Steam Demand Research Articles

Solar Boiler for Almond Processing

Since June of 2022, Sunvapor has been successfully operating the first solar boiler used for nut processing in the USA. Sunvapor engineered, managed the construction, and commissioned the turnkey solar steam generating facility for California Custom Processing (“CCP”), one of California’s leading almond processors located in Madera, California. CCP takes in raw almonds and performs a range of processes, including pasteurization, that require process steam. CCP was seeking to add steaming capacity to its boiler room, which has three 500 kWth (the subscript “th” means we are referring to thermal energy) gas boilers in order to raise its daytime production rate. The 2 MWth solar boiler developed by Sunvapor not only satisfied the need for additional daytime steaming capacity, but in clear sky conditions has supplied 100% of all the plant steam demand - with no greenhouse gas emissions. In this paper we present all phases of the life cycle of this first-of-a-kind solar boiler for nut processing; development, construction, commissioning, and operations.

Optimisation of Water-Use in Pulp and Paper Mills: A Streamlined Review of Scientific Journal Publications

The water-, and energy footprints of the processes in the pulp and paper industry are sizable enough to warrant investment of money and commitment of time truncate the same. Besides, there is also a nexus between water and energy here, with optimisation of the use of one of these resoruces enabling that of the other too. This streamlined review focuses on journal publications (originating from different parts of the world, and targeted at researchers and decision-makers in the industry) which train the lens on the optimisation of water use in this particular sector of the (forestry) bioeconomy. The synergies and complementarities which exist among different sustainable development goals (SDGs) , promise positive ripple effects, caused by attending to the truncation of the water footprint. The articles, in general, recommend effective in-plant wastewater treatment in combinaton with recirculating the treated effluent, and looking upon the water streams as carriers or bearers of valorisable substances – organics which can yield a host of bio-products in bio-refineries, including bio-energy. Availing of water-pinch analysis as a tool to uncover possibilities of water use in a cascade (depending upon the requirements imposed on the water, by processes downstream in the cascade), has been shown to aid in the optimisation of both water use and energy demand within the plant. One case study, for example, showed that the demand for steam can be decreased by about 4 GJ per ton of output, by recovering the waste heat in the water streams.

Energetic-environmental-economic assessment of utilizing weak black liquor to produce syngas for replacing evaporation based on coal water slurry gasification

As the main pollutant of paper mills, black liquor has brought great pressure to the wastewater treatment process of paper mills. Based on the coal-water slurry gasification (GS-CWS) technology, this paper designed the gasification system of black liquid coal-water slurry (GS-BLCWS) by utilizing weak black liquor of pulp mills, investigated and modeled the energy requirements of the GS-BLCWS. Feasibility assessment of the GS-BLCWS and the traditional alkali recovery systems (TARS) were carried out, including energy efficiency, economic feasibility and environmental impacts. The comparison results showed that the steam demands of two technologies can be self-sufficient. But the total energy efficiency of GS-BLCWS (69.78%) is higher than that of the TARS integrating GS-CWS (63.07%), and the energy output ratio of black liquor increased from 9.9% to 69.78%. From an economic point of view, GS-BLCWS can generate syngas, which can be used for drying in the papermaking workshop and shows better economic efficiency. Meanwhile, GS-BLCWS has lower environmental impacts that there is no emission of sulfur oxides and particulate matter. Considering the short payback period (5.81 years) of GS-BLCWS, the small environmental impact, and the self-sufficiency of steam and electricity, it has broad application prospects.

Optimal control of combined heat and power station operation

Combined heat and power stations have become one of the most utilized units of district heating systems. These stations usually contain several boilers for burning fossil fuels and renewable resources used for heating up steam, which can be used either for residential and commercial heating or electricity generation. To ensure efficiency, a boiler should either run continuously (for at least a given period) on a power output higher than a given threshold or switch off. The optimal control of the plant operations should combine an efficient setup for the turbine and boilers in operation, reflecting the demand for steam and the price of electricity, and a schedule that describes which boilers should be in operation at a given time. This paper proposes a method for optimal control of combined heat and power station operation for a given time horizon. The method is based on a two-level approach. The lower-level models correspond to finding the optimal setup of the combined heat and power station parameters for an hourly demand for different kinds of steam. The upper-level model corresponds to the optimal schedule of the operations of the individual boilers, which is planned for the entire time horizon. The lower-level model is modeled as a mixed-integer linear programming problem and is solved using parametric programming. A dynamic programming algorithm solves the upper-level model with a rolling horizon. The validity of the proposed method and its computational complexity for different granularity of the time horizon, different ranges of the parameters, varying demand for various kinds of steam, and varying electricity prices are investigated in a case study. The presented approach can be readily applied to other control problems with a similar structure.

