Co-processing Of Bio-oil Research Articles

Multi-objective design and optimization of co-processing of bio-oil and vacuum gas oil in a hydro-cracking unit integrating green hydrogen and green electricity

To reduce the carbon emissions from the hydrocracking unit in refinery, this work proposes the coupling of bio-oil co-processing technology with green hydrogen and green electricity in the hydrocracking unit. However, the higher costs associated with biomass feedstock, green hydrogen, and green electricity result in an elevated overall cost for this process. To investigate the relationship between economic costs and carbon emissions in the co-processing hydrocracking unit with coupled green hydrogen and green electricity, a multi-objective optimization model is introduced, targeting to minimize total cost and carbon emissions simultaneously. Three scenarios are proposed for better comparison under different objectives: the minimum cost scenario, minimum carbon emissions scenario, and trade-off scenario. The minimum cost scenario incurs a total cost of only 15,494.1 MRMB/y (million Renminbi per year, currency in China), but with a high emission of 5.95 Mt CO2/y. The minimum carbon emissions scenario results in costs and emissions of 20,421.9 MRMB/y and 4.97 Mt CO2/y, respectively. The trade-off scenario yields cost and carbon emission values of 15,580.9 MRMB/y and 5.76 Mt CO2/y. Furthermore, sensitivity analysis reveals that the co-processing ratio of bio-oil has the most substantial influence on the overall process. The proposed model and results provide a theoretical foundation for the design and optimization of the co-processing hydrocracking unit.

Perspectives for Thermochemical Conversions of Lignocellulosic Biomass.

The biorefinery concept of lignocellulosic biomass with focus on thermochemical conversions will be presented and discussed with respect to the advantages, impacts, and methods. Analytics regarding the reaction mechanisms for the decomposition of cellulose, hemicellulose and lignin, respectively, will be presented along with new trends and perspectives within plasma and catalytic pyrolysis of lignin-fractions, artificial neural networks, hydrothermal liquefaction, torrefaction, gasification and combustion, pyrolysis and hydro pyrolysis as well as supercritical fluids for the catalytic thermochemical conversion of biomass and co-processing of upgraded bio-oil in fluidized catalytic cracking (FCC). A few examples are mentioned at this point; however, more details are given in the respective chapters. Concerning the catalytic conversion of lignin fractions the concept of the "catalyst philosophy" has been adapted from crude oil refining by using the hierarchical pore structure of the catalyst to arrive at the desired final products, like fuelcomponents or phenols. As a consequence, the same hierarchical catalysts can be applied in the co-processing of bio-oil with crude oil refined fractions. As a preliminary conclusion, the thermochemical conversion of lignocellulosic biomass has already reached a certain level of insight and understanding, however, there is still room for improvement and even a better understanding, and, last but not least, an upscaling to an industrial scale remains.

Synergistic effect in co-processing a residue from a transesterification process with vacuum gas oil in fluid catalytic cracking

• Co-processing of bio-oil in existing fluid catalytic cracking unit produces biofuel. • Bio-oil oxygen content determines its blends level with vacuum gas oil or VGO. • Distillation residue from biodiesel production using waste fats and oil is used. • Synergistic effect of bio-oil and VGO shows yield of gasoline higher than predicted. • Cracking of 10 wt% bio-oil has the closest coke characteristics compared to VGO. The catalytic co-processing of bottom fuel oil (BFO) with refinery vacuum gas oil (VGO) using a commercial fluid catalytic cracking (FCC) zeolite equilibrium catalyst was carried out to ascertain its potential as a source for biofuels. The BFO used was the distillation residue from biodiesel transesterification process using waste fats and oil; being a mixture of saturated and unsaturated fatty acid methyl esters. The catalytic cracking experiments were performed in a laboratory fixed bed micro activity test (MAT) reactor at 516 °C and atmospheric pressure. As well as the VGO and BFO, three different blends were used with BFO to VGO mass ratios of 10:90, 20:80 and 50:50, and catalyst-to-oil (C/O) ratios of 3.0 – 5.7. The synergistic effect of BFO in VGO blends includes the yield of gasoline, and LPG being higher than predicted for the blends of 10 wt% BFO in VGO. Also, the formation of more CO 2 with the increase in BFO blend level suggests CO 2 production through decarboxylation reactions as a possible route. The compositions of the produced gasoline for pure VGO and 10 wt% BFO are similar as well. The cracking of 10 wt% BFO gives a higher fraction of aromatics, alkenes and naphthenes than other blends. However, some deterioration was observed when higher substitution levels of BFO were used, resulting in a decrease in the gasoline yield and higher yields of LCO, HCO and coke as predicted. Overall, co-processing BFO with VGO may be economically attractive because the BFO is obtained from waste oils and fats which are one of the under-exploited sources of biodiesel feedstocks and add value to waste management.

