| 1. |
- Abdelaziz, Omar, et al.
(author)
-
A conceptual framework for an integrated lignin biorefinery-petroleum refinery
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - 9788361506515 ; , s. 4027-4037
-
Conference paper (peer-reviewed)abstract
- Co-feeding of renewable feedstocks in general, and lignin streams in particular, in petroleum refineries is an attractive means of increasing the proportion of renewable fuel. Four separate units in an integrated refinery can be envisioned using lignin as a feedstock: the hydrotreater, the fluidised catalytic cracker, the hydrocracker and the slurry hydrotreater. A conceptual process design study, including cost assessments, is presented on the possibility of co-feeding lignin in one of these stages in a conventional crude oil refinery. The addition of lignin to an existing diesel hydrotreating unit is investigated in a refinery environment. Rigorous process simulation models were developed for such an integrated lignin-petroleum refinery based on real data. The lignin product shows good potential of ending up in the gasoline pool with about one third having a boiling point within the gasoline range, one third in the diesel range and the final third ending up in the LPG and kerosene pools. The total production cost of gasoline from lignin is estimated to be 0.82 €/L. If all or most tax reductions on fuels from sustainable sources could be utilised, lignin would be a viable resource for the production of biomass-based gasoline.
|
|
| 2. |
- Ayele, Getnet Tadesse, et al.
(author)
-
Exergy analysis and thermo-economic optimization of a district heating network with solar-photovoltaic and heat pumps
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : Institute of Thermal Technology. - 9788361506515 ; , s. 1947-1959
-
Conference paper (peer-reviewed)abstract
- Electrification of district heating networks, especially using heat pumps, is widely recommended in literature. Installing heat pumps affects both electricity and heating networks. Due to lack of suitable modelling tools, size optimization of heat pumps in the heating network with the full consideration of the electric distribution network is not well addressed in literature. This paper presents an optimization of a district heating network consisting of solar photovoltaic and heat pumps with the consideration of the detail parameters of heating and electric distribution networks. An extended energy hub approach is used to model the energy system. Exergy and energy analyses are applied to identify and isolate lossy branches in a meshed heating network. Both methods resulted into the same reduced topology. Particle swarm optimization is then applied on the reduced topology in order to find out the most economical temperature profiles and size of distributed heat pumps. The thermo-economic results are found to be highly influenced by the heat demand distribution, the power loss in both electric and heat distribution network, the cost of generation, the temperature limits and the coupling effect of the heat pumps.
|
|
| 3. |
- Balderrama, S., et al.
(author)
-
Automated evaluation of levelized cost of energy of isolated micro-grids for energy planning purposes in developing countries
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : Institute of Thermal Technology. - 9788361506515 ; , s. 2999-3012
-
Conference paper (peer-reviewed)abstract
- Countries around the world are preparing to give the last leap to accomplish a 100 % of rural energy access. Nonetheless, country-wide electrification planning requires the analysis of hundreds of un-electrified villages with different social, economical and geographical backgrounds. State-of-the-art planning models typically handle this computationally challenging task relying on highly-simplified technological characterizations, at the expense of a proper estimation of the cost-optimal potential of off-grid technologies, particularly micro-grids. In this paper, we propose a machine-learning method to improve such technological characterization while keeping the computational tractability of the problem under control. Firstly, field surveys from rural un-electrified villages in Bolivia are used as an input for a stochastic load generator model, creating several demand scenarios for a set of different village archetypes; secondly, renewable energy time series for representative locations of Bolivia are created using the NASA database. For each demand and renewables potential combination, a two-stage stochastic sizing model is adopted to obtain the corresponding cost-optimal micro-grid configuration. Finally, these data are used to train a Gaussian process regression with the levelized cost of energy (LCOE) as dependent variable and the daily average demand, renewable energy, and techno-economic characteristics of the components as independent variables. The results show that the trained algorithm is ultimately able to identify the LCOE of microgrids in given conditions, out of the training dataset, with satisfying accuracy and limited computational effort.
|
|
| 4. |
- Conti, Davide, et al.