Optimization of Heat Transfer Area and Steam Requirement in Multiple Effects Evaporator for Concentration of Juice in Sugar Factory

<strong>ABSTRACT.</strong> In maintaining the existence of sugar factories that exist and are still actively operating in Indonesia, efforts should be made to carry out intensification and extensification. In terms of the intensification of the process, it is necessary to periodically evaluate the performance of process tools, especially those that require utilities so that the process is effective and efficient. The process of making sugar passes through six stages, namely: milling, purification, evaporation (evaporation), cooking, screening, and packaging processes or the final stage. The evaporation process is a crucial process that determines the success of the entire process because the juice is concentrated from 11% to 64%. The evaporator is designed to use a multiple effect evaporator to increase the value of steam economy. The research objective is to optimize the number of effects that require a minimum total cost. To achieve this goal, it is necessary to survey the sugar factory to obtain the necessary valid data. Furthermore, a mathematical model is compiled based on the principle of mass and heat balance and then a software program is made so that the optimization solution can be done accurately. The conclusions that can be drawn are as follows: for a mass flow rate of 125,000 kg/hour with a concentration of 11% juice and a feed temperature of 100<sup>o</sup>C, the optimum conditions are obtained with a minimum annual production cost of IDR. 22,090,361,779.00 which is owned by the evaporator with 4 effects, total evaporator area = 2,443.81 m<sup>2</sup>, steam economy = 3.98 and steam demand = 26,028.2 kg/hour. The number of evaporator effects of 4 is common in Indonesia.

Data-driven multi-period modeling and optimization for the industrial steam system of large-scale refineries

Steam system modeling and optimization contributes toward low energy consumption for large-scale industrial refineries. However, formidable challenges have been generated by steam demand variation, the optimization of CO2 emissions and outsourced steam, the uncertainty of sudden equipment failures, and the introduction of new equipment. To address this issue, this work presents a novel steam system model with periodic process steam demand. The multiple cost factors of CO2 emission treatment and outsourced steam are considered and formulated as a mixed integer nonlinear programming optimization problem. A strategy to discretize the uncertainty of equipment failure into three main scenarios is proposed. The proposed model, strategy, and introduction of new equipment are demonstrated on three cases of industrial refinery steam systems. In case 1, the optimized operating costs have reduced by 1.5%. In case 2, the optimized average operating cost is 1,135,402 CNY/h. In case 3, with the introduction of the aromatics turbocharged turbine (ATT) and the letdown valve, the optimized operating costs are 1,292,182 CNY/h and 1,316,227 CNY/h respectively, confirming the feasibility of introducing ATTs.

A multi-period design method for the steam and power systems coupling solar thermal energy and waste heat recovery in refineries

It is imperative to reduce carbon emissions by comprehensively utilizing renewable energies and waste heat in refineries. However, the intermittent supply of solar thermal energy, the periodic changes of waste heat, and the variable demands of steam and electricity in refineries hinder optimal design and stable operation of the steam and power systems. In this work, an optimal design method for coordination of solar thermal energy and waste heat to produce steam and electricity in refineries was proposed, which features a multi-period mathematical programming model to synchronously determine the economy, the optimal capacity configuration, and the power scheduling scheme for the steam and power system. The influence of the serial and parallel structures of solar thermal energy supply, the model processing method for continuity of energy storage among different subperiods, and parametric analysis on the results were analyzed and discussed in detail. The results show that the cost of the solar thermal collectors and the energy storage system accounts for the significant proportion of the investment cost of the system. The cost of solar thermal collectors accounts for the largest proportion of the investment cost of the system, which is about 60% in the case study. The parallel structure of solar thermal energy supply can significantly reduce the total cost of the system. The coordination of solar thermal energy and waste heat recovery can jointly meet the steam demand to ensure the stability of the energy supply of the system. The comprehensive interactions and coordination between the solar steam generation systems, waste heat systems, energy storage systems, and demands are analyzed. The battery is necessary for short-time energy storage, whereas thermal energy storage should be used for either long-term or short-term energy storage. These results provide fundamental support for the optimal design of the steam and power systems in refineries by the comprehensive utilization of solar thermal energy and waste heat.

