Approximation of theoretical energy-saving potentials for the petrochemical industry using energy balances for 68 key processes

We prepared energy and carbon balances for 68 petrochemical processes in the petrochemical industry for Western Europe, the Netherlands and the world. We analysed the process energy use in relation to the heat effects of the chemical reactions and quantified in this way the sum of all energy inputs into the processes that do not end up in the useful products of the process, but are lost as waste heat to the environment. We showed that both process energy use and heat effects of reaction contribute significantly to the overall energy loss of the processes studied and recommend addressing reaction effects explicitly in energy-efficiency studies. We estimated the energy loss in Western Europe in the year 2000 at 1620 PJ of final energy and 1936 PJ of primary energy, resulting in a total of 127 Mt CO₂. The losses identified can be regarded as good approximations of the theoretical energy-saving potentials of the processes analysed. The processes with large energy losses in relative (per tonne of product) and absolute (in PJ per year) terms are recommended for more detailed analysis taking into account further thermodynamic, economic, and practical considerations to identify technical and economic energy-saving potentials.     

Energy policy and the role of bioenergy in Poland

Poland, as many other countries, has ambitions to increase the use of renewable energy sources. In this paper, we review the current status of bioenergy in Poland and make a critical assessment of the prospects for increasing the share of bioenergy in energy supply, including policy implications. Bioenergy use was about 4% (165 PJ) of primary energy use (3900 PJ) and 95% of renewable energy use (174 PJ) in 2003, mainly as firewood in the domestic sector. Targets have been set to increase the contribution of renewable energy to 7.5% in 2010, in accordance with the EU accession treaty, and to 14% in 2020. Bioenergy is expected to be the main contributor to reaching those targets. From a resource perspective, the use of bioenergy could at least double in the near term if straw, forestry residues, wood-waste, energy crops, biogas, and used wood were used for energy purposes. The long-term potential, assuming short rotation forestry on potentially available agricultural land is about one-third, or 1400 PJ, of current total primary energy use. However, in the near term, Poland is lacking fundamental driving forces for increasing the use of bioenergy (e.g., for meeting demand increases, improving supply security, or further reducing sulphur or greenhouse gas emissions). There is yet no coherent policy or strategy for supporting bioenergy. Co-firing with coal in large plants is an interesting option for creating demand and facilitating the development of a market for bioenergy. The renewable electricity quota obligation is likely to promote such co-firing but promising applications of bioenergy are also found in small- and medium-scale applications for heat production. Carbon taxes and, or, other financial support schemes targeted also at the heating sector are necessary in the near term in order to reach the 7.5% target. In addition, there is a need to support the development of supply infrastructure, change certain practices in forestry, coordinate RD&D efforts, and support general capacity building. The greatest challenge for the longer term lies in reforming and restructuring the agricultural sector.     

Quantification of the European industrial heat demand by branch and temperature level

We present the first comprehensive estimate of the final energy demand for heat in all EU28 member states for the reference year 2012, differentiated by temperature levels, comparing two different approaches. Two different calculation approaches based on different data sets yielded estimates of the total final energy demand for heat in the EU28 of 8150 PJ and 8518 PJ in 2012, respectively. Approach 1 distinguishes between three different process heat (PH) temperature levels and results in final energy demand for heat <100°C: 2077 PJ, 100–400°C: 2214 PJ and >400°C: 3859 PJ. The second approach distinguishes between low temperature space heat and hot water (<100°C: 1161 PJ) and four different PH temperature levels with a resulting energy demand of <100°C: 1027 PJ, 100–500°C: 1785 PJ, 500–1000°C: 1679 PJ and >1000°C: 2865 PJ. The high share of high‐temperature heat illustrates the limits to the potential decarbonisation of industrial thermal processes with renewable energy sources such as (non‐concentrating) solar thermal, geothermal or environmental heat. Therefore specific information on required temperature levels is of the essence. This, in turn, points out the relevance of renewable electricity and synthetic fuels based on renewable power for a significant reduction of CO₂ emissions from the industry sector in Europe. Considering current data quality, it is recommended to develop a consistent, comprehensive methodology to significantly improve the data basis on industrial heat demand. Copyright © 2015 John Wiley & Sons, Ltd.     