(author)
-
A techno-economic assessment for optimizing methanol production for maritime transport in Sweden
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : Institute of Thermal Technology. - 9788361506515 ; , s. 4703-4712
-
Conference paper (peer-reviewed)abstract
- The maritime transport sector is currently highly dependent on oil-based fuels. International regulations enforce tight limits regarding NOx emissions from the exhaust gases and maximum sulphur content in the fuel, enhancing the sector interest towards the development of cleaner alternative fuels. A transition to biomass-based liquid fuels is of interest as a common solution for reducing pollutant emissions and for CO2 emissions mitigation. In this paper, a case study on Sweden analyses the potential of methanol production, using gasification of woody residues from sawmills to cover domestic and international maritime energy demand. Methanol seems to be a promising alternative to heavy and light fossil oils as maritime fuel, and sawmills residues are an abundant resource in Sweden. The study considers the entire methanol production chain, starting by assessing the availability of sawmill by-products and ending with the energy demand of final users, identified as the Swedish ports. The analysis considers two scenarios until year 2035, assuming different share of energy demand covered by methanol. When considering the production and use of biofuels, the cost for transportation of the feedstock and the final product have a great impact on the final cost. An optimization model is used to locate the methanol production plants, so to minimize the cost of the production chain. Four possible plant sizes are considered, 100, 200, 300 and 400 MW of biomass fuel thermal input. The production plant is modelled to determine the material and energy streams involved in the process and to obtain the cost and efficiency of producing methanol at the synthesis plant. The results include the final methanol cost and an estimation of the CO2 emissions reduction potential from replacing oil fuels with methanol for the assumed scenarios.
|
|
| 5. |
- Harahap, Fumi, 1983-, et al.
(author)
-
The role of oil palm biomass to meet liquid biofuels target in Indonesia
- 2019
-
In: Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - Poland : Institute of Thermal Technology. - 9788361506515 ; , s. 1509-1524
-
Conference paper (peer-reviewed)abstract
- Indonesia aims at reducing the dependence on oil import by liquid biofuels consumption (i.e., biodiesel and bio-ethanol) in industry, transport and power sectors. The palm oil industry has played significant role in the development of biodiesel in the country producing crude palm oil (CPO) and palm fatty acid distillate (PFAD) based biodiesel. Opportunity exists for the industry to contribute to the development of bio-ethanol program by utilising the lignocellulosic biomass such as the empty fruit bunches (EFB). This study evaluates the potential of liquid biofuels production from oil palm biomass and the domestic demand for biofuels as per biofuel blending target set by the Indonesian government. The existing infrastructures as well as the investment opportunity of each type of biofuel are analyzed. While technology for biodiesel production is proven at large scale, the bio-ethanol production from EFB is not commercialized yet. The study shows that meeting the biodiesel blending target is at risk if Indonesia continues to solely reliance on the production of CPO and PFAD based biodiesel. Palm oil industry can produce nearly 7 billion litres biodiesel from CPO and PFAD in 2025 but the biodiesel domestic demand is 30% higher. The bio-ethanol program faces higher risk. EFB based ethanol through gasification and synthesis of alcohol can contribute to around 13% of the target in 2025, however the infrastructure is not ready yet. Feedstock diversification to produce liquid biofuels should be prioritized. We recommend a review of the current plan to a more achievable targets or prolong the timeline in order to secure domestic biofuels demand while continuing export. The study provides database for future modelling exercise on multi-period optimization study of palm biofuels supply chain in Indonesia in a geographically explicit way.
|
|
| 6. |
- Herrera, I., et al.