Design and testing of a Multi-Fuel industrial burner suitable for syn-gases, flare gas and pure hydrogen

The complete design and validation procedure of a novel Multi-Fuel heavy-duty burner is illustrated, starting from the conception and CFD analysis, up to an extensive experimental campaign assessing the actual performance of an industrial scale prototype.The need for an innovative burner to be employed in utility boilers comes from the context of energy transition with still increasing steam demand for process/industrial applications. The capability to burn a wide range of fuels, going from natural gas to flare-gases, syn-gases and fuels with even lower heating values, up to pure hydrogen, with high efficiency and low emissions is mandatory: it is shown and explained how all the above tasks are pursued starting from the early stage of conceptual design, leading to the development of a 2.5 MW prototype; then the burner operation is studied more in depth by CFD analysis, with particular attention to the implementation of MILD combustion regime: internal recirculation along with mixing, namely fuel dilution in flue gases leads to distributed volumetric reaction with oxygen, involving low peak temperatures with high conversion efficiency. Furthermore, numerical analysis helps to investigate the effectiveness of a central stabilizing flame, the coupling between furnace and burner in view of the tests, and also helps to evaluate different injection patterns for the fuel jets.As a final step, a 1.5 MW prototype is tested in a refractory lined furnace: the performance is assessed with natural gas, either pure or diluted with nitrogen to mimic a low heating value syn-gas, and with increasing percentage of hydrogen up to 95% as thermal input. Different levels of input to the central stabilizing flame are tested, and excellent flame stability of burner operation is proven. NOx emissions decrease for lower heating value fuels, increase for hydrogen/natural gas mixtures up to 35% H2, and remain almost constant above this threshold. Though, keeping a very low excess of air and almost no carbon monoxide in the exit flue gases, the absolute NOx levels compare very well with state of the art Ultra-Low-NOx industrial burners developed for standard fossil fuels. The presented data set can be relevant both for industrial designers, as a reference for heavy-duty burners operating with a wide range of fuels, up to pure hydrogen, and for academic researchers investigating on combustion, even in MILD regime.

내러티브로 만들어가는 유아 중심 STEAM 놀이 프로그램에 대한 원장과 교사의 인식 및 요구도 분석

Objectives The purpose of this study is to examine the perceptions and needs of the director and teachers for child-centered STEAM play program that is made into a narrative, and to analyze the differences in perceptions and needs between the director and teachers.
 Methods In order to achieve the purpose of this study, 36 directors, 240 teachers, and a total of 276 early childhood teachers who agreed to participate in the study were surveyed among early childhood teachers in kindergartens in Seoul, Busan, Gangwon, and Gyeongnam. For data processing and analysis, frequency analysis, cross- analysis, chi-square (x2) test, descriptive statistical analysis, and independent sample t-test were performed.
 Results First, both the director and teachers were generally well aware of STEAM education for young children, and it was found that they recognized the need for the child-centered STEAM play program made of narrative. Second, it was found that both the director and the teacher had diverse needs for the development and operation of the child-centered STEAM play program made of narrative. Third, both the director and teachers showed high demands for teacher training related to the child-centered STEAM play program.
 Conclusions Through the results of this study, the importance and demand for the child-centered STEAM play program created as a narrative in the 2019 revised Nuri-Curriculum, which is an child-centered⋅play-centered curriculum, was confirmed. Therefore, the researchers propose to develop and operate an child-centered STEAM play program that creates a narrative based on the results of this study.