Woody biomass supply potential for thermal power plants in Japan

Biomass energy is one of mitigation method of CO₂ reduction. In Japan, it aimed to reduce fossil fuels supply 670,000 kL of crude oil equivalent in thermal power plants and 340,000 kL of crude oil equivalent in the utilization of heat by biomass. It was decided to use 25% or more of the forestry products such as logging residues. Japanese government aim to supply 634 PJ of woody biomass for power generation in 2010. This amount of energy accounts for 2.8% of total primary energy. More than 68% of Japan is covered by forests, and more than 40% of these forests are plantations. But the use of woody biomass is limited because it is still not seen as economically viable. In this article, we developed a large scale forestry economic model which can estimate the wood chips supply for coal thermal power plants across all around Japan. By using this model, wood chips supply potential is currently 32,000 m³/year and supply will increase drastically when wood chips price increase or carbon credit is installed and we found that biomass production of 15 PJ that is the numeric target of Japanese government is possible. Especially, the lengthening of rotation period of forestry and the decrease of wood chips transportation cost is important for wood chips use in coal thermal plant.     

The potential of solar heat for industrial processes in Germany

Industry represents a very promising application area for solar thermal technology, since it accounts for 27% of the total final energy consumption in Germany and uses 74% of its energy consumption as thermal energy. In order to develop this application area, it is necessary to know which industrial sectors have the highest potential and which processes within these sectors are most suitable for the integration of solar heat. For this paper the industrial heat consumption in Germany was analyzed, which leads to the selection of the most promising sectors within industry. Furthermore, the quantitative potential for Germany in total and for 11 selected sectors, that were identified to be most promising for the use of solar heat, was calculated. These are Chemicals, Food and beverages, Motor vehicles, Paper, Fabricated metal, Machinery and equipment, Rubber and plastic, Electrical equipment, Textiles, Printing and Wood. These sectors are analyzed to identify suitable processes for the integration of solar heat. In total the theoretical potential of solar heat for industrial processes below 300 °C in Germany accounts for 134 TWh per year, the technical potential being 16 TWh per year or 3.4% of the overall industrial heat demand. This is the highest share of the European potential of 72 TWh per year. The results of this study facilitate the prioritized application of solar thermal energy in industrial sectors and processes for Germany and other countries.     

Allocation of energy inputs among the end-uses in the US petroleum and coal products industry

This paper models the allocation of energy inputs in the US petroleum and coal products industry by allocating combustible fuel and renewable energy inputs among generic end-uses, including intermediate conversions through onsite power and steam generation. This analysis, called an energy end-use model, showed that 72% of the fuel input in the US petroleum and coal products industry goes to onsite steam and power generation, whereas 28% goes directly to end-uses. Eight percent of the boiler output is used for power generation, 72% goes directly to end-uses, and 20% is waste heat. Among the end-uses, process heating is the biggest energy user with a total energy consumption of 2338 PJ, whereas machine drive is the biggest electricity consumer with a consumption of 168 PJ. This paper also provides estimates of the uncertainty of the data. The approach to create this model is applicable to all other industries for which data is available and the model is consistent with US Department of Energy data for 1998. When used in conjunction with similar models for other years, it can be used to identify the changes and trends in energy utilization even at the prime mover level of detail.     

Performance analysis for glass furnace regenerator

Glass manufacturing is an energy intensive process where fossil fuel is used to maintain high temperature (about 1700 °C) for glass melting. Heat recovery from flue gas (1350–1500 °C) is usually in the form of combustion air pre-heating (900–1200 °C) using a regenerator. Dust from flue gas which is carried over from the furnace gets deposited in the regenerator storage matrix path. This leads to a deterioration of regenerator efficiency. A regenerator model is developed to estimate the actual performance of the regenerator and to compare it with the target performance. The proposed model is based on mass and energy balance of streams along with heat transfer characteristic equations. The model is illustrated for a 130 TPD (Ton per Day) furnace regenerator of an industrial glass plant at Mumbai, India. Model results for the regenerator studied indicate a blockage of 50% on the doghouse side and 22% on the non-doghouse side of the regenerator. The actual performance of the regenerator is found to be 7% lower than its target performance for the doghouse side regenerator. The model developed can also be used in other industrial sectors like steel, chemical etc.     

