and hydrocarbon chemicals (BTX and olefins). The production process, operating costs and capital costs were simulated based on the model data, experimental data, and literature data. Minimum product selling price (MPSP), maximum investment cost (MIC) and net present value (NPV) were used to evaluate and compare the economic performance of three portfolios with a 10% internal rate of return (IRR). A bio-refinery concept integrating all products was proposed to improve the flexibility to respond to changes in the market prices of the proposed products. The ratio of bio-oil upgrading to different product groups was manipulated to maximize the NPV under different price situations. Several major conclusions were drawn from this study. Due to high capital costs and operating costs associated with biofuels production, hydrocarbon chemical and biochemical products can be attractive bio-refinery products. However, there has been limited development of the hydrocarbon chemical and biochemical product technologies. This study attempts to address this risk by evaluating the uncertainty in the NPV and MIC. In particular, the biochemicals scenario has the highest MIC, which indicates that it has the greatest potential for remaining profitable with increased capital investment. The hydrocarbon chemicals production yields relatively high revenues and is more robust to fluctuations in market prices based on historical data. Biofuels production is economically attractive only when the price of transportation fuels is at historically high values

Importance of microalgae and municipal waste in bioenergy products hierarchy—integration of biorefineries for microalgae and municipal waste processing : A review

In the context of global advancements, the imperative of a sustainable energy supply looms large. Biomass, an adaptable and renewable resource, has garnered attention for its potential contributions, although economic uncertainties persist due to the intricate web of processing pathways. In response, the biorefinery concept emerges as a structured strategy to optimize the processing of microalgae and municipal solid waste (MSW), capitalizing on their multifaceted potential to yield diverse end-products. This review underscores the critical significance of a cohesive biorefinery paradigm that unites the processing of microalgae and MSW, unveiling their capacity to generate a spectrum of high-value products. The utilization of mixed-integer linear programming paves the way for an optimal biorefinery model that navigates through complex decisions. Challenges encompass the array of diverse feedstocks and the preliminary nature of data availability. The overarching goal of this research is to discern optimal pathways for the conversion of MSW and microalgae into energy and valuable products, with a focus on enhancing waste utilization and augmenting the energy supply. In the broader landscape, this comprehensive review advances strategies for sustainable energy generation and waste management, invigorating innovative approaches to shape future progress. By illuminating pathways towards maximizing the potential of biomass resources, this review contributes to the ongoing discourse on sustainable energy and waste utilization