Energy Saving Analysis of a Marine Main Engine during the Whole Voyage Utilizing an Organic Rankine Cycle System to Recover Waste Heat

In this study, a main marine engine with a rating power of 21,840 kW for a ship sailing in an actual voyage was obtained as the research object. The engine’s exhaust gas and jacket cooling water were adopted as the heat source of the organic Rankine cycle (ORC) system developed for the main marine engine. The engine can consume high-sulfur or low-sulfur fuel oil, respectively, according to the different emission control requirements. The impact of the use of high-sulfur or low-sulfur fuel oil, and variations in engine load, amount of recoverable waste heat, outboard seawater temperature, and the ship’s steam demand were comprehensively considered, and the validated ORC system model was used for the analysis of the system’s performance and the ship’s energy saving for the whole voyage. The results demonstrated that when the ship adopted high-sulfur or low-sulfur fuel oil, the maximum total net power output of the ORC system was 449.3 kW and 753.1 kW, respectively. During the whole voyage of 1610.7 nautical miles, when high-sulfur fuel oil was used, the ORC system reduced carbon emission by 40.3 tons and 33.8 tons, respectively, in summer and in winter, and the fuel saving rates were 2.53% and 2.12%; when low-sulfur fuel oil was used, the ship’s carbon emissions were reduced by 62.1 tons and 61.8 tons, respectively, in summer and in winter, and the fuel saving rates were 3.91% and 3.89%.

ANALYSIS THE EFFICIENCY OF BOILER 2011 UA WATER TUBE TYPE AT PT PERTAMINA RU III (PERSERO) PLAJU

One of the most important tools in steam production in the oil and gas industry is a boiler. Along with the increasing demand for steam, it is necessary to think about ways to increase the efficiency of the boiler. A boiler or steam boiler is a closed vessel-shaped device used to produce steam or steam. Boilers are designed to transfer heat from a combustion source. With Used the direct method (Direct Method) to calculate boiler efficiency. The pressure and temperature data of the feed water and steam is processed through the data interpolation process to obtain the enthalpy value of the feed water and steam enthalpy. Based on the calculation results obtained boiler efficiency results of 78.11%, 78.27%, and 79.75% with an average efficiency of 78.71%, and from the results of boiler efficiency calculations from the report of PT Pertamina RU III (Persero) obtained results of 89,75% in 1991. The efficiency of the above boiler has decreased by 11.04%. The decrease was caused by several factors, namely shells, valves, and instrumentation that had been eaten by age and damaged tubes.

Exergy Analysis of Inlet Air Absorption Cooling Effects on Basic Cogeneration Systems

The use of the electrical energy is increasing in our life and in the world. The electrical energy is lost in the connection lines about 11%, as it is known. By producing the electrical and the heat energy in a cogeneration system to meet the needs, it can be obtained more efficiency in the use of fuel, and that can reduce energy costs. In a cogeneration cycle, by the absorption cooling system, the air entering into the compressor is cooled, and the cooling is obtained from energy of the heat of the exhaust gases. The system in this study is analyzed by using exergy analysis method and 1. and 2. laws of thermodynamics. Some of the heat energy is consumed to cool the air, in this cycle and the remaining heat is used to produce steam. The performance analysis of the whole cycle and also the devices that make up the cycle such as compressor, combustion chamber, turbine and heat exchanger were obtained and discussed. Also exergy losses, exergy efficiency and other performance parameters of the devices were obtained and discussed. The results showed that using absorption cooling (abc) system in a basic cycle made better than the basic one in electrical efficiency. However, because of the absorption cooling (abc) system the exergy efficiency is slightly less than the basic one. The absorption cooling (abc) cogeneration system can be used when the steam demand decreases or electrical demand increases for production more electricity.

Optimisation of cogeneration system design with extended automated targeting model (ATM)

In this work, a mathematical optimisation technique known as automated targeting model (ATM) was extended for techno-economic evaluation of gas turbine (GT), steam turbine and combined cycle CHP systems. The objective is to introduce a systematic methodology for rigorous targeting of steam and power generation from complex CHP systems. In particular, the non-linear model of GT was linearised and incorporated for use in ATM. The extended ATM was applied to target minimum total annualised cost (TAC) for CHP systems in various scenarios. The extended technique was demonstrated with case studies of glycerine distillation and oleochemical plants. For the glycerine distillation plant, the result showed that combined cycle CHP system is the most cost-effective and environmental friendly scheme for the scenario, with minimum TAC of $ 5,668,000/y and carbon footprint of 69,008 t CO2e/y. In Scenario 1 of the oleochemical plant case study, with constant steam and power demand, the result showed that GT-CHP is the most cost-efficient scheme with minimum TAC and carbon footprint of $ 2,184,000/y and 24,363 t CO2e/y respectively. Meanwhile, for Scenario 2 with fluctuating steam and power demand according to plant production capacity, which is more realistic, its minimum TAC for GT-CHP only increases by 2 %. The new approach allows the identification of the optimum mode of operation at different demand conditions.