Targeting for energy efficiency and improved energy collaboration between different companies using total site analysis (TSA)

Rising fuel prices, increasing costs associated with emissions of green house gases and the threat of global warming make efficient use of energy more and more important. Industrial clusters have the potential to significantly increase energy efficiency by energy collaboration. In this paper Sweden’s largest chemical cluster is analysed using the total site analysis (TSA) method. TSA delivers targets for the amount of utility consumed and generated through excess energy recovery by the different processes. The method enables investigation of opportunities to deliver waste heat from one process to another using a common utility system.The cluster consists of 5 chemical companies producing a variety of products, including polyethylene (PE), polyvinyl chloride (PVC), amines, ethylene, oxygen/nitrogen and plasticisers. The companies already work together by exchanging material streams. In this study the potential for energy collaboration is analysed in order to reach an industrial symbiosis. The overall heating and cooling demands of the site are around 442 MW and 953 MW, respectively. 122 MW of heat is produced in boilers and delivered to the processes.TSA is used to stepwise design a site-wide utility system which improves energy efficiency. It is shown that heat recovery in the cluster can be increased by 129 MW, i.e. the current utility demand could be completely eliminated and further 7 MW excess steam can be made available. The proposed retrofitted utility system involves the introduction of a site-wide hot water circuit, increased recovery of low pressure steam and shifting of heating steam pressure to lower levels in a number heat exchangers when possible. Qualitative evaluation of the suggested measures shows that 60 MW of the savings potential could to be achieved with moderate changes to the process utility system corresponding to 50% of the heat produced from purchased fuel in the boilers of the cluster.Further analysis showed that after implementation of the suggested energy efficiency measures there is still a large excess of heat at temperatures of up to 137 °C.     

Assessing the sustainability of the UK society using thermodynamic concepts: Part 2

By building on the first part of our analysis, this second part attempts to provide a further understanding of the UK society's metabolism, its impact and offer policy suggestions that could promote a shift towards sustainability. The methodologies employed in this second part include Exergy Analysis (EA) and Extended Exergy Analysis (EEA). Exergy inputs and outputs amounted to 17423.9 and 11888.7 PJ, respectively, with energy carries, mainly fossil fuels, being both the predominant inputs (15597.1 PJ) and outputs (5147.1 PJ). Exergy consumption and efficiency for various economic sectors and subsectors have been calculated with the residential and service sector showing the lowest exergy conversion efficiencies (11.2% and 12.3%, respectively) while certain industrial subsectors, such as the aluminium and iron/steel industries showed the highest exergy conversion factors (67.0 and 62.1%). Extended exergy efficiencies were somewhat different owing to the different calculation procedure. Extended exergy efficiencies were 91.4% for the extraction sector, 38.9% for the conversion sector, 49.1% for the agriculture sector, 31.5% for the transportation sector, 38.6% for the industrial sector and 80.0% for the tertiary sector.     

Understanding industrial energy use: Physical energy intensity changes in Indian manufacturing sector

This study develops and examines physical energy intensity indicators in five industrial sub-sectors—iron and steel, aluminum, textiles, paper, and cement—and investigates mitigation options for energy related CO₂ emissions (during 1991–2005). Decomposition analysis has been employed to separate the structural effect (share of different products in the sector) from pure intensity effect (efficiency increase through technical improvement) for each industry. The results show that the combined effect (considering both structural and intensity effects together) on both iron and steel and paper and pulp industries is negative while it is positive for aluminum and textiles. The intensity effect for all the industries, barring textiles, is negative showing improvement in energy efficiency; iron and steel in particular, has seen a decrease of 134 PJ in energy consumption owing to improvements in efficiency. However, energy intensity in textiles has risen by 47 PJ due to increased mechanization. Structural effect is positive in aluminum and iron and steel industries indicating a movement towards higher energy-intensive products. In the case of aluminum, positive structural effect dominates over negative intensive effect whereas negative intensive effect dominates iron and steel industry. The paper helps in designing policies for improving productivity and reduce energy consumption in India's manufacturing sector.     