Characterization of Trace Oxygenates from Co-processing of Bio-oils with Petroleum-Derived Feed with GC × GC–MS

Characterization of Trace Oxygenates from Co-processing of Bio-oils with Petroleum-Derived Feed with GC × GC–MS

Fully integrated CO2 mitigation strategy for an existing refinery: A case study in Colombia

The oil and gas industry is responsible for 6% of total global CO2 emissions, from exploration to downstream petrochemical production and account for another 50% when including the use of its products. Thus, this industry has a significant role in realising the target of net “zero” CO2 emissions by 2070, essential to limit global warming to 1.8 °C [2], as introduced under the Paris agreement. Currently, the interactions of an extensive set of individual and combined CO2 mitigation measures along the value chain and over time are poorly assessed. This paper aims to assess a bottom-up CO2 mitigation potential for a complex refinery, including portfolios of combined mitigation options, considering synergies, overlap, and interactions over time for more realistic insight into the costs and constraints of the mitigation portfolio. A total of 40 measures were identified, covering a wide range of technologies such as energy efficiency measures (EEM), carbon capture and storage (CCS), bio-oil co-processing, blue and green hydrogen (BH2, GH2), green electricity import, and electrification of refining processes linked to the transition of the Colombian energy systems. Five deployment pathways were assessed to achieve different specific targets: 1-base case scenario, 2-less effort, 3-maximum CO2 avoidance, 4-INDC, and 5-measures below 200 €/t CO2. Two scenarios (3 and 5) gave the highest GHG emission reduction potentials of 106% and 98% of refining process emissions, respectively. Although significant, it represent only around 13% of the life-cycle emissions when including upstream and final-use emissions of the produced fuels. Bio-oil co-processing options account for around 60% of the mitigation options portfolio, followed by CCS (23%), green electricity (7%) and green H2 (6%). The devised methodological approach in this study can also be applied to assess other energy-intensive industrial complexes and shed light on the bias for estimating CO2 mitigation potentials, especially when combining different mitigation options. This is turn is vital to define optimal transition pathways of industrial complexes.

Catalyst Stacking Technology as a Viable Solution to Ultralow Sulfur Diesel Production

Production of ultralow sulfur diesel (ULSD) is a tough challenge for refineries previously producing low sulfur diesel. Some common solutions to meet the stricter standards are revamping pre-existing units, building new facilities, purchasing high-activity catalysts, adapting alternative desulfurization techniques, and changing the feedstock; however, these methods usually entail high capital investments or are simply not viable. Another option, generally overlooked, is to place different catalysts in multibed configurations to produce a synergistic effect between them, i.e., catalyst stacking technology. This work aims to broaden the current knowledge and scope of this technology and suggest it as a viable low-investment solution for ULSD production. As we have described, the differences between the catalysts can be exploited to maximize the performance and minimize the operating costs of HDS units. Moreover, any new HDS catalyst performance could benefit from a fitting stacked-bed system, especially if it has high production costs. However, the synergistic effect between the catalysts is not fully understood yet, and designing the best stacking system (number, order, and proportions of the catalysts) is not straightforward. Many factors must be considered, such as the characteristics of the catalysts (active phase, support, and kinetic parameters), feedstock composition, operating constraints, and target end product. Currently, the selection of the optimal configuration is inadequately approached case by case and requires multiple catalytic evaluations on an industrially relevant scale because a reliable predictive method has not been established yet. Therefore, valuable time and resources could be saved by thoroughly studying the influences of the variables on the synergetic effects and developing new mathematical models. Furthermore, there are still many alternative applications of this technology that could solve current and future issues of the refining industry, like the reuse of spent catalysts and the coprocessing of bio-oils with conventional feedstocks.