Energy efficiency concepts in sugar house operation – what is old, what is new?

Energy efficiency is a key performance indicator for the efficient operation of a sugar refinery. Water intake via the fine liquor and the amount of wash water used in centrifugals are crucial indicators for steam demand. A range of concepts have for several decades been used in crystallization to automate the process, thus making it to a large extent reproducible. Depending on the crystal size aimed for, one- or two-stage seeding processes are often applied. The water intake by wash water applied in the centrifugals can be significantly reduced by applying syrup washing. This paper describes the principles of the process steps mentioned and their importance for refinery and recovery in a sugar refinery. It also addresses the reasons why the use of these process steps is time and again called into question. On this basis, the paper presents opportunities that can result from a reassessment of precisely these process steps, taking into account state-of-the-art process monitoring methods.

Static and dynamic modeling of steam integration for a NuScale small modular reactor and pulp and paper mill coupling for carbon-neutral manufacturing

Small modular reactors (SMRs) are reactor designs producing less than 300 MWe and are generally planned for deployment as multimodule nuclear power plants. The possibility of factory-manufactured, flexibly sized plants expands the opportunities for nuclear power to different communities and industries, including manufacturing plants that currently utilize fossil fuels to produce both steam and electricity. This paper examines the feasibility of coupling a NuScale SMR with a midsize pulp and paper mill in the Southeastern United States. A steady-state mill model was developed in Aspen HYSYS, based on real data from the operation of the mill, and modified it to include the SMR while maintaining steam quality requirements and making as few changes as possible to existing equipment. Dynamic plant models were also developed Dymola to demonstrate possible plant conditions, using three configurations.Preliminary results suggest that, while SMR coupling is physically feasible, its economic feasibility is limited by the differences in steam and electricity demands. Because of limitations in the amount of steam the mill can take from the SMR, sizing the SMR for the plant’s steam demand may result in an electricity deficit, or vice versa. Dynamic analyses show that the addition of a thermal storage system could reduce such deficits, but this entails its own challenges. Each plant must determine the best configuration and control scheme for itself, based on its electricity and heat needs, including the peak duration and intensity for both. Ultimately, an implementation of SMRs with manufacturing processes would benefit from partnering with a local utility to purchase excess electricity generated by the SMR. This will help manufacturing facilities meet their environmental and cost-savings goals, in addition to meeting the need for cost-effective baseload power across the United States.

Simulation of sewage sludge air gasification and application of electricity and steam generation: Case study of Pantai 1 sewage treatment plant

This paper proposes an improved model to predict the performance of sewage sludge updraft gasification more accurately by using Aspen Plus. The reaction rate of gas-gas and gas-solid reactions as well as the formation and destruction of tar composition were not adequately accounted for in the previous models. To solve that, a pair of Continuous Stirred Tank Reactor and Plug Flow Reactor blocks was configured for reaction zones of the gasifier. The number of tar compositions inserted in the model was increased to 6 components including benzene, toluene, phenol, naphthalene, acid palmitic, and indene. In comparison to the previous model, the accuracy of syngas composition prediction increased by 10–20%, particularly, the error of prediction was below 40% for all compositions at an equivalence ratio of 0.15. To make the first comprehensive study on energy production from sewage sludge treatment in Malaysia, the validated gasification model was applied to develop an integrated waste-to-energy with gasification model for Pantai 1 sewage treatment plant.There was a higher energy generating efficiency for the steam generation of 15.5–16.5% than for electricity generation of 1.4–1.9%. The electricity demand for sewage sludge treatment was fully satisfied, while 5.4% of the steam demand was met.