Performance of unglazed solar ventilation air pre-heaters for broiler barns

Solar radiation is an interesting heat source for applications requiring a limited amount of energy, such as pre-heating cold fresh air used in venting livestock barns. The objective of this study was to evaluate the energy recovery efficiency of a solar air pre-heater consisting of an unglazed perforated black corrugated siding where the incoming fresh ventilation air picks up heat from its face and back. Installed on the southeast wall of two broiler barns located 40 km east of Montreal, Canada, the performance of solar air pre-heaters was monitored over 2 years. Sensors inside the barns monitored the temperature of the ambient air, that pre-heated by the solar collector and that exhausted by one of the three operating fans. An on-site weather station measured ambient air temperature, wind direction and velocity and radiation energy absorbed on a vertical plane parallel to the unglazed solar air pre-heaters. The measured vertical solar radiation value was used to evaluate the heat recovery efficiency of the unglazed solar air pre-heaters. Using data from the Varennes Environment Canada weather station located 30 km northwest, the solar sensors were found to measure the absorbed solar radiation with a maximum error of 7%, including differences in exterior air moisture. Unglazed, the efficiency of the solar air pre-heaters reached 65% for wind velocities under 2 m/s, but dropped below 25% for wind velocities exceeding 7 m/s. Nevertheless, the unglazed solar air pre-heaters were able to reduce the heating load especially in March of both years. Over a period starting in November and ending in March, the solar air heaters recovered an energy value equivalent to an annual return on investment of 4.7%.     

Benchmarking the energy use of energy-intensive industries in industrialized and in developing countries

Improved energy efficiency is among the key measures for CO₂ emission abatement in the industry. Energy benchmark curves provide data measured at individual plants and they offer a basis to estimate the sectoral energy efficiency improvement potentials (IP) compared to a best practice technology (BPT) currently in operation worldwide. In this paper, we estimate the BPT energy use of 17 industry sectors based on such curves or energy indicators prepared at country-level. We compare BPT data with current energy use to estimate the IP. According to our analysis, BPT offers improvement potentials of 27 ± 8% worldwide. This is equivalent to 32.5 ± 9.6 EJ (exajoules) of final energy savings worldwide, of which three-quarters can be achieved in developing countries. Due to lack of benchmark curves and limited data availability for developing countries, our results include uncertainties. We used literature data at country-level and international energy statistics to fill data gaps and to develop energy indicators. Quality of these data should be improved and benchmark data needs to be collected for more sectors. By doing so, energy benchmarking could become a key tool to estimate energy saving potentials and energy indicators could serve as strong supplementary methodology.     

A framework for reviewing the trade-offs between, renewable energy, food, feed and wood production at a local level

High fuel prices and concerns about energy security and anthropogenic climate change are encouraging a transition towards a low carbon economy. Although energy policy is typically set at a national level, tools are needed for people to engage with energy policy at regional and local levels, and to guide decisions regarding land use, distributed generation and energy supply and demand. The aim of this paper is to develop a per-capita approach to renewable energy demand and supply within a landscape and to illustrate the key trade-offs between renewable energy, food, (animal) feed and wood production. The chosen case study area (16,000 ha) of Marston Vale, England is anticipated to have a population density midway between that for England and the UK. The daily per capita demand for energy for heat (31 kWh), transport (34 kWh) and electricity (15 kWh) when combined (80 kWh) was seven-fold higher than the combined demand for food (2 kWh), animal feed (6 kWh), and wood (4 kWh). Using described algorithms, the combined potential energy supply from domestic wind and photovoltaic panels, solar heating, ground-source heat, and municipal waste was limited (<10 kWh p⁻¹ d⁻¹). Additional electricity could be generated from landfill gas and commercial wind turbines, but these have temporal implications. Using a geographical information system and the Yield-SAFE tree and crop yield model, the capacity to supply bioethanol, biodiesel, and biomass, food, feed and wood was calculated and illustrated for three land-use scenarios. These scenarios highlight the limits on meeting energy demands for transport (33%) and heat (53%), even if all of the arable and grassland area was planted to a high yielding crop like wheat. The described framework therefore highlights the major constraints faced in meeting current UK energy demands from land-based renewable energy and the stark choices faced by decision makers.     