Renewable-carbon recovery in the co-processing of vacuum gas oil and bio-oil in the FCC process – Where does the renewable carbon go?

This study aims to quantify the renewable-carbon content in the products produced by co-processing vacuum gas oil with up to 20 wt% bio-oil in the fluid catalytic cracking (FCC) process. The renewable-carbon content of 40 product samples collected at a demonstration-scale FCC unit was quantified by 14C isotopic analysis.The renewable-carbon mass balance closure ranged between 90% and 110%. The biogenic-carbon content of the liquid effluent increased linearly as a function of the amount of bio-oil fed to the FCC. Most of the biogenic carbon was recovered as coke. Moreover, the renewable-carbon recovery in the liquid effluent remained at approximately 30 wt%, independent of the percentage of bio-oil fed to the FCC process. The FCC process is generally considered the largest single source of greenhouse gas (GHG) emissions in a petroleum refinery. These results will enable the life-cycle assessment from the co-processing of bio-oil in an FCC.The renewable carbon present in the coke deposited on the FCC catalyst, which is later burned during catalyst regeneration in the FCC, would contribute to GHG emission abatement. Additionally, the use of bio-oil as an FCC feed could contribute to reducing the carbon intensity of gasoline, diesel, and fuel oil.

Supply chain design and integration for the Co-Processing of bio-oil and vacuum gas oil in a refinery

Co-processing of bio-oil and vacuum gas oil (VGO) helps to add renewable carbon to co-processing products and decrease the production cost of bio-fuels by using refinery existing infrastructures. Designing an effective supply chain for the co-processing system of bio-oil and VGO is very important for the further reduction of the production cost. However, it still remains unclear about how to integrate and coordinate the biomass supply and the crude oil supply. In this work, a mathematical model was proposed for the design and integration of the supply chain for the co-processing system to obtain the optimal supply chain network between the biomass supply and the crude oil supply. The obtained optimal supply chain network involved collections, storages and transportations of the biomass and the crude oil. The case study suggested that each storage site should be located within the relevant village to reduce the transportation cost; that the optimal transportation mode between the collection site and the storage site was electric truck while the optimal one between the storage site and co-processing site was heavy truck; that the crude oil cost contributed more than 99% for the total annualized cost; and that the biomass transportation cost was close to the biomass cost. Sensitivity analysis was also conducted to evaluate the effects of parameters on the total cost.

Fluid catalytic co-processing of bio-oils with petroleum intermediates: Comparison of vapour phase low pressure hydrotreating and catalytic cracking as pretreatment

For co-processing of bio-oil and conventional fossil feed in existing refinery fluid catalytic cracking (FCC) units, little attention has been paid to the increased aromatics and basic nitrogen content in the feed associated with the introduction of bio-oil and how it affects FCC performance. In this contribution, the effect of blending two bio-oils obtained from different catalytic treatment of wheat-straw pyrolysis vapors with atmospheric residue was tested using a microactivity testing unit (MAT). The catalysts used for the pyrolysis vapor phase upgrading included i) a Na/γ-Al2O3 deoxygenation catalyst, and ii) a Pt/TiO2 catalyst in combination with H2 atmosphere. The oxygen content of both bio-oils was similar at ~ 7–8 wt%, but the Na/γ-Al2O3 bio-oil had a lower total acid number (TAN) of 5 mg KOH/g and a higher basic nitrogen (BN) content of 0.7 wt% compared to the Pt/TiO2 bio-oil (15 mg KOH/g, 0.4 wt% BN).The processing of the upgraded bio-oils in blends with atmospheric residue in MAT increased the yields of dry gas, CO, CO2, and coke at the expense of naphtha (decrease by 2.8 percentage points) and decreased the conversion by ~ 2.5 percentage points. This is attributed to the high aromaticity and basic nitrogen content of the two bio-oils. The lower basic nitrogen content and higher degree of saturation for the Pt/TiO2 bio-oil may explain its slightly higher conversion (by ≤ 1 percentage points) compared to the Na/γ-Al2O3 bio-oil.This contribution provides important information for refinery operators interested in FCC co-processing of fossil oils and biomass-derived pyrolysis oils with elevated content of nitrogen and aromatics.

