Analyzing Potential Benefits of Heat Integration Designs for a DTBP Production Plant

This thesis looks at the implementation of various heat integration designs for a ditertiary butyl peroxide (DTBP) production plant. Heat integration, also known as process integration, is a common industrial practice in the chemical process industry to reduce utility costs. Heat integration is commonly analyzed using pinch technology, which focuses producing a heat exchanger design that pairs hot streams with excess energy with cold streams that need to be heated. These designs usually cut utility costs, but they also require the building of more heat exchangers to place within the process

Reducing process cost and CO2 emissions for extractive distillation by double-effect heat integration and mechanical heat pump

Double-effect heat integration and mechanical heat pump technique are investigated for the extractive distillation process of the acetone–methanol minimum boiling azeotropic mixture with entrainer water and compared from the economical view by the total annual cost (TAC) and environmental aspect by CO2 emissions. Firstly, A novel optimal partial heat integration (OPHI) process is proposed and optimized through the minimization of a newly defined objective function called OF2 that describes the energy consumption used per product unit flow rate and allows comparison with the literature direct partial and full heat integration processes. We find that the minimum TAC is not achieved by the full heat integration process as intuition, but by the new OPHI process. Secondly, the vapour recompression (VRC) and bottom flash (BF) mechanical heat pump processes are evaluated with respect to energy and CO2 emissions. We proposed a new partial VRC and a new partial BF process in order to reduce the high initial capital cost of compressors. Overall the results show that compared to the conventional extractive distillation process the proposed OPHI process gives a 32.2% reduction in energy cost and a 24.4% saving in TAC while the full BF process has the best performance in environmental aspect (CO2 emissions reduce by 7.3 times)

Heat Integration in a Cement Production

The cement industry sector is an energy-intensive industrial sector; cement is the most widely used material for construction and modern infrastructure needs. The cement industry is one of the largest consumers of carbon-containing primary energy sources and one of the primary polluters of the environment. Energy consumption represents the largest part of the production cost for cement factories and has a significant influence on product prices. The potential of waste heat utilization of cement production was determined and a recovery potential accounting site wide in demand is defined by the process integration technique. The author has analyzed the energy consumption of a cement factory to obtain minimum energy needs of production and proposed the options to improve energy efficiency by the process integration approach. The authors conclude that the energy consumption of the cement factory can be reduced by 30%. The results help to the cement plant’s profitability and reduce environmental impact of the cement industry as well as sustainability. Given that it is realized in modern society that infrastructural projects lead to a higher level of economy and sustainability for countries, reducing the production cost in the cement industry is a very important problem

Heat Integration optimization in a Multiproduct Biorefinery

The biorefining is a fast-growing topic and laboratory data about biorefineries accumulate sharply, but this type of process is still mainly unknown at the industrial scale. In this context, it is necessary to propose a method that permits to evaluate the industrial interest in order to design and to build the biorefinery. Moreover, the optimization of water and energy consumption represents two of the most important operating costs in a biorefinery. Thus, to limit utilities consumption, energy integration has to be incorporated for all process design alternatives. The proposed MILP program minimizes utilities consumption in coupling cold streams and hot streams through heat exchangers

Теплоэнергетическая интеграция установки первичной переработки нефти АВТ А12/2 при работе с вакуумным блоком в зимнее время

Heat network retrofit with extended heat integration allows to decrease specific fuel consumption in 3 times on the investigated uni