(author)
-
Analysis for the integration of solar energy to sugarcane bagasse cogeneration power plant in the Cuban context : A case study
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : Institute of Thermal Technology. - 9788361506515 ; , s. 3597-3605
-
Conference paper (peer-reviewed)abstract
- Cuba is a small island located in the Caribbean Sea, with an extension of 109,886 km2 and a population of about 11,000,000 of which 98.2% have access to electric energy services. The national electric network has a power capacity of 7,741 MW, but only 4.3% is generated from Renewable Energy Sources (RES). In this context a new policy for the development of RES has been launched by the government, in order to increase its share in the energy matrix and decrease energy cost. A special contribution is expected from sugarcane bagasse cogeneration power plants. The installed capacity in this sector is 470 MW, it is expected to rise up to 872 MW from 2018 to 2030, generating electricity at a cost lower than 0.15 USD/kWh. To this purpose, 25 facilities will be upgraded to bioelectric plants with an expected annual generation of 4,300 GWh, avoiding 3.65 MMtonCO2/year. For modernizing the energy scheme of sugar cane enterprises many technical possibilities exist, for example: increase working pressure, increase working temperature, use the maximum amount of residue as fuel, etc. Economic aspects should be considered, in order to achieve low energy costs in a sustainable way. One of the problem related to the power generation in the sugar industry is the seasonality, as the facilities must stop once the harvesting period ends due to the lack of fuel (bagasse). However, if some solar energy could be added to the process some bagasse could be stored and used to run the power plants off season and hence improve their economic performance. In this work the integration of solar energy to a small sugarcane bagasse cogeneration power plant was studied. The cane crushing capacity is 2,300 TCD (Tonnes of Cane/Day) and the crushing season is from December to April. Every season 60,400 tons of bagasse are available. The process steam pressure is 2.5 bar(abs). A parabolic solar field for heating the boiler feed water was studied. With a field of 34,500 m2, the facility could run for two month off season, with an internal return rate of 6% and a payback period of 10 years. Additional studies are needed to improve the economic indicators.
|
|
| 7. |
- Sherif, Nourhan, et al.
(author)
-
Process synthesis and simulation of furfural production from rice straw biowaste
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - 9788361506515 ; , s. 4105-4113
-
Conference paper (peer-reviewed)abstract
- Rice straw is regarded as one of the main cereal straws that are produced every year in substantial amounts. Typically, rice straw is burned by farmers as they could not find a more promising technique to dispose it. This burning produces particulates and carbon monoxide causing many adverse effects on the environment and the public health, and finding a way to efficiently utilise this biowaste resource is of great importance. This research investigates the process synthesis of the acid-hydrolysis of rice straw to produce furfural, a versatile platform molecule for biofuels and biochemicals. The kinetic model and operating conditions used for simulation are obtained from previous studies. Results of reactor simulations are validated with the experimental work. Optimisation will follow to manipulate several parameters including acid concentration, reaction temperature, acid/rice straw ratio, catalyst concentration and type of acid to increase the furfural yield and reaction conversion. The second phase of this research will consider a full flowsheet simulation and sensitivity study to reach an optimum process with respect to environment and economics. Aspen Plus® simulation package is employed for process simulation, sizing and analysis.
|
|
| 8. |
- Zetterholm, Jonas, 1989-, et al.
(author)
-
Evaluating investments in integrated biofuel production - factoring in uncertainty through real options analysis
- 2019
-
In: ECOS 2019 - Proceedings of the 32nd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems. - : Silesian University of Technology. - 9788361506515 ; , s. 1911-1922
-
Conference paper (peer-reviewed)abstract
- In the endeavour to reduce CO2 emissions from the transport sector, biofuels from forest industry by-products are key. The adaptation of forest-based biorefinery technologies has so far been low which can partly be attributed to uncertainties in the form of policy instability, market prices, and technology costs. These uncertainties in combination with technology learning, which can be expected to reduce future investment costs, could make it favourable to postpone an investment decision. When applying real options theory, it is recognised that there is an opportunity cost associated with the decision to invest, since the option to wait for more favourable market conditions to occur is forfeited. In traditional discounted cash flow analysis, the impact of uncertainty and the value of reducing it (e.g. by waiting), is usually not taken into consideration. This paper uses a real options framework that incorporates the option to postpone an investment to reduce market uncertainties and wait for technology learning to occur. The focus is to investigate how the usage of an investment decision rule based on real options analysis affects technology choice, the economic performance, and when in time it is favourable to invest in pulp mill integrated biofuel production, compared with using a decision rule based on traditional discounted cash flow analysis. As an illustrative case study we examine a pulp mill which has the option, but not the obligation, to invest in either of two different biofuel production technologies that both use the pulp mill by-product black liquor as feedstock: (1) black liquor gasification followed by fuel synthesis, and (2) membrane separation of lignin followed by hydrodeoxygenation. With the usage of the real options framework and the inclusion of the uncertainties regarding future market prices and investment costs, the decision to invest is made later, compared with using traditional cash flow analysis. The usage of real options also reduces the likeliness of a net loss occurring if an investment is made, as well as increases the expected economic returns, showing the added economic value of flexibility in the face of uncertain future conditions.
|
|