Use of material flow accounting for assessment of energy savings: A case of biomass in Slovakia and the Czech Republic

Anthropogenic material and energy flows are considered to be the major cause of many environmental problems humans face today. In order to measure material and energy flows, and to mitigate related problems, the technique of material flow and energy flow analysis has been conceived. The aim of this article is to use material and energy flow accounting approaches to quantify the amount of biomass that is available, but that so far has not been used for energy purposes in Slovakia and the Czech Republic and to calculate how much consumed fossil fuels and corresponding CO₂ emissions can be saved by utilising this biomass. Based on the findings presented, 3544 kt/yr of the total unused biomass in Slovakia could replace 53 PJ/yr of energy from fossil fuels and 6294 kt/yr of the total unused biomass in the Czech Republic could replace 91 PJ/yr of energy. Such replacement could contribute to a decrease in total CO₂ emissions by 9.2% in Slovakia and by 5.4% in the Czech Republic and thus contribute to an environmental improvement with respect to climate change.     

Allocation of energy resources for power generation in India: Business as usual and energy efficiency

This paper deals with MARKAL allocations for various energy sources, in India, for Business As Usual (BAU) scenario and for the case of exploitation of energy saving potential in various sectors of economy. In the BAU scenario, the electrical energy requirement will raise up to 5000 bKwh units per year or 752 GW of installed capacity with major consumers being in the industry, domestic and service sectors. This demand can be met by a mix of coal, hydro, nuclear and wind technologies. Other reneawbles i.e. solar and biomass will start contributing from the year 2040 onwards. By full exploitation of energy saving potential, the annual electrical energy demand gets reduced to 3061 bKwh (or 458 GW), a reduction of 38.9%.The green house gas emissions reduce correspondingly. In this scenario, market allocations for coal, gas and large hydro become stagnant after the year 2015.     

A dynamic linear programming approach to market allocation of renewable resources in the italian energy system: The case of solar thermal and biogas technologies

In Italy solar thermal energy and energy from biogas are two possible means of reducing dependence on energy imports. Using a multiperiod LP model (MARKAL) the authors assessed the likely potential of both technologies under various circumstances. The study covered the period 1980–2005, in five segments of five years. It focused only on the subsystem of the energy end-uses which can be substituted for by solar thermal and biogas technologies. The overall non-renewable sources which can be saved in 20 years by these technologies total 450 PJ (1 PJ = 10^{1 5} J) if the fuel prices rise at 0 per cent average annual, 1450 PJ if the fuel prices rise at 4.2 per cent average annual, 1860 PJ if the fuel prices rise at 7.2 per cent average annual and 3780 PJ if the fuel prices rise at 15 per cent average annual. However the most competitive technologies appear to be solar water heaters used mainly in the private and commercial sectors and biogas systems used mainly in the agricultural sector. The study was carried out by APRE under ENEA (formerly CNEN) contract and was intended to serve as an analytical basis for establishing an overall development and demonstration strategy for end-use renewable technologies in Italy.     

Geographic distribution of economic potential of agricultural and forest biomass residual for energy use: Case study Croatia

This paper provides methodology for regional analysis of biomass energy potential and for assessing the cost of the biomass at the power plant (PP) location considering transport distance, transport costs and size of the power plants. Also, methodology for determination of an upper-level price of the biomass which energy plant can pay to the external suppliers has been proposed. The methodology was applied on the case of Croatia and energy potential of biomass in the Croatian counties was calculated, using different methodologies, for wheat straw, corn stover and forestry residues, types of biomass considered economically viable at the moment. Results indicate that the average energy potential of wheat straw is 8.5 PJ, corn stover 7.2 PJ and forestry residues 5.9 PJ.     