Multiperiod Design and Optimization of Coprocessing of Vacuum Gas Oil and Bio-oil Integrating Supply Fluctuations of Lignocellulosic and Algal Biomass

The coprocessing of bio-oil and vacuum gas oil has been demonstrated as a cost-effective way to utilize bioenergy. A multiperiod model is built to design and optimize of the coprocessing system by ...

Comparative Life Cycle Assessment of Co-Processing of Bio-Oil and Vacuum Gas Oil in an Existing Refinery

The co-cracking of vacuum gas oil (VGO) and bio-oil has been proposed to add renewable carbon into the co-processing products. However, the environmental performance of the co-processing scheme is still unclear. In this paper, the environmental impacts of the co-processing scheme are calculated by the end-point method Eco-indicator 99 based on the data from actual industrial operations and reports. Three scenarios, namely fast pyrolysis scenario, catalytic pyrolysis scenario and pure VGO scenario, for two cases with different FCC capacities and bio-oil co-processing ratios are proposed to present a comprehensive comparison on the environmental impacts of the co-processing scheme. In Case 1, the total environmental impact for the fast pyrolysis scenario is 1.14% less than that for the catalytic pyrolysis scenario while it is only 26.1% of the total impacts of the pure VGO scenario. In Case 2, the environmental impact of the fast pyrolysis scenario is 0.07% more than that of the catalytic pyrolysis and only 64.4% of the pure VGO scenario impacts. Therefore, the environmental impacts can be dramatically reduced by adding bio-oil as the FCC co-feed oil, and the optimal bio-oil production technology is strongly affected by FCC capacity and bio-oil co-processing ratio.

Quantitative Determination of Biomass-Derived Renewable Carbon in Fuels from Coprocessing of Bio-Oils in Refinery Using a Stable Carbon Isotopic Approach

Increasing renewable carbon incorporation into conventional fuels through coprocessing with vacuum gas oil (VGO, a petroleum refining feedstock) is a critical step in biofuel development, scaling-u...

Bio-oil transformation into 2nd generation biofuels

The article summarized the possible transformations of pyrolysis bio-oil from lignocellulose into 2nd generation biofuels. Although a lot has been published about this topic, so far, none of the published catalytic pro-cesses has found commercial application due to the rapid deactivation of the catalyst. Most researches deal with bio-oil hydrotreatment at severe conditions or its pro-cessing by catalytic cracking to prepare 2nd generation biofuels directly. However, this approach is not commercially applicable due to high consumptions of hydrogen and fast catalyst deactivation. Another way, crude bio-oil co-processing with petroleum fractions in hydrotreatment or FCC units seems to be more promising. The last approach, bio-oil mild hydrotreatment followed by final co-processing with petroleum feedstock using common refining processes (FCC and hydrotreatment) seems to be the most promising way to produce 2nd generation biofuels from pyrolysis bio-oil. Co-processing of bio-oil with petroleum fraction in FCC increases conversion to gasoline and, thus, it could be a preferable process in the USA. Otherwise, co-hydrotreatment of hydrotreated bio-oil with LCO leads not only to the reduction of hydrogen consumption but also to the conversion preferably to diesel. This process seems to be more suitable for Europe. Further research on bio-oils upgrading is still necessary before the commercialization of the bio-oil conversion into biofuels suitable for cars. However, the first commercial bio-refinery that will convert bio-oil into biofuel for marine transport is planned to be built in the Netherlands.

Sustainable design and optimization of co-processing of bio-oil and vacuum gas oil in an existing refinery

In order to lower the production cost of bio-fuels and add renewable carbon into the fossil fuels, the co-cracking of bio-oil and vacuum gas oil (VGO) has been proposed by utilizing the existing infrastructures in a refinery. The co-processing technique demonstrates an excellent economic viability for its further commercialization. However, the environmental impacts of the co-processing system consisting of the co-processing process and the bio-oil production process remain unclear. In this work, a multi-objective model was built to achieve the optimum biomass raw material and bio-oil production technology by simultaneously minimizing the total cost and the environmental impacts of the co-process system. An investigation was also conducted into the effects of the FCC capability and the bio-oil/VGO feed ratio on the economic and environmental objectives. Two cases were proposed to demonstrate the multi-objective model. The results shown that the optimum biomass raw material and bio-oil production technology were heavily dependent on the objectives. The most efficiency way to reduce total cost was to lower the biomass consumption while the most efficiency way to mitigate the environmental impacts was to decrease the VGO consumption, which is because the impact of the non-renewable raw material remains the most significantly contributory to all the environmental impacts.