Using waste to supply steam for industry transition: Selection of target industries through economic evaluation and statistical analysis

AbstractGlobal warming mitigation requires worldwide action in a wide range of fields, including waste treatment and management. In Japan, demands to transform waste into energy as a greenhouse gas emissions reduction strategy are increasing. The use of steam generated from waste treatment plants as a source of energy in industries is a promising energy recovery method. In recent years, the feasibility and economic potential of conversion of waste into energy have been evaluated; however, economic efficiency is not always achieved. Therefore, it is necessary to classify steam supply targets based on profitability. Herein, we selected appropriate industries from different types and scales of industries for steam supply based on analyses carried out in Aichi Prefecture. Therefore, industries were classified based on their production shipment value. We also calculated the maximum profit potential from steam supply from waste treatment plants and the steam demand potential of each mesh. We applied data envelopment analysis (DEA) to evaluate energy efficiency and regression analysis to evaluate the potential effects on growth. The appropriate industry was estimated through decision tree analysis based on DEA scores for the mixed industries cluster. We extracted four appropriate industries: pulp, textiles, ceramics, and steel. For each industry, we calculated the number of firms required in the mesh for economic benefit. We also selected industries that could be used to explore the potential of adopting the developed methodology for other regions and industries and for identification of waste treatment plants that could participate in steam supply.

Implementation of a multi-setpoint strategy for fire-tube boilers utilized in food and beverage industry: Estimating the fuel saving potential

The present work aims at estimating the fuel saving potential of implementing a multi-setpoint control strategy for a fire-tube boiler that addresses a steam demand with a notable (daily) variation in the requested pressure level. The daily steam consumption profile of an Italian cheese factory is accordingly considered as the case study. Next, a dynamic PID controller is developed and tuned, aiming at enhancing the boiler’s controllability at partial load conditions (in comparison with a traditional PID controller). In the next step, a multi-setpoint strategy is implemented, in which the pressure setpoint (following the desired pressure profile) is dynamically modified. The yearly fuel consumption of the boiler is then determined and is compared with the consumed fuel while employing the currently utilized constant-setpoint approach. The obtained results demonstrate that employing the proposed strategy results in reducing the yearly fuel consumption by 4.5%. The approach that is proposed in the present study can be employed by many steam end-users in the food and beverage industry, specifically in Italy, whose needed pressure level is highly variable.

Performance improvements on energy and exergy basis for an ammonia-water absorption refrigeration system in a coffee industry

Ammonia-water absorption refrigeration systems have broad applications in industrial and commercial facilities, easily driven by any available waste heat of low-medium temperatures. The objective is to evaluate, identify and propose improvements in the existing coffee industry using refrigeration system with a double absorption stage and single ammonia generator. A complete energy and exergy modeling and analysis are applied - components and overall efficiencies, including physical and chemical irreversibilities. Thermal system modeling uses Engineering Equation Solver containing 34 streams and 22 components. The main findings indicate that coupled energy-exergy analysis proves the ability to identify poor performance components and processes. Therefore, allowing to propose feasible modifications in the real facility by improving the systeḿs efficiency on 1st and 2nd Thermodynamics laws basis, respectively β and ε from 0.259 and 0.204 to reaching 0.388 and 0.304. As a result of the irreversibility analysis, the ammonia generator, regenerative heat exchanger and the pressure reducing valve had the most improvement in their performances when applying the proposed modifications. Altogether, about 33% lower fuel consumption at the steam generator, once the steam demand significantly reduced to 1.66 kg.s−1 in comparison to original demand of 2.49 kg.s−1.

Control of falling-film evaporators with modeling of fouling

Fouling is an undesirable phenomenon in milk evaporation, which affects the cost of production and the quality of the product. This phenomenon can be reduced by using different approaches, where process control is a feasible alternative. There are a large number of proposals for the control of a multi-effect falling-film evaporator (MEFFE), but the effect of process control on fouling has been omitted. In this work, a PID control strategy for MEFFE is developed under a dynamic model with computing of fouling and falling-film thickness. The strategy proposes several control configurations, from which the best option is selected by considering control stability, low fouling thickness and low demand of motive steam. The control strategy was applied to two case studies; the results were validated with experimental data and compared with other control techniques. The results show that this strategy is suitable for MEFFE, and guarantees the quality of the concentrated product.