Total site methodology as a tool for planning and strategic decisions

A Total Site (TS) is defined as a set of processes (industrial plants, residential, business and agriculture units) linked through the central utility system. The utility system incorporates a number of operating units such as boilers, steam turbines, gas turbines and letdown stations. Many sites are using the TS system representation. Heat Integration at TS level has been well developed and successfully implemented. However, sites typically develop with time and even minor changes/extensions can affect TS heat recovery significantly. It is beneficial to plan their strategic development in advance, to increase or at least not to decrease the rate of heat recovery when integration of additional processes takes place. Even when this has not been done at the initial stage, the TS methodology can still be used as a tool for the strategic planning decision making. This work illustrates how the TS methodology can contribute to the strategic development and the extension planning of already existing TS. The aim is to reveal the potentials for Heat Integration, when new units or processes are considered for the inclusion in the TS. Moreover, some operating parameters (e.g. temperature or capacity) of the unit can be proposed to achieve the best possible heat recovery. The degrees of freedom for TS changes can be on two levels: (i) only adding an operating unit to the current utility system (the Total Site Profiles remain the same) or (ii) changing of the TS by including more processes (the Total Site Profiles are changed). The first group of changes includes the integration of heat engines to produce electricity utilising heat at higher temperature and returning it to the system at lower temperature, which is still acceptable for the heat recovery and simultaneously for the electricity production. The second group of changes is more complex. For evaluating these changes a plus/minus principle is developed allowing the most beneficial integration of new units to the TS. Combinations of both types of changes are also considered

Profitability of green hydrogen production and feasibility of waste heat integration to DHS in the Ísafjörður’s energy system: A techno-economic analysis

Hydrogen production by electrolysis using renewable energy sources is essential for hydrogen to be able to contribute to the green energy transition. Producing the hydrogen on the site of use minimizes the transportation costs and footprint, and utilization of all by-products increases the electric efficiency of hydrogen production. During hydrogen production by electrolysis the chief part of energy losses are in the form of thermal energy or heat. This thesis evaluates the profitability of a small-scale electrolytic hydrogen production in northwest Iceland and the feasibility of waste heat integration to the local district heating system. Here we show that the hydrogen production is profitable for a broad range of operation scenarios, hydrogen selling prices and electricity prices and that the integration of waste heat is feasible to the low temperature district heating plant in Ísafjörður. A sensitivity study is conducted for the calculations, for a optimistic, realistic and pessimistic scenario. The heat integration saves 13, 7 and 2% of the annual power consumption for the district heating plant for each scenario respectively. The waste heat integration affects the efficiency of the electrolyser, increasing it by 3.7% for the optimistic scenario. The economic effects of waste heat integration were found to be small. The heat integration was found to save a maximum of 5% of the DHS annual power costs. The waste heat sale revenue of the hydrogen production was found to be maximum 1.7% of net sales, which are hydrogen and heat sales in this thesis. The financial analysis of the hydrogen production conducted as a sensitivity study of an optimistic, realistic, and pessimistic scenario show that the hydrogen prices required for the project to reach profitability are 1.5 €, 3 € and 6 € per kg hydrogen when electricity prices are up to 24 €/MWh. This thesis is anticipated to spur for further research on the feasibility of hydrogen production with waste heat utilization in cold areas in Iceland, where no geothermal heat is available for district heating

Design and Optimization of Heat Integrated Distillation

Process integration is currently considered as the main trend to improve process performance, and is one of the major approaches to reduce the annual operating and capital costs in the plant. For distillation systems, heat integration technique provides such an approach to improve the traditional simple column sequences. This work presents the optimization of distillation column sequences based on creation of maximum possible heat integration and minimizing the total annual cost of process. All the optimum simple sequences and possible heat integrated sequences are designed and considered to find the best heat integrated sequence with the minimum total annual cost. Sequences are simulated and the objective function is modeled. Basic operation parameters of sequences are changed according to the process constraints to find all the possible heat integration and minimize the objective function. The best structures with the minimum total annual cost are designed and compared for the considered industrial case study. Results show the height percent of optimization of process costs by the internal heat recovery of integration.Key words: Distillation; Sequence; Modeling; Integration; Optimizatio

Теплоэнергетическая интеграция установки первичной переработки нефти АВТ А12/2 при работе в летнее время

Heat network retrofit with extended heat integration allows to decrease specific fuel consumption in 3 times on the investigated unit. Pay-back period is not more than 6 months