Bio-oil co-processing can substantially contribute to renewable fuel production potential and meet air quality standards

Co-processing raw bio-oil derived from lignocellulosic biomass in existing petroleum refineries represents a near-term greenhouse gas mitigation strategy by producing partially renewable and infrastructure-compatible hydrocarbon fuel with minimal capital requirements. One deterrent for risk-averse refinery owners is that a modification to their air permit may be required prior to any changes to refinery operations due to potential air emission changes. However, a lack of information on potential air emission changes resulting from bio-oil co-processing yields uncertainty, which could cause delay in obtaining required permit. To address this concern, we perform a quantitative evaluation of air emission changes across a range of bio-oil co-processing fractions in refineries’ fluid catalytic cracking units. We find that 92% of U.S. petroleum refineries could co-process 5% or more (up to 20%, by weight) raw bio-oil without triggering major permitting requirements. We then develop an upper bound estimate of the potential for co-processing bio-oil considering permitting and technical limits; our results suggest that U.S. refineries could co-process 573,000 barrels per day (0.79 cubic meter per second) of raw bio-oil, implying ~1.92 billion gallons gasoline equivalent of renewable fuel per year (0.23 cubic meter per second), equivalent to 1.4% of U.S. gasoline consumption or 18% of ethanol production in 2018. This first-of-its-kind analysis integrates process and environmental engineering with air permitting analysis and demonstrates the importance of coupling regulatory considerations with engineering analysis to guide informed decision-making to minimize investment risks while fully leveraging refinery infrastructure. This novel approach is also applicable to refineries in other jurisdictions.

Tracking renewable carbon in bio-oil/crude co-processing with VGO through 13C/12C ratio analysis

Biomass-derived pyrolosis oil (aka. Bio-oil) contains high oxygen and other heteroatoms that prevent it from being directly used as a conventional fuel due to its thermal instability, non-volatility and corrosivity. Co-processing the bio-oil with vacuum gas oil (VGO, a petroleum refining feedstock) leverages the existing petroleum refining infrastructure which significantly reduces Capex for the bio-oil pathway. Increasing renewable carbon incorporation into conventional fuels is a critical step in biofuels development and adoption. To take advantage of this approach, a fast, economic and accurate method with a potenial online monitoring capability is needed for tracking the renewable carbon through processing and then using the information to guide optimization of the co-processing parameters to maximize renewable carbon incorporation in fuel products. Here, we have developed a high-precision analytical protocol that enables accurate 13C/12C ratio analysis for bio-oil/crude samples. Our study demonstrates that high-precision 13C/12C ratio analysis can be a viable way to track renewable carbon incorporation in bio-oil co-processing products including the feedstock derived from C3 plants and guide the optimization of the co-processing parameters. Comparison of δ13C with radiocarbon (14C) results obtained by an accelerator mass spectrometer (AMS) reveals a significant correlation (R2 = 0.998) and confirms δ13C applicability for tracking renewable carbon in co-processing systems. Because C4 plant-derived bio-oils (−13‰) possesess more distinct δ13C values than C3 plant-derived bio-oils (-26‰) relative to VGO (~−30‰), the use of C4 plant-derived feedstock will greatly increase the renewable C traceability through 13C/12C ratio analysis in bio-oil co-processing.