Status and potential of biogas energy from animal wastes in Turkey

Biogas is a potentially important energy source that can be used for the production of heat, electricity and fuel. It can be produced at wastewater treatment plants, landfills, food and other industrial operations throughout the world. There is largely untapped potential in agricultural operations where animal waste is often land applied or otherwise disposal of without conversion to energy. According to the last agricultural census (2009) in Turkey; there are a total of 3,076,650 agricultural enterprises and approximately 70% of these enterprises are running livestock farming. 10,811,165 of total animal is cattle, 26,877,793 of total animal is small ruminant and 234,082,206 is poultry. The amount of wet waste of these animals is about 120,887,280 t. These wastes could be a major problem for enterprises and cannot be utilized properly. The best way to utilize waste is to produce biogas. In this study, biogas amount which will be obtained from animal waste was calculated for all provinces by using the number of livestock animals and also considering various criteria such as the rate of dry matter and availability. Animal origin waste map of Turkey was also produced with these calculated values. The biogas energy potential of Turkey was found to be 2,177,553,000 m³ (2.18 Gm³) by using the animal numbers in the last agricultural census (2009). The total biogas potential is originated from 68% cattle, 5% small ruminant and 27% poultry. Biogas energy equivalence of Turkey is approximately 49 PJ (1170.4 ktoe). When the prepared waste map is examined; provinces that have more than 1 GJ of biogas energy potential are found to be; Bolu, Bal?kesir, ?zmir, Sakarya, Konya, Manisa, Erzurum, Afyon, Kars and Ankara respectively.     

Energy,exergy and economic analysis of industrial boilers

In this paper, the useful concept of energy and exergy utilization is analyzed, and applied to the boiler system. Energy and exergy flows in a boiler have been shown in this paper. The energy and exergy efficiencies have been determined as well. In a boiler, the energy and exergy efficiencies are found to be 72.46% and 24.89%, respectively. A boiler energy and exergy efficiencies are compared with others work as well. It has been found that the combustion chamber is the major contributor for exergy destruction followed by heat exchanger of a boiler system. Furthermore, several energy saving measures such as use of variable speed drive in boiler's fan energy savings and heat recovery from flue gas are applied in reducing a boiler energy use. It has been found that the payback period is about 1 yr for heat recovery from a boiler flue gas. The payback period for using VSD with 19 kW motor found to be economically viable for energy savings in a boiler fan.     

Assessment of the availability of agricultural and forest residues for bioenergy production in Romania

This paper provides a resource-based assessment of availability of biomass resources for energy production in Romania, at NUTS-3 level. The estimation of available biomass includes the residues generated from crop production, pruning of vineyards and orchards, forestry operations and wood processing. The estimation of crop residue availability considers several site-specific factors such as crop yields, multi-annual yield variation, environmental constraints and competitive uses. The evaluation of agricultural residues was based on specific residue to product ratios, depending on crop type and crop yield. An estimate of pruning residues is proposed, based on current orchard and vineyard areas and specific ratios of residues. Woody biomass considers forest and forestry residues (including firewood) and wood processing by-products, taking into account the type and share of the unused part of the tree biomass and technical and economic aspects, including availability and competitive use. The amount of agricultural and forest residues available for bioenergy in Romania was estimated at 228.1 PJ on average, of which 137.1 PJ was from annual crop residues, 17.3 PJ residues from permanent crops and 73.7 PJ/year from forestry residues, firewood and wood processing by-products. The biomass availability shows large annual and spatial variations, between 135.6 and 320.0 PJ, due to the variation in crop production and forestry operations. This variation, which is even larger at the NUTS-3 level, if not properly considered may result in shortages in biomass supply in some years, when biomass is available in a lower amount than the average.