Bosting an Oil Refinery into a Biorefinery

The use of biofuels is increasingly important in order to mitigate the consumption of petroleum and increase the energy use of renewable sources. The estimative is that in 2040 the demand for oil will intensificate by 26% and part of it will have to be supplied by renewable energy. Biofuels offer a reliable alternative and among the process associated to biofuels production, thermal cracking results on a liquid product (bio-oil) with similar characteristics to the fossil fuels, particularly when performed with triglyceride sources (TG). In this sense, the main goal of this work is to propose an alternative sequence of chemical processes aiming to boost an oil refinery chain into a green refinery by producing, co-processing and improving bio-oil characteristics obtained from triglyceride source. Some bio-oil characteristics like density, acidity (AI), iodine index (II), oxygen content (OC), carbon number distribution and chemical compositions are presented. The properties of bio-oil obtained from the thermal cracking of triglycerides might be compared to petroleum and its derivate. Although the characteristics are similar between them, the bio-oil requires upgrading to reduce its high acid index, until achieve levels acceptable for its processing at a refinery. The content of olefins and oxygen might be reduced through hydrotreatment process. The hydrotreatment can promote the saturation of the double bonds and remove the oxygen atoms. The hydrotreatment unit is present in most of the refineries and further investigations are required to evaluate the hydrogen consumption. The proposal of this work is divided in four steps: the first is to produce bio-oil through triglyceride’s thermal cracking in a continuous and steady state regime; the second process is to promote the esterification of bio-oil to reduce its acid index; the third stage is co-processing bio-oil in a distillation unit being fractionated into desired fractions; the fourth step involves hydrotreatment to reduce both iodine index and oxygen content. Thus, the co-processing of bio-oil appears to be a promising approach to increasing the biofuels content in an oil refinery, to reduce sulfur and to maintain the quality parameters of commercial fuels.

Design and Integration of Bio-Oil Co-Processing with Vacuum Gas Oil in a Refinery

Due to the climate change and the strong dependence on fossil fuels, biomass-derived liquid transportation fuels and energy products have been proposed to deal with such situations. Usually, the prices of the bio-diesel and bio-gasoline are much higher than those of fossil fuels. The co-processing of bio-oil and vacuum gas oil (VGO) in a fluid catalytic cracker of a refinery has been proposed to utilize the existing refinery infrastructures and decrease the prices of bio-fuels. However, the integration between the bio-oil production and the existing refinery is not clear. In this work, a superstructure model is built to design and optimize the co-processing process with minimum total annual cost which features to select the optimal bio-oil production technology (fast pyrolysis or catalytic pyrolysis) and obtain the optimal integration scheme. Furthermore, the impacts of the prices of biomass and hydrogen, the bio-oil co-processing ratio on the economics of the co-processing system are also investigated. The optimal integration scheme of the co-processing of bio-oil and VGO can be obtained by solving the proposed model.

Techno-economic analysis of bio-oil co-processing with vacuum gas oil to transportation fuels in an existing fluid catalytic cracker

The co-processing of bio-oil and vacuum gas oil (VGO) in an existing fluid catalytic cracker (FCC) for productions of gasoline and diesel has been proposed and regarded as a possible technique to realize partial replacement of fossil fuels. A techno-economic analysis (TEA) was conducted to evaluate the economics of two co-processing scenarios, the co-processing of VGO and the fast pyrolysis oil or the catalytic pyrolysis oil. As revealed by the TEA results, the capital cost can be reduced significantly by using the existing refinery infrastructures and the minimum gasoline selling prices under the two scenarios were $2.63 and $2.60 per gallon respectively, which can be competing with that of petroleum-derived gasoline. As shown by the sensitivity analysis, the gasoline price was extremely sensitive to the fluctuations of the fuel yields, VGO and diesel prices, and FCC capability. Therefore, the co-processing technique to produce bio-transportation fuels can be identified as a partial replacement for the petroleum-derived fuels.

Design and optimization of bio-oil co-processing with vacuum gas oil in a refinery

The prices of the bio-diesel and bio-gasoline are normally significantly high when compared to the petroleum-derived fuels. The co-processing of bio-oil and vacuum gas oil in a fluid catalytic cracker (FCC) has been proposed to utilize existing refinery infrastructures while lowering bio-fuel prices. Nonetheless, the integration of the bio-oil production and the existing refinery remains unknown. In this work, a superstructure model is proposed to design and optimize the co-processing process by selecting the optimal biomass feedstock and the bio-oil production process (fast pyrolysis or catalytic pyrolysis). Furthermore, the impacts of the FCC processing capability and bio-oil co-processing ratio on the economics as well as the selection of bio-oil production process are also investigated. As revealed by the results of two scenarios, pulpwood is the optimal biomass feedstock and the fast pyrolysis ought to be selected for producing bio-oil when its co-processing ratio and the FCC processing capability are both relatively high.